阅读说明：本技术 显示设备 (Display device ) 是由 裵光洙 朴钒首 吴旻贞 赵荣济 于 2020-04-30 设计创作，主要内容包括：一种显示设备,包括：基板；显示元件,该显示元件被布置在基板上,并且包括像素电极、对电极以及在像素电极与对电极之间的发射层；以及限定气腔的顶层,气腔被布置成围绕显示元件,其中,顶层的折射率大于气腔的折射率。(A display device, comprising: a substrate; a display element which is arranged on a substrate and includes a pixel electrode, a counter electrode, and an emission layer between the pixel electrode and the counter electrode; and a top layer defining an air cavity arranged to surround the display element, wherein a refractive index of the top layer is greater than a refractive index of the air cavity.)

1. A display device, comprising:

a substrate;

a display element disposed on the substrate and including a pixel electrode, a counter electrode, and an emission layer between the pixel electrode and the counter electrode; and

a top layer defining an air cavity arranged to surround the display element,

wherein the refractive index of the top layer is greater than the refractive index of the air cavity.

2. The display device according to claim 1,

the top layer includes an inorganic insulating layer.

3. The display device according to claim 2,

the top layer includes at least one of silicon nitride, silicon oxide, and silicon oxynitride.

4. The display device of claim 3,

the top layer includes a side portion inclined with respect to a main surface of the substrate.

5. The display device of claim 4,

the side portion has an inclination angle equal to or greater than 50 ° with respect to a plane parallel to the major surface of the substrate.

6. The display device according to claim 1,

the top layer includes at least one aperture.

7. The display device of claim 1, further comprising:

a thin film encapsulation layer covering the display element and including at least one organic encapsulation layer and at least one inorganic encapsulation layer,

wherein the at least one organic encapsulation layer has a refractive index greater than the refractive index of the air cavity.

8. The display device according to claim 7,

the air cavity is positioned above the thin film packaging layer.

9. The display device according to claim 7,

the air cavity is located below the thin film encapsulation layer.

10. The display device of claim 1, further comprising:

a pixel defining layer covering edges of the pixel electrodes and including openings corresponding to the pixel electrodes,

wherein the air cavity is located on the pixel defining layer.

11. The display device according to claim 1,

a portion of the air cavity overlaps with an edge of the pixel electrode.

12. The display device according to claim 11,

the edge of the pixel electrode is located inside the air cavity.

13. The display device according to claim 12,

the top layer includes an opening having a width smaller than a width of the pixel electrode.

14. A display device, comprising:

a substrate;

a display element disposed on the substrate and including a pixel electrode, a counter electrode, and an emission layer between the pixel electrode and the counter electrode; and

a top layer defining an air cavity and including inclined side portions located on a propagation path of light emitted from the display element, and the inclined side portions defining an interface between the top layer and the air cavity to change the propagation path of the light from a direction inclined with respect to a thickness direction of the substrate to a direction at least parallel to the thickness direction of the substrate,

wherein the refractive index of the top layer is greater than the refractive index of the air cavity.

15. The display device of claim 14,

the top layer includes at least one aperture.

16. The display device of claim 14,

the air cavity completely surrounds the display element.

17. The display device of claim 14,

the difference between the refractive index of the top layer and the refractive index of the air cavity is equal to or greater than 0.7.

18. The display device of claim 14,

the top layer includes an inorganic insulating layer, and an inclination angle of the inclined side portion with respect to a plane parallel to a main surface of the substrate is equal to or greater than 50 °.

19. The display device of claim 14,

the top layer includes an opening corresponding to the emissive layer of the display element.

20. The display device of claim 19, further comprising:

a thin film encapsulation layer covering the display element and including at least one organic encapsulation layer and at least one inorganic encapsulation layer,

wherein a difference between a refractive index of the at least one organic encapsulation layer and the refractive index of the air cavity is equal to or greater than 0.5.

Technical Field

One or more embodiments relate to a display device, and more particularly, to a configuration that improves efficiency of propagating light and brightness thereof due to lack of dispersion of the propagating light.

Background

Recently, application arrays in which display devices can be used have become more diversified. As display devices become thinner and lighter, such arrays continue to evolve as users become more dependent on them to perform personal and professional tasks. Therefore, it is important to reliably ensure their performance in generating images to be displayed.

Disclosure of Invention

One or more embodiments include a display that can provide high quality images.

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 one or more embodiments, a display apparatus includes: a substrate; a display element which is arranged on a substrate and includes a pixel electrode, a counter electrode, and an emission layer between the pixel electrode and the counter electrode; and a top layer defining an air cavity arranged to surround the display element, wherein a refractive index of the top layer may be greater than a refractive index of the air cavity.

The top layer may comprise an inorganic insulating layer.

The top layer may include at least one of silicon nitride, silicon oxide, and silicon oxynitride.

The top layer may comprise side portions inclined with respect to the main surface of the substrate.

The side portion may have an inclination angle with respect to a plane parallel to the major surface of the substrate equal to or greater than about 50 °.

The top layer may comprise at least one aperture.

The display device may further include: a thin film encapsulation layer covering the display element and including at least one organic encapsulation layer and at least one inorganic encapsulation layer, wherein the at least one organic encapsulation layer may have a refractive index greater than a refractive index of the air cavity.

The air cavity may be located on the thin film encapsulation layer.

The air cavity may be located below the thin film encapsulation layer.

The display device may further include: and a pixel defining layer covering edges of the pixel electrodes and including openings corresponding to the pixel electrodes, wherein the air cavity may be located on the pixel defining layer.

The air cavity may overlap with an edge of the pixel electrode.

The edge of the pixel electrode may be located inside the air cavity.

The top layer may include an opening having a width smaller than that of the pixel electrode.

According to one or more embodiments, a display apparatus includes: a substrate; a display element which is arranged on a substrate and includes a pixel electrode, a counter electrode, and an emission layer between the pixel electrode and the counter electrode; and a top layer defining an air cavity and including inclined side portions, the inclined side portions being located on a propagation path of light that can be emitted from the display element, and the inclined side portions defining an interface between the top layer and the air cavity to change the propagation path of the light from a direction that can be inclined with respect to a thickness direction of the substrate to a direction that can be at least parallel to the thickness direction of the substrate, wherein a refractive index of the top layer is greater than a refractive index of the air cavity.

The top layer may comprise at least one aperture.

The air cavity may completely surround the display element.

The difference between the refractive index of the top layer and the refractive index of the air cavity may be equal to or greater than about 0.7.

The top layer may include an inorganic insulating layer, and an inclination angle of the inclined side portion with respect to a plane parallel to the major surface of the substrate may be equal to or greater than about 50 °.

The top layer may comprise openings corresponding to the emissive layer of the display element.

The display device may further include: a thin film encapsulation layer covering the display element and including at least one organic encapsulation layer and at least one inorganic encapsulation layer, wherein a difference between a refractive index of the at least one organic encapsulation layer and a refractive index of the air cavity may be equal to or greater than about 0.5.

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

Drawings

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

fig. 1 illustrates a plan view of a display device according to an embodiment;

fig. 2 shows a schematic diagram of an equivalent circuit of one of the pixels of the display device according to the embodiment;

FIG. 3 shows a schematic cross-sectional view of a portion of the display device taken along line A-A' of FIG. 1, in accordance with an embodiment;

fig. 4A to 4C respectively show plan views of a part of a display device according to an embodiment;

FIG. 5 shows a schematic cross-sectional view of a path of light emitted from a display element of the display device taken along line A-A' of FIG. 1, in accordance with an embodiment;

fig. 6A to 6F illustrate schematic cross-sectional views taken along line a-a' of fig. 1 of a process of manufacturing a display apparatus according to an embodiment;

FIG. 6G shows a plan view of FIG. 6A;

FIG. 7 shows a schematic cross-sectional view of a portion of a display device according to an embodiment, taken along line A-A' of FIG. 1;

FIG. 8 shows an enlarged view of region VIII of FIG. 7;

FIG. 9 shows a schematic cross-sectional view of a portion of a display device according to an embodiment, taken along line A-A' of FIG. 1;

fig. 10A to 10C respectively show plan views of a part of a display device according to an embodiment;

fig. 11 shows a schematic cross-sectional view of a part of a display device according to an embodiment, taken along line a-a' of fig. 1;

fig. 12A to 12E respectively show sectional views of a part of a display apparatus according to an embodiment taken along line a-a' of fig. 1;

fig. 13 shows a schematic cross-sectional view of a part of a display device according to an embodiment, taken along line a-a' of fig. 1;

fig. 14 illustrates an enlarged cross-sectional view taken along line a-a' of fig. 1 of an air chamber of a display device and its surroundings according to an embodiment;

fig. 15A and 15B illustrate a plan view of a part of a display device according to an embodiment;

fig. 16 shows a schematic cross-sectional view of a part of a display device according to an embodiment, taken along line a-a' of fig. 1;

fig. 17A to 17F illustrate schematic sectional views taken along line a-a' of fig. 1 of a process of manufacturing a display apparatus according to an embodiment;

FIG. 17G shows a plan view of FIG. 17A;

fig. 18 shows a schematic cross-sectional view of a display device according to an embodiment, taken along line a-a' of fig. 1; and is

Fig. 19 illustrates a schematic cross-sectional view of a display apparatus according to an embodiment, taken along line a-a' of fig. 1.

Detailed Description

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In this regard, the embodiments may have different forms and should not be construed as limited to the description set forth herein. Accordingly, the embodiments described below are merely to explain the described aspects by referring to the figures. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression "at least one of a, b and c" means all or a variant of only a, only b, only c, both a and b, both a and c, both b and c, a, b and c.

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 components are used only to distinguish one component from another.

As used herein, the singular forms "a", "an" and "the" may include the plural forms as well, unless the context clearly indicates otherwise.

It will be further understood that the terms "comprises" and/or "comprising," when used herein, specify the presence of stated features or components, but may not preclude the presence or addition of one or more other features or components.

It will be understood that when a layer, region or component is referred to as being "formed on" another layer, region or component, it can be directly or indirectly formed on the other layer, region or component. That is, for example, intervening layers, regions, or components may be present.

The size of elements in the drawings may be exaggerated for convenience. In other words, since the sizes and thicknesses of components in the drawings are arbitrarily illustrated for convenience of explanation, the following embodiments are not limited thereto.

When an embodiment may be implemented differently, the particular process sequence may be performed in an order different than that described. For example, two processes described in succession may be executed substantially concurrently or in the reverse order to that described.

It will be understood that when a layer, region or component is referred to as being "connected" to another layer, region or component, it can be "directly connected" to the other layer, region or component or can be "indirectly connected" to the other layer, region or component with the other layer, region or component interposed therebetween. For example, it will be understood that when a layer, region or component is referred to as being "electrically connected" to another layer, region or component, it can be "directly electrically connected" to the other layer, region or component or can be "indirectly electrically connected" to the other layer, region or component with the other layer, region or component interposed therebetween.

Further, in the present specification, the phrase "in a plan view" means when the object portion is viewed from above, and the phrase "in a sectional view" means when a section taken by perpendicularly cutting the object portion is viewed from the side. In addition, the terms "overlap" or "overlapping" mean that the first object may be above, below, or to the side of the second object, and vice versa. Additionally, the term "overlap" may include a layer, stack, facing, extending over …, covering or partially covering, or any other suitable term as will be appreciated and understood by one of ordinary skill in the art. The term "facing" means that the first object may be directly or indirectly opposite the second object. In the case where the third object is interposed between the first object and the second object, the first object and the second object may be understood as being indirectly opposite to each other, although still facing each other.

For ease of description, spatially relative terms "below," "beneath," "lower," "above," "upper," and the like may be used herein to describe one element or component's relationship to another element or component as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, in the case where the devices illustrated in the drawings are turned over, a device located "below" or "beneath" another device may be placed "above" the other device. Thus, the illustrative term "below" may include both a lower position and an upper position. The device may also be oriented in other directions, and the spatially relative terms may therefore be interpreted differently depending on the orientation.

"about" or "approximately" as used herein includes the stated value, and is meant to be within an acceptable range of deviation of the stated value as determined by one of ordinary skill in the art, taking into account the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or, for example, within ± 30%, 20%, 10%, 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In the following examples, the x-axis, y-axis, and z-axis are not limited to the three axes of a rectangular coordinate system, and may be explained in a broader sense. For example, the x-axis, y-axis, and z-axis may be perpendicular to each other, or may represent different directions that are not perpendicular to each other.

Fig. 1 illustrates a plan view of a display device 10 according to an embodiment.

The display device 10 may include a display area DA and a peripheral area PA adjacent to the display area DA. The display device 10 may include pixels P disposed in the display area DA. Each pixel P may be connected to a scan line SL and a data line DL. It is to be understood that fig. 1 illustrates a diagram of a substrate 100 of the display device 10. For example, it is understood that the substrate 100 includes a display area DA and a peripheral area PA.

A scan driver 1100, a data driver 1200, and a main power line (not shown) may be disposed in the peripheral area PA, the scan driver 1100 supplying a scan signal to each pixel P through a scan line SL, the data driver 1200 supplying a data signal to each pixel P through a data line DL, and the main power line supplying a first power voltage and a second power voltage.

Although fig. 1 illustrates that the data driver 1200 may be disposed on the substrate 100, the data driver 1200 may be disposed on a Flexible Printed Circuit Board (FPCB) electrically connected to a pad disposed on one side of the display device 10.

The display device 10 according to the embodiment may include an organic light emitting display, an inorganic light emitting display, a liquid crystal display, an electrophoretic display, a field emission display, a surface conduction electron emitter display, a quantum dot display, a plasma display, and a cathode ray display. Although the display device according to the embodiment may be described as an organic light emitting display device as an example, the display device according to the present disclosure may not be limited thereto.

Fig. 2 shows a schematic diagram of an equivalent circuit of one of the pixels of the display device according to the embodiment.

Referring to fig. 2, the pixel P may include a pixel circuit PC and a display element connected to the pixel circuit PC. The display element may comprise, for example, an organic light emitting diode OLED. The pixel circuit PC may include a first thin film transistor T1, a second thin film transistor T2, and a storage capacitor Cst. Each pixel P may emit, for example, red, green or blue light, or red, green, blue or white light through the organic light emitting diode OLED.

The second thin film transistor T2 may be a switching thin film transistor, and may be connected to the scan line SL and the data line DL. The second thin film transistor T2 may transfer a data voltage input through the data line DL to the first thin film transistor T1 in response to a scan voltage input through the scan line SL. The storage capacitor Cst may be connected to the second thin film transistor T2 and the driving voltage line PL, and may store a voltage corresponding to a difference between the voltage transferred from the second thin film transistor T2 and the first power supply voltage ELVDD supplied through the driving voltage line PL.

The first thin film transistor T1 may be a driving thin film transistor, may be connected to the driving voltage line PL and the storage capacitor Cst, and may control a driving current flowing from the driving voltage line PL through the organic light emitting diode OLED in response to a voltage stored in the storage capacitor Cst. The organic light emitting diode OLED may emit light having a predetermined luminance according to the driving current. A counter electrode (e.g., a cathode electrode) of the organic light emitting diode OLED may receive the second power supply voltage ELVSS.

Although the pixel circuit PC may include two thin film transistors and one storage capacitor, the present disclosure may not be limited thereto. The number of thin film transistors and the number of storage capacitors may be variously changed depending on the design of the pixel circuit PC.

Fig. 3 illustrates a schematic cross-sectional view of a portion of the display apparatus according to the embodiment, taken along line a-a' of fig. 1, and fig. 4A to 4C illustrate plan views of a portion of the display apparatus according to the embodiment.

Referring to fig. 3, the pixel circuit PC may be disposed on the substrate 100. The pixel circuit PC may be covered with an insulating layer 110. The organic light emitting diode OLED may be disposed over and electrically connected to the pixel circuit PC. The top layer 410 may be disposed over the organic light emitting diode OLED, and the top layer 410 may define the air cavity AC as a light control pattern. In other words, one or more portions of the top layer 410 forming the air cavity AC may control the pattern of light in the region adjacent to the top layer 410 and the air cavity AC at the interface of the air cavity AC and the top layer 410. For example, one or more portions of the top layer 410 may serve as a light controlling means for forming a propagation path for light emitted from the light emitting diodes OLED, such that the emitted light may be guided from the top layer 410 at the interface of the air cavity AC to form a controlled pattern of emitted light.

The substrate 100 may include a glass material or a polymer resin. In an embodiment, the substrate 100 may include a material including SiO₂A glass substrate as a main component. In another embodiment, the substrate 100 may include a base layer including a polymer resin and a barrier layer including an inorganic insulating material. For example, the substrate 100 may include a first polymer resin layer, a first inorganic barrier layer, a second polymer resin layer, and a second inorganic barrier layer, which are sequentially stacked. The first and second polymer resin layers may include polyether sulfone (PES), polyarylate, Polyetherimide (PEI), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyphenylene sulfide (PPS), Polyimide (PI), Polycarbonate (PC), cellulose Triacetate (TAC), and/or Cellulose Acetate Propionate (CAP), and the like. The first inorganic barrier layer and the second inorganic barrier layer may include silicon nitride, silicon oxide, and/or silicon oxynitride.

As described with reference to fig. 2, the pixel circuit PC may include a transistor and a storage capacitor. An insulating layer such as silicon nitride, silicon oxide and/or silicon oxynitride may be provided between the electrodes of the transistor and/or between the electrodes of the storage capacitor.

The pixel circuit PC may be covered with an insulating layer 110. The pixel electrode 221 on the insulating layer 110 may be electrically connected to the pixel circuit PC through a contact hole formed in the insulating layer 110. The insulating layer 110 may include an organic insulating layer and/or an inorganic insulating layer. The organic insulating layer may include an organic insulating material such as general-purpose polymers such as Polymethylmethacrylate (PMMA) and Polystyrene (PS), polymer derivatives having a phenol group, acrylic polymers, imide-based polymers, aryl ether-based polymers, amide-based polymers, fluorine-based polymers, p-xylene-based polymers, vinyl alcohol-based polymers, or a mixture thereof. The inorganic insulating layer may include at least one of silicon nitride, silicon oxide, and silicon oxynitride.

The pixel electrode 221 may include a reflective layer including Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or a compound thereof. In another embodiment, the pixel electrode 221 may further include a layer including Indium Tin Oxide (ITO), Indium Zinc Oxide (IZO), zinc oxide (ZnO), or indium oxide (In) on/under the reflective layer₂O₃)。

The pixel defining layer 120 may be disposed on the pixel electrode 221, and the pixel defining layer 120 may cover an edge of the pixel electrode 221. By increasing the distance between the counter electrode 223 and the edge of the pixel electrode 221, the pixel defining layer 120 can prevent an arc or the like from occurring between the counter electrode 223 and the edge of the pixel electrode 221. In other words, the pixel defining layer 120 may be disposed over the edge of the pixel electrode 221 and between the edge and the counter electrode 223 to increase the distance, and thus suppress such arc formation. The pixel defining layer 120 may include an organic insulating material such as polyimide or Hexamethyldisiloxane (HMDSO). The pixel defining layer 120 may include an inorganic insulating material, or may include an organic insulating material and an inorganic insulating material. The pixel defining layer 120 may include an opening 120OP overlapping or facing a central region of the pixel electrode 221. The central region of the pixel electrode 221 may be exposed through the opening 120OP of the pixel defining layer 120.

The intermediate layer 222 may be disposed on the pixel electrode 221. The intermediate layer 222 may include an emission layer 222 b. The emission layer 222b may overlap the opening 120OP of the pixel defining layer 120 or face the opening 120OP of the pixel defining layer 120. The emission layer 222b may include a polymer or a low molecular weight organic material that can emit light of a predetermined color.

The first functional layer 222a and the second functional layer 222c may be disposed under the emission layer 222b and on the emission layer 222b, respectively. The first functional layer 222a may include, for example, a Hole Transport Layer (HTL), or may include an HTL and a Hole Injection Layer (HIL). The second functional layer 222c may be disposed on the emission layer 222b, or may be omitted. The second functional layer 222c may include an Electron Transport Layer (ETL) and/or an Electron Injection Layer (EIL). Like the counter electrode 223, which will be described below, the first functional layer 222a and/or the second functional layer 222c may be a common layer that completely covers the substrate 100.

The counter electrode 223 may include a conductive material having a small work function. For example, the counter electrode 223 may include a (semi) transparent layer including Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, or an alloy thereof. Alternatively, the counter electrode 223 may further include ITO, IZO, ZnO, or In on a (semi) transparent layer including the above-described material₂O₃Of (2) a layer of (a).

The organic light emitting diode OLED may be covered by a thin film encapsulation layer 300, which may be an encapsulation member. The organic light emitting diode OLED may include a pixel electrode 221, an intermediate layer 222, and a counter electrode 223. The thin film encapsulation layer 300 may include at least one inorganic encapsulation layer and at least one organic encapsulation layer. In an embodiment, the thin film encapsulation layer 300 may include a first inorganic encapsulation layer 310, an organic encapsulation layer 320, and a second inorganic encapsulation layer 330, which may be sequentially stacked (i.e., stacked in the order described).

The first and second inorganic encapsulation layers 310 and 330 may include at least one of inorganic materials including aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide, silicon nitride, and silicon oxynitride.

The organic encapsulation layer 320 may include a polymer-based material. The organic encapsulation layer 320 may include a material, wherein a difference between a refractive index of the material and a refractive index of an air cavity AC, which will be described below, may be equal to or greater than about 0.5. For example, the organic encapsulation layer 320 may include an organic material having a refractive index ranging from about 1.5 to about 1.6. The organic encapsulation layer 320 may include acrylic resin, epoxy resin, polyimide, polyethylene, and/or the like. In an embodiment, the organic encapsulation layer 320 may include an acrylate.

The air cavity AC may be disposed on a propagation path of light emitted from the organic light emitting diode OLED. The propagation path of the light may include a path traveling in a direction that may be inclined to the thickness direction (i.e., z direction) of the display device 10. In the schematic cross-sectional view of fig. 3, the air cavity AC may be disposed on the thin film encapsulation layer 300, and disposed in an oblique direction between a direction perpendicular to the main surface 101 of the substrate 100 (i.e., z-direction) and a direction parallel to the main surface 101 of the substrate 100 (i.e., x-direction). In an embodiment, the air cavity AC may be disposed on the thin film encapsulation layer 300, and may overlap with the pixel defining layer 120 or face the pixel defining layer 120. In other words, the air cavity AC may be disposed on the thin film encapsulation layer 300 to be inclined with respect to the z-direction and the x-direction.

The air cavity AC may be defined by the top layer 410. The top layer 410 may include a lower portion contacting the thin film encapsulation layer 300, an upper portion spaced apart from the top surface of the thin film encapsulation layer 300 so that the air cavity AC may be between the thin film encapsulation layer 300 and the upper portion, and a side portion connecting the lower portion to the upper portion. The inclination angle α of the side portion of the top layer 410 (e.g., the inclination angle α of the side portion with respect to a virtual plane parallel to the major surface 101 of the substrate 100) may be equal to or greater than about 50 °. For example, the inclination angle α may be equal to or greater than about 60 °. One or more portions of the top layer 410 forming the air cavity AC may be disposed on the thin film encapsulation layer 300 to be inclined with respect to the z-direction and the x-direction. For example, one or more portions of the top layer 410 may be disposed offset from the emissive layer 222 b. The one or more air cavities AC may be disposed to be offset from the emission area EA (or the opening 120OP of the pixel defining layer 120). The height h of the air cavity AC may be about 1.5 μm to about 3.5 μm. For example, the height h of the air cavity AC may be about 1.5 μm to about 3.5 μm, or about 2 μm to about 3 μm.

The top layer 410 may comprise an inorganic material. In an embodiment, the top layer 410 may include an inorganic insulating layer. The top layer 410 may comprise silicon oxide, silicon nitride, and/or silicon oxynitride.

The top layer 410 may have a refractive index greater than the refractive index n of the air cavity AC (i.e., the refractive index n of the air inside the air cavity AC) (about 1.0). As an example, the difference between the refractive index of the air cavity AC and the refractive index of the top layer 410 may be equal to or greater than about 0.5. As another example, the difference between the refractive index of the air cavity AC and the refractive index of the top layer 410 may be equal to or greater than about 0.6. As another example, the difference between the refractive index of the air cavity AC and the refractive index of the top layer 410 may be equal to or greater than about 0.7. In an embodiment, in the case that the top layer 410 may include silicon nitride, the difference between the refractive index of the air cavity AC and the refractive index of the top layer 410 may be adjusted by adjusting the amount of silicon of the top layer 410. The refractive index of the top layer 410 may be from about 1.7 to about 1.9.

Referring to fig. 3 and 4A to 4C, the air cavity AC may completely surround the periphery of the emission area EA so as to surround (e.g., completely surround) the emission area EA in a plan view. The inner width (e.g., a width W2 of the air cavity AC disposed between two opposite side portions of the emission area EA between the portions of the air cavity AC) may be equal to or greater than the width W1 of the emission area EA. The width W1 of the emission area EA may be defined as the width of the opening 120OP of the pixel defining layer 120.

The top layer 410 may include holes 410H overlapping or facing the air cavity AC. The holes 410H of the top layer 410 may be formed during the process of forming the air cavity AC. One hole 410H may be provided in the top layer 410, or a plurality of holes 410H may be provided in the top layer 410. In an embodiment, as shown in fig. 4A, one hole 410H may be provided to completely surround the periphery of the emission area EA so as to surround the emission area EA. As shown in fig. 4B, the holes 410H may each have a slit shape and may be disposed along one side of the emission area EA. As shown in fig. 4C, the holes 410H may be disposed to completely surround the periphery of the emission area EA so as to surround the emission area EA, and may be spaced apart from each other.

The top layer 410 may include an opening 410OP overlapping with or facing the emission area EA and/or the opening 120OP of the pixel defining layer 120. Like the hole 410H, the opening 410OP of the top layer 410 forms a through hole through the top and bottom surfaces of the top layer 410. The width W3 of the opening 410OP of the top layer 410 may be equal to or greater than the width W1 of the opening 120OP of the pixel defining layer 120.

The top layer 410 may be covered by a planarization layer 500. The planarization layer 500 may include an organic insulating material. The planarization layer 500 may be formed by coating and hardening an organic material having viscosity. As described above, although the top layer 410 may include at least one hole 410H, an organic material, which may be the same as the organic material of the planarization layer 500, may be prevented from being located inside the air hole AC by adjusting the viscosity of the organic material constituting the planarization layer 500.

Fig. 5 illustrates a schematic cross-sectional view of a path of light emitted from a display element of a display device according to an embodiment.

Referring to fig. 5, light emitted from the organic light emitting diode OLED and propagating in a thickness direction (i.e., z direction) may travel in the thickness direction. That is, light may travel along path "a" without changing the path. Further, and when considering examples different from the embodiments herein, in a case where there may be no top layer 410 defining the air cavity AC, light emitted from the organic light emitting diode OLED and traveling in an oblique direction (e.g., an oblique direction between the z-direction and the x-direction) immediately and continuously travels in the oblique direction. As a result, the luminance of light emitted from the organic light emitting diode OLED may be reduced. However, according to the embodiment, as described with reference to fig. 3 to 5, for example, since the top layer 410 defining the air cavity AC may also be obliquely disposed on the above-described oblique propagation path of light, total reflection of light may occur on the interface between the air cavity AC and the top layer 410. In other words, since the air cavity AC and one or more portions of the top layer 410 forming the air cavity AC are offset from the emission area EA, the propagation path of light may be changed to travel along the path "B" from the case where light propagates completely obliquely with respect to the z-direction and the x-direction (i.e., when the top layer 410 is not present). As an example, the path "B" may define a path defining portion thereof at least parallel to the z-direction (i.e., the thickness direction of the display device 10). Accordingly, the light emitting efficiency of the organic light emitting diode OLED may be improved, and the luminance of light emitted from the organic light emitting diode OLED may be increased. In other words, when light may be emitted intensively along paths "a" and "B" when compared to examples other than the embodiments herein, a larger amount of light may be emitted and reflected with increased brightness.

Fig. 6A to 6F illustrate schematic sectional views taken along line a-a' of fig. 1 for explaining a process of manufacturing a display apparatus according to an embodiment, and fig. 6G illustrates a plan view of fig. 6A.

Referring to fig. 6A, the pixel circuit PC may be formed on the substrate 100, and an insulating layer 110 covering the pixel circuit PC may be formed on the substrate 100. The pixel electrode 221 may be formed to be electrically connected to the pixel circuit PC through a contact hole of the insulating layer 110. The pixel electrode 221 may be formed through a process that may include forming a material layer constituting the pixel electrode 221 and etching the material layer. As shown in fig. 6A, the pixel electrode 221 may be formed in an island shape to correspond to each pixel.

The pixel defining layer 120 including the opening 120OP may be formed, and the intermediate layer 222 and the counter electrode 223 may be sequentially formed. The emission layer 222b of the intermediate layer 222 may be positioned to correspond to each pixel such that the emission layer 222b may overlap with the pixel electrode 221 or face the pixel electrode 221. The first and second functional layers 222a and 222c and the counter electrode 223 of the intermediate layer 222 may each be formed in one body so as to cover a plurality of pixels.

The thin film encapsulation layer 300 may be formed on the counter electrode 223. The first inorganic encapsulation layer 310 and the second inorganic encapsulation layer 330 of the thin film encapsulation layer 300 may be formed by Chemical Vapor Deposition (CVD). The organic encapsulation layer 320 may be formed by coating and hardening a monomer, or may be formed by coating a polymer. The materials of the organic light emitting diode OLED and the thin film encapsulation layer 300 may be the same as those described above.

The organic structure 60 may be formed by disposing a photosensitive organic material on the thin film encapsulation layer 300 and patterning the photosensitive organic material. The organic structure 60 may include a photosensitive organic material that may react with a specific wavelength band of light (e.g., Ultraviolet (UV) light, etc.). As shown in fig. 6G, the organic structure 60 may completely surround the periphery of the emission area EA so as to surround the emission area EA of the organic light emitting diode OLED. In other words, the organic structure 60 may completely surround the periphery of the opening 120OP of the pixel defining layer 120. The inner width W2' between the portions of the organic structure 60 (the emission area EA is the opening 120OP of the pixel defining layer 120 between the portions of the organic structure 60) may be equal to or greater than the width W1 of the opening 120OP of the pixel defining layer 120.

The organic structure 60 may have inclined side surfaces. The cross-section of the organic structure 60 may have an approximately trapezoidal shape. The inclination angle α of the side surface of the organic structure 60 may be equal to or greater than about 50 °. For example, the inclination angle α may be equal to or greater than about 60 °.

Referring to fig. 6B, an inorganic insulating layer 410A may be formed on the organic structure 60. The inorganic insulating layer 410A may be completely formed over the substrate 100. The inorganic insulating layer 410A may directly contact the top and side surfaces of the organic structure 60 and the top surface of a layer (e.g., the thin film encapsulation layer 300) disposed under the organic structure 60.

The inorganic insulating layer 410A may be formed by CVD. The inorganic insulating layer 410A may include silicon nitride. The inorganic insulating layer 410A may include silicon oxide and/or silicon oxynitride. In an embodiment, the refractive index of the inorganic insulating layer 410A including silicon nitride may be adjusted by adjusting the amount of silicon of the inorganic insulating layer 410A. For example, the inorganic insulating layer 410A may have a refractive index of from about 1.7 to about 1.9.

Referring to fig. 6C and 6D, the top layer 410 may be formed by patterning the inorganic insulating layer 410A. As shown in fig. 6C, a photosensitive organic layer 62 may be formed on the inorganic insulating layer 410A. The photosensitive organic layer 62 may be patterned by using a mask M including a first transmission part M-h1 and a second transmission part M-h 2. The photosensitive organic layer 62 may include holes 62h and openings 62OP, wherein the holes 62h and the openings 62OP may be formed while portions of the photosensitive organic layer 62 corresponding to the first and second transmitting portions M-h1 and M-h2, respectively, are removed.

As shown in fig. 6D, the top layer 410 including the hole 410H and the opening 410OP may be formed by etching the inorganic insulating layer 410A using the photosensitive organic layer 62. The openings 410OP and the holes 410H may correspond to through holes passing through the top and bottom surfaces of the top layer 410.

The width W3 of the opening 410OP of the top layer 410 may be equal to or greater than the width W1 of the opening 120OP of the pixel defining layer 120. The width W4 of aperture 410H may be about 1 μm to about 3 μm.

Referring to fig. 6E, the organic structure 60 may be removed through the hole 410H of the top layer 410. In an embodiment, the organic structure 60 may be removed by a developing process, and the air cavity AC may be formed in a space resulting from the removal of the organic structure 60 through the hole 410H of the top layer 410.

As shown in fig. 6F, a planarization layer 500 may be formed. The planarization layer 500 may include an organic insulating material. In an embodiment, the planarization layer 500 may be formed by coating an organic material having viscosity and then hardening the organic material. Although the holes 410H may be formed in the top layer 410, an organic material including the same material as that of the planarization layer 500 may not be disposed inside the air cavity AC, or a small amount of the organic material may be present inside the air cavity AC as a result of adjusting the viscosity of the organic material constituting the planarization layer 500.

Fig. 7 shows a schematic cross-sectional view of a part of a display apparatus according to an embodiment, and fig. 8 shows an enlarged view of a region VIII of fig. 7.

Referring to fig. 7, the pixel circuit PC may be located on the substrate 100, and the pixel electrode 221 of the organic light emitting diode OLED may be disposed on the insulating layer 110 covering the pixel circuit PC. The organic light emitting diode OLED may include a pixel electrode 221, an intermediate layer 222, and a counter electrode 223, and an edge of the pixel electrode 221 may be covered by the pixel defining layer 120.

The air cavity AC may be between the pixel defining layer 120 and the thin film encapsulation layer 300. For example, the air chamber AC may be located on the counter electrode 223. The top layer 410 defining the air cavity AC may include an upper portion 140a (fig. 8), a lower portion 140b (fig. 8), and a side portion 140c (fig. 8), the upper portion 140a being spaced apart from the top surface of the counter electrode 223 such that the air cavity AC may be between the upper portion 140a of the top layer 410 and the counter electrode 223. The lower portion 140b may be located below the upper portion 140a, and the side portion 140c may connect the upper portion 140a to the lower portion 140 b. The lower portion 140b may contact the top surface of the counter electrode 223.

The lower portion 140b of the top layer 410 may extend in a direction that may be away from the air cavity AC and may contact the top surface of the counter electrode 223. In case that a capping layer may be disposed on the counter electrode 223, the lower portion 140b of the top layer 410 may contact the top surface of the capping layer. The capping layer may include LiF, an inorganic insulating material, and/or an organic insulating material.

The side 140c of the top layer 410 may be inclined with respect to a virtual plane parallel to the main surface 101 of the substrate 100. The side 140c may have an inclination angle α equal to or greater than about 50 °. For example, the inclination angle α may be equal to or greater than about 60 °. The height h of the air cavity AC defined by the top layer 410 may be about 1.5 μm to about 3.5 μm, or about 2 μm to about 3 μm.

The top layer 410 may include an inorganic insulating layer comprising an inorganic material (e.g., silicon nitride, silicon oxide, and/or silicon oxynitride). The top layer 410 may have a refractive index that is greater than the refractive index n (about 1.0) of the air cavity AC. The difference between the refractive index of the air cavity AC and the refractive index of the top layer 410 may be equal to or greater than about 0.7. For example, the top layer 410 may have a refractive index of from about 1.7 to about 1.9. Since light emitted from the organic light emitting diode OLED propagates obliquely with respect to the z-direction and the x-direction, such light may be totally reflected on and through an interface between the air cavity AC and the top layer 410, for example, the side portion 140c (fig. 8) of the top layer 410. As a result, the light emitting efficiency of the organic light emitting diode OLED may be improved, and the luminance of light that may be emitted may be improved.

The thin film encapsulation layer 300 may be located on the top layer 410. The thin film encapsulation layer 300 may include at least one inorganic encapsulation layer and at least one organic encapsulation layer. As shown in fig. 7, in an embodiment, the thin film encapsulation layer 300 may include a first inorganic encapsulation layer 310, an organic encapsulation layer 320, and a second inorganic encapsulation layer 330.

The first inorganic encapsulation layer 310 may be formed on the top layer 410. The first inorganic encapsulation layer 310 may contact the top layer 410. As shown in fig. 8, the first inorganic encapsulation layer 310 may be located on a top surface of the top layer 410 and a side surface 410S of the top layer 410 defining the hole 410H. Since the top layer 410 may include the hole 410H formed in the upper portion thereof, a small amount of the inorganic material 310R may be present inside the air cavity AC, the inorganic material 310R including the same material as that of the first inorganic encapsulation layer 310.

The organic encapsulation layer 320 may include a material, wherein a difference between a refractive index of the material and a refractive index of the air cavity AC may be equal to or greater than about 0.5. For example, the material may be an organic material having a refractive index ranging from about 1.5 to about 1.6. In the case where the difference between the refractive index of the organic encapsulation layer 320 and the refractive index of the air cavity AC satisfies the above range, the propagation path of light emitted from the organic light emitting diode OLED may be changed. For example, by more effectively changing the path of light that can be emitted from the organic light emitting diode OLED and continuously travel in an oblique direction with respect to the above-described z-direction and x-direction to a path that can be at least parallel to the z-direction or thickness direction of the display device 10, the luminance of the display device can be effectively improved.

Although fig. 7 shows that the air cavity AC defined by the top layer 410 may be disposed at two opposite sides of the emission area EA, in a plan view, as described with reference to fig. 4A to 4C, the air cavity AC may be disposed to completely surround the periphery of the emission area EA so as to surround the emission area EA. As described with reference to fig. 4A, one hole 410H of the top layer 410 may be provided to completely surround the emission area EA. As shown in fig. 4B, a plurality of holes 410H each having a slit shape may be disposed along an edge of the emission area EA. As shown in fig. 4C, the plurality of holes 410H may be disposed to completely surround the periphery of the emission area EA so as to surround the emission area EA, and may be spaced apart from each other. The apertures 410H of the top layer 410 may have a width in a range from about 1 μm to about 3 μm.

The top layer 410 may include an opening 410OP corresponding to the emission area EA. The width W3 of the opening 410OP of the top layer 410 may be equal to or greater than the width W1 of the opening 120OP of the pixel defining layer 120, and may be less than the width W2 between portions of the air cavity AC located at two opposite sides of the opening 120OP, between which the opening 120OP of the pixel defining layer 120 is located.

Fig. 9 illustrates a schematic cross-sectional view of a part of a display apparatus according to an embodiment, and fig. 10A to 10C illustrate plan views of a part of a display apparatus according to an embodiment.

Although the top layer 410 described with reference to fig. 7 may include the opening 410OP overlapping with or facing the opening 120OP of the pixel defining layer 120, the top layer 410 may not include the opening 410OP, wherein, as may be shown in fig. 9, the opening 410OP may not be present.

Referring to fig. 9 and 10A to 10C, the top layer 410 may include a hole 410H corresponding to the air cavity AC, and may be continuously formed so as to completely cover the emission area EA. The top layer 410 may comprise silicon nitride, silicon oxide, and/or silicon oxynitride. In other words, the top layer 410 may simultaneously serve as an inorganic encapsulation layer, similar to the first inorganic encapsulation layer 310.

In the case where the top layer 410 may be formed to completely cover the remaining area (e.g., the display area DA including the emission area EA (see fig. 1)) except for the at least one hole 410H, the top layer 410 may serve as an inorganic encapsulation layer similar to the first inorganic encapsulation layer 310. In an embodiment, the first inorganic encapsulation layer 310 shown in fig. 9 may be omitted.

The top layer 410 may include one hole 410H around the periphery of the emission area EA so as to surround the emission area EA (as shown in fig. 10A), holes 410H each having a slit shape and extending along one side of the emission area EA (as shown in fig. 10B), or holes 410H that may be spaced apart from each other along the edge of the emission area EA (as shown in fig. 10C).

Fig. 11 shows a schematic cross-sectional view of a part of a display device according to an embodiment.

Referring to fig. 11, the display device may further include a planarization layer 500 disposed on the thin film encapsulation layer 300. The thin film encapsulation layer 300 may be disposed over the air cavity AC. Since the thin film encapsulation layer 300 may include the organic encapsulation layer 320, the organic encapsulation layer 320 may improve the flatness of the display device 10 while completely covering the elements thereunder. The planarization layer 500 may be further disposed on the thin film encapsulation layer 300, and thus the flatness of the display device 10 may be further improved. The planarization layer 500 may prevent members (e.g., the touch input layer 610 and/or the optical function layer 620) located on the planarization layer 500 from being separated or detached from the display device 10.

The touch input layer 610 may include touch electrodes disposed in the x-direction and the y-direction. The touch input layer 610 may sense an external input by using a mutual capacitance method and/or a self capacitance method. Although fig. 11 shows that the touch input layer 610 may be disposed on the planarization layer 500, in an embodiment, the touch input layer 610 may be disposed between the thin film encapsulation layer 300 and the planarization layer 500.

The optically functional layer 620 may include an anti-reflection layer. The anti-reflective layer may include a retarder and a polarizer. In another embodiment, the anti-reflection layer may include a color filter layer. In another embodiment, the anti-reflective layer may comprise a destructive interference structure. The destructive interference structure may include a first reflective layer and a second reflective layer disposed on different layers. The first and second reflected lights respectively reflected by the first and second reflective layers may destructively interfere with each other, and thus the external light reflectance may be reduced.

The touch input layer 610 and/or the optically functional layer 620 described with reference to fig. 11 may be equally applicable to the embodiments described with reference to fig. 3 and 9 and the embodiments derived therefrom.

Fig. 12A to 12E show schematic cross-sectional views of a part of a display device according to another embodiment.

Referring to fig. 12A, the pixel circuit PC may be formed on the substrate 100, and an insulating layer 110 covering the pixel circuit PC may be formed on the substrate 100. The pixel electrode 221 may be formed to be electrically connected to the pixel circuit PC through a contact hole of the insulating layer 110.

The pixel defining layer 120 may be formed to include the opening 120OP, and the intermediate layer 222 and the counter electrode 223 may be formed. A capping layer may be further formed on the counter electrode 223 to include LiF, an inorganic insulating material, or an organic insulating material. Hereinafter, the capping layer may be omitted for convenience of description.

As described above, the organic light emitting diode OLED including the pixel electrode 221, the intermediate layer 222, and the counter electrode 223 may be formed, and the organic structure 60 may be formed. The organic structure 60 may be formed by disposing a photosensitive organic material layer over the substrate 100 and then patterning the photosensitive organic material layer. The organic structure 60 may include a photosensitive organic material. The organic structure 60 may be formed to completely surround the periphery of the emission area EA so as to surround the emission area EA of the organic light emitting diode OLED, which may be, for example, the opening 120OP of the pixel defining layer 120 as described with reference to fig. 6G.

The organic structure 60 may have inclined side surfaces. The cross-section of the organic structure 60 may have an approximately trapezoidal shape. The inclination angle α of the side surface of the organic structure 60 may be equal to or greater than about 50 °. For example, the inclination angle α may be equal to or greater than about 60 °.

Referring to fig. 12B, an inorganic insulating layer 410A may be formed on the organic structure 60. The inorganic insulating layer 410A may be formed by CVD. The inorganic insulating layer 410A may include silicon nitride, silicon oxide, and/or silicon oxynitride. In an embodiment, the refractive index of the inorganic insulating layer 410A including silicon nitride may be adjusted by adjusting the amount of silicon of the inorganic insulating layer 410A. For example, the inorganic insulating layer 410A may have a refractive index of from about 1.7 to about 1.9.

As shown in fig. 12C, the top layer 410 may be formed by patterning the inorganic insulating layer 410A to include a hole 410H. Similar to the description made with reference to fig. 6C, the process of patterning the inorganic insulating layer 410A may be performed by using a mask and a photosensitive organic layer. The top layer 410 may be continuously formed to cover an area corresponding to the opening 120OP of the pixel defining layer 120. Although fig. 12C illustrates that the top layer 410 may cover the opening 120OP of the pixel defining layer 120, the top layer 410 may include an opening 410OP corresponding to the emission area EA (as described with reference to fig. 6D).

Referring to fig. 12D, an air cavity AC may be formed by removing the organic structure 60 through the hole 410H of the top layer 410.

The first inorganic encapsulation layer 310 may be formed on the top layer 410 in which the hole 410H may be formed. The first inorganic encapsulation layer 310 may be formed by CVD. A small amount of inorganic material 310R may be disposed inside the air cavity AC during the process of forming the first inorganic encapsulation layer 310, the inorganic material 310R including the same material as that of the first inorganic encapsulation layer 310. As shown in the enlarged view of fig. 12D, the first inorganic encapsulation layer 310 may be located on the top surface of the top layer 410 and the side surface 410S of the top layer 410 defining the hole 410H.

Referring to fig. 12E, an organic encapsulation layer 320 and a second inorganic encapsulation layer 330 may be sequentially formed on the first inorganic encapsulation layer 310. The organic encapsulation layer 320 may be formed by coating and hardening a monomer, or by coating a polymer.

Fig. 13 shows a schematic cross-sectional view of a part of a display device according to another embodiment, and fig. 14 shows an enlarged cross-sectional view of the air cavity AC of the display device according to such an embodiment and its surroundings.

Referring to fig. 13, a pixel circuit PC may be disposed on the substrate 100, and a pixel electrode 221 of the organic light emitting diode OLED may be disposed on an insulating layer 110 covering the pixel circuit PC.

The air cavity AC may be disposed in a traveling direction of light emitted from the organic light emitting diode OLED. In an embodiment, the air cavity AC may be between the insulating layer 110 and the thin film encapsulation layer 300. For example, the air cavity AC may be located on the pixel electrode 221. The top layer 410 defining the air cavity AC may include an upper portion, a lower portion, and a side portion, the upper portion being spaced apart from the top surface of the insulating layer 110, so that the air cavity AC may be between the upper portion of the top layer 410 and the insulating layer 110. The lower portion may be located below the upper portion, and the side portion may connect the upper portion to the lower portion. One side of the lower portion of the top layer 410 may contact the top surface of the pixel electrode 221, and the other side of the lower portion of the top layer 410 may contact the top surface of the insulating layer 110.

The top layer 410 may include an opening 410OP overlapping with or facing the pixel electrode 221, and a width W3 of the opening 410OP may be less than a width W5 of the pixel electrode 221. The opening 410OP of the top layer 410 may correspond to the emission area so as to define the emission area EA. The air cavity AC may be defined by the top layer 410 and cover the edge of the pixel electrode 221. The top layer 410 defining the air cavity AC may not only define the emission area EA, but also prevent an arc or the like from occurring between the counter electrode 223 and the edge of the pixel electrode 221 by increasing the distance between the counter electrode 223 and the edge of the pixel electrode 221, as similarly described above.

The side of the top layer 410 may be inclined with respect to a virtual plane parallel to the main surface 101 of the substrate 100. The inclination angle α of the side portion may be equal to or greater than about 50 °. For example, the inclination angle α may be equal to or greater than about 60 °. The height h of the air cavity AC defined by the top layer 410 may be about 1.5 μm to about 3.5 μm, or about 2 μm to about 3 μm.

The top layer 410 may have a refractive index that is greater than the refractive index n (about 1.0) of the air cavity AC. The difference between the refractive index of the air cavity AC and the refractive index of the top layer 410 may be equal to or greater than about 0.5. The difference between the refractive index of the air cavity AC and the refractive index of the top layer 410 may be equal to or greater than about 0.6. The difference between the refractive index of the air cavity AC and the refractive index of the top layer 410 may be equal to or greater than about 0.7.

The top layer 410 may comprise an inorganic material. For example, the top layer 410 may include an inorganic insulating layer such as silicon nitride, silicon oxide, and/or silicon oxynitride. In an embodiment, in the case where the top layer 410 includes silicon nitride, the difference between the refractive index of the air cavity AC and the refractive index of the top layer 410 may be adjusted by adjusting the amount of silicon of the top layer 410. The refractive index of the top layer 410 may be from about 1.7 to about 1.9.

Referring to fig. 13, 15A and 15B, the air cavity AC may be disposed to completely surround the periphery of the emission area EA so as to surround the emission area EA, and the air cavity AC may have a ring shape. The inner width W2 of the air cavity AC having the annular shape may be equal to or greater than the width W1 of the emission area EA. The holes 410H of the top layer 410 may be spaced apart from each other as shown in fig. 15A and 15B. For example, the holes 410H each having a slit shape may be spaced apart from each other along one side of the emission area EA (see fig. 15A), or may be disposed to completely surround the periphery of the emission area EA so as to surround the emission area EA (see fig. 15B).

The middle layer 222 may include an emission layer 222b, and the emission layer 222b may overlap the opening 410OP of the top layer 410 or face the opening 410OP of the top layer 410. The first functional layer 222a may be disposed under the emission layer 222b, and the second functional layer 222c may be disposed on the emission layer 222 b. The first functional layer 222a may include a hole transport layer and/or a hole injection layer, and the second functional layer 222c may include an electron injection layer and/or an electron transport layer.

Like the electrode 223, the first functional layer 222a and/or the second functional layer 222c may be a layer that completely covers the substrate 100. A small amount of a material layer Rm may exist inside the air cavity AC, the material layer Rm including the same material as each of the first functional layer 222a, the second functional layer 222c, and the counter electrode 223 provided on the top layer 410 defining the air cavity AC. For example, as shown in fig. 14, there may be a small amount of material layer (i.e., material residue) Rm disposed inside the air cavity AC, the material layer Rm including a first material layer 222a ', a second material layer 222 c', and a third material layer 223 ', the first material layer 222 a' including the same material as that of the first functional layer 222a, the second material layer 222c 'including the same material as that of the second functional layer 222c, and the third material layer 223' including the same material as that of the counter electrode 223.

The organic light emitting diode OLED may be covered by the thin film encapsulation layer 300, and includes a pixel electrode 221, an intermediate layer 222, and a counter electrode 223. The thin film encapsulation layer 300 may include, for example, a first inorganic encapsulation layer 310, an organic encapsulation layer 320, and a second inorganic encapsulation layer 330. The first inorganic encapsulation layer 310 may be formed on the top layer 410 and on the top surface of the top layer 410 and the side surface 410S of the top layer 410 defining the hole 410H. As shown in fig. 14, a fourth material layer 310 'may be located inside the air cavity AC, the fourth material layer 310' including the same material as that of the first inorganic encapsulation layer 310.

The organic encapsulation layer 320 may include a material, wherein a difference between a refractive index of the material and a refractive index of the air cavity AC may be equal to or greater than about 0.5. For example, the material may be an organic material having a refractive index ranging from about 1.5 to about 1.6. In the case where the difference between the refractive index of the organic encapsulation layer 320 and the refractive index of the air cavity AC satisfies the above range, the propagation path of light emitted from the organic light emitting diode OLED may be changed. For example, by more effectively changing the path of light that may be emitted from the organic light emitting diode OLED and continuously travel obliquely with respect to the z-direction and the x-direction to a path at least parallel to the z-direction or the thickness direction of the display device 10, the luminance of the display device may be effectively improved.

Fig. 16 shows a schematic cross-sectional view of a part of a display device according to another embodiment.

Referring to fig. 16, the display device may further include a planarization layer 500 disposed on the thin film encapsulation layer 300. The thin film encapsulation layer 300 may be disposed on the air cavity AC. In other words, the thin film encapsulation layer 300 may be disposed on the top layer 410 forming the air cavity AC. Since the thin film encapsulation layer 300 may include the organic encapsulation layer 320, the organic encapsulation layer 320 may improve the flatness of the display device 10 by completely covering the elements thereunder. The planarization layer 500 may be further disposed on the thin film encapsulation layer 300, and may further improve the flatness of the display device 10. The planarization layer 500 may prevent members (e.g., the touch input layer 610 and/or the optical function layer 620) located on the planarization layer 500 from being separated or detached from the display device 10.

Fig. 17A to 17F illustrate schematic cross-sectional views of a process of manufacturing a display device according to another embodiment, and fig. 17G illustrates a plan view of fig. 17A.

Referring to fig. 17A, the pixel circuit PC may be formed on the substrate 100, and an insulating layer 110 covering the pixel circuit PC may be formed on the substrate 100. The pixel electrode 221 may be formed to be electrically connected to the pixel circuit PC through a contact hole of the insulating layer 110.

The organic structure 60 may be formed. The organic structure 60 may be formed by forming a photosensitive organic material on the substrate 100 and then patterning the photosensitive organic material. As shown in fig. 17G, the organic structure 60 may completely surround the periphery of the edge of the pixel electrode 221 so as to surround the edge of the pixel electrode 221.

The organic structure 60 may have inclined side surfaces. The cross-section of the organic structure 60 may have an approximately trapezoidal shape. The inclination angle α of the side surface of the organic structure 60 may be equal to or greater than about 50 °. For example, the inclination angle α may be equal to or greater than about 60 °.

Referring to fig. 17B, an inorganic insulating layer 410A may be formed on the organic structure 60. The inorganic insulating layer 410A may be formed by CVD. The inorganic insulating layer 410A may include silicon nitride. The inorganic insulating layer 410A may include silicon oxide or silicon oxynitride. In an embodiment, the refractive index of the inorganic insulating layer 410A including silicon nitride may be adjusted by adjusting the amount of silicon of the inorganic insulating layer 410A. For example, the inorganic insulating layer 410A may have a refractive index of from about 1.7 to about 1.9.

The inorganic insulating layer 410A may be completely formed over the substrate 100. The inorganic insulating layer 410A may directly contact the top surface and the side surfaces of the organic structure 60 and the top surface of the layer including the pixel electrode 221 and the insulating layer 110 disposed under the organic structure 60.

Referring to fig. 17C, a top layer 410 may be formed by patterning the inorganic insulating layer 410A. The top layer 410 may include holes 410H and openings 410 OP. Similar to the description with reference to fig. 6C, the process of patterning the top layer 410 may be performed by using a mask and a photosensitive organic layer. The opening 410OP of the top layer 410 may correspond to the emission area EA (as described with reference to fig. 13). The opening 410OP of the top layer 410 may define an emission area EA.

As shown in fig. 17D, an air cavity AC may be formed in the space in which the organic structure 60 may be disposed by removing the organic structure 60 through the hole 410H of the top layer 410. As described with reference to fig. 17G, since the organic structure 60 may be disposed around the edge of the pixel electrode so as to surround the edge of the pixel electrode 221, the air chamber AC may also surround or surround the edge of the pixel electrode 221. The edge of the pixel electrode 221 may be covered by the top layer 410 and positioned inside the air cavity AC.

Referring to fig. 17E, a first functional layer 222a may be formed on the top layer 410. The emission layer 222b may be formed at a position corresponding to the opening 410OP of the top layer 410. The second functional layer 222c and the counter electrode 223 may be sequentially formed on the emission layer 222 b. The first functional layer 222a, the second functional layer 222c, and the counter electrode 223 may be integrally formed so as to cover at least the display area DA.

The first functional layer 222a, the second functional layer 222c, and the counter electrode 223 may each be formed by thermal evaporation. The materials constituting each of the first functional layer 222a, the second functional layer 222c, and the counter electrode 223 may also be located inside the air cavity AC through the holes 410H of the top layer 410 during the process of forming each of the layers. Fig. 17E shows that the material layer Rm may be provided to include the same material as that of the first functional layer 222a, the second functional layer 222c, and the counter electrode 223.

As shown in fig. 17F, the first inorganic encapsulation layer 310, the organic encapsulation layer 320, and the second inorganic encapsulation layer 330 may be sequentially formed.

The first inorganic encapsulation layer 310 and the second inorganic encapsulation layer 330 may be formed by CVD, and the first inorganic encapsulation layer 310 may be located on the top surface of the top layer 410 and the side surfaces of the top layer 410 defining the hole 410H. During the process of forming the first inorganic encapsulation layer 310, a small amount of deposition material of the first inorganic encapsulation layer 310 may exist inside the air cavity AC, and the deposition material may be disposed through the hole 410H. The specific structure thereof may be the same as that described with reference to fig. 14. No material of the organic encapsulation layer 320 or a small amount of the organic encapsulation layer 320 is disposed inside the air cavity AC through adjustment of the viscosity of the organic material constituting the organic encapsulation layer 320. The organic encapsulation layer 320 may be formed by coating a monomer and then hardening the monomer or coating a polymer.

Fig. 18 shows a schematic cross-sectional view of a display device 10A according to another embodiment.

Referring to fig. 18, the display device 10A may emit one lane of light of a different color for each pixel. For example, the first, second, and third organic light emitting diodes OLED1, OLED2, and OLED3 corresponding to the respective pixels may be disposed over the substrate 100. The first, second and third organic light emitting diodes OLED1, OLED2 and OLED3 may emit light of different colors, for example, red light L_RGreen light L_GAnd blue light L_B. The first organic light emitting diode OLED1 may be located in a red pixel, the second organic light emitting diode OLED2 may be located in a green pixel, and the third organic light emitting diode OLED3 may be located in a blue pixel.

Red light L emitted from the first, second, and third organic light emitting diodes OLED1, OLED2, and OLED3, respectively_RGreen light L_GAnd blue light L_BMay travel in a direction away from the substrate 100, and the obliquely traveling light may be totally reflected on an interface between the air cavity AC and the top layer 410 and may travel approximately in the z direction. For example, the obliquely traveling light may be totally reflected from the side of the top layer 410 forming the air cavity AC.

The emission layer provided to each of the first, second, and third organic light emitting diodes OLED1, OLED2, and OLED3 may include a low molecular weight organic material or a polymer organic material. The emission layer provided to each of the first, second, and third organic light emitting diodes OLED1, OLED2, and OLED3 may include an organic material and/or quantum dots.

Referring to fig. 18, a specific structure of each pixel of the display device 10A may have a structure according to the embodiment described with reference to and/or derived from fig. 3 to 17G.

Fig. 19 shows a schematic cross-sectional view of a display device 10B according to an embodiment.

Referring to fig. 19, the display device 10B may include first, second, and third organic light emitting diodes OLED1, OLED2, and OLED3 corresponding to respective pixels, the first, second, and third organic light emitting diodes OLED1, OLED2, and OLED3 emitting blue light L_B。

Blue light L emitted from the corresponding pixel_BCan be converted into red light L while passing through a color conversion filter and a color filter located on the propagation path of light, respectively_RGreen light L_GAnd blue light L_B。

For example, blue light L emitted from the first organic light emitting diode OLED1_BMay be converted into red light by the first color converter 631, and the color purity of the converted light may be improved and may be emitted to the outside when the converted light passes through the red color filter 641. The first color converter 631 may include quantum dots and scattering particles. The quantum dot may have a core-shell structure including a core and a shell, the core including the nanocrystal, and the shell surrounding the core. Quantum dotsThe core of (a) may include one of a group VI compound, a group III-V compound, a group IV-VI compound, a group IV element, a group IV compound, and combinations thereof.

Blue light L emitted from the second organic light emitting diode OLED2_BMay be converted into green light by the second color converter 632, and the color purity of the converted light may be improved and may be emitted to the outside when the converted light passes through the green color filter 642. The second color converter 632 may include quantum dots and scattering particles. The quantum dot may have a core-shell structure including a core and a shell, the core including the nanocrystal, and the shell surrounding the core. The core of the quantum dot may include one of a group II-VI compound, a group III-V compound, a group IV-VI compound, a group IV element, a group IV compound, and combinations thereof. The size and/or structure of the quantum dots of the second color converter 632 may be different from the size and/or structure of the quantum dots of the first color converter 631.

Blue light L emitted from the third organic light emitting diode OLED3_BMay pass through the transmissive region 633 and the blue color filter 643 and may be immediately emitted to the outside. The transmissive region 633 may comprise, for example, TiO₂The scattering particles of (1).

The light shielding portion 650 may be provided between two elements adjacent to each other among the first color converter 631, the second color converter 632, and the transmissive region 633, and/or between two elements adjacent to each other among the red color filter 641, the green color filter 642, and the blue color filter 643. The light shielding portion 650 may include a black matrix.

Referring to fig. 19, a specific structure of each pixel of the display device 10B may have a structure according to the embodiment described with reference to and/or derived from fig. 3 to 17G.

The display device according to one or more embodiments may improve emission efficiency of light emitted from the display element, improve luminance, and extend a lifetime of the display device.

It is to be understood that the embodiments described herein are to be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should generally be considered as available for other similar features or aspects in other embodiments. Although one or more 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 as defined by the appended claims.