阅读说明：本技术 显示装置 (Display device ) 是由 黄京旭 安浩荣 崔濬熙 孔基毫 韩周宪 于 2019-09-12 设计创作，主要内容包括：一种显示装置包括：基板；发光层；共用发光层的多个颜色转换层；以及绝缘层,提供在发光层和所述多个颜色转换层之间并具有比发光层小的折射率。(A display device includes: a substrate; a light emitting layer; a plurality of color conversion layers sharing the light emitting layer; and an insulating layer provided between the light emitting layer and the plurality of color conversion layers and having a refractive index smaller than that of the light emitting layer.)

1. A display device, comprising:

a substrate;

a light emitting layer provided on the substrate and configured to emit light;

a plurality of color conversion layers provided on the light emitting layer, each of the plurality of color conversion layers being disposed on a portion of the light emitting layer and configured to convert light emitted by the light emitting layer into light of a different color;

at least one barrier disposed on the light emitting layer and between the plurality of color conversion layers to spatially separate the plurality of color conversion layers from each other;

a first insulating layer provided between the plurality of color conversion layers and the light emitting layer, the first insulating layer including a plurality of first openings corresponding to the plurality of color conversion layers, respectively; and

a second insulating layer provided between the first insulating layer and the plurality of color conversion layers.

2. The display device according to claim 1, wherein a refractive index of at least one of the first insulating layer and the second insulating layer is equal to or less than 1.6.

3. The display device according to claim 1, wherein at least one of the first insulating layer and the second insulating layer comprises SiO₂、SiN、Al₂O₃And TiO₂At least one of (1).

4. The display device according to claim 1, further comprising a first reflective layer provided on an upper surface of the light-emitting layer, the first reflective layer being configured to reflect light incident from the light-emitting layer back to the light-emitting layer.

5. The display device according to claim 4, wherein an upper surface and a side surface of the first reflective layer are covered with the first insulating layer.

6. The display device of claim 4, wherein the first reflective layer is provided between and spaced apart from the plurality of first openings.

7. The display device according to claim 1, further comprising a plurality of first electrodes provided over the light-emitting layer, each of the plurality of first electrodes being in contact with the light-emitting layer through one of the plurality of first openings, respectively.

8. The display device according to claim 7, wherein at least one of the plurality of first electrodes comprises a transparent electrode, and

wherein the one of the plurality of first electrodes extends along an upper surface of the first insulating layer.

9. The display device according to claim 8, wherein the transparent electrode contacts an entire area of the light emitting layer exposed through the plurality of first openings.

10. The display device according to claim 8, further comprising a first electrode pad in contact with the transparent electrode.

11. The display device according to claim 10, wherein the first electrode pad is provided in a region of the transparent electrode that does not overlap with the plurality of first openings.

12. The display device according to claim 7, further comprising a second reflective layer which is provided over at least one of the plurality of first electrodes and includes a second opening which at least partially overlaps with one of the plurality of first openings.

13. The display device according to claim 12, wherein at least a portion of the second reflective layer overlaps the first insulating layer.

14. The display device according to claim 12, wherein the second reflective layer comprises a third reflective layer and a fourth reflective layer having different reflection characteristics.

15. The display device according to claim 14, wherein the third reflective layer faces the light-emitting layer,

wherein the fourth reflective layer faces one of the plurality of color conversion layers, and

wherein the fourth reflective layer has a reflectivity higher than a reflectivity of the third reflective layer.

16. The display device according to claim 7, wherein at least one of the plurality of first electrodes comprises a reflective electrode including a third opening overlapping one of the plurality of first openings and extending along an upper surface of the first insulating layer.

17. The display device according to claim 16, wherein a first width of the third opening is smaller than a second width of the one of the plurality of first openings.

18. The display device according to claim 16, wherein the second insulating layer is in contact with the light-emitting layer through the first opening and the third opening.

19. The display device according to claim 7, further comprising a second electrode which contacts the light-emitting layer.

20. The display device according to claim 19, wherein the plurality of first electrodes are provided in one-to-one correspondence with the plurality of color conversion layers, and the second electrode is provided so as to correspond to at least one of the plurality of color conversion layers.

21. The display device according to claim 19, wherein the light-emitting layer comprises a first semiconductor layer, an active layer, and a second semiconductor layer which are sequentially provided,

wherein each of the plurality of first electrodes contacts the second semiconductor layer, and

wherein the second electrode contacts the first semiconductor layer.

22. The display device according to claim 21, wherein the second electrode comprises:

a via electrode passing through the first insulating layer and contacting the first semiconductor layer; and

a second electrode pad provided on the first insulating layer and contacting the via electrode.

23. The display device according to claim 21, wherein the second electrode is provided on a lower surface of the first semiconductor layer.

24. The display device according to claim 1, wherein one of the at least one barrier comprises at least one of a black matrix, a resin, and a polymer that absorb light.

25. The display device of claim 1, wherein one of the at least one barrier comprises:

a core; and

a shell surrounding a side surface of the core and reflecting incident light.

26. The display device of claim 1, wherein the plurality of color conversion layers comprises at least one of a red conversion layer that emits red light, a green conversion layer that emits green light, and a blue conversion layer that emits blue light.

27. The display device according to claim 1, further comprising a light absorbing layer which is disposed on a lower surface of the light emitting layer and absorbs incident light.

28. A display device, comprising:

a substrate;

a light emitting layer provided on the substrate;

a first color conversion element provided on a first portion of the light emitting layer and a second color conversion element provided on a second portion of the light emitting layer;

a barrier element provided between the first color conversion element and the second color conversion element; and

a first insulating layer provided on the light emitting layer,

wherein the first insulating layer includes a first opening corresponding to the first color conversion element and a second opening corresponding to the second color conversion element.

29. The display device according to claim 28, wherein the first opening is provided directly over the first color conversion element, and wherein the second opening is provided directly over the second color conversion element.

Technical Field

Example embodiments consistent with the present disclosure relate to a display device and a method of manufacturing the same, and more particularly, to a display device having improved color quality.

Background

As display devices, Liquid Crystal Displays (LCDs) and Organic Light Emitting Diode (OLED) displays are widely used. Recently, a technology for manufacturing a high-resolution display device by using a micro Light Emitting Diode (LED) is attracting attention. However, manufacturing a high-resolution display device requires efficient compact LED chips, and requires difficult transfer techniques to arrange the compact LED chips in place.

Disclosure of Invention

A high resolution display device having improved optical efficiency and color quality is provided.

Additional aspects will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the presented embodiments.

According to an aspect of the present disclosure, there is provided a display device including: a substrate; a light emitting layer provided on the substrate and configured to emit light; a plurality of color conversion layers provided on the light emitting layer, each of the plurality of color conversion layers being disposed on a portion of the light emitting layer and configured to convert light emitted by the light emitting layer into light of a different color; at least one barrier disposed on the light emitting layer between the plurality of color conversion layers to spatially separate the plurality of color conversion layers from each other; a first insulating layer provided between the plurality of color conversion layers and the light emitting layer, the first insulating layer including a plurality of first openings corresponding to the plurality of color conversion layers, respectively; and a second insulating layer provided between the first insulating layer and the plurality of color conversion layers.

At least one of the first insulating layer and the second insulating layer may have a refractive index equal to or less than 1.6.

At least one of the first insulating layer and the second insulating layer may include SiO₂、SiN、Al₂O₃And TiO₂At least one of (1).

The display device may further include a first reflective layer provided on an upper surface of the light emitting layer, the first reflective layer configured to reflect light incident from the light emitting layer back to the light emitting layer.

The upper surface and the side surfaces of the first reflective layer may be covered with a first insulating layer.

The first reflective layer may include a metal.

A first reflective layer may be provided between and spaced apart from the plurality of first openings.

The display device may further include a plurality of first electrodes provided on the light emitting layer, each of the plurality of first electrodes being in contact with the light emitting layer through one of the plurality of first openings, respectively.

At least one of the plurality of first electrodes may include a transparent electrode, and wherein the one of the plurality of first electrodes extends along an upper surface of the first insulating layer.

The transparent electrode may contact the entire area of the light emitting layer exposed through the plurality of first openings.

The display device may further include a first electrode pad contacting the transparent electrode.

The first electrode pad may be provided in a region of the transparent electrode that does not overlap the plurality of first openings.

The display device may further include a second reflective layer provided on at least one of the plurality of first electrodes and including a second opening at least partially overlapping one of the plurality of first openings.

At least a portion of the second reflective layer may overlap the first insulating layer.

The second reflective layer may include a third reflective layer and a fourth reflective layer having different reflective characteristics.

The third reflective layer may face the light emitting layer, wherein the fourth reflective layer may face one of the plurality of color conversion layers, and wherein the fourth reflective layer has a reflectance higher than that of the third reflective layer.

At least one of the plurality of first electrodes may include a reflective electrode including a third opening overlapping one of the plurality of first openings and extending along an upper surface of the first insulating layer.

The first width of the third opening may be less than the second width of the one of the plurality of first openings.

The second insulating layer may be in contact with the light emitting layer through the first opening and the third opening.

The display device may further include a second electrode contacting the light emitting layer.

The plurality of first electrodes may be provided in one-to-one correspondence with the plurality of color conversion layers, and the second electrode is provided to correspond to at least one of the plurality of color conversion layers.

The light emitting layer may include a first semiconductor layer, an active layer, and a second semiconductor layer, which are sequentially provided, wherein each of the plurality of first electrodes contacts the second semiconductor layer, and wherein the second electrode contacts the first semiconductor layer.

The second electrode may include: a via electrode passing through the first insulating layer and contacting the first semiconductor layer; and a second electrode pad provided on the first insulating layer and contacting the via electrode.

The second electrode is provided on a lower surface of the first semiconductor layer.

One of the at least one barrier may include at least one of a black matrix, a resin, and a polymer, which absorb light.

One of the at least one barrier may comprise: a core; and a shell surrounding the side surface of the core and reflecting incident light.

The plurality of color conversion layers may include at least one of a red conversion layer emitting red light, a green conversion layer emitting green light, and a blue conversion layer emitting blue light.

The light emitting layer may generate at least one of blue light and ultraviolet rays.

The display device may further include a light absorbing layer disposed on a lower surface of the light emitting layer and absorbing incident light.

According to another aspect of the present disclosure, there is provided a display device including: a substrate; a light emitting layer provided on the substrate; a first color conversion element provided on a first portion of the light emitting layer and a second color conversion element provided on a second portion of the light emitting layer; a barrier member provided between the first color conversion member and the second color conversion member; and a first insulating layer provided on the light emitting layer, wherein the first insulating layer includes a first opening corresponding to the first color conversion element and a second opening corresponding to the second color conversion element.

The first opening may be provided directly above the first color conversion element, and the second opening may be provided directly above the second color conversion element.

Drawings

These and/or other aspects will become apparent and more readily appreciated from the following description of the example embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a sectional view illustrating a display device according to an example embodiment;

FIG. 2 is an enlarged view of region D of FIG. 1;

fig. 3 is a cross-sectional view illustrating a display device including a first electrode pad according to an example embodiment;

fig. 4 is a cross-sectional view illustrating a display device including a first reflective layer according to an example embodiment;

fig. 5 is a cross-sectional view illustrating a display device including a second reflective layer according to an example embodiment;

fig. 6 is a cross-sectional view illustrating a display device including a second reflective layer according to another example embodiment;

fig. 7 is a cross-sectional view illustrating a display device including a first reflective layer and a second reflective layer according to another example embodiment;

fig. 8 illustrates a display device including a second electrode according to another example embodiment;

fig. 9 illustrates a display device including a second electrode according to another example embodiment;

FIG. 10 shows a display device including a barrier according to another example embodiment;

FIG. 11 illustrates a display device including a selectively transparent insulating layer according to an example embodiment;

FIG. 12 illustrates a display device including a selective barrier layer according to an example embodiment;

fig. 13 illustrates a display device including a light absorbing layer according to an example embodiment; and

fig. 14 illustrates a display device including a light absorbing layer according to an example embodiment.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. In the drawings, like reference numerals denote like elements, and the sizes of the elements in the drawings may be exaggerated for clarity and convenience of description. Certain example embodiments described herein are merely examples and may include various modifications.

Throughout the specification, it will also be understood that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements may also be present.

Unless the context clearly dictates otherwise, expressions used in the singular include expressions in the plural. It will be understood that terms such as "comprising" and the like are intended to indicate the presence of elements and are not intended to preclude the possibility that one or more other elements may be added.

Although terms such as "first," "second," etc. may be used herein, the above terms are only used to distinguish one element from another.

Unless the context clearly dictates otherwise, expressions used in the singular include expressions in the plural.

Expressions such as "at least one of … …" when following a list of elements modify the entire list of elements rather than a single element of the list.

Fig. 1 is a sectional view illustrating a display device 10 according to an example embodiment. Fig. 2 shows an enlarged view of a portion D of fig. 1.

Referring to fig. 1 and 2, the display device 10 may include a plurality of pixels. In fig. 1, only two pixels are shown for convenience. Each pixel may include sub-pixels SR, SG, and SB, each configured to output a different color from each other. Specifically, the subpixels SR, SG and SB may include a red subpixel SR, a green subpixel SG and a blue subpixel SB, respectively.

The display device 10 may include a substrate 110, a light emitting layer 120 disposed on the substrate 110, and a plurality of color conversion layers (130R, 130G, and 130B) disposed on the light emitting layer 120.

The substrate 110 may be a substrate for growing the light emitting layer 120. The substrate 110 may include various materials used in a typical semiconductor process. For example, a silicon substrate or a sapphire substrate may be used as the substrate 110. However, this is exemplary, and other various materials may also be used as the substrate 110.

A light emitting layer 120 emitting light is disposed on an upper surface of the substrate 110. The light emitting layer 120 may be an inorganic material based Light Emitting Diode (LED) layer. The light emitting layer 120 may emit, for example, blue light B, but is not limited thereto. The light emitting layer 120 may emit light of a specific wavelength according to a material included in the light emitting layer 120. The light emitting layer 120 may be formed by sequentially growing a first semiconductor layer 121, an active layer 122, and a second semiconductor layer 123 on the upper surface of the substrate 110.

The first semiconductor layer 121 may be disposed on the upper surface of the substrate 110. The first semiconductor layer 121 may include, for example, an n-type semiconductor, but is not limited thereto. According to circumstances, the first semiconductor layer 121 may further include a p-type semiconductor. The first semiconductor layer 121 may include a group III-V based n-type semiconductor, such as n-GaN. The first semiconductor layer 121 may have a single-layer or multi-layer structure.

The active layer 122 may be disposed on an upper surface of the first semiconductor layer 121. The active layer 122 may emit light when electrons and holes are combined with each other. The active layer 122 may have a Multiple Quantum Well (MQW) structure, but is not limited thereto, and may also have a single quantum well (SQM) structure according to circumstances. The active layer 122 may include a group III-V based semiconductor, such as GaN. Although the active layer 122 is illustrated as a two-dimensional thin film as an example, the active layer 122 is not limited thereto and may also have a three-dimensional shape such as a rod or pyramid structure by growth using a mask. According to an example embodiment, the active layer 122 may be directly disposed on the upper surface of the semiconductor layer 121.

The second semiconductor layer 123 may be disposed on an upper surface of the active layer 122. The second semiconductor layer 123 may include, for example, a p-type semiconductor, but is not limited thereto, and may include an n-type semiconductor according to circumstances. The second semiconductor layer 123 may include a group III-V based p-type semiconductor, such as p-GaN. The second semiconductor layer 123 may have a single-layer or multi-layer structure. According to an example embodiment, the second semiconductor layer 123 may be directly disposed on the upper surface of the active layer 122.

A plurality of color conversion layers 130R, 130G, and 130B that convert light emitted from the active layer 122 of the light emitting layer 120 into light of respective colors are disposed on the light emitting layer 120. According to an exemplary embodiment, the color is a predetermined color. Each of the plurality of color conversion layers 130R, 130G, and 130B may be disposed on a portion of the light emitting layer 120. Therefore, the plurality of color conversion layers 130R, 130G, and 130B may share one light emitting layer 120. The plurality of color conversion layers 130R, 130G, and 130B may be formed using photolithography.

For example, the plurality of color conversion layers 130R, 130G, and 130B may include a red conversion layer 130R, a green conversion layer 130G, and a blue conversion layer 130B. Accordingly, the red conversion layer 130R and the portion of the emission layer 120 under the red conversion layer 130R may be a red subpixel SR unit; the green conversion layer 130G and the portion of the light emitting layer 120 under the green conversion layer 130G may be a green sub-pixel SG unit; the blue conversion layer 130B and the portion of the emission layer 120 under the blue conversion layer 130B may be a blue subpixel SB unit.

The red conversion layer 130R may convert light emitted from the active layer 122 into red light R and emit it. The light emitted from the active layer 122 may be blue light. The red conversion layer 130R may include Quantum Dots (QDs) having a certain size, which are excited by blue light and emit red light R. The quantum dots may have a core-shell structure including a core portion and a shell portion or a particle structure without a shell. The core-shell structure may have a single shell or multiple shells. The multiple shells may be, for example, double shells.

The quantum dots may include, for example, at least one of group II-VI based semiconductors, group III-V based semiconductors, group IV-VI based semiconductors, group IV based semiconductors, and graphene quantum dots. Specifically, the quantum dot may include at least one of Cd, Se, Zn, S, and InP, but is not limited thereto. The quantum dots may have a diameter of tens of nanometers or less, for example, a diameter of about 10nm or less. In addition, the red conversion layer 130R may include a phosphor excited by blue light generated in the active layer 122 to emit red light R. The red conversion layer 130R may further include a photoresist having an excellent transmission characteristic or a light dispersing agent that uniformly emits the red light R.

The green conversion layer 130G may convert light generated in the active layer 122 into green light G and emit it. The active layer 122 may generate blue light B. The green conversion layer 130G may include quantum dots having a size excited by the blue light B to emit green light G. In addition, the green conversion layer 130G may include a phosphor excited by the blue light B generated in the active layer 122 to emit green light G. The green conversion layer 130G may further include a photoresist or a light dispersing agent.

The blue conversion layer 130B may emit light generated in the active layer 122 as blue light B. When the light generated in the active layer 122 is blue light B, the blue conversion layer 130B may be a transmissive layer that transmits the blue light B generated in the active layer 122 without wavelength conversion. When blue conversion layer 130B is a transmissive layer, blue conversion layer 130B may not include quantum dots and may include a photoresist or a light dispersing agent such as TiO₂。

Display device 10 may also include at least one barrier 140. According to an example embodiment, the plurality of color conversion layers 130R, 130G, and 130B are spatially spaced apart from each other by the at least one barrier 140 provided between the plurality of color conversion layers 130R, 130G, and 130B. For example, the barrier 140 may be disposed between the red and green conversion layers 130R and 130G and between the green and blue conversion layers 130G and 130B. The barriers 140 may prevent color mixing between the light emitted from the color conversion layers 130R, 130B, and 130G to increase the level of contrast. The barrier 140 may include at least one of a black matrix material, a resin, and a polymer.

The display device 10 may further include an insulating layer 150 between the light emitting layer 120 and the plurality of color conversion layers 130R, 130G, and 130B. The insulating layer 150 may be formed of a material having a refractive index smaller than that of the light emitting layer 120. The insulating layer 150 may be formed of an insulating material having a refractive index of 1.6 or less. For example, the insulating layer 150 may include SiO₂、SiN、Al₂O₃Or TiO₂But is not limited thereto. Accordingly, the insulating layer 150 may totally internally reflect light incident to the light emitting layer 120 at a greater threshold angle. For example, when the light emitting layer 120 is formed of a GaN material and the insulating layer 150 is formed of SiO₂When formed, light incident to the insulating layer 150 at an incident angle of about 35 degrees or more is totally internally reflected to travel in a lateral direction of the light emitting layer 120.

The insulating layer 150 may include a first insulating layer 152 disposed on the light emitting layer 120 and a second insulating layer 154 disposed between the first insulating layer 152 and the plurality of color conversion layers 130R, 130G, and 130B. The first insulating layer 152 may include a plurality of first openings OP1 corresponding to the plurality of color conversion layers 130R, 130G, and 130B, respectively. Current may be applied to the light emitting layer 120 through the first opening OP1, and light generated in the light emitting layer 120 may be incident to the light-corresponding color conversion layers 130R, 130G, and 130B through the first opening OP 1.

Since a current may be applied through the first opening OP1, the first opening OP1 may be referred to as a current injection region, and since light is emitted from the light-emitting layer 120 through the first opening OP1, the first opening OP1 may be referred to as a light-emitting region. Even when the plurality of sub-pixels SR, SG and SB share the light emitting layer 120, the current injection region may be localized such that light is generated in a portion of the light emitting layer 120 corresponding to a predetermined sub-pixel through the first opening OP 1. Therefore, the light emitting region can be limited. Therefore, the influence due to optical interference between sub-pixels can be reduced.

The second insulating layer 154 may be formed on the light emitting layer 120. According to an example embodiment, the second insulating layer 154 may be formed on the entire upper surface of the light emitting layer 120 to increase the total internal reflection effect and the insulating effect. The first and second insulating layers 152 and 154 may have the same or different refractive indices. When the first and second insulating layers 152 and 154 have different refractive indexes, the second insulating layer 154 may have a refractive index smaller than that of the first insulating layer 152. Therefore, light generated in the light emitting layer 120 and having transmitted through the first insulating layer 152 may also be totally internally reflected by the second insulating layer 154.

The display device 10 may further include a first electrode 160 and a second electrode 170 electrically connected to the light emitting layer 120. The first electrode 160 may be electrically connected to the second semiconductor layer 123 of the light emitting layer 120, and the second electrode 170 may be electrically connected to the first semiconductor layer 121 of the light emitting layer 120. When the second semiconductor layer 123 includes a p-type semiconductor, the first electrode 160 may be a p-type electrode, and when the first semiconductor layer 121 includes an n-type semiconductor, the second electrode 170 may be an n-type electrode.

A plurality of first electrodes 160 may be included. The number of the first electrodes 160 may be equal to the number of the sub-pixels. That is, the first electrodes 160 may be spaced apart from each other in some regions of the light emitting layer 120 to correspond to the plurality of color conversion layers 130R, 130G, and 130B, respectively.

Each of the first electrodes 160 contacts the light emitting layer 120 through the first opening OP1, thereby limiting the area of contact between the first electrode 160 and the second semiconductor layer 123. Accordingly, the current injected from the first electrode 160 to the second semiconductor layer 123 may be localized to the first opening OP1 described above. Accordingly, light may be specifically generated only in the region of the active layer 122 under the color conversion layers 130R, 130G, and 130B of the specific color. The generated light may be incident only to the color conversion layers 130R, 130G, and 130B of the respective colors through the first opening OP1, and is less likely to travel to other sub-pixels in the vicinity. Even when light travels in a different direction from toward the first opening OP1, the light is totally internally reflected by the insulating layer 150 having a refractive index smaller than that of the light-emitting layer 120, and thus, light generated in a specific sub-pixel is not emitted through other sub-pixels. Therefore, the deterioration of color quality can be reduced.

The plurality of first electrodes 160 may be arranged to correspond to the plurality of sub-pixels SR, SG, and SB, respectively, that is, one-to-one correspondence to the plurality of color conversion layers 130R, 130G, and 130B. For example, the first electrode 160 may be disposed under the red, green, and blue conversion layers 130R, 130G, and 130B, respectively.

The first electrode 160 may include a transparent conductive material. For example, the first electrode 160 may include Indium Tin Oxide (ITO), ZnO, Indium Zinc Oxide (IZO), Ag, Au, Ni, graphene, or nanowire, but is not limited thereto. Accordingly, light loss caused when light generated in the light emitting layer 120 is incident to the color conversion layers 130R, 130G, and 130B through the first electrode 160 can be reduced.

The plurality of first electrodes 160 may also be electrically connected to the plurality of thin film transistors in a one-to-one correspondence. The thin film transistor selectively drives at least one of the plurality of sub-pixels SR, SG, and SB.

The second electrode 170 may include a via electrode 172 and a first electrode pad 174. According to an example embodiment, the via electrode 172 passes through the first insulating layer 152 to contact the light emitting layer 120, for example, the first semiconductor layer 121. The first electrode pad 174 is disposed on the first insulating layer 152 and contacts the via electrode 172. By sequentially etching the second semiconductor layer 123, the active layer 122, and the first semiconductor layer 121, a groove exposing the first semiconductor layer 121 may be formed, and the second electrode 170 may be provided in the groove. An insulating material may be formed on the inner wall of the groove and on the second semiconductor layer 123 around the groove. The insulating material is the same as that of the first insulating layer 152, and may be formed when the first insulating layer 152 is formed. In addition, a via electrode 172 contacting the first semiconductor layer 121 may be formed, and a first electrode pad 174 contacting the first insulating layer 152 and the via electrode 172 may be formed.

The second electrode 170 may be a common electrode that supplies a common electric signal to the plurality of subpixels SR, SG, and SB. When a common electric signal is supplied from one second electrode 170 to a plurality of sub-pixels, the sizes of the sub-pixels SR, SG, and SB may be reduced.

Referring to fig. 1, the second electrode 170 is arranged to correspond to six sub-pixels SR, SG, and SB in common as an example. However, this is an example, and the number of the sub-pixels SR, SG, and SB that collectively correspond to one second electrode 170 may be varied in various ways. The second electrode 170 may include a highly conductive material.

In the above-described structure, for example, when the thin film transistor corresponding to the red sub-pixel SR is driven to apply a certain voltage between the second electrode 170, which is a common electrode, and the first electrode 160 corresponding to the red sub-pixel SR, light is generated in a portion of the active layer 122 located under the red conversion layer 130R. When the generated light is incident to the red conversion layer 130R, the red conversion layer 130R converts the light into red light R to emit it.

Alternatively, when the thin film transistor corresponding to the green sub-pixel SG is driven to apply a certain voltage between the second electrode 170 as a common electrode and the first electrode 160 corresponding to the green sub-pixel SG, light is generated in a portion of the active layer 122 located under the green conversion layer 130G. When the generated light is incident to the green conversion layer 130G, the green conversion layer 130G emits green light G to the outside.

Alternatively, when the thin film transistor corresponding to the blue subpixel SB is driven to apply a certain voltage between the second electrode 170, which is a common electrode, and the first electrode 160 corresponding to the blue subpixel SB, light is generated in the active layer 122 located under the blue conversion layer 130B. The generated light is transmitted through the blue conversion layer 130B to be emitted to the outside. Fig. 2 illustrates an example in which red, green, and blue light R, G, and B are emitted from the red, green, and blue conversion layers 130R, 130G, and 130B, respectively, to the outside.

According to example embodiments, a display device 10 having high resolution and improved luminous efficiency may be realized. According to the related art, in order to realize the display device 10 having high resolution, compact LED chips corresponding to the sub-pixels SR, SG, and SB will be manufactured separately, and the compact LED chips need to be transferred in place. Here, the active layers 122 are spaced apart from each other for each sub-pixel, and thus, an exposed area of the active layers 122 is increased to reduce light emitting efficiency, and it is difficult to transfer a compact LED chip at a precise position.

In the display device 10 according to an example embodiment, the plurality of sub-pixels SR, SG and SB are disposed on one light emitting layer 120 (specifically, the active layer 122), and thus, the manufacturing of the display device is easier than the related art manufacturing method, because the display device 10 may be manufactured without transfer. In addition, the active layer 122, which is a light emitting region, is not exposed with respect to each sub-pixel, and thus light emitting efficiency may be improved.

In addition, the active layer 122 is shared by a plurality of sub-pixels, and thus, even when most of the generated light is incident to the light-corresponding color conversion layers 130R, 130G, and 130B, a portion of the light moves in a lateral direction of the active layer 122 and proceeds to other sub-pixels. Light traveling to the other sub-pixels may be emitted to the outside through the color conversion layers of the other sub-pixels to emit undesired colors, and thus color quality may be degraded.

However, according to the display device 10 of the example embodiment, the light emitting region (i.e., the region other than the first opening OP 1) of the upper surface of the light emitting layer 120 is covered with the insulating layer 150 having a smaller refractive index than the light emitting layer 120. Therefore, light incident at an incident angle equal to or greater than the threshold angle is totally internally reflected at the boundary between the insulating layer 150 and the light emitting layer 120, thereby reducing light emission through other sub-pixels.

Fig. 3 is a cross-sectional view illustrating a display device 100a including a second electrode pad 162 according to an example embodiment. When comparing fig. 2 and 3, the display device 100a of fig. 3 may further include a plurality of second electrode pads 162 contacting the plurality of first electrodes 160, respectively. The second electrode pads 162 may be directly connected to electrodes of the thin film transistors, respectively. For example, the second electrode pad 162 may be formed when the electrode of the thin film transistor extends. The second electrode pad 162 may be formed of a highly conductive material (e.g., a metal material). The second electrode pad 162 may be disposed on a region of the first electrode 160 not overlapping the first opening OP 1. Therefore, the second electrode pad 162 does not have to be transparent.

Fig. 4 is a cross-sectional view illustrating a display device 100b including a first reflective layer 182 according to an embodiment. When comparing fig. 2 and 4, the display device 100b of fig. 4 may further include a first reflective layer 182, the first reflective layer 182 being in contact with the upper surface of the light emitting layer 120 and reflecting light incident from the light emitting layer 120. The upper surface and all side surfaces of the first reflective layer 182 may be covered by the insulating layer 150 (specifically, the first insulating layer 152). The first reflective layer 182 may be disposed between the sub-pixels SR, SG, and SB. Specifically, the first reflective layer 182 may be disposed between the plurality of first openings OP1 disposed in the first insulating layer 152. The first reflective layer 182 may be spaced apart from the first opening OP1 such that the first reflective layer 182 does not overlap the first opening OP 1.

The first reflective layer 182 may be formed of a material having high light reflectivity, and may include, for example, a metal material. When light generated in the light emitting layer 120 is incident, the light may be reflected. Due to the smaller refractive index of the insulating layer 150 than the light emitting layer 120, light incident at an angle equal to or greater than the threshold angle may be totally internally reflected. However, a portion of light incident at an angle less than the threshold angle may be transmitted through the insulating layer 150 and incident to the color conversion layer of the other color, which is not desired. The light incident to the other color conversion layer may be converted into light of an undesired other color and emitted to the outside. However, the first reflection layer 182 is disposed between the first openings OP1, and thus, even when light is incident at an angle less than a threshold angle, the light may be reflected by the first reflection layer 182, thereby preventing the light from being incident to other color conversion layers of other colors.

Fig. 5 is a cross-sectional view illustrating a display device 100c including a second reflective layer 184 according to an example embodiment. When comparing fig. 2 and 5, the display device 100c of fig. 5 may further include a second reflective layer 184 disposed on the first electrode 160. The second reflective layer 184 may cover at least a portion of the upper surface of the first electrode 160. The second reflective layer 184 may be formed of a material having high light reflectivity, and the second reflective layer 184 may include, for example, a metal material.

The second reflective layer 184 may include a plurality of second openings OP2, and each of the second openings OP2 may overlap at least a portion of one first opening OP1 among the plurality of openings OP1 formed in the first insulating layer 152. In addition to the first opening OP1, the second opening OP2 also serves as an optical path through which light generated in the light emitting layer 120 travels to the color conversion layers 130R, 130G, and 130B. In addition, light generated in the light emitting layer 120 and not passing through the first and second openings OP1 and OP2 may be reflected by the insulating layer 150 or the second reflective layer 184, thus preventing light from being emitted to the outside. According to an example embodiment, the width of each second opening OP2 is less than the width of the corresponding first opening OP 1.

Further, in the second reflective layer 184, when light is incident to the light-corresponding color conversion layers 130R, 130G, and 130B, a part of the light may be reflected by the color conversion layers 130R, 130G, and 130B. The second reflective layer 184 reflects light, which is not incident to the color conversion layers 130R, 130G, and 130B, to the color conversion layers 130R, 130G, and 130B again, thereby improving the efficiency of light incident to the color conversion layers 130R, 130G, and 130B.

Fig. 6 is a cross-sectional view illustrating a display device 100d including a second reflective layer 184a according to another example embodiment. When comparing fig. 5 and 6, the display device 100d of fig. 6 may not include the first electrode 160 but include only the second reflective layer 184 a. The second reflective layer 184a may be formed of a material having high reflectivity and high electrical conductivity. For example, the second reflective layer 184a may be formed of metal.

The second reflective layer 184a may function not only to reflect light but also to serve as an electrode through which current is injected into the light emitting layer 120. Therefore, the second reflective layer 184a may also be referred to as a reflective electrode. For example, the first end of the second reflective layer 184a may be in contact with the light emitting layer 120 through one of the first openings OP1, and the other region of the second reflective layer 184a may extend along the side surface of the first insulating layer 152 onto the upper surface of the first insulating layer 152. In addition, the second reflective layer 184a further includes a plurality of third openings OP3, and each of the third openings OP3 may overlap at least a portion of a corresponding one of the first openings OP 1. The third opening OP3 is smaller in size than the first opening OP 1. According to an example embodiment, the width of the third opening OP3 is less than the width of the first opening OP 1.

Fig. 7 is a cross-sectional view illustrating a display device 100e including a first reflective layer 182 and a second reflective layer 184a according to another embodiment. When comparing fig. 6 and 7, the display device 100e of fig. 7 may further include a first reflective layer 182 disposed between the light emitting layer 120 and the first insulating layer 152. The entire upper surface of the first reflective layer 182 may be covered by the insulating layer 150. The first reflective layer 182 may be spaced apart from the first openings OP1 on the light emitting layer 120 between the first openings OP 1.

At least portions of the first and second reflective layers 182, 184a may overlap each other. Accordingly, when the pixel region of the display device 100e is viewed from above the display device 100e, an optical path region of the upper surface of the light emitting layer 120 (e.g., a region except for a portion where the first opening OP1 and the third opening OP3 overlap each other) may be optically blocked by at least one of the first and second reflective layers 182 and 184 a. Accordingly, light generated in the light emitting layer 120 can be prevented from being emitted to other regions except for a region where the first opening OP1 and the third opening OP3 overlap each other. In addition, the upper surface of the second reflective layer 184a reflects light toward the color conversion layers 130R, 130G, and 130B, and thus the efficiency of light incident to the color conversion layers 130R, 130G, and 130B can be improved.

At least one of the first and second reflective layers 182 and 184a may include two heterogeneous layers having different optical characteristics. For example, the first reflective layer 182 may include a first layer and a second layer having different reflective characteristics. The first layer faces the light emitting layer 120 and may be formed of a material having a relatively low reflectance, and the second layer faces the color conversion layers 130R, 130G, and 130B and may be formed of a highly reflective material. Accordingly, light reflected to travel toward the active layer 122 may increase reflection loss, and light reflected and traveling to the color conversion layers 130R, 130G, and 130B may improve reflection efficiency. In the light traveling to the active layer 122, light loss may occur due to the first layer, and thus light interference may be reduced. In the light traveling to color conversion layers 130R, 130G, and 130B, the light loss is relatively small, and the efficiency of the light incident to color conversion layers 130R, 130G, and 130B can be increased accordingly.

The second reflective layers 184 and 184a may also include a first layer facing the light emitting layer 120 and formed of a material having a relatively low reflectance and a second layer facing the color conversion layers 130R, 130G, and 130B and formed of a material having a relatively high reflectance. The second reflective layers 184 and 184a may also reduce light interference by using the first layer, and may improve light efficiency by using the second layer.

Fig. 8 and 9 illustrate display devices 10b and 10c respectively including second electrodes 170a and 170b according to another example embodiment. Comparing fig. 1 and 8, the second electrode 170a shown in the display device 10b of fig. 8 may be disposed on the lower surface of the light emitting layer 120. Since the second electrode 170a is disposed on the lower surface of the light emitting layer 120, a uniform distance with respect to the first electrode 160 of each sub-pixel may be provided. Accordingly, a uniform current path may be formed in the light emitting layer 120 of each sub-pixel.

The second electrodes 170b shown in the display device 10c of fig. 9 may be spaced apart from each other for each sub-pixel on the lower surface of the light emitting layer 120. The first and second electrodes 160 and 170b may be arranged in one-to-one correspondence in units of sub-pixels. When an electric signal is applied to the first electrode 160 and the second electrode 170b in units of sub-pixels, light generated in the light emitting layer 120 included in the other sub-pixels may be reduced. When the substrate 110 is formed of a conductive material, the substrate 110 may serve as a second electrode.

In the vertical structure in which the second electrodes 170a and 170b, the light emitting layer 120, and the first electrode 160 are sequentially formed, it is not necessary to provide an additional area to form the second electrode 170 in the light emitting layer 120, and thus, a display device having a small sub-pixel or a small pixel size can be realized. Therefore, a high-resolution display device can be realized.

Fig. 10 illustrates a display device 100f including a barrier 140a according to another example embodiment. When comparing fig. 2 and 10, the barrier 140a shown in fig. 10 may include a core 142 and a shell 144. The housing 144 may include a highly reflective material. For example, the case 144 may be formed of a metal material. When the barrier 140a is formed of a black matrix material, light incident to the black matrix may be absorbed, reducing the efficiency of light emitted to the color conversion layers 130R, 130G, and 130B. However, since the barrier 140a of fig. 10 includes the shell 144 having a reflective property, light efficiency of light emitted from the color conversion layers 130R, 130G, and 130B may be improved by reflecting light incident to the shell 144. The core 142 may be formed of not only the black matrix but also an insulating material, a photoresist material, or the like.

Fig. 11 illustrates a display device 100g including a selectively transparent insulating layer 210 according to an example embodiment. When comparing fig. 2 and 11, the display device 100G of fig. 11 may further include a selectively transparent insulating layer 210 between the color conversion layers 130R, 130G, and 130B and the insulating layer 150. The transparent insulating layer 210 may transmit light generated in the active layer 122 of the light emitting layer 120 and reflect light generated in the plurality of color conversion layers 130R, 130G, and 130B. The transparent insulating layer 210 may include a structure including a plurality of layers having different refractive indexes.

Fig. 12 illustrates a display device 100h including a selective blocking layer 220 according to an example embodiment. When comparing fig. 2 and 12, the display device 100h of fig. 12 may further include a selective blocking layer 220 disposed on the color conversion layers 130R, 130G, and 130B. The selective blocking layer 220 may be disposed only on the red conversion layer 130R and the green conversion layer 130G. The selective blocking layer 220 may include a blue blocking filter that prevents blue light B from being emitted from the red and blue conversion layers 130R and 130B to the outside.

Fig. 13 and 14 illustrate display devices 100i and 100j including a light absorbing layer 230 according to example embodiments, respectively. The display device 100i or 100j may further include a light absorbing layer 230 that absorbs light generated in the light emitting layer 120 and returned to the light emitting layer 120. The light absorbing layer 230 may be disposed on the light emitting layer 120. For example, as shown in fig. 13, the light absorbing layer 230 may be disposed on the lower surface of the substrate 110. The light absorbing layer 230 may absorb light generated in the light emitting layer 120 and transmitted through the substrate 110, thereby preventing the light from being reflected by the lower surface of the substrate 110 and proceeding to the upper portion of the substrate 110. The light absorbing layer 230 may include a material having a refractive index similar to that of the substrate 110. For example, the light absorbing layer 230 may include a polymer-based material. Alternatively, as shown in fig. 14, the light absorbing layer 230 may be disposed between the light emitting layer 120 and the substrate 110.

Although not shown in the drawings, an index matching layer may be disposed between the substrate 110 and the first semiconductor layer 121. The index matching layer may reduce the amount of light reflected between the substrate 110 and the first semiconductor layer 121 due to a difference in refractive index of the substrate 110 and the first semiconductor layer 121.

Although blue light B emitted from the active layer of the display device has been described above as an example, it may be modified such that Ultraviolet (UV) light is emitted from the active layer.

The display devices 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, and 100j of fig. 3 to 14 are described based on the display device 10 of fig. 1 or the display device 100 of fig. 2, but are not limited thereto. The display device may also be implemented by combining elements of the display devices 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100i, and 100j shown in fig. 3 to 14.

According to the above-described example embodiment, since one active layer 122 is formed to correspond to the plurality of color conversion layers 130R, 130G, and 130B, an exposed area of the active layer 122 may be minimized, thereby improving optical efficiency. Further, by using an insulating layer having a small refractive index, a contact area of the semiconductor layer with the electrode can be limited, thereby not only reducing a light emitting area of the active layer but also improving color quality by totally reflecting unwanted light.

Further, by disposing a reflective layer between the light emitting layer and the color conversion layer, light incident from the light emitting layer is reflected to prevent emission of unnecessary light, and light incident from the color conversion layer can be reflected to improve efficiency of emitting light.

In addition, by coating a reflective material on the barrier between the color conversion layers, light incident from the color conversion layers can be reflected, thereby improving the efficiency of emitting light.

According to example embodiments, one active layer is formed to correspond to a plurality of color conversion layers, so that an area where the active layer is exposed may be minimized, thereby improving optical efficiency. Further, by using an insulating layer having a small refractive index, a contact area of the semiconductor layer with the electrode can be limited, thereby not only reducing a light emitting area of the active layer but also improving color quality by totally reflecting unwanted light.

Further, by disposing a reflective layer between the light emitting layer and the color conversion layer, light incident from the light emitting layer is reflected to prevent emission of unnecessary light, and light incident from the color conversion layer can be reflected to improve efficiency of emitting light.

In addition, by coating a reflective material on the barrier between the color conversion layers, light incident from the color conversion layers may be reflected, thereby improving the efficiency of emitting light.

It should be understood that the exemplary embodiments described herein should be considered in descriptive sense only and not for purposes of limitation. The description of features or aspects within each example embodiment should generally be considered as available for other similar features or aspects in other embodiments.

Although one or more example embodiments have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope defined by the following claims.

This application claims priority from korean patent application No. 10-2018-0109721, filed by the korean intellectual property office at 13.9.2018, the disclosure of which is incorporated herein by reference.