阅读说明：本技术 显示装置及用于制造显示装置的方法 (Display device and method for manufacturing the same ) 是由 金殷朱 崔允眉 金晙容 于 2020-02-05 设计创作，主要内容包括：本公开提供了显示装置及用于制造显示装置的方法。显示装置包括：第一电极；第二电极,布置成与第一电极隔开且面对第一电极；第一绝缘图案,具有布置成与第一电极重叠的至少部分区域且具有与第一电极的第一端部隔开的第一侧表面；第二绝缘图案,具有布置成与第二电极重叠的至少部分区域且具有与第二电极的面对第一端部的第二端部隔开的第二侧表面,第二侧表面面对第一侧表面；至少一个不平坦的图案,设置在第一绝缘图案和第二绝缘图案上；以及至少一个发光元件,设置在第一绝缘图案与第二绝缘图案之间且具有分别电连接到第一电极和第二电极的相对端部。(The present disclosure provides a display device and a method for manufacturing the same. The display device includes: a first electrode; a second electrode disposed to be spaced apart from and facing the first electrode; a first insulating pattern having at least a partial region arranged to overlap the first electrode and having a first side surface spaced apart from a first end of the first electrode; a second insulation pattern having at least a partial region arranged to overlap the second electrode and having a second side surface spaced apart from a second end of the second electrode facing the first end, the second side surface facing the first side surface; at least one uneven pattern disposed on the first and second insulating patterns; and at least one light emitting element disposed between the first and second insulating patterns and having opposite ends electrically connected to the first and second electrodes, respectively.)

1. A display device, comprising:

a first electrode and a second electrode spaced apart from the first electrode;

a first insulating pattern disposed on and at least partially overlapping the first electrode, and a first side of the first insulating pattern is spaced apart from a first end of the first electrode;

a second insulation pattern disposed on and at least partially overlapping the second electrode, a second side of the second insulation pattern facing the first side being spaced apart from a second end of the second electrode facing the first end;

at least one concave-convex pattern disposed on each of the first and second insulating patterns; and

at least one light emitting element disposed between the first and second insulating patterns, both ends of the light emitting element being electrically connected to the first and second electrodes, respectively.

2. The display device according to claim 1, wherein a distance between the first insulating pattern and the second insulating pattern is greater than a distance between the first electrode and the second electrode.

3. The display device according to claim 2, wherein the concave-convex pattern has a shape in which at least a portion of a top surface of each of the first and second insulating patterns protrudes upward, wherein the concave-convex patterns are spaced apart from each other.

4. The display device according to claim 3, wherein the concave or convex portion of the concave-convex pattern has at least one outer side surface inclined with respect to the top surface of each of the first and second insulating patterns.

5. The display device according to claim 4, wherein at least a part of the concave-convex pattern is located below a reference plane parallel to the first electrode and passing through the both ends of the light emitting element.

6. A display device according to claim 3, wherein the relief pattern has a curved outer face.

7. The display device according to claim 3, wherein the first insulation pattern comprises a first hole pattern spaced apart from the first side surface and formed such that at least a portion of a top surface of the first insulation pattern is recessed, and

the second insulation pattern includes a second hole pattern formed to be spaced apart from the second side surface such that at least a portion of a top surface of the second insulation pattern is recessed.

8. The display device according to claim 7, wherein the concavo-convex pattern is provided between the first hole pattern and the first side surface, and between the second hole pattern and the second side surface.

9. The display device according to claim 1, further comprising:

a fourth insulating pattern disposed between the first insulating pattern and the first electrode;

a fifth insulating pattern disposed between the second insulating pattern and the second electrode; and

a sixth insulation pattern disposed between the fourth insulation pattern and the fifth insulation pattern, and partially covering each of the first end of the first electrode and the second end of the second electrode.

10. The display device according to claim 9, wherein the light emitting element is provided on the sixth insulating pattern.

11. The display device according to claim 10, further comprising:

a first contact electrode disposed between the second insulation pattern and the sixth insulation pattern and contacting one end of the light emitting element; and

a second contact electrode disposed between the fifth and sixth insulation patterns and contacting opposite ends of the light emitting element.

12. The display device according to claim 10, further comprising a third insulating pattern which is provided between the first insulating pattern and the second insulating pattern and is provided over at least a part of a top surface of the light emitting element.

13. The display device according to claim 9, further comprising a bank spaced apart from a third end of the first electrode, the third end of the first electrode being opposite to the first end of the first electrode,

wherein the first insulation pattern is spaced apart from the bank, and the fourth insulation pattern is in contact with the bank.

14. A display device according to claim 13, wherein a third side of the first insulating pattern opposite to the first side of the first insulating pattern is located between the bank and the third end.

15. The display device according to claim 14, wherein a distance between the first insulating pattern and the bank is smaller than a distance between the first insulating pattern and the second insulating pattern.

16. The display device according to claim 13, wherein the bank is integrally formed with the fourth insulating pattern.

17. A display device, comprising:

a first electrode extending in a first direction and a second electrode extending in the first direction and spaced apart from the first electrode;

at least one light emitting element disposed between the first electrode and the second electrode;

a first insulating pattern extending in the first direction and partially overlapping the first electrode;

a second insulating pattern extending in the first direction and spaced apart from the first insulating pattern and overlapping the second electrode; and

at least one concave-convex pattern disposed on each of the first and second insulating patterns.

18. The display device according to claim 17, wherein a distance between the first insulating pattern and the second insulating pattern is greater than a distance between the first electrode and the second electrode.

19. The display device according to claim 18, wherein a first side portion of the first insulation pattern is horizontally spaced inward from one end of the first electrode, and a second side portion of the first insulation pattern opposite to the first side portion protrudes horizontally outward beyond an opposite end of the first electrode.

20. The display device of claim 19, wherein both side portions of the second insulation pattern are horizontally spaced inward from both ends of the second electrode, respectively.

21. The display device according to claim 19, wherein the at least one concave-convex pattern extends in one direction and is spaced apart from each other in a direction different from the one direction.

22. The display device according to claim 21, wherein the first insulating pattern includes a first hole pattern in which at least a portion of a top surface of the first insulating pattern is recessed toward the first electrode,

wherein the second insulation pattern includes a second hole pattern in which at least a portion of a top surface of the second insulation pattern is recessed toward the second electrode, an

Each of the first and second hole patterns extends in the first direction.

23. The display device according to claim 22, wherein the concave-convex pattern provided on the first insulating pattern is provided between the first side portion and the first hole pattern, and

the concavo-convex pattern disposed on the second insulating pattern is disposed between each of two opposite sides of the second insulating pattern and the second hole pattern.

24. A method for manufacturing a display device, the method comprising:

preparing a substrate on which a first electrode and a second electrode are disposed, wherein the second electrode is spaced apart from the first electrode;

placing at least one light emitting element into a space between the first electrode and the second electrode; and

forming at least one insulation pattern spaced apart from the light emitting element and partially overlapping each of the first and second electrodes, wherein the insulation pattern has a concavo-convex pattern in which at least a portion of a top surface of the insulation pattern protrudes upward.

25. The method of claim 24, wherein the at least one insulating pattern comprises:

a first insulating pattern at least partially overlapping the first electrode; and

a second insulation pattern spaced apart from the first insulation pattern and at least partially overlapping the second electrode,

wherein each of the first and second insulation patterns is spaced apart from the light emitting element.

26. The method of claim 25, wherein the concave-convex pattern has a shape in which at least a portion of a top surface of each of the first and second insulating patterns protrudes upward, wherein the concave-convex patterns are spaced apart from each other.

27. The method of claim 26, wherein forming the at least one insulating pattern comprises:

forming an insulating material layer completely covering the first electrode, the second electrode, and the light emitting element; and

exposing two opposite ends of the light emitting element, and forming the first and second insulating patterns on which the concave-convex patterns are formed.

28. The method of claim 27, wherein forming the at least one insulating pattern is performed using a nanoimprint process.

29. The method of claim 27, further comprising forming a first contact electrode in contact with the first electrode and one end of the light emitting element and a second contact electrode in contact with the second electrode and an opposite end of the light emitting element.

Technical Field

The present disclosure relates to a display device and a method for manufacturing the same.

Background

With the development of multimedia, the importance of display devices is increasing. Accordingly, various display devices such as an Organic Light Emitting Display (OLED) device and a Liquid Crystal Display (LCD) device are being used.

A display panel such as an OLED panel or an LCD panel is a device included in a display device to display an image. Among these display panels, a light emitting element may be provided as a light emitting display panel, and examples of a Light Emitting Diode (LED) include an organic LED (oled) using an organic material as a fluorescent material and an inorganic LED using an inorganic material as a fluorescent material.

An inorganic LED using an inorganic semiconductor as a fluorescent material has durability even in a high-temperature environment and has higher blue light efficiency than an organic LED. In a manufacturing process indicated as a limitation of the existing inorganic LED element, a transfer method using a Dielectrophoresis (DEP) method has been developed. Accordingly, research is continuously being conducted on inorganic light emitting diodes having durability and efficiency higher than those of organic light emitting diodes.

Disclosure of Invention

Technical problem

Aspects of the present disclosure provide a display device including a concave-convex pattern for emitting light emitted from a light emitting element upward.

Aspects of the present disclosure also provide a manufacturing process for a display device, in which the device includes a concave-convex pattern such that a reflective member that reflects light emitted from a light emitting element is omitted, thereby reducing the manufacturing process of the device.

It should be noted that aspects of the present disclosure are not limited thereto, and other aspects not mentioned herein will be apparent to those of ordinary skill in the art from the following description.

Technical scheme

According to an embodiment of the present disclosure, a display device includes: a first electrode and a second electrode spaced apart from the first electrode; a first insulation pattern disposed on and at least partially overlapping the first electrode, and a first side of the first insulation pattern is spaced apart from a first end of the first electrode; a second insulating pattern disposed on and at least partially overlapping the second electrode, a second side of the second insulating pattern facing the first side being spaced apart from a second end of the second electrode facing the first end; at least one concave-convex pattern disposed on each of the first and second insulating patterns; and at least one light emitting element disposed between the first and second insulating patterns, both ends of the light emitting element being electrically connected to the first and second electrodes, respectively.

A distance between the first insulation pattern and the second insulation pattern may be greater than a distance between the first electrode and the second electrode.

The concave-convex pattern may have a shape in which at least a portion of a top surface of each of the first and second insulating patterns protrudes upward, wherein the concave-convex patterns may be spaced apart from each other.

The concave or convex portions of the concave-convex pattern may have at least one outer side surface inclined with respect to the top surface of each of the first and second insulating patterns.

At least a portion of the concave-convex pattern may be located below a reference plane parallel to the first electrode and passing through both ends of the light emitting element.

The relief pattern may have a curved outer face.

The first insulation pattern may include a first hole pattern spaced apart from the first side surface and formed such that at least a portion of a top surface of the first insulation pattern is recessed, and the second insulation pattern may include a second hole pattern spaced apart from the second side surface and formed such that at least a portion of a top surface of the second insulation pattern is recessed.

The relief pattern may be disposed between the first hole pattern and the first side surface, and between the second hole pattern and the second side surface.

The display device may further include: a fourth insulation pattern disposed between the first insulation pattern and the first electrode; a fifth insulating pattern disposed between the second insulating pattern and the second electrode; and a sixth insulation pattern disposed between the fourth insulation pattern and the fifth insulation pattern, and partially covering each of the first end of the first electrode and the second end of the second electrode.

The light emitting element may be disposed on the sixth insulation pattern.

The display device may further include: a first contact electrode disposed between the second insulation pattern and the sixth insulation pattern and contacting one end of the light emitting element; and a second contact electrode disposed between the fifth and sixth insulation patterns and contacting opposite ends of the light emitting element.

The display device may further include a third insulation pattern disposed between the first insulation pattern and the second insulation pattern and disposed on at least a portion of the top surface of the light emitting element.

The display device may further include a bank spaced apart from a third end of the first electrode, the third end of the first electrode being opposite to the first end of the first electrode, wherein the first insulation pattern may be spaced apart from the bank, and the fourth insulation pattern is in contact with the bank.

A third side of the first insulation pattern opposite to the first side of the first insulation pattern may be located between the bank and the third end.

A distance between the first insulation pattern and the bank may be less than a distance between the first insulation pattern and the second insulation pattern.

The bank may be integrally formed with the fourth insulation pattern.

According to an embodiment of the present disclosure, a display device includes: a first electrode extending in a first direction and a second electrode extending in the first direction and spaced apart from the first electrode; at least one light emitting element disposed between the first electrode and the second electrode; a first insulating pattern extending in a first direction and partially overlapping the first electrode; a second insulating pattern extending in the first direction and spaced apart from the first insulating pattern and overlapping the second electrode; and at least one concave-convex pattern disposed on each of the first and second insulating patterns.

A distance between the first insulation pattern and the second insulation pattern may be greater than a distance between the first electrode and the second electrode.

A first side portion of the first insulation pattern may be horizontally spaced inward from one end of the first electrode, and a second side portion of the first insulation pattern opposite the first side portion may horizontally protrude outward beyond an opposite end of the first electrode.

Both side portions of the second insulation pattern may be horizontally spaced inward from both ends of the second electrode, respectively.

The at least one concave-convex pattern may extend in one direction and be spaced apart from each other in a direction different from the one direction.

The first insulation pattern may include a first hole pattern in which at least a portion of a top surface of the first insulation pattern is recessed toward the first electrode, wherein the second insulation pattern may include a second hole pattern in which at least a portion of a top surface of the second insulation pattern is recessed toward the second electrode, and each of the first and second hole patterns may extend in the first direction.

The concave-convex pattern disposed on the first insulation pattern may be disposed between the first side portion and the first hole pattern, and the concave-convex pattern disposed on the second insulation pattern may be disposed between each of two opposite side portions of the second insulation pattern and the second hole pattern.

According to an embodiment of the present disclosure, a method for manufacturing a display device includes: preparing a substrate on which a first electrode and a second electrode are disposed, wherein the second electrode is spaced apart from the first electrode; placing at least one light emitting element into a space between a first electrode and a second electrode; and forming at least one insulating pattern that is spaced apart from the light emitting element and partially overlaps each of the first and second electrodes, wherein the insulating pattern has a concave-convex pattern in which at least a portion of a top surface of the insulating pattern protrudes upward.

The at least one insulation pattern may include: a first insulating pattern at least partially overlapping the first electrode; and a second insulating pattern spaced apart from the first insulating pattern and at least partially overlapping the second electrode, wherein each of the first and second insulating patterns may be spaced apart from the light emitting element.

The concave-convex pattern may have a shape in which at least a portion of a top surface of each of the first and second insulating patterns protrudes upward, wherein the concave-convex patterns may be spaced apart from each other.

The forming of the at least one insulation pattern may include: forming an insulating material layer completely covering the first electrode, the second electrode and the light emitting element; and exposing two opposite ends of the light emitting element, and forming a first insulation pattern and a second insulation pattern on which a concave-convex pattern is formed.

Forming the at least one insulation pattern may be performed using a nano-imprinting process.

The method may further include forming a first contact electrode in contact with the first electrode and one end of the light emitting element and a second contact electrode in contact with the second electrode and an opposite end of the light emitting element.

Details of other embodiments are included in the detailed description and the accompanying drawings.

Advantageous effects

A display device according to one embodiment includes an insulating pattern on which light emitted from a light emitting element is incident, and the insulating pattern includes a concave-convex pattern that receives the light and outputs upward. As a result, in a display device without a separate reflective electrode or reflective bank, the concave-convex pattern can output light emitted from the side surface of the light emitting element in an upward direction. Therefore, the top emission efficiency thereof can be improved.

Further, the method for manufacturing a display device according to one embodiment may not have a step of forming the reflective electrode or the reflective bank, and may simultaneously perform a step of forming the concave-convex pattern and a step of forming the insulating pattern. Accordingly, the manufacturing process of the display device can be simplified.

Effects according to the embodiments are not limited to those exemplified above, and more various effects are included in the present disclosure.

Drawings

Fig. 1 is a plan view of a display device according to an embodiment.

FIG. 2 is a sectional view taken along lines IIa-IIa ', IIb-IIb ', and IIc-IIc ' in FIG. 1.

Fig. 3 is a schematic diagram of a light emitting element according to an embodiment.

Fig. 4 is a schematic diagram illustrating a cross-section of a portion of a display device according to an embodiment.

Fig. 5 is an enlarged view of a portion a of fig. 4.

Fig. 6 is a plan view illustrating a top surface of an insulation pattern according to an embodiment.

Fig. 7 is a schematic diagram illustrating a cross-section of one sub-pixel according to an embodiment.

Fig. 8 is a flowchart illustrating a manufacturing process of a display device according to an embodiment.

Fig. 9 to 16 are sectional views illustrating a manufacturing process of a display device according to an embodiment.

Fig. 17 to 19 are sectional views illustrating a concave-convex pattern according to another embodiment.

Fig. 20 and 21 are plan views illustrating a concave-convex pattern according to another embodiment.

Fig. 22 is a sectional view of a display device according to another embodiment.

Fig. 23 and 24 are sectional views of a display device according to another embodiment.

Fig. 25 to 27 are sectional views illustrating some steps of a manufacturing process of the display device of fig. 24.

Fig. 28 is a sectional view of a display device according to still another embodiment.

Fig. 29 and 30 are plan views illustrating hole patterns formed in an insulating pattern according to still another embodiment.

Fig. 31 is a schematic cross-sectional view of a display device according to still another embodiment.

Fig. 32 is a schematic view of a light-emitting element according to another embodiment.

Detailed Description

The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

It will also be understood that when a layer is referred to as being "on" another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. Like reference numerals refer to like elements throughout the specification.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element discussed below could be termed a second element without departing from the teachings of the present invention. Similarly, a second element may also be referred to as a first element.

Hereinafter, embodiments will be described with reference to the accompanying drawings.

Fig. 1 is a plan view of a display device according to an embodiment.

Referring to fig. 1, the display device 10 may include a plurality of pixels PX. Each of the pixels PX may include at least one light emitting element 300 emitting light of a specific wavelength band to display a specific color.

Each of the plurality of pixels PX may include a first sub-pixel PX1, a second sub-pixel PX2, and a third sub-pixel PX 3. The first sub-pixel PX1 may emit light of a first color, the second sub-pixel PX2 may emit light of a second color, and the third sub-pixel PX3 may emit light of a third color. The first color may be red, the second color may be green, and the third color may be blue. The present disclosure is not limited thereto. The subpixels PXn may emit the same color light. Further, fig. 1 shows that a single pixel PX includes three sub-pixels PXn. The present disclosure is not limited thereto. Each pixel PX may include a greater number of sub-pixels PXn.

As used herein, each of the terms "first," "second," and the like refers to each of the components and is used to simply distinguish the components between them, and does not necessarily mean the corresponding component. That is, the components modified with each of the terms "first," "second," etc. are not necessarily limited to a particular structure or location. In some cases, additional reference numbers may be assigned thereto. Therefore, reference numerals assigned to each component may be described based on the drawings and the following description. Furthermore, a first element, a first component, a first region, a first layer, or a first region described below may be referred to as a second element, a second component, a second region, a second layer, or a second region without departing from the spirit and scope of the present disclosure.

Each subpixel PXn of the display apparatus 10 may include a light-emitting region and a non-light-emitting region. The light emitting region is defined as a region where the light emitting element 300 included in the display device 10 is disposed and thus light of a specific wavelength band is output. The non-light-emitting region may refer to a region other than the light-emitting region, and may be defined as a region in which the light-emitting element 300 is not disposed and thus light is not output.

The subpixel PXn of the display apparatus 10 may include a plurality of banks 400, a plurality of electrodes 21 and 22, a light emitting element 300, and at least one insulating layer 600 and 700.

The plurality of electrodes 21 and 22 may be electrically connected to the light emitting element 300. A predetermined voltage may be applied to the plurality of electrodes 21 and 22 so that the light emitting element 300 emits light. In addition, at least a portion of each of the electrodes 21 and 22 may be used to generate an electric field within the subpixel PXn to align the light emitting element 300.

The plurality of electrodes 21 and 22 may include a first electrode 210 and a second electrode 220. In an embodiment, the first electrode 210 may serve as a separate pixel electrode for each subpixel PXn, and the second electrode 220 may serve as a common electrode for the subpixels PXn. One of the first electrode 210 and the second electrode 220 may serve as an anode of the light emitting element 300, and the other thereof may serve as a cathode of the light emitting element 300. However, the present disclosure is not limited thereto. One of the first electrode 210 and the second electrode 220 may serve as a cathode of the light emitting element 300, and the other thereof may serve as an anode of the light emitting element 300.

The first and second electrodes 210 and 220 may include electrode rods 210S and 220S respectively extending in a first direction D1, and at least one electrode branch 210B and at least one electrode branch 220B branching from the electrode rods 210S and 220S respectively and extending in a second direction D2 respectively intersecting the first direction D1.

The first electrode 210 may include a first electrode rod 210S extending in the first direction D1 and at least one first electrode branch 210B branching from the first electrode rod 210S and extending in the second direction D2.

The first electrode rod 210S of one pixel may be discontinuous at the boundary between the adjacent subpixels PXn. The first electrode rod 210S may continuously extend in substantially the same straight line throughout adjacent sub-pixels (sub-pixels adjacent to each other in the first direction D1) belonging to the same row except for a discontinuity at the boundary between the adjacent sub-pixels PXn. Accordingly, the different first electrode rods 210S disposed in the different subpixels PXn may apply different electrical signals to the different first electrode branches 210B, so that the different first electrode branches 210B may be driven individually.

The first electrode branch 210B may branch from at least a portion of the first electrode rod 210S, and may extend in the second direction D2, and may terminate so as to be spaced apart from a second electrode rod 220S, wherein the second electrode rod 220S is opposite the first electrode rod 210S.

The second electrode 220 may include a second electrode rod 220S extending in the first direction D1 and spaced apart from and opposite the first electrode rod 210S, and a second electrode branch 220B branching from the second electrode rod 220S and extending in the second direction D2. In this regard, the second electrode rod 220S in a single pixel PX may continuously extend throughout the plurality of sub-pixels PXn arranged in the first direction D1 without a discontinuity at the boundary between adjacent sub-pixels. Accordingly, the second electrode rod 220S may continuously extend throughout the adjacent pixels PX arranged in the first direction D1 without a discontinuity at the boundary between the adjacent pixels.

The second electrode branch 220B may be spaced from the first electrode branch 210B and extend parallel to the first electrode branch 210B, and may terminate so as to be spaced from the first electrode rod 210S. That is, the second electrode branch 220B may be disposed in the subpixel PXn and have one end connected to the second electrode rod 220S and an opposite end spaced apart from the first electrode rod 210S.

Although fig. 1 shows that two second electrode branches 220B are disposed in each subpixel PXn and a single first electrode branch 210B is disposed between the two second electrode branches 220B, the present disclosure is not limited thereto.

The bank 400 may be disposed at the boundary between the subpixels PXn. As a result, the first electrode rods 210S may be interrupted at the bank 400, and the second electrode rods 220S may continuously extend while passing through the bank 400 and under the bank 400. The bank 400 may extend in the second direction D2 and be disposed at a boundary between the sub-pixels PXn arranged in the first direction D1. However, the present disclosure is not limited thereto. The bank 400 may be disposed at a boundary between the sub-pixels PXn extending in the first direction D1 and arranged in the second direction D2.

The plurality of light emitting elements 300 may be disposed between the first electrode branch 210B and the second electrode branch 220B. Each of at least some of the plurality of light emitting elements 300 may have one end electrically connected to the first electrode branch 210B and an opposite end electrically connected to the second electrode branch 220B.

The plurality of light emitting elements 300 may be arranged and spaced apart from each other in the second direction D2, and may be aligned with each other and may be substantially parallel to each other. The distance between the light emitting elements 300 is not particularly limited. In one example, the plurality of light emitting elements 300 may be spaced apart from each other by a constant distance. In another example, the plurality of light emitting elements 300 may be spaced apart from each other at irregular distances. In yet another example, some of the plurality of light emitting elements 300 may be spaced apart from each other by a constant distance, while other of the plurality of light emitting elements 300 may be spaced apart from each other by an irregular distance.

A plurality of insulating layers 600 and 700 are disposed in each subpixel PXn. The insulation layers 600 and 700 may include a first insulation layer 600 and a second insulation layer 700. Although not shown in the drawings, the first insulating layer 600 may be disposed to cover the entire area of the sub-pixel PXn including the first and second electrode branches 210B and 220B. The first insulating layer 600 may protect the electrodes 21 and 22 and simultaneously insulate the electrodes 21 and 22 from each other such that the electrodes 21 and 22 do not directly contact each other.

The second insulating layer 700 may be disposed on the first insulating layer 600, and at least a portion of the second insulating layer 700 may be disposed to partially overlap each of the electrode branches 210B and 220B. The second insulating layer 700 may include a plurality of insulating patterns 710, 720, and 730. The first and second insulation patterns 710 and 720 may be disposed to overlap the first and second electrode branches 210B and 220B, respectively. The plurality of insulation patterns 710, 720, and 730 may extend in one direction and may be spaced apart from each other in a direction different from the one direction.

The first insulation pattern 710 may extend in the second direction D2 and may be disposed on the first electrode branch 210B. That is, the width of the first insulation pattern 710 may be smaller than the width of the first electrode branch 210B. The first insulation pattern 710 may extend in a direction in which the first electrode branch 210B extends, and may be disposed between two contact electrodes 260, which will be described later. The first insulation pattern 710 may have two opposite sides that are in contact with the two contact electrodes 260, respectively. The present disclosure is not limited thereto. The first insulation pattern 710 may have two opposite sides spaced apart from or overlapping the two contact electrodes 260, respectively.

The second insulation pattern 720 may extend in the second direction D2 and may be disposed to partially overlap the second electrode branch 220B. Unlike the first insulation pattern 710, a portion of the second insulation pattern 720 may be disposed on the second electrode branch 220B, and another portion of the second insulation pattern 720 may be disposed on the first insulation layer 600. One side surface of the second insulation pattern 720 may be disposed to contact, be spaced apart from, or overlap the contact electrode 260, and the other side surface thereof may be disposed between one side portion of the second electrode branch 220B and the bank 400. However, the present disclosure is not limited thereto.

Although not shown in the drawings, the third insulation pattern 730 may be disposed between the first insulation pattern 710 and the second insulation pattern 720. The third insulation pattern 730 may be disposed on the plurality of light emitting elements 300 and extend in one direction (e.g., the second direction D2) in which the light emitting elements 300 are arranged. The third insulation pattern 730 may be disposed on the light emitting element 300 and extend in the second direction D2. Accordingly, the third insulating pattern 730 may be disposed on the first insulating layer 600 and in a region where the light emitting element 300 is not disposed. That is, the third insulation pattern 730 may be formed to substantially surround the outer face of the light emitting element 300.

The shape of each of the plurality of insulating patterns 710, 720, and 730 may be formed by placing a material constituting the second insulating layer 700 to cover the entire area of each pixel PX or sub-pixel PXn and partially patterning the disposed material. However, the present disclosure is not limited thereto. The insulation patterns 710, 720, and 730 of the second insulation layer 700 may be formed in a single process.

In one example, in the display device 10 according to one embodiment, at least one of the first and second insulating layers 600 and 700 may include the concave-convex pattern 650 or 750, and thus may provide a light output path along which light emitted from the light emitting element 300 is output. The concave-convex pattern 650 or 750 may be formed in a portion of the insulation pattern of the first insulation layer 600 or the second insulation layer 700. At least a portion of light emitted from the light emitting element 300 may be incident on the first insulating layer 600 or the second insulating layer 700 and emitted toward the top of each subpixel PXn through the concave-convex pattern 650 or 750. The insulating layers 600 and 700 and the insulating patterns 710, 720, and 730 will be described in detail below with reference to other drawings.

Each contact electrode 260 may be disposed on each of the first and second electrode branches 210B and 220B. In this regard, a substantial portion of each contact electrode 260 may be disposed on the first insulating layer 600, and at least a portion of each contact electrode 260 may contact each of the first and second electrode branches 210B and 220B or may be electrically connected to each of the first and second electrode branches 210B and 220B.

The plurality of contact electrodes 260 may extend in the second direction D2, and may be arranged and spaced apart from each other in the first direction D1. Each of the contact electrodes 260 may contact at least one end of the light emitting element 300, and each of the contact electrodes 260 may be electrically connected to the first electrode 210 or the second electrode 220, and thus receive an electrical signal from the first electrode 210 or the second electrode 220. Accordingly, each of the contact electrodes 260 may transmit an electrical signal transmitted from the first electrode 210 or the second electrode 220 to the light emitting element 300.

The contact electrode 260 may include a first contact electrode 261 and a second contact electrode 262. The first contact electrode 261 may be disposed on the first electrode branch 210B, and may be in contact with one end of the light emitting element 300. The second contact electrode 262 may be disposed on the second electrode branch 220B and may contact an opposite end of the light emitting element 300.

The first electrode rod 210S and the second electrode rod 220S may be electrically connected to a circuit element layer of the display device 10 via contact holes (e.g., a first electrode contact hole CNTD and a second electrode contact hole CNTS), respectively. The drawing shows that one second electrode contact hole CNTS is formed in the second electrode rod 220S of the plurality of subpixels PXn. However, the present disclosure is not limited thereto. In some cases, the second electrode contact hole CNTS may be formed for each subpixel PXn.

The display device 10 may further include a circuit element layer under the electrodes 210 and 220 shown in fig. 1. Hereinafter, the structure of the display device 10 will be described in detail with reference to fig. 2.

FIG. 2 is a sectional view taken along lines IIa-IIa ', IIb-IIb ', and IIc-IIc ' in FIG. 1.

Fig. 2 shows a cross-sectional view of the first sub-pixel PX 1. However, the sectional view may be equally applicable to another pixel PX or sub-pixel PXn. Fig. 2 shows a cross-section between one end and the opposite end of one light emitting element 300.

Referring to fig. 1 and 2, the display device 10 may include a substrate 110, a buffer layer 115, a light blocking layer 180, first and second transistors 120 and 140, and a light emitting element 300 disposed over the first and second transistors 120 and 140, a first insulating layer 600, a second insulating layer 700, and a plurality of electrodes 210 and 220.

The substrate 110 may be implemented as an insulating substrate. The substrate 110 may be made of an insulating material such as glass, quartz, or polymer resin. Further, the substrate 110 may be a rigid substrate, or may be a flexible substrate that can be bent, folded, or rolled.

The light blocking layer 180 may be disposed on the substrate 110. The light blocking layer 180 may include a first light blocking layer 181 and a second light blocking layer 182. The first light blocking layer 181 may be electrically connected to a first drain electrode 123 of the first transistor 120, which will be described later. The second light blocking layer 182 may be electrically connected to a second drain electrode 143 of the second transistor 140, which will be described later.

A first light blocking layer 181 and a second light blocking layer 182 may be disposed to overlap the first active material layer 126 of the first transistor 120 and the second active material layer 146 of the second transistor 140, respectively. Each of the first and second light blocking layers 181 and 182 may include a material blocking light, and thus may prevent light from being incident on each of the first and second active material layers 126 and 146. In one example, each of the first and second light blocking layers 181 and 182 may be made of an opaque metal material that blocks light transmission.

The buffer layer 115 may be disposed on the light blocking layer 180 and the substrate 110. The buffer layer 115 may be disposed to cover the entire region of the substrate 110 including the light blocking layer 180. The buffer layer 115 may prevent diffusion of impurity ions, prevent intrusion of moisture or external air, and perform a surface planarization function. In addition, the buffer layer 115 may insulate the light blocking layer 180 and the first and second active material layers 126 and 146 from each other.

The buffer layer 115 may be provided thereon with a semiconductor layer. The semiconductor layer may include the first active material layer 126 of the first transistor 120, the second active material layer 146 of the second transistor 140, and the auxiliary material layer 163. The semiconductor layer may include polycrystalline silicon, single crystalline silicon, an oxide semiconductor, or the like.

The first gate insulating film 170 may be disposed on the semiconductor layer. The first gate insulating film 170 may be provided to cover the entire region of the buffer layer 115 including the semiconductor layer. The first gate insulating film 170 may function as a gate insulating film of each of the first transistor 120 and the second transistor 140.

A first conductive layer may be disposed on the first gate insulating film 170. The first conductive layer may include a first gate electrode 121 disposed on the first active material layer 126 of the first transistor 120 on the first gate insulating film 170, a second gate electrode 141 disposed on the second active material layer 146 of the second transistor 140, and an electric line 161 disposed on the auxiliary material layer 163.

An interlayer insulating film 190 may be disposed on the first conductive layer. The interlayer insulating film 190 may perform an interlayer insulating function. In addition, the interlayer insulating film 190 may include an organic insulating material and may perform a surface planarization function.

A second conductive layer may be provided on the interlayer insulating film 190. The second conductive layer may include the first drain electrode 123 and the first source electrode 124 of the first transistor 120, the second drain electrode 143 and the second source electrode 144 of the second transistor 140, and a power electrode 162 disposed on the power line 161.

Each of the first drain electrode 123 and the first source electrode 124 may be electrically connected to the first active material layer 126 via a first contact hole extending through the interlayer insulating film 190 and the first gate insulating film 170. Each of the second drain electrode 143 and the second source electrode 144 may be electrically connected to the second active material layer 146 via a second contact hole extending through the interlayer insulating film 190 and the first gate insulating film 170. Further, the first and second drain electrodes 123 and 143 may be electrically connected to the first and second light blocking layers 181 and 182, respectively, via additional contact holes.

A via layer 200 may be disposed on the second conductive layer. The via layer 200 may comprise an organic insulating material and perform a surface planarization function.

The bank 400 and the plurality of electrodes 210 and 220 are disposed on the via layer 200. The bank 400 may be disposed at the boundary between the subpixels PXn such that the subpixels PXn are spaced apart from each other.

The bank 400 may define a boundary between the subpixels PXn. The bank 400 may extend in the first and second directions D1 and D2 to form one grid pattern, and may be disposed at a boundary between the subpixels PXn. When the organic material or the solvent is sprayed using the inkjet printing method in manufacturing the display device 10, the bank 400 may perform a function of preventing the organic material or the solvent from flowing between the sub-pixels PXn. Alternatively, when the display device 10 further includes another member, the other member may be disposed on the dam 400 such that the dam 400 may support the other member. The bank 400 may include polyimide.

However, the present disclosure is not limited thereto. The banks 400 may not necessarily be disposed on the via layer 200. The bank 400 and the insulating layers 600 and 700 may be formed in a single process. In this case, the bank 400 may be integrally formed with the insulating layers 600 and 700, and may have a partially protruding shape.

A plurality of electrodes 210 and 220 may be disposed on the via layer 200. As described above, each of the electrodes 210 and 220 includes each of the electrode rods 210S and 220S and each of the electrode branches 210B and 220B. The line IIa-IIa ' in FIG. 1 extends across the first electrode rod 210S, the line IIb-IIb ' in FIG. 1 extends across the first electrode branch 210B and the second electrode branch 220B, and the line IIc-IIc ' in FIG. 1 extends across the second electrode rod 220S. Each of the electrode rods 210S and 220S and each of the electrode branches 210B and 220B may constitute each of the first electrode 210 and the second electrode 220.

At least a portion of the first electrode rods 210S may overlap the bank 400. As described above, the first electrode rods 210S extend in the first direction D1 and are interrupted at the banks 400. One end of the first electrode bar 210S of the subpixel PXn may overlap the bank 400, and the opposite end thereof may be spaced apart from another bank 400. One end of the first electrode rod 210S overlapping the bank 400 may be connected to the first drain electrode 123 via a first electrode contact hole CNDT extending through the via layer 200 and exposing a portion of the first drain electrode 123 of the first transistor (driving transistor) 120. The first electrode rod 210S may be electrically connected to the first drain electrode 123 of the driving transistor 120, and may receive a predetermined electrical signal from the first drain electrode 123.

The first and second electrode branches 210B and 220B may be spaced apart from each other. The first and second electrode branches 210B and 220B are disposed in the middle area of each subpixel PXn and spaced apart from each other in the second direction D2. The plurality of light emitting elements 300 may be disposed in a space between the first electrode branch 210B and the second electrode branch 220B.

The second electrode rod 220S may extend in one direction and also extend into a non-light emitting region where the light emitting element 300 is not disposed. The second electrode bar 220S may contact the power electrode 162 via a second electrode contact hole CNTS that extends through the via layer 200 and exposes a portion of the power electrode 162. The second electrode rod 220S may be electrically connected to the power electrode 162 and may receive a predetermined electrical signal from the power electrode 162.

Each of the electrodes 210 and 220 may include a transparent conductive material. In one example, each of the electrodes 210 and 220 may include a material such as ITO (indium tin oxide), IZO (indium zinc oxide), ITZO (indium tin zinc oxide), or the like. The present disclosure is not limited thereto. In some embodiments, each of the electrodes 210 and 220 may include a conductive material having a high reflectivity. For example, each of the electrodes 210 and 220 may include a metal such as silver (Ag), copper (Cu), aluminum (Al), or the like as a conductive material having high reflectivity. In this case, light incident on each of the electrodes 210 and 220 may be reflected from the electrodes 210 and 220 and emitted toward the top of each subpixel PXn.

In addition, each of the electrodes 210 and 220 may have a structure in which at least one transparent conductive material layer and at least one metal layer having a high reflectivity are vertically stacked, or may be composed of a single layer including a transparent conductive material and a metal having a high reflectivity. In an embodiment, each of the electrodes 210 and 220 may have a stacked structure of ITO/silver Ag/ITO/IZO, or may include an alloy including aluminum (Al), nickel (Ni), lanthanum (La), or the like. However, the present disclosure is not limited thereto.

The first insulating layer 600 may be disposed to partially cover each of the first and second electrodes 210 and 220. The first insulating layer 600 may be disposed to cover a substantial portion of the top surface of each of the first and second electrodes 210 and 220, but to expose a portion of each of the first and second electrodes 210 and 220. The first insulating layer 600 may include a patterned portion 600P exposing a portion of each of the ends of the electrode branches 210B and 220B facing each other. Accordingly, the first insulating layer 600 may be discontinuous at the patterned portion 600P. The contact electrode 260 may be disposed in the patterned part 600P such that the contact electrode 260 may be in contact with the electrodes 210 and 220. Further, the first insulating layer 600 may be partially disposed in a region between the second electrode branches 220B and the bank 400. The portion of the first insulating layer 600 disposed in the region between the first electrode branch 210B and the second electrode branch 220B may extend in the second direction D2 and thus have an island shape or a line shape.

The first insulating layer 600 may protect the first electrode 210 and the second electrode 220 while insulating them from each other. In addition, the first insulating layer 600 may prevent the light emitting element 300 disposed on the first insulating layer 600 from being directly contacted with and damaged by other members. However, the shape and structure of the first insulating layer 600 are not limited thereto. In some cases, the first insulating layer 600 may have an insulating pattern on which a concave-convex pattern is formed. For example, when the second insulating layer 700 is omitted, the first insulating layer 600 may include the above-described insulating patterns 610, 620, and 630 (shown in fig. 24), and the concave-convex pattern 650 (shown in fig. 24) may be formed on the insulating patterns. In this case, light emitted from the light emitting element 300 may be incident to the first insulating layer 600 and then may be emitted toward the top of the subpixel PXn through the concave-convex pattern 650 of the first insulating layer 600. Which will be described in detail later with reference to other drawings.

The light emitting element 300 may be disposed on the first insulating layer 600. The at least one light emitting element 300 may be disposed on a portion of the first insulating layer 600 disposed between the electrode branches 210B and 220B. Two opposite ends of the light emitting element 300 may be aligned with two opposite ends of the underlying first insulating layer 600, respectively. The light emitting element 300 may partially overlap the electrodes 210 and 220. The light emitting element 300 may overlap each of ends of the first and second electrode branches 210B and 220B facing each other, and may be electrically connected to each of the electrodes 210 and 220 via the contact electrode 260.

In one example, the light emitting element 300 may include a plurality of layers arranged in a direction parallel to the via layer 200. The light emitting element 300 of the display device 10 according to an embodiment may include a semiconductor layer (which has a conductive type as described above) and an active layer, which may be sequentially arranged in a direction parallel to the via layer 200. As shown in the drawing, the light emitting element 300 may include a first conductive type semiconductor 310, an active layer 330, a second conductive type semiconductor 320, and a conductive electrode layer 370, which may be sequentially arranged in a direction parallel to the via layer 200. The present disclosure is not limited thereto. The order in which the plurality of layers of the light emitting element 300 are arranged may be vice versa. In some cases, when the light emitting element 300 has a structure different from the above structure, a plurality of layers may be arranged in a direction perpendicular to the via layer 200.

The second insulating layer 700 may be partially disposed on the first insulating layer 600 and the light emitting element 300. The second insulating layer 700 may include the first insulating pattern 710, the second insulating pattern 720, and the third insulating pattern 730 as a plurality of insulating patterns. The first and second insulation patterns 710 and 730 may be disposed to overlap the first and second electrode branches 210B and 220B, respectively, and the third insulation pattern 730 may be disposed on the light emitting element 300.

The third insulating pattern 730 may protect the light emitting element 300 and simultaneously perform a function of fixing the light emitting element 300 in the manufacturing process of the display device 10. The third insulation pattern 730 may be disposed to partially surround the outer face of the light emitting element 300. That is, a portion of the material of the third insulation pattern 730 may be disposed between the bottom surface of the light emitting element 300 and the first insulation layer 600. The third insulation pattern 730 may extend in the second direction D2 and between the first and second electrode branches 210B and 220B, and thus may have an island shape or a line shape in a plan view.

The first and second insulation patterns 710 and 720 are disposed on the first insulation layer 600. The first and second insulation patterns 710 and 720 may be spaced apart from the patterned portion 600P of the first insulation layer 600. That is, each of sides of the first and second insulation patterns 710 and 720 facing each other may be disposed on the first insulation layer 600, and may be horizontally spaced apart from the patterned part 600P. In one example, the drawing shows that each of the sides of the first and second insulation patterns 710 and 720 facing each other is inclined at a predetermined angle. The present disclosure is not limited thereto. Each of the sides of the first and second insulation patterns 710 and 720 facing each other may extend perpendicular to the top surface of the first insulation layer 600.

In one embodiment, the first and second insulation patterns 710 and 720 may overlap the electrodes 210 and 220 or the electrode branches 210B and 220B, respectively. At least one side of each of the first and second insulation patterns 710 and 720 may vertically overlap each of the electrode branches 210B and 220B, and may be horizontally spaced apart from the corresponding side of each of the electrode branches 210B and 220B.

The first insulation pattern 710 may overlap the first electrode branch 210B. Two opposite sides of the first insulation pattern 710 may overlap the first electrode branch 210B and may be horizontally spaced apart from the two opposite sides of the first electrode branch 210B, respectively. Although not shown in the drawings, opposite sides of the first insulation pattern 710 may overlap the first electrode branch 210B and may be horizontally spaced apart from opposite sides of the first electrode branch 210B. Accordingly, two opposite sides of the first insulation pattern 710 may be spaced apart from the light emitting element 300. Alternatively, two opposite sides of the first insulation pattern 710 may be aligned with two opposite sides of the first electrode branch 210B, respectively.

The second insulation pattern 720 may overlap the second electrode branch 210B. One side of the second insulation pattern 720 may overlap the second electrode branch 210B and be horizontally spaced apart from one side of the second electrode branch 220B. Accordingly, one side of the second insulation pattern 720 may be spaced apart from the light emitting element 300. However, opposite sides of the second insulation pattern 720 may be located between opposite sides of the second electrode branch 220B and the bank 400. That is, only a portion of the second insulation pattern 720 may overlap the second electrode branch 220B, and the entirety of the first insulation pattern 710 may overlap the first electrode branch 210B.

According to one embodiment, the second insulation layer 700 may include a plurality of concave-convex patterns 750 disposed on the first insulation pattern 710 and the second insulation pattern 720, respectively. The concave-convex pattern 750 may have a shape in which a top surface of each of the first and second insulating patterns 710 and 720 partially protrudes upward. The plurality of concave-convex patterns 750 may be spaced apart from each other. The light emitted from the light emitting element 300 may travel nondirectionally. At least some of the light beams may travel in the direction in which the light emitting elements 300 extend (i.e., in a direction parallel to the top surface of the via layer 200). As described above, the first and second insulation patterns 710 and 720 may be spaced apart from the light emitting element 300 and face the light emitting element 300. Accordingly, a portion of light emitted from the light emitting element 300 may be incident on the first and second insulating patterns 710 and 720 (i.e., on the second insulating layer 700).

In an embodiment, the second insulating layer 700 and the first insulating layer 600 may include materials having different refractive indexes. Light incident to the second insulating layer 700 may be reflected from an interface between the flat bottom surface of the second insulating layer 700 and the flat top surface of the first insulating layer 600, and then may be emitted toward the concave-convex pattern 750 and then output from the concave-convex pattern 750. The concave-convex pattern 750 may be formed by patterning a top surface of the second insulating layer 700 during a process of forming the second insulating layer 700 or performing a nano-imprinting method on the top surface of the second insulating layer 700. In one example, the vertical dimension measured from the via layer 200 to the top surface of the third insulating pattern 730 may be approximately an average of the vertical dimension measured from the via layer 200 to the top surface of the first insulating pattern 710 or the second insulating pattern 720 and the vertical dimension measured from the via layer 200 to the top surface of the concave-convex pattern 750. That is, a vertical dimension measured from the via layer 200 to the top surface of the third insulating pattern 730 may be greater than a vertical dimension measured from the via layer 200 to the top surface of the first insulating pattern 710 or the second insulating pattern 720, but may be less than a vertical dimension measured from the via layer 200 to the top of the concave-convex pattern 750. The present disclosure is not limited thereto.

The drawing shows that the concave-convex pattern 750 has five convex portions on each of the first and second insulating patterns 710 and 720. The present disclosure is not limited thereto. The concave-convex pattern 750 may be formed on the entire area of the top surface of each of the first and second insulation patterns 710 and 720. In some cases, the concave-convex pattern 750 may be formed on a portion of the top surface of each of the first and second insulation patterns 710 and 720 spaced apart from two opposite sides of each of the first and second insulation patterns 710 and 720. Further, the shape of the convex or concave portion of the concave-convex pattern 750 is not limited to the rectangular shape. The shape of the convex or concave portion of the concave-convex pattern 750 may have various shapes. Which will be described in detail later with reference to other drawings.

The contact electrode 260 may be disposed on each of the electrodes 210 and 220, the first insulating layer 600, and the second insulating layer 700. The first and second contact electrodes 261 and 262 may be disposed on the third insulation pattern 730 of the second insulation layer 700 and spaced apart from each other. Accordingly, the second insulating layer 700 may insulate the first and second contact electrodes 261 and 262 from each other.

In an embodiment, the first contact electrode 261 may be in contact with a portion of the first electrode 210 exposed through the patterned portion 600P of the first insulating layer 600 and one end of the light emitting element 300. The second contact electrode 262 may contact a portion of the second electrode 220 exposed through the patterned portion 600P and an opposite end of the light emitting element 300. The first and second contact electrodes 261 and 262 may contact two opposite lateral end surfaces of the light emitting element 300, for example, the first conductive type semiconductor 310, the second conductive type semiconductor 320, or the conductive electrode layer 370, respectively. Two opposite sides of the first insulating layer 600 disposed between the first and second electrode branches 210B and 220B and corresponding to the patterned portion 600P may be aligned with two opposite side ends of the light emitting element 300, respectively. Accordingly, the contact electrode 260 may smoothly contact both opposite side ends of the light emitting element 300.

In addition, the first and second contact electrodes 261 and 262 may contact the first and second insulation patterns 710 and 720 disposed on the first insulation layer 600, respectively. The first and second contact electrodes 261 and 262 may be disposed on two portions of the first insulating layer 600 adjacent to the patterned portion 600P and facing each other, respectively, and may extend toward the first and second insulating patterns 710 and 720. The drawing shows that the lower ends of the first and second contact electrodes 261 and 262 extend to the first and second insulation patterns 710 and 720, respectively, and are in contact with the first and second insulation patterns 710 and 720. However, the present disclosure is not limited thereto. The first and second contact electrodes 261 and 262 may be spaced apart from the first and second insulation patterns 710 and 720, respectively, or may partially and vertically overlap the first and second insulation patterns 710 and 720, respectively.

The contact electrode 260 may include a conductive material. Examples of the conductive material may include ITO, IZO, ITZO, aluminum (Al), and the like. However, the present disclosure is not limited thereto.

A passivation layer 800 may be disposed on the bank 400, the first insulating layer 600, the second insulating layer 700, and the contact electrode 260. The passivation layer 800 may serve to protect components disposed on the via layer 200 from the external environment.

Each of the first insulating layer 600, the second insulating layer 700, and the passivation layer 800 as described above may include an inorganic insulating material or an organic insulating material. In an embodiment, each of the first insulating layer 600, the second insulating layer 700, and the passivation layer 800 may include an inorganic insulating material such as silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum oxide (Al2O3), aluminum nitride (AlN), or the like. Alternatively, each of the first insulating layer 600, the second insulating layer 700, and the passivation layer 800 may include an organic insulating material including acrylic resin, epoxy resin, phenol resin, polyamide resin, polyimide resin, unsaturated polyester resin, polystyrene resin, polyphenylene sulfide resin, benzocyclobutene, Cardo resin, siloxane resin, silsesquioxane resin, polymethyl methacrylate, polycarbonate, polymethyl methacrylate-polycarbonate synthetic resin, and the like. However, the present disclosure is not limited thereto.

Fig. 3 is a schematic diagram of a light emitting element according to an embodiment.

The light emitting element 300 may be a light emitting diode. Specifically, the light emitting element 300 may be implemented as an inorganic light emitting diode made of an inorganic material and having a size of nanometer to micrometer. The light emitting element 300 may be disposed between two electrodes facing each other. When an electric field of a specific orientation is generated between the two electrodes and thus each of the two electrodes is polarized, the light emitting elements ED may be aligned in the same orientation between them.

The light emitting element 300 may have a shape extending in one direction. The light emitting element 300 may have a shape such as a nanorod, a nanowire or a nanotube. In an embodiment, the light emitting element 300 may be cylindrical or rod-shaped. However, the shape of the light emitting element 300 is not limited thereto. The light emitting element 300 may have various shapes. In another example, the light emitting element 300 may have a shape of a polygonal prism such as a cube, a rectangular parallelepiped, or a hexagonal prism. A plurality of semiconductors included in the light emitting element 300 to be described later may be sequentially arranged or stacked in the one direction.

The light emitting element 300 may include a semiconductor crystal doped with impurities of any conductivity type (e.g., p-type or n-type). The semiconductor crystal may receive an electrical signal applied from an external power source and emit light in a specific wavelength band using the electrical signal.

The light emitting element 300 according to one embodiment may emit light of a specific wavelength band. In an embodiment, the light emitted from the active layer 330 may be blue light having a central wavelength band in a range of 450nm to 495 nm. However, it should be understood that the central wavelength band of blue light is not limited to the above range, and includes all wavelength ranges in which light can be recognized as blue light in the art. In addition, light emitted from the active layer 330 of the light emitting element 300 is not limited thereto. The light emitted from the active layer 330 of the light emitting element 300 may be green light having a central wavelength band in the range of 495nm to 570nm or red light having a central wavelength band in the range of 620nm to 750 nm.

In one example, the light emitting element 300 according to one embodiment may include a first conductive type semiconductor 310, a second conductive type semiconductor 320, an active layer 330, and an insulating film 380. In addition, the light emitting element 300 according to an embodiment may further include at least one conductive electrode layer 370. Fig. 3 shows that the light emitting element 300 further comprises a conductive electrode layer 370. The present disclosure is not limited thereto. In some cases, the light emitting element 300 may include a greater number of the conductive electrode layers 370, or may not have the conductive electrode layers 370. The following description of the light emitting element 300 may be equally applicable to the case where the number of the conductive electrode layers 370 is changed or the light emitting element 300 further includes another component.

Referring to fig. 3, the first conductive type semiconductor 310 may be, for example, an n-type semiconductor. The first conductive type semiconductor layer 310 may include a semiconductor material having a chemical formula of AlxGayIn1-x-yN (0. ltoreq. x.ltoreq.1, 0. ltoreq. y.ltoreq.1, 0. ltoreq. x + y. ltoreq.1). For example, the first conductive type semiconductor 310 may be made of at least one of AlGaInN, GaN, AlGaN, InGaN, AlN, and InN, and may be doped with an n-type dopant. The n-type dopant doped into the first conductive type semiconductor 310 may be Si, Ge, Sn, etc. In an embodiment, the first conductive type semiconductor 310 may be n-GaN doped with n-type Si. The length of the first conductive type semiconductor 310 may be in the range of 1.5 μm to 5 μm. The present disclosure is not limited thereto.

The second conductive type semiconductor 320 may be disposed on an active layer 330 which will be described later. The second conductive type semiconductor 320 may be, for example, a p-type semiconductor. In one example, when the light emitting element 300 emits light in a blue or green wavelength band, the second conductive type semiconductor 320 may include a semiconductor material having a chemical formula of AlxGayIn1-x-yN (0. ltoreq. x.ltoreq.1, 0. ltoreq. y.ltoreq.1, 0. ltoreq. x + y. ltoreq.1). For example, the second conductive type semiconductor layer 320 may be made of at least one of AlGaInN, GaN, AlGaN, InGaN, AlN, and InN, and may be doped with a p-type dopant. The p-type dopant doped into the second conductive type semiconductor layer 320 may be Mg, Zn, Ca, Se, Ba, etc. In an embodiment, the second conductive type semiconductor 320 may be p-GaN doped with p-type Mg. The length of the second conductive type semiconductor 320 may be in the range of 0.08 μm to 0.25 μm. The present disclosure is not limited thereto.

In one example, the figure shows that each of the first conductivity type semiconductor 310 and the second conductivity type semiconductor 320 is comprised of a single layer. The present disclosure is not limited thereto. In some cases, each of the first conductive type semiconductor 310 and the second conductive type semiconductor 320 may include a greater number of layers, for example, a cladding layer or a TSBR (tensile strain barrier reduction) layer, based on the material of the active layer 330.

The active layer 330 may be disposed between the first conductive type semiconductor 310 and the second conductive type semiconductor 320. The active layer 330 may include a material of a single quantum well structure or a multiple quantum well structure. When the active layer 330 includes a material of a multi-quantum well structure, the active layer 330 may have a structure in which a plurality of quantum layers and a plurality of well layers are alternately stacked on each other. The active layer 330 may emit light via a combination between electrons and holes according to an electrical signal applied through the first and second conductive type semiconductors 310 and 320. In one example, when the active layer 330 emits light of a blue wavelength band, the active layer 330 may include materials such as AlGaN and AlGaInN. Specifically, when the active layer 330 has a structure in which a plurality of quantum layers and a plurality of well layers are alternately stacked on each other, the quantum layers may include a material such as AlGaN or AlGaInN, and the well layers may include a material such as GaN or AlInN. In an embodiment, when the active layer 330 includes AlGaInN as a material of the quantum layer and AlInN as a material of the well layer, as described above, the active layer 330 may emit blue light having a central wavelength band in the range of 450nm to 495 nm.

However, the present disclosure is not limited thereto. The active layer 330 may have a structure in which a plurality of first layers made of a semiconductor material having a larger band gap energy and a plurality of second layers made of a semiconductor material having a smaller band gap energy are alternately stacked on each other. The active layer 330 may include group III to group V semiconductor materials according to a wavelength band of emitted light. The light emitted from the active layer 330 is not limited to light of a wavelength band corresponding to blue. In some cases, the light emitted from the active layer 330 may be light of a wavelength band corresponding to red or green. The length of the active layer 330 may be in the range of 0.05 μm to 0.25 μm. The present disclosure is not limited thereto.

In one example, light emitted from the active layer 330 may be emitted not only from the outer face in the length direction of the light emitting element 300 but also from two opposite lateral end faces of the light emitting element 300. The directivity of light emitted from the active layer 330 is not limited to one direction.

The conductive electrode layer 370 may be an ohmic contact electrode. The present disclosure is not limited thereto. The conductive electrode layer 370 may be a schottky contact electrode. The conductive electrode layer 370 may include a conductive metal. For example, the conductive electrode layer 370 may include at least one of aluminum (Al), titanium (Ti), indium (In), gold (Au), silver (Ag), ITO (indium tin oxide), IZO (indium zinc oxide), and ITZO (indium tin zinc oxide). In addition, the conductive electrode layer 370 may include a semiconductor material doped with n-type or p-type dopants. The conductive electrode layer 370 may include the same material or different materials. The present disclosure is not limited thereto.

As described above, the insulating film 380 may be provided to surround the outer faces of the plurality of semiconductors. In an embodiment, the insulating film 380 may be disposed to surround at least an outer face of the active layer 330, and may extend in one direction in which the light emitting element 300 extends. The insulating film 380 may perform a function of a protective member. In one example, the insulating film 380 may be formed to surround the side of the member so that two opposite ends in the length direction of the light emitting element 300 may be exposed.

The drawing shows that the insulating film 380 extends in the length direction of the light emitting element 300 and covers a region from the first conductivity type semiconductor 310 to the conductive electrode layer 370. The present disclosure is not limited thereto. The insulating film 380 may cover an outer face of only one of the conductive type semiconductors and an outer face of the active layer 330, or may cover only a portion of an outer face of the conductive electrode layer 370, so that another portion of the outer face of the conductive electrode layer 370 may be exposed.

The thickness of the insulating film 380 may be in the range of 10nm to 1.0 μm. The present disclosure is not limited thereto. Preferably, the thickness of the insulating film 380 may be 40 nm.

The insulating film 380 may include a material having insulating ability, for example, silicon oxide (SiOx), silicon nitride (SiNx), silicon oxynitride (SiOxNy), aluminum nitride (AlN), aluminum oxide (Al2O3), or the like. Accordingly, the insulating film 380 can prevent an electrical short that may occur when the active layer 330 is in direct contact with an electrode through which an electrical signal is transmitted to the light emitting element 300. In addition, the insulating film 380 protects the outer face of the light emitting element 300 including the active layer 330, so that the reduction of light emitting efficiency can be prevented.

Further, in some embodiments, the insulating film 380 may be surface-treated. During the manufacturing process of the display device 10, the light emitting elements 300 may be ejected onto the electrodes while being dispersed in a predetermined ink, and may be aligned with each other. In this regard, in order to maintain a state in which the light emitting elements 300 are not aggregated with other adjacent light emitting elements 300 in the ink but the light emitting elements 300 are dispersed in the ink, the insulating film 380 may have a hydrophobic or hydrophilic surface.

In one example, the light emitting element 300 may have a length h of 1 μm to 10 μm or 2 μm to 6 μm, and preferably has a length of 4 μm to 5 μm. Further, the diameter of the light emitting element 300 may be in the range of 300nm to 700nm, and the aspect ratio of the light emitting element 300 may be in the range of 1.2 to 100. The present disclosure is not limited thereto. The plurality of light emitting elements 300 included in the display device 10 may have different diameters due to differences between compositions of the active layers 330 thereof. Preferably, the diameter of the light emitting element 300 may have about 500 nm.

Fig. 4 is a schematic diagram illustrating a cross-section of a portion of a display device according to an embodiment. Fig. 5 is an enlarged view of a portion a of fig. 4. Fig. 6 is a plan view illustrating a top surface of an insulation pattern according to an embodiment.

In fig. 4, some components of the display device 10 are omitted or briefly illustrated in order to illustrate the progress of light emitted from the light emitting element 300 into the second insulating layer 700. Fig. 4 shows only the via layer 200, the first electrode 210, the second electrode 220, the first insulating layer 600, the light emitting element 300, the second insulating layer 700, and the contact electrode 260, but the structure of the display device 10 is not limited thereto. The display device 10 may include components as described above with reference to fig. 2. Hereinafter, the insulating layers 600 and 700 of the display device 10 will be described in detail with reference to other drawings including fig. 4.

Referring to fig. 4 to 6, at least a portion of light emitted from the light emitting element 300 may be incident to the second insulating layer 700. Light may be incident on one side 710S of the first insulation pattern 710 and one side 720S of the second insulation pattern 720. The second insulating layer 700 may include an inorganic material or an organic insulating material having a predetermined refractive index. The light beams incident on the first and second insulation patterns 710 and 720 may be refracted on one side 710S and 720S, respectively, and travel in the first and second insulation patterns 710 and 720, respectively.

As shown in fig. 2, each of the first and second insulating patterns 710 and 720 may include a top surface interfacing with the passivation layer 800 disposed thereon and a bottom surface interfacing with the underlying first insulating layer 600. Light incident to the first and second insulating patterns 710 and 720 may be reflected or refracted on the top and bottom surfaces of each of the insulating patterns 710 and 720, where an interface is formed between layers having different refractive indexes. The light beams reflected from the interface may not be output from the insulation patterns 710 and 720, so that the light efficiency of the display apparatus 10 may be reduced.

According to one embodiment, the second insulating layer 700 may include the concave-convex pattern 750 disposed on each of the insulating patterns 710 and 720, and thus provide an optical path through which light incident to the second insulating layer 700 is output. Light may be reflected and moved in the second insulating layer 700 and then may be output from the second insulating layer 700 through the concave-convex pattern 750 (EL in fig. 4). The concave-convex pattern 750 has a shape in which a portion of the top surface of the second insulating layer 700 protrudes upward. The protruded regions may change an incident angle at which light is incident toward the top surface of the second insulating layer 700 in a total reflection manner. Light incident on the concave-convex pattern 750 may be refracted at an interface between the concave-convex pattern 750 and the outside thereof, and then may be output from the concave-convex pattern 750. The second insulating layer 700 may provide a traveling path of incident light and simultaneously output light through the concave-convex pattern 750P, so that light efficiency of the display device 10 may be improved.

The concave-convex pattern 750 is substantially integrated with the second insulating layer 700. The concave-convex pattern 750 may be formed by patterning a top surface of the second insulating layer 700 in a process of forming the second insulating layer 700 or pressing the top surface with a mold. The present disclosure is not limited thereto.

Fig. 4 shows that the side surface of the concave-convex pattern 750 extends in a direction perpendicular to the top surface of the second insulating layer 700 or the first insulating pattern 710, and the top surface of the concave-convex pattern 750 extends in parallel with the top surface of the first insulating pattern 710. That is, the concave or convex portions of the concave-convex pattern 750 may have a quadrangular shape having right-angled corners. However, the present disclosure is not limited thereto. One side surface of the concave or convex portion of the concave-convex pattern 750 may be inclined, or the concave or convex portion of the concave-convex pattern 750 may have a partially curved shape.

According to one embodiment, the concave-convex pattern 750 may have a shape in which at least a portion thereof extends in one direction. As shown in fig. 6, the concave-convex pattern 750 may be formed on the top surface of the second insulating layer 700, and may be patterned to extend in substantially the same direction as the direction in which the first and second insulating patterns 710 and 720 extend. In one example, the concave-convex pattern 750 may be disposed on the first and second insulation patterns 710 and 720, and may extend in parallel with one direction (e.g., the second direction D2) in which the insulation patterns 710 and 720 extend. However, the present disclosure is not limited thereto. The concave-convex pattern 750 may extend in a direction different from one direction in which the insulating patterns 710 and 720 extend, or the concave-convex pattern 750 may be divided into repeating units that may be spaced apart from each other.

In one example, each of the plurality of concave-convex patterns 750 may have a predetermined vertical dimension or depth Gd or a predetermined pitch Gp. The depth Gd and the pitch Gp of the concave-convex pattern 750 may vary based on the refractive index N of the material constituting the second insulating layer 700 and the wavelength λ of light incident to the concave-convex pattern 750. In an embodiment, each of the pitch Gp and the depth Gd of the concave-convex pattern 750 may be inversely proportional to a refractive index of a material of the second insulating layer 700, and may be proportional to a wavelength λ of incident light. That is, each of the pitch Gp and the depth Gd of the concave-convex pattern 750 may be smaller as the refractive index of the material of the second insulating layer 700 is larger or the wavelength λ of incident light is smaller. Accordingly, the concave-convex pattern 750 may be dense on the second insulating layer 700. In contrast, each of the pitch Gp and the depth Gd of the concave-convex pattern 750 may be larger as the refractive index of the second insulating layer 700 is smaller or the wavelength λ of light is larger.

Fig. 7 is a schematic diagram illustrating a cross-section of one sub-pixel according to an embodiment.

In fig. 7, some components of the display apparatus 10 are omitted or shown in a simpler manner in order to show a structure in which the first and second insulating patterns 710 and 720 of the second insulating layer 700 are arranged in each subpixel PXn. Fig. 7 shows only the via layer 200, the first electrode 210, the second electrode 220, the bank 400, the first insulating layer 600, and the second insulating layer 700. However, the structure of the display device 10 is not limited thereto.

Referring to fig. 7, each subpixel PXn includes a bank 400, a first electrode 210, a second electrode 220, a first insulating layer 600, and a second insulating layer 700. One subpixel PXn may include one first electrode branch 210B and two second electrode branches 220B, and may include one first insulation pattern 710 and two second insulation patterns 720 overlapping the one first electrode branch 210B and the two second electrode branches 220B, respectively.

The first electrode branch 210B and the second electrode branch 220B disposed in each subpixel PXn may have the same width. The width LE1 of the first electrode branch 210B is the same as the width LE2 of the second electrode branch 220B. In contrast, in an embodiment, the width LI1 of the first insulation pattern 710 may be less than the width LI2 of the second insulation pattern 720. As described above, the insulation patterns 710 and 720 may overlap the electrode branches 210B and 220B, respectively, and at least one side of each of the insulation patterns 710 and 720 may overlap each of the electrode branches 210B and 220B, but be horizontally spaced apart from one side of each of the electrode branches 210B and 220B. Accordingly, one face of each of the first and second insulation patterns 710 and 720 may be spaced apart from the light emitting element 300 disposed between the electrode branches 210B and 220B.

Unlike the second electrode branch 220B, the first electrode branch 210B may have two opposite sides horizontally spaced apart from two opposite sides of the second electrode branch 220B, respectively. One side of the second electrode branch 220B may face the first electrode branch 210B, and an opposite side of the second electrode branch 220B may face the bank 400. Accordingly, two opposite sides of the first insulation pattern 710 may overlap the first electrode branch 210B, but may be horizontally spaced apart from two opposite sides of the first electrode branch 210B, respectively. One side of the second insulation pattern 720 may be disposed between the second electrode branch 220B and the bank 400. That is, the width LI1 of the first insulation pattern 710 may be less than the width LI2 of the second insulation pattern 720.

According to an embodiment, a distance LIp between the first and second insulation patterns 710 and 720 may be greater than a distance LEP between the first and second electrode branches 210B and 220B. Further, a distance LIg between the second insulation patterns 720 and the banks 400 may be less than a distance LIp between the first insulation patterns 710 and the second insulation patterns 720. As described above, at least one side of each of the first and second insulation patterns 710 and 720 may overlap each of the electrode branches 210B and 220B, but may be horizontally spaced apart from one side of each of the electrode branches 210B and 220B. Therefore, the distances therebetween may be different from each other. In an embodiment, each of the widths LI1 and LI2 of the first and second insulation patterns 710 and 720 may be in a range of 10 μm to 20 μm. However, the present disclosure is not limited thereto.

The display apparatus 10 according to one embodiment includes the second insulating layer 700, the second insulating layer 700 including the concave-convex pattern 750 as described above, and the second insulating layer 700 may provide a light traveling path along which light emitted from the light emitting element 300 is output toward the top of each pixel PX or sub-pixel PXn. Accordingly, the display device 10 may have improved top emission efficiency. In addition, the device may not have a separate bank structure or a reflective layer to reflect light emitted from the light emitting element 300 upward. Therefore, the manufacturing cost of the display device 10 can be reduced.

Hereinafter, a method for manufacturing the display device 10 according to an embodiment will be described.

Fig. 8 is a flowchart illustrating a manufacturing process of a display device according to an embodiment. Fig. 9 to 16 are sectional views illustrating a manufacturing process of a display device according to an embodiment.

Referring to fig. 8, a method for manufacturing the display device 10 according to an embodiment includes: preparing a substrate on which a first electrode 210 and a second electrode 220 are disposed, and placing a light emitting element 300 between the first electrode 210 and the second electrode 220 (S100); and forming at least one insulation pattern 710 and 720 spaced apart from the light emitting element 300, partially overlapping the first and second electrodes 210 and 220, and having a concave-convex pattern 750 formed on at least a portion of a top surface thereof (S200).

The display device 10 according to an embodiment may be manufactured by placing the light emitting element 300 on a substrate on which the first electrode 210 and the second electrode 220 are formed and then forming the insulating patterns 710 and 720 having the concave-convex pattern 750, respectively. Each of the insulating patterns 710 and 720 may be formed by forming the second insulating material layer 700' so as to completely overlap the first electrode 210 and the second electrode 220 and then by etching at least a portion of the second insulating material layer 700' or performing a process of pressing at least a portion of the second insulating material layer 700' with a predetermined mold. In particular, in the embodiment, the insulating patterns 710 and 720 may be formed by performing a patterning method or a nanoimprinting method such that the concave-convex pattern 750 may be disposed thereon, while the insulating patterns 710 and 720 may be spaced apart from the light emitting element 300. Hereinafter, a manufacturing process of the display device 10 will be described in detail with reference to other drawings.

First, referring to fig. 9, the first electrode 210 and the second electrode 220 provided on the via layer 200 are prepared, and a first insulating material layer 600' provided to cover the entire area of the first electrode 210 and the second electrode 220 is formed. The first electrode 210 and the second electrode 220 are spaced apart from each other. It is understood that the first electrode 210 and the second electrode 220 in fig. 9 may substantially function as the first electrode branch 210B and the second electrode branch 220B, respectively. The description of the structure is the same as above.

Although not shown in the drawings, a bank 400 as described above in fig. 2 may be provided on the via layer 200. In an embodiment, the banks 400 may be disposed directly on the via layer 200. In some cases, the bank 400 may be formed simultaneously with the first insulating material layer 600'. However, in the following drawings including fig. 9, the bank 400 will be omitted and the formation of the insulating patterns 710 and 720 will be described in detail.

The first insulating material layer 600' may be patterned in a step to be described later to form the first insulating layer 600. The first insulating material layer 600' may be provided to cover the entire area of the via layer 200 and the top surfaces of the first and second electrodes 210 and 220. In a subsequent process, a patterned portion 600P exposing a portion of each of the first and second electrodes 210 and 220 is formed. In an embodiment, the first insulating material layer 600' may include an inorganic insulating material. The present disclosure is not limited thereto. The first insulating material layer 600' may include an organic insulating material.

Next, referring to fig. 10, at least one light emitting element 300 may be placed in a region between the first and second electrodes 210 and 220 and on the first insulating material layer 600'. In the step of placing the light emitting element 300, ink containing the light emitting element 300 may be ejected, and then an electric signal may be applied to each of the electrodes 210 and 220. Accordingly, an electric field may be generated on the ejected ink via an electrical signal applied to each of the electrodes 210 and 220. Therefore, the light emitting element 300 may be subjected to dielectrophoretic force generated by the electric field. Accordingly, the light emitting element 300 subjected to the dielectrophoretic force may be oriented in one direction and may be disposed between the electrodes 210 and 220.

Next, referring to fig. 11, a second insulating material layer 700 'covering the first insulating material layer 600' and the entire area of the top surface of the light emitting element 300 is formed. The second insulating material layer 700' may be partially removed in a subsequent process to form the insulating patterns 710, 720, and 730. In an embodiment, the second insulating material layer 700' may include an organic insulating material. When the second insulating material layer 700 'includes an organic insulating material, the second insulating material layer 700' may be formed in an uncured state such that the concave-convex pattern 750 is formed in a subsequent process. However, the present disclosure is not limited thereto.

Next, referring to fig. 12 and 13, a portion of the second insulating material layer 700' is processed to form a plurality of insulating patterns 710, 720 and 730S 200. The insulation patterns may include first and second insulation patterns 710 and 720 respectively including the concave-convex pattern 750 and a third insulation pattern 730 disposed on the light emitting element 300 and exposing at least a portion of the light emitting element 300. The descriptions of the structures and shapes of the first, second, and third insulating patterns 710, 720, and 730 are the same as those described above, and thus detailed descriptions thereof will be omitted.

According to an embodiment, in the step of forming the insulation patterns 710, 720, and 730, at least a portion of the light emitting element 300 may be exposed, and each of the plurality of concave-convex patterns 750 may be formed on at least a portion of each of the insulation patterns 710, 720, and 730. That is, the step of forming the concave-convex pattern 750 of the display device 10 and the step of exposing the two opposite sides of the light emitting element 300 contacting the contact electrode 260 may occur in the same process. In an embodiment, this process may be performed using a nanoimprint method or a patterning method. Hereinafter, an example in which this process is performed using a nanoimprinting method will be described.

As shown in fig. 12, the top surface of the second insulating material layer 700 'is pressed using a MOLD having one face with a partial protrusion, and then the top surface of the second insulating material layer 700' is irradiated with ultraviolet rays hv or subjected to a heat treatment H process. The MOLD has a first region having a concave-convex structure opposite to the concave-convex pattern 750 disposed on each of the first and second insulating patterns 710 and 720, and a second region having a structure allowing opposite sides of the light emitting element 300 to be exposed and opposite to that of the third insulating pattern 730, so as to form the third insulating pattern 730. A concave-convex structure corresponding to the inverse concave-convex structure formed in the MOLD mol may be formed on the second insulating material layer 700' including the uncured organic material. The concave-convex pattern 750 may be formed on a region of the second insulating material layer 700' contacting the first region of the MOLD mol, while the third insulating pattern 730 may be formed on a region of the second insulating material layer 700' contacting the second region of the MOLD, and both opposite side surfaces of the light emitting element 300 may be exposed in a region of the second insulating material layer 700' contacting the second region of the MOLD mol.

As shown in fig. 13, after the MOLD has pressed the second insulating material layer 700 'and the ultraviolet hv irradiation and heat treatment H process has been performed, the second insulating material layer 700' may be sufficiently hardened. Then, the MOLD mol is removed from the second insulating material layer 700' to form the second insulating layer 700. The second insulating layer 700 may include a first insulating pattern 710, a second insulating pattern 720, and a third insulating pattern 730. Each of the exposed two opposite sides of the light emitting element 300 may be spaced apart from each of one sides 710S and 720S of the first and second insulation patterns 710 and 720. A portion of the first insulating material layer 600' may be exposed in the spaced area and may be etched away in a subsequent process, so that the patterned portion 600P may be formed.

In one example, the process of forming the second insulating layer 700 is not limited thereto. In the process of forming the second insulating layer 700, the concave-convex pattern 750 may be formed using not a MOLD mol but a patterning process.

Fig. 14a, 14b and 14c schematically illustrate a process of forming the second insulating layer 700. The second insulating layer 700 includes the third insulating pattern 730 and the concave-convex pattern 750, so that the top surface of the second insulating layer 700 may not be flat and a step may be formed on the top surface thereof. Specifically, the concave-convex pattern 750 having a fine size and a fine pitch may be formed by patterning the top surface of the second insulating material layer 700 'in different regions of the second insulating material layer 700' with different pressing strengths. In one example, the process of forming the second insulating layer 700 may be performed by a patterning process using a half-tone mask or a slit mask. First, as shown in fig. 14a, a portion of the second insulating material layer 700' may be patterned to expose two opposite sides of the light emitting element 300. A first insulating pattern 710, a second insulating pattern 720, and a third insulating pattern 730 may be formed. Then, each of the top surfaces of the first and second insulation patterns 710 and 720 may be partially patterned to form the concave-convex pattern 750. In this regard, the concave-convex pattern 750 may be formed using a half-tone MASK1 as shown in fig. 14b or using a slit MASK2 as shown in fig. 14 c.

Each of the top surfaces of the first and second insulation patterns 710 and 720 may be exposed to a light beam using a half-tone MASK1 or a slit MASK 2. In this case, even when light is irradiated toward the entire area of the mask, only some of the light beams corresponding to portions of the mask pass through the mask. Accordingly, the concave-convex pattern 750 having a fine size and a fine pitch may be formed on the top surface of each of the first and second insulation patterns 710 and 720. The method for manufacturing the display device 10 according to one embodiment may design the shape of the half tone MASK1 or the slit MASK2 to obtain the first and second insulating patterns 710 and 720 in which the concave-convex pattern 750 is formed. However, the present disclosure is not limited thereto.

Next, as shown in fig. 15 and 16, a portion of the first insulating material layer 600' exposed through a space between each of two opposite side surfaces of the light emitting element 300 and each of the first and second insulating patterns 710 and 720 may be etched to form a patterned portion 600P. The first insulating material layer 600' may be interrupted at the patterned portion 600P to form the first insulating layer 600.

Next, although not shown in the drawings, the first and second contact electrodes 261 and 262, which are respectively in contact with the exposed two opposite side surfaces of the light emitting element 300, are formed, and then the passivation layer 800 covering the first and second contact electrodes 261 and 262 is formed. In this way, the display device 10 can be manufactured. When the second insulating layer 700 including the plurality of insulating patterns 710, 720, and 730 is formed during the manufacture of the display device 10 using the process as described above, a process of exposing two opposite side surfaces of the light emitting element 300 and a process of forming the concave-convex pattern 750 on the first and second insulating patterns 710 and 720 may be simultaneously performed.

Further, forming the first and second insulating patterns 710 and 720, which respectively include the concave-convex pattern 750, may allow the omission of the reflective electrode that reflects light emitted from the light emitting element 300, so that the number of process steps for manufacturing the display device 10 may be reduced, thereby improving manufacturing efficiency.

In one example, as described above, the shape of the concave-convex pattern 750 of the display device 10 is not limited to the shape shown in fig. 4. In some cases, the concave or convex portions of the concave-convex pattern 750 may have inclined sides, or have a curved shape.

Fig. 17 to 19 are sectional views illustrating a concave-convex pattern according to another embodiment. Fig. 17 to 19 show enlarged cross sections of portions corresponding to the portion a of fig. 4 according to another embodiment.

Referring to fig. 17 to 19, the concave or convex portion of the concave-convex pattern 750 according to one embodiment may have an inclined side surface extending from the top surface of the second insulating layer 700 or the first insulating pattern 710. The concave or convex portions of the concave-convex pattern 750 in fig. 17 have two opposite side surfaces having a predetermined inclination angle Θ g. The concave or convex portions of the concave-convex pattern 750 in fig. 18 may have one inclined side surface and an opposite side surface that may extend in a perpendicular manner to the top surface of the first insulation pattern 710. The convex portions of the concave-convex pattern 750 in fig. 19 may have a curved shape protruding upward. Light incident on the first insulation pattern 710 may be incident on the concave-convex pattern 750 at different incident angles according to the shape of the concave or convex portions of the concave-convex pattern 750. The percentage of the amount of light that is not reflected from the concave-convex pattern 750 but is output to the outside through the concave-convex pattern 750 may be increased.

In addition, as shown in fig. 18 and 19, when the concave or convex portions of the concave-convex pattern 750 have a prism shape or a microlens shape having a curved outer face, the concave-convex pattern 750 can scatter incident light thereon, and the top emission efficiency of the device can be further improved.

Fig. 20 and 21 are plan views illustrating a concave-convex pattern according to another embodiment.

First, referring to fig. 20, the concave-convex pattern 750 may be disposed on the first and second insulation patterns 710 and 720 and have a shape extending in one direction. The direction in which the concave-convex pattern 750 extends is not particularly limited. In one example, the concave-convex pattern 750 may extend in a direction different from the second direction D2 in which the first insulation pattern 710 extends. In one example, as shown in fig. 20, the concave-convex pattern 750 may extend in a direction inclined with respect to the second direction D2.

Further, referring to fig. 21, the concave-convex pattern 750 does not extend in one direction and forms one unit. A plurality of the concave-convex patterns 750 may be arranged and the plurality of concave-convex patterns 750 are spaced apart from each other. That is, the concave-convex pattern 750 may be arranged in a single grid pattern on the first insulation pattern 710 or the second insulation pattern 720.

The concave-convex pattern 750 of these various structures may be formed using a mold having a convex or concave structure opposite to the convex or concave structure of the concave-convex pattern 750 during a manufacturing process of the display device 10. When the opposite convex or concave structure of the MOLD has a shape extending in one direction, the concave and convex patterns 750 formed on the first and second insulation patterns 710 and 720 may extend in one direction. When the opposite convex or concave structure of the MOLD has a grid pattern, the concave-convex pattern 750 formed on the first and second insulation patterns 710 and 720 may have a grid pattern. However, the present disclosure is not limited thereto.

Hereinafter, other embodiments of the display device 10 will be described.

Fig. 22 is a sectional view of a display device according to another embodiment.

Referring to fig. 22, according to an embodiment, the display device 10_1 may include electrodes 210_1 and 220_1 including a material having a high reflectivity. That is, each of the electrodes 210_1 and 220_1 of the display device 10_1 may function as a reflective electrode that reflects incident light. The display device 10_1 of fig. 22 is the same as the display device 10 of fig. 2 except that the material constituting the electrodes 210_1 and 220_1 is different from the material constituting the electrodes 210 and 220 in the display device 10 of fig. 2. Therefore, redundant description will be omitted.

Light emitted from the light emitting element 300 may be reflected or refracted on an interface between each of the first and second insulation patterns 710 and 720 and another layer, and then may travel. At an interface between each of the first and second insulation patterns 710 and 720 and the first insulation layer 600, at least a portion of light may not be reflected but refracted, and then may be incident on each of the electrodes 210_1 and 220_ 1.

The display device 10_1 according to an embodiment may include the electrodes 210_1 and 220_1 made of a material having a high reflectivity so that light may be reflected from the electrodes 210_1 and 220_ 1. In one example, each of the electrodes 210_1, 220_1 may be made of a material having a high reflectivity including a metal such as silver (Ag), copper (Cu), aluminum (Al), or the like, or may have a stacked structure of ITO/silver (Ag)/ITO/IZO, or may be made of an alloy including aluminum (Al), nickel (Ni), lanthanum (La), or the like. However, the present disclosure is not limited thereto. The display device 10_1 may include the electrodes 210_1 and 220_1 made of a material having a high reflectivity, and thus may have a reduced light loss for each pixel PX or each sub-pixel PXn, and thus may have an improved top emission efficiency.

Fig. 23 and 24 are sectional views of a display device according to another embodiment.

Referring to fig. 23, in the display device 10_2 according to an embodiment, the first insulating layer 600_2 and the bank 400_2 may be formed in the same process. That is, the first insulating layer 600_2 and the bank 400_2 may be integrated into one layer. The display device 10_2 in fig. 23 is the same as the display device 10 in fig. 2 except that the first insulating layer 600_2 and the bank 400_2 are integrated into a single layer. Therefore, redundant description will be omitted.

The first insulating layer 600_2 may be formed by patterning an inorganic material or an organic insulating material, or may be formed by using a nanoimprint method. Specifically, in one example, when the first insulating layer 600_2 is formed using a nanoimprint method, the first insulating layer 600_2 having different steps may be formed over the substrate on which the electrodes 210 and 220 are formed. The present disclosure is not limited thereto. The first insulating layer 600_2 having different steps may be formed using a slit mask or a half-tone mask, and the bank 400_2 may be simultaneously formed. As a result, a process of forming the separate bank 400 is omitted, so that there is an advantage in the manufacturing process of the display device 10_ 2.

Referring to fig. 24, in the display device 10_3 according to an embodiment, the second insulating layer 700 may be omitted, and the first insulating layer 600_3 may include a plurality of insulating patterns 610_3, 620_3, and 630_ 3. Unlike the first insulating layer 600 in fig. 2, the first insulating layer 600_3 in fig. 24 may have a plurality of insulating patterns 610_3, 620_3, and 630_3 having different steps. As described above, the first insulating layer 600_3 may be formed using a nanoimprint method. According to an embodiment, in the process of forming the first insulating layer 600_3, some of the insulating patterns 610_3, 620_3, and 630_3 may have a thickness smaller than that of another one of the insulating patterns 610_3, 620_3, and 630_ 3.

In an embodiment, the fourth and fifth insulation patterns 610_3 and 620_3 may be spaced apart from the sixth insulation pattern 630_3 via the patterned portion 600P _ 3. The contact electrodes 261 and 262 may be disposed in the patterned part 600P _3, and the contact electrodes 261 and 262 may be in contact with the electrode branches 210B and 220B, respectively. In the display device 10_3 of fig. 22, the second insulating layer 700 is omitted such that portions of the first and second contact electrodes 261 and 262 on the top surface of the light emitting element 300, not on the top surface of the third insulating pattern 730, are spaced apart from each other.

In addition, in the display device 10_3 of fig. 24, the first insulating layer 600_3 and the bank 400_3 may be formed in the same process. Accordingly, the bank 400_3 may be integrated with a partial insulation pattern of the first insulation layer 600_ 3. The description of the bank 400_3 integrated with the first insulating layer 600_3 is the same as that described above with reference to fig. 23.

The first insulation layer 600_3 may include a fourth insulation pattern 610_3, a fifth insulation pattern 620_3, and a sixth insulation pattern 630_ 3. The fourth and fifth insulation patterns 610_3 and 620_3 may at least partially overlap the electrode branches 210B and 220B, respectively. The sixth insulation pattern 630_3 may be disposed between the fourth insulation pattern 610_3 and the fifth insulation pattern 620_3, and may be disposed to cover one end of each of the electrode branches 210B and 220B. In an embodiment, the sixth insulation pattern 630_3 may have a thickness measured in one direction that is less than a thickness of each of the fourth insulation pattern 610_3 and the fifth insulation pattern 620_ 3. That is, the insulation patterns 610_3, 620_3, and 630_3 may have different vertical dimensions from the via layer 200 such that steps are formed on the top surfaces thereof. The light emitting element 300 may be disposed on the sixth insulating pattern 630_3, the sixth insulating pattern 630_3 having a vertical dimension smaller than that of each of the other insulating patterns 610_3 and 620_ 3. The sixth insulation pattern 630_3 of fig. 24 may correspond to a portion of the first insulation layer 600 of fig. 2 disposed between the electrode branches 210B and 220B and spaced apart from other portions of the first insulation layer 600 via the patterned portion 600P.

In one embodiment, each of the fourth and fifth insulation patterns 610_3 and 620_3 may include a concave-convex pattern 650_3 in which at least a portion of a top surface thereof protrudes upward in the concave-convex pattern 650_ 3. The fourth and fifth insulation patterns 610_3 and 620_3 of fig. 24 may correspond to the first and second insulation patterns 710 and 720 of fig. 2, respectively.

In an embodiment, as in the first insulation pattern 710 of fig. 2, the fourth insulation pattern 610_3 may be formed such that two opposite sides thereof are spaced apart from two opposite sides of the first electrode branch 210B and horizontally spaced apart, respectively, while overlapping the first electrode branch 210B. A width measured in one direction of the fourth insulation pattern 610_3 may be less than a width of the first electrode branch 210B. The fourth insulation pattern 610_3 may be spaced apart from the sixth insulation pattern 630_3 via the patterned portion 600P _3, and at least one side of the fourth insulation pattern 610_3 may be spaced apart from the light emitting element 300.

As in the second insulation pattern 720 of fig. 2, the fifth insulation pattern 620_3 may be formed such that one side thereof is horizontally spaced apart from one side of the second electrode branch 210B while vertically overlapping the second electrode branch 210B. However, opposite sides of the fifth insulation pattern 620_3 may be integrally formed with the bank 400_ 3. Unlike the second insulating pattern 720 in fig. 2, the fifth insulating pattern 620_3 may not be spaced apart from the bank 400_ 3. That is, the fifth insulation pattern 620_3 and the bank 400_3 may be integrated into a single layer.

Each of the plurality of concave and convex patterns 650_3 may be formed on at least a portion of each of the top surfaces of the fourth and fifth insulation patterns 610_3 and 620_ 3. The concave-convex pattern 650_3 may be formed on a region thereof overlapping each of the electrode branches 210B and 220B. However, the present disclosure is not limited thereto. In particular, the concave and convex pattern 650_3 formed on the fifth insulation pattern 620_3 may extend to the bank 400_ 3. Unlike the display device 10 of fig. 2, the display device 10_3 of fig. 24 may be configured such that a portion of the insulation pattern of the first insulation layer 600_3 may include the concave-convex pattern 650_3 positioned above the light emitting element 300 in a cross-sectional view, such that light emitted from the light emitting element 300 is incident on the fourth insulation pattern 610_3 and the fifth insulation pattern 620_ 3.

The display device 10_3 in fig. 24 may include the concave-convex pattern 650_3 providing a traveling path of light emitted from the light emitting element 300, and may not have the second insulating layer 700, and thus may be advantageous in the manufacturing process of the display device 10_ 3.

Fig. 25 to 27 are sectional views illustrating some steps of a manufacturing process of the display device of fig. 24.

In the display device 10_3 of fig. 24, the second insulating layer 700 is omitted, and the first insulating layer 600_3 includes a plurality of insulating patterns 610_3, 620_3, and 630_ 3. The manufacturing process of the display device 10_3 may not form the second insulating layer 700, and may include forming the first insulating layer 600_3 on the electrodes 210 and 220 and placing the light emitting element 300.

Referring to fig. 25, the first electrode 210 and the second electrode 220 are formed on the via layer 200, and a first insulating material layer 600' _3 covering the entire area of the first electrode 210 and the second electrode 220 is formed. Unlike the first insulating material layer 600 'of fig. 9, the first insulating material layer 600' _3 of fig. 25 may have a relatively large thickness. In a subsequent process, a portion of the first insulating material layer 600' _3 in fig. 25 may be patterned to form a space in which the light emitting element 300 is disposed.

Next, referring to fig. 26, at least a portion of the first insulating material layer 600' _3 is patterned, thereby forming fourth and fifth insulating patterns 610_3 and 620_3 including concave and convex patterns 650_3, respectively. The first insulating material layer 600' _3 may have a shape in which a portion thereof is depressed such that the fourth insulating pattern 610_3 and the fifth insulating pattern 620_3 are spaced apart from and face each other. The fourth and fifth insulation patterns 610_3 and 620_3 include one sides 610S _3 and 620S _3, respectively, spaced apart from each other and facing each other. Each of one side surface 610S _3 of the fourth insulation pattern 610_3 and one side surface 620S _3 of the fifth insulation pattern 620_3 may be formed to be inclined with respect to each top surface on which each concave-convex pattern 650_3 is formed. A spaced area between the fourth insulation pattern 610_3 and the fifth insulation pattern 620_3 overlaps with a spaced area between the first electrode 210 and the second electrode 220. In a subsequent process, the light emitting element 300 may be placed in a spaced area between the fourth insulation pattern 610_3 and the fifth insulation pattern 620_ 3.

Next, referring to fig. 27, at least one light emitting element 300 is placed in a spaced area between the fourth insulation pattern 610_3 and the fifth insulation pattern 620_ 3. The patterned portion 600P _3 partially exposing the first and second electrodes 210 and 220 is formed by etching at least a portion of the first insulating material layer 600' _ 3. The patterned portions 600P _3 may be formed along and on two opposite sides of the light emitting element 300 disposed on the first insulating material layer 600' _3, respectively. Sixth insulation patterns 630_3 may be formed between the patterned parts 600P _ 3. The fourth and fifth insulation patterns 610_3 and 620_3 may be spaced apart from each other via the patterned part 600P _3, and may be spaced apart from the sixth insulation pattern 630_3 via the patterned part 600P _ 3.

Next, although not shown in the drawings, the first and second contact electrodes 261 and 262 disposed in the patterned portion 600P _3 are formed, and then the passivation layer 800 covering the first and second contact electrodes 261 and 262 is formed. Accordingly, the display device 10_3 of fig. 24 can be manufactured.

Fig. 28 is a sectional view of a display device according to still another embodiment. Fig. 29 and 30 are plan views illustrating hole patterns formed in an insulating pattern according to still another embodiment.

Referring to fig. 28, the display device 10_4 according to an embodiment may include each of hole patterns 710h and 720h in which at least a portion of each of the first and second insulation patterns 710_4 and 720_4 is recessed. The display device 10_4 in fig. 26 is the same as the display device 10 in fig. 4 except that each of the first and second insulation patterns 710_4 and 720_4 further includes each of the hole patterns 710h and 720 h. Hereinafter, redundant description will be omitted, and description will be made focusing on differences.

According to one embodiment, the first and second insulation patterns 710_4 and 720_4, to which light emitted from the light emitting element 300 is incident, may include at least one hole pattern 710h and at least one hole pattern 720h, respectively. Light incident to the first and second insulating patterns 710_4 and 720_4 may be reflected on an interface between each of the insulating patterns and another layer, and then output through the concave-convex pattern 750_ 4. However, in some cases, some of the light beams traveling in the first and second insulation patterns 710_4 and 720_4 may not be output through the concave-convex pattern 750_4, but may be continuously reflected in the insulation patterns and travel in the insulation patterns.

In particular, although not shown in the drawings, when the bank 400 is integrally formed with the second insulating layer 700, a portion of light incident on the second insulating patterns 720_4 may travel to a position where the bank 400 is located, and may not be output to the outside. The first and second insulation patterns 710_4 and 720_4 according to an embodiment may include at least one hole pattern 710h and at least one pattern hole 720h, respectively, to change a path of light traveling in the insulation patterns so as to minimize light loss of incident light. The hole patterns 710h and 720h may include a first hole pattern 710h formed in the first insulation pattern 710_4 and a second hole pattern 720h formed in the second insulation pattern 720_ 4. As shown in the drawing, a portion of light traveling in each of the first and second insulation patterns 710_4 and 720_4 may be reflected from each of the hole patterns 710h and 720h, and then may be output through the concave-convex pattern 750_ 4.

Each of the hole patterns 710h and 720h may be formed by etching at least a portion of each of the top surfaces of the first and second insulating patterns 710_4 and 720_ 4. Each of the depths of the hole patterns 710h and 720h is not particularly limited. Each of depths of the hole patterns 710h and 720h may be less than a thickness of each of the first and second insulation patterns 710_4 and 720_4 such that the first insulation layer 600 is not exposed.

Each of two opposite sides of the first insulation pattern 710_4 may face the light emitting element 300 while being spaced apart from the light emitting element 300. The first hole pattern 710h may be located at the center of the first insulation pattern 710_ 4. In contrast, one side of the second insulating pattern 720_4 faces the light emitting element 300, and the opposite side of the second insulating pattern 720_4 faces the bank 400. Accordingly, the second hole pattern 720h may be disposed adjacent to the bank 400 and in the second insulating pattern 720_ 4. The present disclosure is not limited thereto. The plurality of hole patterns 710h spaced apart from each other and the plurality of hole patterns 720h spaced apart from each other may be formed in the first and second insulating patterns 710_4 and 720_4, respectively.

Referring to fig. 29, in one embodiment, each of the hole patterns 710h and 720h may have a shape extending in one direction and along each of the first and second insulation patterns 710_4 and 720_ 4. Like the concave-convex pattern 750, each of the hole patterns 710h and 720h may extend in one direction (the second direction D2) in which each of the first and second insulation patterns 710_4 and 720_4 extends.

Further, the present disclosure is not limited thereto. Each of the number of hole patterns 710h and the number of hole patterns 720h may be larger to define the hole patterns 710h and 720h of a single cell. Referring to fig. 30, a plurality of hole patterns 710h spaced apart from each other may be formed in the first insulation pattern 710_4 to form a grid pattern. A plurality of hole patterns 720h spaced apart from each other may be formed in the second insulation pattern 720_4 to form a grid pattern.

Fig. 31 is a schematic cross-sectional view of a display device according to still another embodiment.

Referring to fig. 31, in the display device 10_5 according to an embodiment, the light emitting element 300 may be positioned above the concave-convex pattern 750_ 5. That is, in the display device 10_5, a vertical dimension measured from the via layer 200 to the top surface of the light emitting element 300 in the cross-sectional view may be larger than a vertical dimension measured from the via layer 200 to the bottom surface of the concave-convex pattern 750_ 5. At least a portion of the concave-convex pattern 750_5 may be located below a virtual plane parallel to the top surface of the via layer 200 and flush with the top surface of the light emitting element 300.

The display device 10 according to one embodiment may include the concave-convex pattern 750 such that light emitted from the light emitting element 300 travels toward the top of each subpixel PXn. In the display device 10 as described above, light emitted from the light emitting element 300 may be incident on the first insulating layer 600 or the second insulating layer 700, and may travel in the first insulating layer 600 or the second insulating layer 700, and may be output to the outside through the concave-convex pattern 650 or 750. In contrast, in the display device 10_5 of fig. 31, light emitted from the light emitting element 300 may not be incident on the first insulating layer 600 or the second insulating layer 700, but may directly travel toward the concave-convex pattern 750_5, and may then be reflected from the concave-convex pattern 750_5 and may be emitted toward the top of each subpixel PXn.

The concave-convex pattern 750_5 of the display device 10_5 according to one embodiment may have at least one side surface having a shape inclined with respect to a top surface of each of the first and second insulation patterns 710_5 and 720_5 so that light emitted from the light emitting element 300 may be reflected thereon. The inclined side surfaces of the concave-convex pattern 750_5 have a predetermined inclination angle with respect to a plane parallel to the top surface of the via layer 200. Light emitted from the light emitting element 300 and traveling in a direction parallel to the top surface of the via layer 200 may be reflected from the inclined side surfaces of the concave-convex pattern 750_5, and may then be emitted in an upward direction. In the display device 10_5 of fig. 31, light may not be incident on the insulating pattern, thereby reducing light loss as compared to the display device 10.

In one example, the structure of the light emitting element 300 is not limited to the structure as shown in fig. 3, and may have a different structure.

Fig. 32 is a schematic view of a light-emitting element according to another embodiment.

Referring to fig. 32, the light emitting element 300' may be formed such that a plurality of layers are not stacked in one direction, but each of the layers surrounds an outer face of another adjacent layer. The light emitting element 300' in fig. 32 is the same as the light emitting element 300 in fig. 3 except that the shape of each layer is different from that of each layer of the light emitting element 300 in fig. 3. Hereinafter, the same contents will be omitted and differences will be described.

According to one embodiment, the first conductive type semiconductor 310 'may extend in one direction, and each of two opposite ends of the first conductive type semiconductor 310' may be tapered. The first conductivity type semiconductor 310' in fig. 32 may have a rod-shaped or cylindrical body and a conical portion on each of upper and lower ends of the body. The conical portion on the upper end of the body may have a steeper slope than the slope of the conical portion on the lower end thereof.

The active layer 330 'surrounds the outer face of the body of the first conductive type semiconductor 310'. The active layer 330' may have a ring shape extending in one direction. The active layer 330 'does not surround each of the conical portions of the first conductive type semiconductor 310'. That is, the active layer 330 'may contact only the parallel side surfaces of the first conductive type semiconductor 310'.

The second conductive type semiconductor 320' surrounds the outer face of the active layer 330' and the upper conical portion of the first conductive type semiconductor 310 '. The second conductive type semiconductor 320' may include an annular body extending in one direction and an upper conical portion on an upper end of the body. That is, the second conductive type semiconductor 320' may directly contact the parallel side of the active layer 330' and the inclined side of the upper conical portion of the first conductive type semiconductor 310 '. However, the second conductive type semiconductor 320 'does not surround the lower conical portion of the first conductive type semiconductor 310'.

The electrode material layer 370 'may be disposed to surround the outer face of the second conductive type semiconductor 320'. That is, the shape of the electrode material layer 370 'may be substantially the same as the shape of the second conductive type semiconductor 320'. That is, the electrode material layer 370 'may contact the entire area of the outer face of the second conductive type semiconductor 320'.

An insulating film 380' may be disposed to surround the outer face of the electrode material layer 370' and the outer face of the first conductive type semiconductor 310 '. The insulating film 380' may directly contact the exposed lower end of each of the active layer 330' and the second conductive type semiconductor 320', the outer face of the electrode material layer 370', and the lower conical portion of the first conductive type semiconductor 310 '.

At the conclusion of the detailed description, those skilled in the art will appreciate that many variations and modifications may be made to the preferred embodiments without substantially departing from the principles of the present invention. Accordingly, the disclosed preferred embodiments of the invention are used in a generic and descriptive sense only and not for purposes of limitation.