Display device

Abstract

The present application relates to a display device. The display device includes a substrate having a display area and a peripheral area surrounding the display area. A plurality of display elements are arranged above the display area. A spacer is provided between the plurality of display elements and includes a lateral side having a first slope. A thin film encapsulation layer covers the display area and includes a buffer encapsulation layer, an inorganic encapsulation layer, an organic encapsulation layer, and a composite encapsulation layer stacked one on top of the other. The composite encapsulation layer includes a plurality of sublayers stacked one on top of the other. The thickness of each of the plurality of sublayers is less than the thickness of the inorganic encapsulation layer. The upper surface of the buffer encapsulation layer has a second slope, the inclination angle of the second slope being less than the inclination angle of the first slope. The second slope overlaps the first slope in the thickness direction of the substrate.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2019-0108931 filed on September 3, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] One or more embodiments relate to a display device, and more particularly, to a display device including a flexible thin film encapsulation layer. Background Art

[0004] Flat panel display devices having desirable characteristics such as being thin and lightweight and having low power consumption have been developed. There has been considerable research and development in the display industry for flexible display devices.

[0005] A thin and flexible display device may include a thin film encapsulation layer to prevent penetration of external moisture or oxygen. The thin film encapsulation layer may have a structure in which inorganic films and organic films are alternately stacked. Summary of the Invention

[0006] One or more exemplary embodiments include a display device including a flexible thin film encapsulation layer.

[0007] However, the above purpose is for example, and exemplary embodiments of the present inventive concept are not limited thereto.

[0008] 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 exemplary embodiments of the inventive concepts.

[0009] According to one or more exemplary embodiments of the present invention, a display device includes a substrate having a display area and a peripheral area surrounding the display area. A plurality of display elements are arranged above the display area. A spacer is provided between the plurality of display elements and includes a lateral side having a first slope. A thin film encapsulation layer covers the display area and includes a buffer encapsulation layer, an inorganic encapsulation layer, an organic encapsulation layer, and a composite encapsulation layer stacked one on top of the other. The composite encapsulation layer includes a plurality of sublayers stacked one on top of the other. The thickness of each of the plurality of sublayers is less than the thickness of the inorganic encapsulation layer. The upper surface of the buffer encapsulation layer has a second slope, the inclination angle of the second slope being less than the inclination angle of the first slope. The second slope overlaps with the first slope in the thickness direction of the substrate.

[0010] The modulus of the composite encapsulation layer may be less than the modulus of the inorganic encapsulation layer.

[0011] The modulus of the composite encapsulating layer may be about 0.05 to about 0.2 times the modulus of the inorganic encapsulating layer.

[0012] The buffer encapsulation layer may include an organic-inorganic hybrid material.

[0013] The buffer encapsulation layer may include silicon oxide containing carbon.

[0014] The composite encapsulation layer may include 1.5 to 10 doublets. In this regard, one doublet may be a stacked structure of a first sub-layer and a second sub-layer, wherein the second sub-layer includes a different material or a different component ratio than the first sub-layer.

[0015] The display device may further include a cover layer between the plurality of display elements and the thin film encapsulation layer, wherein the cover layer may include a refractive index in a range of about 1.6 to about 3.

[0016] The display device may further include a protective layer between the cover layer and the thin film encapsulation layer, wherein the protective layer may include an inorganic material, wherein a refractive index of the protective layer may be lower than a refractive index of the cover layer.

[0017] The display device may further include an inorganic barrier layer between the plurality of display elements and the buffer encapsulation layer, wherein a thickness of the inorganic barrier layer may be smaller than a thickness of the inorganic encapsulation layer.

[0018] The thickness of the inorganic barrier layer can be about to about within the range.

[0019] According to one or more exemplary embodiments of the present invention, a display device includes a substrate including a display area and a peripheral area surrounding the display area. A plurality of display elements are arranged above the display area. Spacers are provided between the plurality of display elements. A cover layer is arranged above the plurality of display elements and the spacers. A thin film encapsulation layer is arranged above the cover layer and covers the display area. The thin film encapsulation layer includes a buffer encapsulation layer, an inorganic encapsulation layer, an organic encapsulation layer, and a composite encapsulation layer stacked one on top of the other. The composite encapsulation layer includes a plurality of sublayers stacked one on top of the other. The thickness of each sublayer is less than the thickness of the inorganic encapsulation layer. The upper surface of the buffer encapsulation layer is flat.

[0020] The display device may further include a protective layer between the cover layer and the buffer encapsulation layer, wherein the protective layer may include an inorganic material, and wherein a refractive index of the protective layer may be lower than a refractive index of the cover layer.

[0021] The protective layer may include lithium fluoride (LiF).

[0022] The display device may further include an inorganic barrier layer between the cover layer and the buffer encapsulation layer, wherein a thickness of the inorganic barrier layer may be smaller than a thickness of the inorganic encapsulation layer.

[0023] The thickness of the inorganic barrier layer can be about to about

[0024] The modulus of the composite encapsulation layer may be less than the modulus of the inorganic encapsulation layer.

[0025] The modulus of the composite encapsulating layer may be about 0.05 to about 0.2 times the modulus of the inorganic encapsulating layer.

[0026] The buffer encapsulation layer may include an organic material.

[0027] The composite encapsulation layer may include 1.5 to 10 doublets. In this regard, one doublet may be a stacked structure of a first sub-layer and a second sub-layer, wherein the second sub-layer includes a different material or a different component ratio than the first sub-layer.

[0028] According to one or more exemplary embodiments of the present inventive concepts, a display device includes a substrate having a display area and a peripheral area surrounding the display area. A plurality of display elements are arranged above the display area. A thin film encapsulation layer covers the display area. The thin film encapsulation layer includes an inorganic encapsulation layer, an organic encapsulation layer, and a composite encapsulation layer stacked one on top of the other. The composite encapsulation layer includes a plurality of sublayers stacked one on top of the other, and the thickness of the composite encapsulation layer is less than that of the inorganic encapsulation layer.

[0029] The thin film encapsulation layer may further include a buffer encapsulation layer between the plurality of display elements and the inorganic encapsulation layer, wherein the buffer encapsulation layer may include an organic material or an organic-inorganic hybrid material.

[0030] The buffer encapsulation layer may include SiO x C y H z (x>0, y>0, z≥0).

[0031] The display device may further include a cover layer between the plurality of display elements and the thin film encapsulation layer, wherein the cover layer may include a refractive index in a range of about 1.6 to about 3.

[0032] The display device may further include a protective layer between the cover layer and the thin film encapsulation layer, wherein the protective layer may include an inorganic material, wherein a refractive index of the protective layer may be lower than a refractive index of the cover layer.

[0033] The plurality of sub-layers may include first sub-layers and second sub-layers alternately stacked on each other, wherein the first sub-layers may include an inorganic film and the second sub-layers may include an organic-inorganic hybrid material.

[0034] According to one or more exemplary embodiments of the present invention, a flexible display device includes a flexible substrate including a display area and a peripheral area surrounding the display area. A plurality of display elements are arranged above the display area. A spacer is disposed between the plurality of display elements. The spacer includes a lateral side having a first slope. A thin film encapsulation layer covers the display area. The thin film encapsulation layer includes a buffer encapsulation layer disposed above the display area and an inorganic encapsulation layer disposed above the buffer encapsulation layer. The buffer encapsulation layer includes an organic material or an organic-inorganic hybrid material. The upper surface of the buffer encapsulation layer has a second slope, the second slope having a smaller inclination angle than the first slope. The second slope overlaps the first slope in the thickness direction of the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and other aspects, features and advantages of certain exemplary embodiments of the present inventive concept will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0036] Figure 1A is a top plan view of a display device according to an exemplary embodiment of the present inventive concept;

[0037] Figure 1B is a perspective view of a substrate of a flexible display device in a bent configuration according to an exemplary embodiment of the present inventive concept;

[0038] Figure 2 is an exemplary embodiment according to the present invention. Figure 1A A cross-sectional view of the display device taken along line II';

[0039] Figure 3 According to an exemplary embodiment of the present invention Figure 2 an enlarged cross-sectional view of region III;

[0040] Figure 4A is a cross-sectional view of a composite encapsulation layer according to an exemplary embodiment of the present inventive concept;

[0041] Figure 4B is a cross-sectional view of another composite encapsulation layer according to an exemplary embodiment of the present inventive concept;

[0042] Figure 5 According to an exemplary embodiment of the present invention Figure 2 an enlarged cross-sectional view of a region V;

[0043] Figure 6 According to other exemplary embodiments of the present invention Figure 1A A cross-sectional view of the display device taken along line II';

[0044] Figure 7According to other exemplary embodiments of the present invention Figure 1A A cross-sectional view of the display device taken along line II';

[0045] Figure 8 According to other exemplary embodiments of the present invention Figure 1A A cross-sectional view of the display device taken along line II'; and

[0046] Figure 9 According to other exemplary embodiments of the present invention Figure 1A 1-1' is a cross-sectional view of the display device taken along line II'. DETAILED DESCRIPTION

[0047] Reference will now be made in detail to exemplary embodiments of the present invention, examples of which are shown in the accompanying drawings, in which like reference numerals refer to like elements throughout. In this regard, the exemplary embodiments may have different forms and should not be construed as being limited to the description set forth herein. Accordingly, only exemplary embodiments are described below with reference to the accompanying drawings to explain various aspects of the description. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Throughout this disclosure, the expression "at least one of a, b, and c" indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0048] Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like elements throughout and repeated descriptions thereof will be omitted.

[0049] Although terms such as "first" and "second" may be used to describe various components, these components are not necessarily limited to the above terms. The above terms are only used to distinguish one component from another component.

[0050] As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0051] It will be understood that the terms “comprising” and “having” as used herein specify the presence of stated features or components, but do not preclude the presence or addition of one or more other features or components.

[0052] It will also be understood that when a layer, region, or component is referred to as being "on" another layer, region, or component, the layer, region, or component can be directly or indirectly on the other layer, region, or component. That is, for example, intervening layers, regions, or components may be present. However, when a layer, region, or component is referred to as being "directly on" another layer, region, or component, there may not be any intervening layers, regions, or components.

[0053] For the convenience of explanation, the sizes of components in the drawings may be exaggerated or reduced. For example, for the convenience of explanation, since the sizes and thicknesses of components in the drawings are arbitrarily shown, the exemplary embodiments of the present inventive concept are not limited thereto.

[0054] When the exemplary embodiments can be implemented in different ways, a specific process sequence may be performed in a different order than described. For example, two consecutively described processes may be performed substantially simultaneously or in a reverse order than described.

[0055] When a layer, region, or component is “connected,” the layer, region, or component may not only be “directly connected” but also be “indirectly connected” via other layers, regions, or components. For example, in this description, when a layer, region, or component is electrically connected, the layer, region, or component may not only be directly electrically connected but also be indirectly electrically connected via other layers, regions, or components.

[0056] Figure 1A is a top plan view of a display device according to an exemplary embodiment of the inventive concept. Figure 1B is a perspective view of a substrate 110 of a flexible display device in a bent configuration according to an exemplary embodiment of the inventive concept.

[0057] Reference Figure 1A The substrate 110 can be divided into a display area DA that displays an image and a peripheral area PA arranged around the display area DA (for example, surrounding the display area DA in the X direction and / or the Y direction, which are directions parallel to the upper surface of the substrate 110 and intersecting each other).

[0058] In an exemplary embodiment, the substrate 110 may include various materials, such as glass, metal, or plastic. According to an exemplary embodiment of the present inventive concept, the substrate 110 may include a flexible material. In this regard, a flexible material refers to a substrate that is bendable and may be foldable or rollable. In an exemplary embodiment, the substrate 110 including the flexible material may include ultra-thin glass, metal, or plastic.

[0059] like Figure 1B As shown in the exemplary embodiment of FIG, a portion of the substrate 110 can be bent to have a curvature. In an embodiment, the bendable portion of the substrate 110 may include the display area DA. In other embodiments, the bendable portion of the substrate 110 may be arranged in the peripheral area PA. In other exemplary embodiments, the bendable portion of the substrate 110 may be arranged in both the display area DA and the peripheral area PA. Furthermore, the substrate 110 can be rolled or folded and unfolded.

[0060] Pixels PX including various display elements such as organic light-emitting diodes (OLEDs) may be arranged in the display area DA of the substrate 110. Each pixel PX may emit, for example, red, green, blue, or white light via the organic light-emitting diode OLED. The pixels PX described herein may be understood as pixels that emit one of red, green, blue, and white light, as described above. The emission areas of the plurality of pixels PX may be arranged in various forms, such as stripes, pen tiles, or mosaics, to display an image.

[0061] The pixel PX may further include a plurality of thin film transistors, for example, a first thin film transistor TFT1 and a second thin film transistor TFT2 (see FIG. Figure 2 ) for controlling the display element and the storage capacitor Cst. However, the number of thin film transistors, such as the first thin film transistor TFT1 and the second thin film transistor TFT2, included in one pixel PX may be variously modified. For example, in an exemplary embodiment of the present inventive concept, the number of thin film transistors may be between 2 and 7. However, exemplary embodiments of the present inventive concept are not limited thereto.

[0062] like Figure 1A As shown in the exemplary embodiment of FIG, the display area DA may have a rectangular shape (e.g., extending in the X and Y directions). However, exemplary embodiments of the present inventive concept are not limited thereto. For example, in other exemplary embodiments, the display area DA may have a polygonal shape, such as a triangle, a pentagon, a hexagon, or the like, or a circular shape, an elliptical shape, an irregular shape, or the like.

[0063] The peripheral area PA of the substrate 110, which is an area arranged around the display area DA (e.g., surrounding the display area DA), may be an area where no image is displayed. Various wires for transmitting electrical signals to be applied to the display area DA, embedded circuit parts for generating some signals, and pads for attaching a printed circuit board or a driver integrated circuit (IC) chip may be located in the peripheral area PA. Figure 1A In the exemplary embodiment, the peripheral area PA is disposed around the four sides of the rectangular display area DA. However, exemplary embodiments of the present inventive concept are not limited thereto. In other exemplary embodiments, the display area DA may extend to at least one edge of the substrate 110 and the peripheral area PA may not surround at least one side of the display area DA.

[0064] The thin film encapsulation layer 300 may be arranged to cover the display area DA of the substrate 110. The thin film encapsulation layer 300 may cover the display area DA and a portion of the peripheral area PA. The thin film encapsulation layer 300 is a component for protecting the display element in the display area DA. The thin film encapsulation layer 300 can prevent external contaminants such as moisture from penetrating into the display element or the pixel circuit used to drive the display element.

[0065] When the substrate 110 has Figure 1B When the thin film encapsulation layer 300 is bent in the bent configuration shown in FIG, the thin film encapsulation layer 300 disposed thereon may also be bent according to the shape of the substrate 110. When the thin film encapsulation layer 300 is bent, stress is concentrated on the thin film encapsulation layer 300.

[0066] Although, for the sake of convenience of explanation, an organic light-emitting display is described below as an example of a display element of a display device, exemplary embodiments of the present inventive concept are not limited thereto. For example, in other exemplary embodiments, the display device may include various other display elements, such as an inorganic light-emitting display, a quantum dot light-emitting display, a liquid crystal display, and the like.

[0067] In the following, reference will be made to Figures 2 to 5 Components included in a display device according to one or more exemplary embodiments are described in detail.

[0068] Figure 2 is an exemplary embodiment according to the present invention. Figure 1A 1-1' is a cross-sectional view of the display device taken along line II'. Figure 3 yes Figure 2 1 is an enlarged cross-sectional view of a region III of FIG. 1 and illustrates a portion of a composite encapsulation layer 340 according to an exemplary embodiment of the present inventive concept. Figure 4A is an enlarged cross-sectional view of an example of a composite encapsulation layer 340 applicable to exemplary embodiments of the present inventive concepts. Figure 4B is an enlarged cross-sectional view of an example of a composite encapsulation layer 340 applicable to exemplary embodiments of the present inventive concepts. Figure 5 yes Figure 2 FIG. 3 is an enlarged view of a region V of FIG. 3 and illustrates the relationship between the spacer SPC and the buffer encapsulation layer 310 .

[0069] Reference Figure 2 , a display device according to an exemplary embodiment of the present inventive concept includes a substrate 110, an organic light emitting diode OLED disposed on the substrate 110 and serving as a display element, a spacer SPC, and a thin film encapsulation layer 300. In an exemplary embodiment, the thin film encapsulation layer 300 may include a buffer encapsulation layer 310, an inorganic encapsulation layer 320, an organic encapsulation layer 330, and a composite encapsulation layer 340.

[0070] The substrate 110 may include various materials such as glass, metal, or plastic. According to an exemplary embodiment of the present inventive concept, the substrate 110 may be a flexible substrate and may include, for example, a polymer resin such as at least one compound selected from polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, and cellulose acetate propionate. However, exemplary embodiments of the present inventive concept are not limited thereto.

[0071] The buffer layer 111 may be located on the substrate 110, and thus, may reduce or prevent penetration of foreign matter, moisture, or external air from the bottom of the substrate 110, and may provide a flat surface on the substrate 110. In exemplary embodiments, the buffer layer 111 may include an inorganic material such as oxide or nitride, an organic material, or an organic-inorganic composite material, and may have a multilayer structure or a single layer structure including an inorganic material and an organic material. Figure 2 As shown in the exemplary embodiment of FIG, the buffer layer 111 may be directly disposed on the substrate 110 (e.g., in the Z direction, which is the thickness direction of the substrate 110 and is perpendicular to the X and Y directions). However, exemplary embodiments of the present inventive concept are not limited thereto. For example, in other exemplary embodiments, a barrier layer for preventing external air from penetrating may also be disposed between the substrate 110 and the buffer layer 111 (e.g., in the Z direction).

[0072] The first thin film transistor TFT1 may include a first semiconductor layer A1, a first gate electrode G1, a first source electrode S1, and a first drain electrode D1, and the second thin film transistor TFT2 may include a second semiconductor layer A2, a second gate electrode G2, a second source electrode S2, and a second drain electrode D2. In an exemplary embodiment, the first thin film transistor TFT1 may be connected to the organic light emitting diode OLED to function as a driving thin film transistor for driving the organic light emitting diode OLED. The second thin film transistor TFT2 may be connected to the data line DL to function as a switching thin film transistor. Although Figure 2 The exemplary embodiment includes two thin film transistors, but exemplary embodiments of the present inventive concept are not limited thereto.

[0073] In an exemplary embodiment, the first semiconductor layer A1 and the second semiconductor layer A2 may each include amorphous silicon or polycrystalline silicon. In other exemplary embodiments, the first semiconductor layer A1 and the second semiconductor layer A2 may each include an oxide of at least one material selected from the group consisting of indium (In), gallium (Ga), tin (Sn), zirconium (Zr), vanadium (V), hafnium (Hf), cadmium (Cd), germanium (Ge), chromium (Cr), titanium (Ti), and zinc (Zn). The first semiconductor layer A1 and the second semiconductor layer A2 may each include a channel region and a source region and a drain region doped with impurities. The channel region, source region, and drain region of each of the first semiconductor layer A1 and the second semiconductor layer A2 may be arranged in the X direction.

[0074] The first gate electrode G1 and the second gate electrode G2 may be disposed on the first semiconductor layer A1 and the second semiconductor layer A2, respectively, with the first gate insulating layer 112 interposed therebetween (e.g., in the Z direction). In an exemplary embodiment, the first gate electrode G1 and the second gate electrode G2 may each include at least one material selected from molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and may each have a single-layer structure or a multi-layer structure. For example, the first gate electrode G1 and the second gate electrode G2 may each include a single Mo layer.

[0075] In an exemplary embodiment, the first gate insulating layer 112 may include a layer selected from silicon oxide (SiO 2 ), silicon nitride (SiN x ), silicon oxynitride (SiON), aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), and zinc oxide (ZnO2). However, exemplary embodiments of the present inventive concept are not limited thereto.

[0076] The second gate insulating layer 113 may be provided to cover the first gate electrode G1 and the second gate electrode G2. Figure 2 As shown in the exemplary embodiment of the present invention, the second gate insulating layer 113 may be directly disposed on the first gate insulating layer 112, the first gate electrode G1, and the second gate electrode G2 (for example, in the Z direction). In the exemplary embodiment, the second gate insulating layer 113 may include a material selected from (SiO2), silicon nitride (SiN x ), silicon oxynitride (SiON), aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2) and zinc oxide (ZnO2) or at least one compound thereof.

[0077] The first electrode CE1 of the storage capacitor Cst may overlap with the first thin film transistor TFT1 (eg, in the Z direction). Figure 2As shown in the exemplary embodiment of FIG, the first gate electrode G1 of the first thin film transistor TFT1 may serve as the first electrode CE1 of the storage capacitor Cst. However, exemplary embodiments of the present inventive concept are not limited thereto.

[0078] like Figure 2 As shown in the exemplary embodiment of FIG, the second electrode CE2 of the storage capacitor Cst overlaps the first electrode CE1, with the second gate insulating layer 113 interposed therebetween (e.g., in the Z direction). In this embodiment, the second gate insulating layer 113 may serve as a dielectric layer for the storage capacitor Cst. In the exemplary embodiment, the second electrode CE2 may include a conductive material including at least one material selected from molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and may have a single-layer structure or a multi-layer structure including the above materials. For example, the second electrode CE2 may include a single Mo layer or have a multi-layer structure of Mo / Al / Mo.

[0079] The first source electrode S1 and the first drain electrode D1 and the second source electrode S2 and the second drain electrode D2 may be disposed on the interlayer insulating layer 115. For example, Figure 2 As shown in the exemplary embodiment of FIG, the interlayer insulating layer 115 may be directly disposed on the second gate insulating layer 113 (e.g., in the Z direction) and the first source electrode S1 and the first drain electrode D1 may be directly disposed on the interlayer insulating layer 115 (e.g., in the Z direction). The first source electrode S1 and the first drain electrode D1, as well as the second source electrode S2 and the second drain electrode D2, may be spaced apart from each other in the X direction. However, exemplary embodiments of the present inventive concept are not limited thereto. The first source electrode S1 and the first drain electrode D1, as well as the second source electrode S2 and the second drain electrode D2 may each include a conductive material including at least one material selected from molybdenum (Mo), aluminum (Al), copper (Cu), titanium (Ti), etc., and may each have a single-layer structure or a multilayer structure including the above materials. For example, the first source electrode S1 and the first drain electrode D1, as well as the second source electrode S2 and the second drain electrode D2 may each have a multilayer structure of Ti / Al / Ti.

[0080] The planarization layer 118 may be located on the first source electrode S1 and the first drain electrode D1 and the second source electrode S2 and the second drain electrode D2, and the organic light emitting diode OLED may be located on the planarization layer 118. For example, Figure 2 As shown in the exemplary embodiment of , the planarization layer 118 may be directly disposed on the first source electrode S1 and the first drain electrode D1 and the second source electrode S2 and the second drain electrode D2 (e.g., in the Z direction), and the organic light emitting diode OLED may be directly disposed on the planarization layer 118 (e.g., in the Z direction).

[0081] The planarization layer 118 may have a flat upper surface (e.g., extending substantially in the X direction) so that the pixel electrode 210 disposed thereon may be flat. The planarization layer 118 may have a single-layer structure or a multi-layer structure including a film, and the film includes an organic material. In an exemplary embodiment, the planarization layer 118 may include a general polymer selected from at least one compound of benzocyclobutene (BCB), polyimide, polymethyl methacrylate (PMMA), or polystyrene (PS), a polymer derivative having a phenol group, an acrylic polymer, an imide-based polymer, an aromatic ether-based polymer, an amide-based polymer, a fluorine-based polymer, a paraxylene-based polymer, a vinyl alcohol-based polymer, and a mixture thereof.

[0082] The organic light emitting diode OLED is arranged on the planarization layer 118 (for example, in the Z direction). For example, the bottom surface of the organic light emitting diode OLED may directly contact the top surface of the planarization layer 118. The organic light emitting diode OLED includes a pixel electrode 210, an intermediate layer 220 including an organic emission layer, and an opposite electrode 230. For example, Figure 2 As shown in the exemplary embodiment of , the intermediate layer 220 may be directly disposed on the pixel electrode (eg, in the Z direction) and the opposing electrode 230 may be directly disposed on the intermediate layer 220 (eg, in the Z direction).

[0083] The planarization layer 118 may include a via hole exposing one of the first source electrode S1 and the first drain electrode D1 of the first thin film transistor TFT1, and the pixel electrode 210 may contact the first source electrode S1 or the first drain electrode D1 through the via hole and thus may be electrically connected to the first thin film transistor TFT1.

[0084] The pixel electrode 210 may include a light-transmitting electrode or a reflective electrode. In an exemplary embodiment, the pixel electrode 210 may include a reflective film and a transparent or translucent electrode layer on the reflective film, wherein the reflective film includes silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), or a compound thereof. The transparent or translucent electrode layer may include at least one compound selected from the group consisting of the following materials: indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide (In2O3), indium gallium oxide (IGO), and aluminum zinc oxide (AZO).

[0085] The pixel definition film 119 may be disposed on the planarization layer 118. For example, Figure 2 As shown in the exemplary embodiment of , the pixel defining film 119 may be directly disposed on the planarization layer 118 and on the lateral edges of the pixel electrode 210 (e.g., in the Z direction). The pixel defining film 119 may have an opening 119OP corresponding to each pixel. The opening 119OP exposes at least a central portion of the pixel electrode 210 and may thus define the emission area of ​​the pixel. The pixel defining film 119 may prevent arcing on the edge of the pixel electrode 210 by increasing the distance between the edge of the pixel electrode 210 and the opposing electrode 230 disposed on the pixel electrode 210. In an exemplary embodiment, the pixel defining film 119 may be formed by a method such as spin coating using one or more organic insulating materials selected from a group including the following materials: polyimide, polyamide, acrylic resin, BCB, and phenolic resin.

[0086] The spacer SPC may be disposed on the pixel definition film 119. For example, Figure 2 As shown in the exemplary embodiment of , the spacer SPC may be directly disposed on the pixel defining film 119 (e.g., in the Z direction). The spacer SPC may be arranged between a plurality of display elements (e.g., in the X direction, between the organic light emitting diodes OLED formed by the pixel electrode 210, the intermediate layer 220, and the relative electrode 230) and may protrude in a direction away from the substrate 110 (e.g., in the Z direction). In an exemplary embodiment, the spacer SPC may be a component for preventing imprints during a mask process. In other exemplary embodiments, the spacer SPC may change the optical path. In an exemplary embodiment, the spacer SPC may be formed by a method such as spin coating using one or more organic insulating materials selected from a cluster including the following materials: polyimide, polyamide, acrylic resin, BCB, and phenolic resin. In some exemplary embodiments, the spacer SPC may include the same material as the pixel defining film 119 and may be formed simultaneously with the pixel defining film 119 by a process utilizing a halftone mask.

[0087] The intermediate layer 220 of the organic light-emitting diode (OLED) may include an organic emission layer. In an exemplary embodiment, the organic emission layer may include an organic material including a fluorescent material or a phosphorescent material that emits red, green, blue, or white light. In an exemplary embodiment, the organic emission layer may include a low molecular weight organic material or a polymer organic material, and functional layers such as a hole transport layer (HTL), a hole injection layer (HIL), an electron transport layer (ETL), and an electron injection layer (EIL) may also be selectively arranged above or below the organic emission layer. In some exemplary embodiments, the intermediate layer 220 may correspond to each of the plurality of pixel electrodes 210. In other exemplary embodiments, the intermediate layer 220 may include an integral layer above the plurality of pixel electrodes 210. For example, the organic emission layer may correspond to each of the plurality of pixel electrodes 210, and the functional layers disposed above and / or below the organic emission layer may be integrally provided in the plurality of pixels. In other exemplary embodiments, the intermediate layer 220 may be integrally provided above the plurality of pixel electrodes 210.

[0088] The opposing electrode 230 may include a light-transmitting electrode or a reflective electrode. In some exemplary embodiments, the opposing electrode 230 may include a transparent or translucent electrode and may include a metal film having a low work function and including Li, Ca, LiF / Ca, LiF / Al, Al, Ag, Mg, or a compound thereof. Furthermore, a transparent conductive oxide (TCO) film such as ITO, IZO, ZnO, or In2O3 may also be disposed on the metal film. In an exemplary embodiment, the opposing electrode 230 may extend across multiple pixels (e.g., in the X direction) and may be integrally formed in multiple organic light-emitting diodes (OLEDs) to correspond to multiple pixel electrodes 210.

[0089] In an exemplary embodiment, the cover layer 123 may be disposed on the opposite electrode 230. For example, Figure 2As shown in the exemplary embodiment of FIG, the capping layer 123 may be disposed directly on the opposing electrode 230 (e.g., in the Z direction). The capping layer 123 may be disposed on the opposing electrode 230 and may thereby protect the organic light emitting diode OLED. The capping layer 123 may also help provide efficient emission of light generated by the organic light emitting diode OLED. For example, the capping layer 123 may include an organic material such as a-NPD, NPB, TPD, m-MTDATA, Alq3, or CuPc. In an exemplary embodiment, the refractive index of the capping layer 123 may be in the range of about 1.6 to about 3.0.

[0090] The thin film encapsulation layer 300 may be disposed on the cover layer 123 to seal the plurality of organic light emitting diodes OLED. Figure 2 As shown in the exemplary embodiment of FIG, the bottom surface of the thin film encapsulation layer 300 may be directly disposed on the top surface of the cover layer 123. Figure 2 As shown in the exemplary embodiment of FIG, the thin film encapsulation layer 300 may include a buffer encapsulation layer 310, an inorganic encapsulation layer 320, an organic encapsulation layer 330, and a composite encapsulation layer 340 sequentially stacked on one another (eg, in the Z direction).

[0091] The composite encapsulation layer 340 may include multiple groups of multiple sub-layers 340a and 340b stacked on each other (e.g., in the Z direction). The thickness of each of the multiple groups of multiple sub-layers 340a and 340b of the composite encapsulation layer 340 (e.g., the length in the Z direction) is less than the thickness T1 of the inorganic encapsulation layer 320. For example, in an exemplary embodiment, the total thickness T2 of the composite encapsulation layer 340 may be less than the thickness T1 of the inorganic encapsulation layer 320. The respective thicknesses of the multiple sub-layers 340a and 340b included in the composite encapsulation layer 340 may be very small and the composite encapsulation layer 340 may be densely formed. Therefore, although the composite encapsulation layer 340 includes multiple groups of multiple sub-layers 340a and 340b, the total thickness T2 of the composite encapsulation layer 340 may be less than the total thickness T1 of the single-layer inorganic encapsulation layer 320.

[0092] The inorganic encapsulation layer 320 may be introduced to prevent the occurrence of cracks, such as in instances where the shape of the thin film encapsulation layer 300 changes as the user bends the substrate 110 and is bent. In an exemplary embodiment, the modulus (e.g., bending modulus) of the composite encapsulation layer 340 may be less than the modulus of the inorganic encapsulation layer 320. For example, in an exemplary embodiment, the modulus of the composite encapsulation layer 340 may be equivalent to about 0.05 times to about 0.2 times the modulus of the inorganic encapsulation layer 320 (e.g., in the range of about 5% to about 20%). In an exemplary embodiment, the modulus of the composite encapsulation layer 340 may be in the range of about 6 GPa to about 10 GPa. The modulus of the inorganic encapsulation layer 320 may be in the range of about 60 GPa to about 100 GPa.

[0093] When the display area DA of the display device has a curved surface, the uppermost layer of the thin film encapsulation layer 300 may be subjected to greater stress than other layers and may therefore crack. In this exemplary embodiment, a composite encapsulation layer 340 having a small modulus may be introduced into the uppermost layer of the thin film encapsulation layer 300 to prevent or reduce the occurrence of cracks in the uppermost layer of the thin film encapsulation layer 300. The composite encapsulation layer 340 will be described in more detail below.

[0094] Since the inorganic encapsulation layer 320 is closer to the substrate 110 (e.g., in the Z direction) than the composite encapsulation layer 340, the stress caused by the curvature (e.g., bending) of the display device may have a relatively small effect on the inorganic encapsulation layer 320. However, the inorganic encapsulation layer 320 is formed according to the shape of the element arranged below the inorganic encapsulation layer 320 (e.g., in the Z direction). Therefore, the inorganic encapsulation layer 320 may be affected by the stress caused by the step-forming component (e.g., the spacer SPC located below the inorganic encapsulation layer 320 (e.g., in the Z direction)).

[0095] In an exemplary embodiment of the present inventive concept, the buffer encapsulation layer 310 is introduced to prevent such stress from being concentrated on the inorganic encapsulation layer 320 .

[0096] The buffer encapsulation layer 310 may be disposed between the organic light emitting diode OLED, which is a display element, and the inorganic encapsulation layer 320 (eg, in the Z direction). Figure 2 As shown in the exemplary embodiment of FIG, the bottom surface of the buffer encapsulation layer 310 directly contacts the top surface of the capping layer 123 and the top surface of the buffer encapsulation layer 310 directly contacts the bottom surface of the inorganic encapsulation layer 320. The buffer encapsulation layer 310 reduces the step formed by the step portion such as the spacer SPC. For example, as the area of ​​the spacer SPC is enlarged Figure 5 As shown in the exemplary embodiment of FIG, a portion of the upper surface of the buffer encapsulation layer 310 may have a slope with an inclination angle θ2 (e.g., with respect to the X direction), and the inclination angle θ2 may be more gentle (e.g., smaller) than the inclination angle θ1 of the lateral side of the spacer SPC (e.g., with respect to the X direction). The portion of the upper surface of the buffer encapsulation layer 310 having the more gentle slope with the inclination angle θ2 may overlap with the lateral side of the spacer SPC having the inclination angle θ1 (e.g., in the Z direction).

[0097] Since the buffer encapsulation layer 310 can be formed to reduce the step formed by the spacer SPC, the buffer encapsulation layer 310 can have a first height h1 (e.g., length in the Z direction) corresponding to the center of the spacer SPC and a second height h2 corresponding to the periphery of the spacer SPC that is smaller than the first height h1.

[0098] In an exemplary embodiment, the buffer encapsulation layer 310 may include an organic-inorganic hybrid material. For example, the buffer encapsulation layer 310 may include silicon oxide containing carbon or silicon oxide containing carbon and hydrogen. In an exemplary embodiment, the buffer encapsulation layer 310 may include silicon oxide containing SiO x C y H z wherein x>0, y>0, and z≥0. As the component ratio of x increases, the buffer encapsulation layer 310 may have properties similar to those of an inorganic film, and as the component ratio of y increases, the buffer encapsulation layer 310 may have properties similar to those of an organic film.

[0099] In exemplary embodiments of the present inventive concept, the component ratio of y can be increased to allow the buffer encapsulation layer 310 to have properties similar to those of an organic film. Therefore, the buffer encapsulation layer 310 can have flowable and flexible properties and, therefore, can have a slope that is gentler (e.g., smaller) than that of the spacer SPC. The organic-inorganic hybrid material of the buffer encapsulation layer 310 has lower permeability to gases to be removed or moisture than organic materials such as monomers. Therefore, changes in the characteristics of the organic light-emitting diode OLED caused by the buffer encapsulation layer 310 can be reduced.

[0100] In an exemplary embodiment, the buffer encapsulation layer 310 may include silicon in a range of about 20 atomic percent to about 50 atomic percent, oxygen in a range of about 10 atomic percent to about 40 atomic percent, and carbon in a range of about 30 atomic percent to about 60 atomic percent, based on the total number of atoms of silicon, oxygen, and carbon. In other exemplary embodiments, the buffer encapsulation layer 310 may include silicon in a range of about 30 atomic percent to about 40 atomic percent, oxygen in a range of about 18 atomic percent to about 28 atomic percent, and carbon in a range of about 40 atomic percent to about 50 atomic percent. In other exemplary embodiments, the buffer encapsulation layer 310 may include silicon in a range of about 33 atomic percent to about 36 atomic percent, oxygen in a range of about 20 atomic percent to about 23 atomic percent, and carbon in a range of about 42 atomic percent to about 45 atomic percent. In this regard, the ratio of oxygen to silicon (O / Si) may be equal to or greater than 0.4 and less than or equal to 1.

[0101] In an exemplary embodiment, the buffer encapsulation layer 310 may be formed by plasma enhanced chemical vapor deposition (PECVD). For example, the source gas may be hexamethyldisiloxane, and the reaction gas may be N2O. For example, when hexamethyldisiloxane is used as the source gas and N2O with a low flow rate at low power, hexamethyldisiloxane may be formed into SiO2 having the properties of an organic film.x C y H z .

[0102] The inorganic encapsulation layer 320 is disposed on the buffer encapsulation layer 310. For example, Figure 2 As shown in the exemplary embodiment of the present invention, the bottom surface of the inorganic encapsulation layer 320 may directly contact the top surface of the buffer encapsulation layer 310. In the exemplary embodiment, the inorganic encapsulation layer 320 may include a material selected from ceramics, metal oxides, metal nitrides, metal carbides, metal oxynitrides, indium oxide (In2O3), tin oxide (SnO2), indium tin oxide (ITO), silicon oxide (SiO x ), silicon nitride (SiN x ) and / or at least one compound of silicon oxynitride (SiON). However, exemplary embodiments of the present inventive concept are not limited thereto. The inorganic encapsulation layer 320 may be arranged on the buffer encapsulation layer 310. Due to the buffer encapsulation layer 310, the stress caused by the step of the spacer SPC, such as when the display device is bent, may have only a small effect on the inorganic encapsulation layer 320. The inorganic encapsulation layer 320, in its essence, is formed according to the structure below, and therefore, the upper surface of the inorganic encapsulation layer 320 may not be flat.

[0103] The organic encapsulation layer 330 may cover the inorganic encapsulation layer 320. For example, Figure 2 As shown in the exemplary embodiment of FIG, the bottom portion of the organic encapsulation layer 330 may contact the top portion of the inorganic encapsulation layer 320. Unlike the inorganic encapsulation layer 320, the organic encapsulation layer 330 may be substantially flat. For example, the organic encapsulation layer 330 may have a substantially flat upper surface at a portion corresponding to the display area DA. In an exemplary embodiment, the organic encapsulation layer 330 may include one or more materials selected from the group consisting of acrylic acid, methacrylic acid, polyester, polyethylene, polypropylene, polyethylene terephthalate (PET), polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, and polyarylate.

[0104] The composite encapsulation layer 340 is disposed on the organic encapsulation layer 330. For example, Figure 2 As shown in the exemplary embodiment of FIG, the bottom surface of the composite encapsulation layer 340 may directly contact the top surface of the organic encapsulation layer 330. Figures 3 to 4B Composite encapsulation layer 340 is described.

[0105] The composite encapsulation layer 340 may include multiple groups of multiple sub-layers 340a and 340b stacked on each other (e.g., in the Z direction). The multiple groups of multiple sub-layers 340a and 340b are different layers from each other. For example, the multiple groups of multiple sub-layers 340a and 340b may include different materials or different component ratios from each other. The thickness t of each of the multiple sub-layers 340a and 340b is t s1 and t s2 (eg, length in the Z direction) may be less than the thickness T1 of the inorganic encapsulation layer 320. For example, in an exemplary embodiment, the thickness t1 of each of the plurality of sub-layers 340a and 340b is less than the thickness T2 of the inorganic encapsulation layer 320. s1 and t s2 Each of the sub-layers 340a and 340b may correspond to about 0.01 times to about 0.1 times (eg, about 1% to about 10%) the thickness T1 of the inorganic encapsulation layer 320. In some exemplary embodiments, the thickness t s1 and t s2 Each of to Furthermore, the thickness T1 of the inorganic encapsulation layer 320 may be several micrometers (μm).

[0106] In some exemplary embodiments, the total thickness T2 of the composite encapsulation layer 340 (eg, the thickness t2 of each of the plurality of sub-layers 340a and 340b) is s1 and t s2 The sum of the thickness T1 and the thickness T2 of the inorganic encapsulation layer 320 may be less than the thickness T1 of the inorganic encapsulation layer 320. The thickness t1 of each of the plurality of sub-layers 340a and 340b included in the composite encapsulation layer 340 may be less than the thickness T2 of the inorganic encapsulation layer 320. s1 and t s2 It may be very small and densely formed, and accordingly, although the composite encapsulation layer 340 includes multiple groups of sub-layers 340 a and 340 b , the total thickness T2 of the composite encapsulation layer 340 may be smaller than the thickness T1 of the single-layer inorganic encapsulation layer 320 .

[0107] In an exemplary embodiment, the plurality of sub-layers 340a and 340b of the composite encapsulation layer 340 may include an organic-inorganic hybrid material. For example, the plurality of sub-layers 340a and 340b may include silicon oxide containing carbon or silicon oxide containing carbon and hydrogen. For example, the plurality of sub-layers 340a and 340b may include silicon oxide containing SiO x C y H z wherein x>0, y>0, and z≥0. As the component ratio of x increases, the plurality of sub-layers 340a and 340b may have properties similar to those of an inorganic film, and as the component ratio of y increases, the plurality of sub-layers 340a and 340b may have properties similar to those of an organic film.

[0108] In some exemplary embodiments, the first sublayer 340a may have a component that provides properties similar to an inorganic film, and the second sublayer 340b may have a component that provides properties similar to an organic film. In this case, the first sublayer 340a and the second sublayer 340b may be alternately stacked.

[0109] When a first sub-layer 340a and a second sub-layer 340b are stacked on top of each other (eg, in the Z direction), the composite encapsulation layer 340 is said to include a dyad of sub-layers. In some exemplary embodiments, the composite encapsulation layer 340 may include 1.5 to 10 dyads. Figure 2 and Figure 3 shows a composite encapsulation layer 340 arranged in 2.5 dyads, Figure 4A Composite packaging layers 340 arranged in 1.5 dyads are shown, and Figure 4B Composite encapsulation layers 340 are shown arranged in ten dyads.

[0110] Reference Figure 3 In an exemplary embodiment, the composite encapsulation layer 340 includes a total of five sublayers stacked one on top of the other (e.g., in the Z direction), including a first sublayer 340a / a second sublayer 340b / a first sublayer 340a / a second sublayer 340b / a first sublayer 340a. This embodiment of the composite encapsulation layer 340 is a structure having layers stacked in 2.5 dyads. In this regard, the first sublayer 340a may include an organic-inorganic hybrid material or an inorganic film having properties of an inorganic film. The second sublayer 340b may include an organic-inorganic hybrid material or an organic film having properties of an organic film. Figure 3 In the exemplary embodiment, the top layer of the composite encapsulation layer 340 is the first sub-layer 340 a , and the first sub-layer 340 a can effectively prevent the penetration of moisture.

[0111] Reference Figure 4A In the exemplary embodiment of the present invention, composite encapsulation layer 340 includes a total of three sub-layers stacked one on top of the other (e.g., in the Z direction), including first sub-layer 340a / second sub-layer 340b / first sub-layer 340a. This embodiment of composite encapsulation layer 340 has a structure having layers stacked in 1.5 dyads.

[0112] Reference Figure 4B In an exemplary embodiment, composite encapsulation layer 340 has a stacked structure including first sublayer 340a / second sublayer 340b repeated 10 times. This embodiment of composite encapsulation layer 340 has a structure including layers stacked in 10 pairs. When composite encapsulation layer 340 includes multiple sublayers, its topmost layer does not necessarily need to be an inorganic film to prevent moisture penetration.

[0113] In an exemplary embodiment, when the plurality of sub-layers 340a and 340b include an organic-inorganic hybrid material SiO x C y H z When the plurality of sub-layers 340a and 340b are formed, the plurality of sub-layers 340a and 340b may be formed by PECVD. For example, the source gas may be hexamethyldisiloxane, and the reaction gas may be N2O.

[0114] For example, when hexamethyldisiloxane is used as a source gas and N2O with a low flow rate is used at low power, hexamethyldisiloxane can be formed into SiO2 having the properties of an organic film. x C y H z .

[0115] When HMDS is used as the source gas and N2O with a high flow rate at high power, HMDS can be deposited as SiO2 with the properties of an inorganic film. x .

[0116] In other exemplary embodiments, the first sublayer 340a of the composite encapsulation layer 340 may include an inorganic film such as silicon oxide (SiO2), silicon nitride (SiN), silicon oxynitride (SiON), etc., and the second sublayer 340b may include an organic-inorganic hybrid material having properties similar to those of an organic film. For example, the second sublayer 340b may include SiO2 with a high component ratio of y. x C y H z .

[0117] In this embodiment, the first sub-layer 340a may be formed by atomic layer deposition (ALD). Therefore, the first sub-layer 340a may have a nanometer-scale thickness and a dense structure.

[0118] Each of the respective thicknesses of the plurality of sub-layers 340a and 340b may be approximately 10 nm. In some exemplary embodiments, the thickness t of the first sub-layer 340a is about 1000 nm. s1 may be smaller than the thickness t of the second sub-layer 340b s2 In other exemplary embodiments, the thickness t of the first sub-layer 340a is s1 The thickness of the second sub-layer 340b may be s2 Basically the same.

[0119] As described above, the thin film encapsulation layer 300 of the display device according to the exemplary embodiment of the present inventive concept includes the composite encapsulation layer 340 having a small modulus and the buffer encapsulation layer 310 with a reduced step. Therefore, cracks in the thin film encapsulation layer 300 can be prevented during shape change of the display device.

[0120] Figure 6 is a schematic cross-sectional view of a display device according to another exemplary embodiment of the present inventive concept. Figure 6 In, with Figure 2 The same elements as those in FIG. 1 are designated by the same reference numerals, and thus repeated description thereof will be omitted.

[0121] Reference Figure 6 In the exemplary embodiment, the display device includes a substrate 110, an organic light emitting diode OLED disposed on the substrate 110 and serving as a display element, a spacer SPC, and a thin film encapsulation layer 300. The thin film encapsulation layer 300 may include a buffer encapsulation layer 310, an inorganic encapsulation layer 320, an organic encapsulation layer 330, and a composite encapsulation layer 340.

[0122] The composite encapsulation layer 340 may include a plurality of sublayers stacked on top of each other (e.g., in the Z direction). The thickness of each of the plurality of sublayers (e.g., the length in the Z direction) is less than the thickness T1 of the inorganic encapsulation layer 320. In an exemplary embodiment, the thickness of each of the plurality of sublayers may be approximately tens to hundreds of nanometers (e.g., in the range of about 10 nm to about 200+ nm). In an exemplary embodiment, some of the plurality of sublayers may include an organic-inorganic hybrid material.

[0123] The modulus (e.g., flexural modulus) of the composite encapsulation layer 340 may be less than the modulus of the inorganic encapsulation layer 320. For example, the modulus of the composite encapsulation layer 340 may be approximately 0.05 times to approximately 0.2 times (e.g., approximately 5% to approximately 20%) the modulus of the inorganic encapsulation layer 320. In an exemplary embodiment, the modulus of the composite encapsulation layer 340 may be in the range of approximately 6 GPa to approximately 10 GPa. The modulus of the inorganic encapsulation layer 320 may be in the range of approximately 60 GPa to approximately 100 GPa.

[0124] The buffer encapsulation layer 310 may be arranged between the spacer SPC and the inorganic encapsulation layer 320 (e.g., in the Z direction) and reduce the step formed by the spacer SPC. In an exemplary embodiment, the buffer encapsulation layer 310 may include an organic-inorganic hybrid material. For example, the buffer encapsulation layer 310 may include silicon oxide containing carbon or silicon oxide containing carbon and hydrogen. The buffer encapsulation layer 310 may have the properties of an organic film and therefore may have a slope that is gentler (e.g., smaller) than the slope of the spacer SPC.

[0125] The thin film encapsulation layer 300 of the display device according to the present embodiment includes the composite encapsulation layer 340 having a small modulus and the buffer encapsulation layer 310 having a reduced step, and thus, cracks in the thin film encapsulation layer 300 may be prevented during shape change of the display device.

[0126] exist Figure 6 In the exemplary embodiment shown in , the protective layer 124 may also be arranged on the cover layer 123. For example, Figure 6 As shown in the exemplary embodiment of FIG, the bottom surface of the protective layer 124 may directly contact the top surface of the capping layer 123, and the top surface of the protective layer 124 may directly contact the bottom surface of the buffer encapsulation layer 310. The protective layer 124 can prevent damage to the organic light emitting diode OLED and the like during the process of forming the thin film encapsulation layer 300, which will be formed on the protective layer 124, and can also increase light extraction efficiency for light emitted from the organic light emitting diode OLED.

[0127] In an exemplary embodiment, the protective layer 124 may include an inorganic material and may have a refractive index lower than that of the cap layer 123. The refractive index of the protective layer 124 may be in the range of about 1.35 to about 1.45. As described above, when the protective layer 124 has a low refractive index, light generated in the organic light emitting diode OLED can be prevented from being substantially absorbed or reflected while being emitted to the outside, thereby increasing the light extraction efficiency of the display device. In an exemplary embodiment, the protective layer 124 may include lithium fluoride (LiF).

[0128] Figure 7 is a schematic cross-sectional view of a display device according to another exemplary embodiment of the present inventive concept. Figure 7 In, with Figure 2 The same elements as those in FIG. 1 are designated by the same reference numerals, and thus repeated description thereof will be omitted.

[0129] Reference Figure 7 In the exemplary embodiment, the display device includes a substrate 110, an organic light emitting diode OLED disposed on the substrate 110 and serving as a display element, a spacer SPC, and a thin film encapsulation layer 300. The thin film encapsulation layer 300 may include a buffer encapsulation layer 310, an inorganic encapsulation layer 320, an organic encapsulation layer 330, and a composite encapsulation layer 340.

[0130] The composite encapsulation layer 340 may include a plurality of sub-layers stacked on top of each other (e.g., in the Z direction). The thickness of each of the plurality of sub-layers (e.g., the length in the Z direction) is less than the thickness T1 of the inorganic encapsulation layer 320. The thickness of each of the plurality of sub-layers may be approximately tens to hundreds of nanometers (e.g., in the range of about 10 nm to about 200+ nm). In an exemplary embodiment, some of the plurality of sub-layers may include an organic-inorganic hybrid material.

[0131] The modulus (e.g., flexural modulus) of the composite encapsulation layer 340 may be less than the modulus of the inorganic encapsulation layer 320. For example, the modulus of the composite encapsulation layer 340 may be approximately 0.05 times to approximately 0.2 times (e.g., approximately 5% to approximately 20%) the modulus of the inorganic encapsulation layer 320. In an exemplary embodiment, the modulus of the composite encapsulation layer 340 may be in the range of approximately 6 GPa to approximately 10 GPa. The modulus of the inorganic encapsulation layer 320 may be in the range of approximately 60 GPa to approximately 100 GPa.

[0132] The buffer encapsulation layer 310 may be arranged between the spacer SPC and the inorganic encapsulation layer 320 (e.g., in the Z direction) and reduce the step formed by the spacer SPC. In an exemplary embodiment, the buffer encapsulation layer 310 may include an organic-inorganic hybrid material. For example, the buffer encapsulation layer 310 may include silicon oxide containing carbon or silicon oxide containing carbon and hydrogen. The buffer encapsulation layer 310 may have the properties of an organic film and therefore may have a slope that is gentler than the slope of the spacer SPC.

[0133] The thin film encapsulation layer 300 of the display device according to the present embodiment includes the composite encapsulation layer 340 having a small modulus and the buffer encapsulation layer 310 having a reduced step, and thus, cracks in the thin film encapsulation layer 300 may be prevented during shape change of the display device.

[0134] like Figure 7 As shown in the exemplary embodiment of FIG, the inorganic barrier layer 125 may also be disposed between the organic light emitting diode OLED and the buffer encapsulation layer 310 (eg, in the Z direction). Figure 7 As shown in the exemplary embodiment of FIG, the bottom surface of the inorganic barrier layer 125 may directly contact the top surface of the capping layer 123, and the top surface of the inorganic barrier layer 125 may directly contact the bottom surface of the buffer encapsulation layer 310. The inorganic barrier layer 125 may be introduced to prevent the gas to be exhausted generated in the buffer encapsulation layer 310 from penetrating into the organic light emitting diode OLED.

[0135] In an exemplary embodiment, the inorganic barrier layer 125 may include a silicon oxide (SiO x ), silicon nitride (SiN x) and at least one compound of silicon oxynitride (SiON). In exemplary embodiments, the inorganic barrier layer 125 may be formed very thinly and densely by ALD.

[0136] For example, the thickness T3 (eg, length in the Z direction) of the inorganic barrier layer 125 may be less than the thickness T1 of the inorganic encapsulation layer 320. In an exemplary embodiment, the thickness T3 of the inorganic barrier layer 125 may be about 1000 mm / s. to When the inorganic barrier layer 125 is thick, its modulus may increase, and thus, stress may be concentrated thereon. Therefore, the inorganic barrier layer 125 may be formed to be thin in order to prevent stress from being concentrated thereon.

[0137] Figure 8 is a schematic cross-sectional view of a display device according to another exemplary embodiment of the present inventive concept. Figure 8 In, with Figure 2 The same elements as those in FIG. 1 are designated by the same reference numerals, and thus repeated description thereof will be omitted.

[0138] Reference Figure 8 In the exemplary embodiment, the display device includes a substrate 110, an organic light emitting diode OLED disposed on the substrate 110 and serving as a display element, a spacer SPC, and a thin film encapsulation layer 300. The thin film encapsulation layer 300 may include a buffer encapsulation layer 310', an inorganic encapsulation layer 320, an organic encapsulation layer 330, and a composite encapsulation layer 340.

[0139] The composite encapsulation layer 340 may include a plurality of sublayers stacked on top of each other (e.g., in the Z direction). The thickness of each of the plurality of sublayers (e.g., the length in the Z direction) is less than the thickness T1 of the inorganic encapsulation layer 320. In an exemplary embodiment, the thickness of each of the plurality of sublayers may be approximately tens to hundreds of nanometers (e.g., in the range of about 10 nm to about 200+ nm). In an exemplary embodiment, some of the plurality of sublayers may include an organic-inorganic hybrid material.

[0140] The modulus (e.g., flexural modulus) of the composite encapsulation layer 340 may be less than the modulus of the inorganic encapsulation layer 320. For example, the modulus of the composite encapsulation layer 340 may be approximately 0.05 times to approximately 0.2 times (e.g., approximately 5% to approximately 20%) the modulus of the inorganic encapsulation layer 320. In an exemplary embodiment, the modulus of the composite encapsulation layer 340 may be in the range of approximately 6 GPa to approximately 10 GPa. The modulus of the inorganic encapsulation layer 320 may be in the range of approximately 60 GPa to approximately 100 GPa.

[0141] The buffer encapsulation layer 310' may be arranged between the spacer SPC and the inorganic encapsulation layer 320 (e.g., in the Z direction) and reduce the step formed by the spacer SPC. In an exemplary embodiment, the buffer encapsulation layer 310' may include an organic-inorganic hybrid material. Alternatively, the buffer encapsulation layer 310' may include an organic material. For example, the buffer encapsulation layer 310' may include at least one material selected from the group consisting of acrylic acid, methacrylic acid, polyester, polyethylene, polypropylene, PET, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, and polyarylate.

[0142] exist Figure 8 In the exemplary embodiment shown in , the upper surface of the buffer encapsulation layer 310' may be flat (e.g., generally extending in the X-direction). In an exemplary embodiment in which the buffer encapsulation layer 310' comprises an organic-inorganic hybrid material, when the buffer encapsulation layer 310' has properties similar to those of an organic film, fluidity may be increased, and thus, its upper surface may be flat. In an exemplary embodiment in which the buffer encapsulation layer 310' comprises an organic material, the buffer encapsulation layer 310' may be formed by applying a liquid organic material and then hardening the liquid organic material, and thus, its upper surface may be flat.

[0143] The thin film encapsulation layer 300 of the display device according to the present embodiment includes the composite encapsulation layer 340 having a small modulus and the buffer encapsulation layer 310 ′ having a reduced step, and thus, the occurrence of cracks in the thin film encapsulation layer 300 may be prevented during shape change of the display device.

[0144] like Figure 8 As shown in the exemplary embodiment of FIG, a protective layer 124 including an inorganic material may be disposed below the buffer encapsulation layer 310'. For example, the protective layer 124 may be disposed between the cover layer 123 and the buffer encapsulation layer 310' (e.g., in the Z direction). For example, the bottom surface of the protective layer 124 may directly contact the top surface of the cover layer 123, and the top surface of the protective layer 124 may directly contact the bottom surface of the buffer encapsulation layer 310'.

[0145] The protective layer 124 may increase light extraction efficiency of light emitted from the organic light emitting diode OLED, and may also prevent the gas to be exhausted generated in the buffer encapsulation layer 310 ′ from penetrating into the organic light emitting diode OLED.

[0146] In an exemplary embodiment, the protective layer 124 may include an inorganic material and may have a refractive index lower than that of the cover layer 123. For example, the refractive index of the protective layer 124 may be in the range of about 1.35 to about 1.45. As described above, when the refractive index of the protective layer 124 is lower than that of the cover layer 123, light generated in the organic light emitting diode OLED can be prevented from being substantially absorbed or reflected while being emitted to the outside, and thus the light extraction efficiency of the display device can be increased.

[0147] In an exemplary embodiment, the protective layer 124 may include lithium fluoride (LiF). The protective layer 124 includes an inorganic material, and thus, even when the buffer encapsulation layer 310 ′ includes an organic material, the protective layer 124 may block the gas to be exhausted generated in the organic material.

[0148] Figure 9 is a schematic cross-sectional view of a display device according to another exemplary embodiment of the present inventive concept. Figure 9 In, with Figure 2 The same elements as those in FIG. 1 are designated by the same reference numerals, and thus repeated description thereof will be omitted.

[0149] Reference Figure 9 In the exemplary embodiment, the display device includes a substrate 110, an organic light emitting diode OLED disposed on the substrate 110 and serving as a display element, a spacer SPC, and a thin film encapsulation layer 300. The thin film encapsulation layer 300 may include a buffer encapsulation layer 310', an inorganic encapsulation layer 320, an organic encapsulation layer 330, and a composite encapsulation layer 340.

[0150] The composite encapsulation layer 340 may include a plurality of sublayers stacked on top of each other (e.g., in the Z direction). The thickness of each of the plurality of sublayers (e.g., the length in the Z direction) is less than the thickness T1 of the inorganic encapsulation layer 320. In an exemplary embodiment, the thickness of each of the plurality of sublayers may be approximately tens to hundreds of nanometers (e.g., in the range of about 10 nm to about 200+ nm). In an exemplary embodiment, some of the plurality of sublayers may include an organic-inorganic hybrid material.

[0151] The modulus (e.g., flexural modulus) of the composite encapsulation layer 340 may be less than the modulus of the inorganic encapsulation layer 320. For example, the modulus of the composite encapsulation layer 340 may be approximately 0.05 times to approximately 0.2 times (e.g., approximately 5% to approximately 20%) the modulus of the inorganic encapsulation layer 320. In an exemplary embodiment, the modulus of the composite encapsulation layer 340 may be in the range of approximately 6 GPa to approximately 10 GPa. The modulus of the inorganic encapsulation layer 320 may be in the range of approximately 60 GPa to approximately 100 GPa.

[0152] The buffer encapsulation layer 310' may be arranged between the spacer SPC and the inorganic encapsulation layer 320 (e.g., in the Z direction) and reduce the step formed by the spacer SPC. In an exemplary embodiment, the buffer encapsulation layer 310' may include an organic-inorganic hybrid material. Alternatively, the buffer encapsulation layer 310' may include an organic material. For example, the buffer encapsulation layer 310' may include at least one material selected from the group consisting of acrylic acid, methacrylic acid, polyester, polyethylene, polypropylene, PET, polyethylene naphthalate, polycarbonate, polyimide, polyethylene sulfonate, polyoxymethylene, and polyarylate.

[0153] exist Figure 9 In the exemplary embodiment shown in , the upper surface of the buffer encapsulation layer 310' may be flat (e.g., generally extending in the X-direction). In an exemplary embodiment in which the buffer encapsulation layer 310' comprises an organic-inorganic hybrid material, when the buffer encapsulation layer 310' has properties similar to those of an organic film, fluidity may be increased, and thus, its upper surface may be flat. In an exemplary embodiment in which the buffer encapsulation layer 310' comprises an organic material, the buffer encapsulation layer 310' may be formed by applying a liquid organic material and then hardening the liquid organic material, and thus, its upper surface may be flat.

[0154] The thin film encapsulation layer 300 of the display device according to the present embodiment includes the composite encapsulation layer 340 having a small modulus and the buffer encapsulation layer 310 ′ having a reduced step, and thus, the occurrence of cracks in the thin film encapsulation layer 300 may be prevented during shape change of the display device.

[0155] like Figure 9 As shown in the exemplary embodiment of FIG, an inorganic barrier layer 125 may be further disposed between the organic light emitting diode OLED and the buffer encapsulation layer 310' (e.g., in the Z direction). For example, the bottom surface of the inorganic barrier layer 125 may directly contact the top surface of the cover layer 123, and the top surface of the inorganic barrier layer 125 may directly contact the bottom surface of the buffer encapsulation layer 310'. The inorganic barrier layer 125 may be introduced to prevent the gas to be removed generated in the buffer encapsulation layer 310' from penetrating into the organic light emitting diode OLED.

[0156] The inorganic barrier layer 125 may include a silicon oxide (SiO x ), silicon nitride (SiN x ) and at least one compound of silicon oxynitride (SiON). In exemplary embodiments, the inorganic barrier layer 125 may be formed very thinly and densely by ALD.

[0157] For example, the thickness T3 of the inorganic barrier layer 125 may be less than the thickness T1 of the inorganic encapsulation layer 320. In an exemplary embodiment, the thickness T3 of the inorganic barrier layer 125 may be about to When the inorganic barrier layer 125 is thick, its modulus may increase, and thus, stress may be concentrated thereon. Therefore, the inorganic barrier layer 125 may be formed to be thin in order to prevent stress from being concentrated thereon.

[0158] Although the present description has been given with reference to one or more exemplary embodiments shown in the drawings, this is merely an example, and those skilled in the art will appreciate that various changes through and among the embodiments may be made.

[0159] For example, refer to Figure 6 The protective layer 124 described with reference to Figure 7 The inorganic barrier layer 125 described above may be applied simultaneously. Figure 4A and Figure 4B The composite encapsulation layer 340 described may be applied to Figure 2 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 wait.

[0160] According to one or more of the exemplary embodiments described above, a buffer encapsulation layer may be used, and thus, flexibility may be obtained and stress concentration on the inorganic encapsulation layer may also be prevented. However, exemplary embodiments of the present inventive concept are not limited to such effects.

[0161] It should be understood that the exemplary embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects in each exemplary embodiment should generally be considered applicable to other similar features or aspects in other exemplary embodiments. Although one or more exemplary embodiments have been described with reference to the accompanying drawings, it will be understood by those skilled in the art that various modifications in form and detail may be made therein without departing from the spirit and scope as defined by the following claims.

Claims

1. A display device comprising: a substrate comprising a display area and a peripheral area surrounding the display area; a plurality of display elements, the plurality of display elements being arranged above the display area; a spacer disposed between the plurality of display elements, the spacer comprising a lateral side having a first slope; as well as a thin film encapsulation layer, the thin film encapsulation layer covering the display area, the thin film encapsulation layer comprising a buffer encapsulation layer, an inorganic encapsulation layer, an organic encapsulation layer and a composite encapsulation layer stacked one on top of the other, The composite encapsulation layer includes a plurality of sub-layers stacked on each other, and the thickness of each of the plurality of sub-layers is less than the thickness of the inorganic encapsulation layer. The upper surface of the buffer encapsulation layer has a second slope, the inclination angle of the second slope is smaller than the inclination angle of the first slope, and the second slope overlaps with the first slope in the thickness direction of the substrate.

2. The display device according to claim 1, wherein The modulus of the composite encapsulation layer is smaller than the modulus of the inorganic encapsulation layer.

3. The display device according to claim 2, wherein: The modulus of the composite encapsulation layer is in a range of 5% to 20% of the modulus of the inorganic encapsulation layer.

4. The display device according to claim 1, wherein The buffer encapsulation layer includes an organic-inorganic hybrid material.

5. The display device according to claim 4, wherein The buffer encapsulation layer includes silicon oxide containing carbon.

6. The display device according to claim 1, wherein: A doublet is a stacked structure of a first sublayer and a second sublayer, wherein the first sublayer and the second sublayer comprise different materials or different component ratios; and The composite encapsulation layer includes 1.5 to 10 dyads.

7. The display device according to claim 1, further comprising: a covering layer, the covering layer being arranged between the plurality of display elements and the thin film encapsulation layer, Wherein, the cover layer has a refractive index in the range of 1.6 to 3.

8. The display device according to claim 7, further comprising: a protective layer, the protective layer being disposed between the cover layer and the thin film encapsulation layer, the protective layer comprising an inorganic material, Wherein, the refractive index of the protective layer is smaller than the refractive index of the covering layer.

9. The display device according to claim 1 , further comprising an inorganic barrier layer disposed between the plurality of display elements and the buffer encapsulation layer. in, The thickness of the inorganic barrier layer is smaller than the thickness of the inorganic encapsulation layer.

10. The display device according to claim 9, wherein The thickness of the inorganic barrier layer is to within the range.

11. A display device comprising: a substrate comprising a display area and a peripheral area surrounding the display area; a plurality of display elements, the plurality of display elements being arranged above the display area; a spacer disposed between the plurality of display elements; a cover layer disposed above the plurality of display elements and the spacer; as well as a thin film encapsulation layer, the thin film encapsulation layer being arranged above the cover layer and covering the display area, the thin film encapsulation layer comprising a buffer encapsulation layer, an inorganic encapsulation layer, an organic encapsulation layer and a composite encapsulation layer stacked one on top of the other, The composite encapsulation layer includes a plurality of sub-layers stacked on each other, and the thickness of each of the plurality of sub-layers is less than the thickness of the inorganic encapsulation layer. Wherein, the upper surface of the buffer encapsulation layer is flat.

12. The display device according to claim 11, further comprising: a protective layer, the protective layer being arranged between the cover layer and the buffer encapsulation layer, the protective layer comprising an inorganic material, Wherein, the refractive index of the protective layer is smaller than the refractive index of the covering layer.

13. The display device according to claim 12, wherein: The protective layer includes lithium fluoride.

14. The display device according to claim 11, further comprising: an inorganic barrier layer, the inorganic barrier layer being arranged between the cover layer and the buffer encapsulation layer, Wherein, the thickness of the inorganic barrier layer is smaller than the thickness of the inorganic encapsulation layer.

15. The display device according to claim 14, wherein The thickness of the inorganic barrier layer is to within the range.

16. The display device according to claim 11, wherein The modulus of the composite encapsulation layer is smaller than the modulus of the inorganic encapsulation layer.

17. The display device according to claim 16, wherein: The modulus of the composite encapsulation layer is in a range of 5% to 20% of the modulus of the inorganic encapsulation layer.

18. The display device according to claim 11, wherein The buffer encapsulation layer includes an organic material.

19. The display device according to claim 11, wherein: A doublet is a stacked structure of a first sublayer and a second sublayer, wherein the first sublayer and the second sublayer comprise different materials or different component ratios; and The composite encapsulation layer includes 1.5 to 10 dyads.

20. A display device comprising: a substrate comprising a display area and a peripheral area surrounding the display area; a plurality of display elements, the plurality of display elements being arranged above the display area; as well as a thin film encapsulation layer, the thin film encapsulation layer covering the display area, the thin film encapsulation layer comprising an inorganic encapsulation layer, an organic encapsulation layer and a composite encapsulation layer stacked one on top of the other, wherein the composite encapsulation layer comprises a plurality of sublayers stacked on each other, and a thickness of the composite encapsulation layer is less than a thickness of the inorganic encapsulation layer, wherein at least one of the plurality of sublayers comprises an organic-inorganic hybrid material, Wherein, the composite encapsulation layer is the uppermost layer of the thin film encapsulation layer, Wherein, a thickness of a portion of the organic encapsulation layer is greater than a thickness of the inorganic encapsulation layer.

21. The display device according to claim 20, wherein: The thin film encapsulation layer further includes a buffer encapsulation layer, which is disposed between the plurality of display elements and the inorganic encapsulation layer. Wherein, the buffer encapsulation layer includes organic material or organic-inorganic hybrid material.

22. The display device according to claim 21, wherein The buffer encapsulation layer includes SiO x C y H z , Where x>0, y>0, and z≥0.

23. The display device according to claim 20, further comprising: a covering layer, the covering layer being arranged between the plurality of display elements and the thin film encapsulation layer, Wherein, the cover layer has a refractive index in the range of 1.6 to 3.

24. The display device according to claim 23, further comprising: a protective layer, the protective layer being disposed between the cover layer and the thin film encapsulation layer, the protective layer comprising an inorganic material, Wherein, the refractive index of the protective layer is smaller than the refractive index of the covering layer.

25. The display device according to claim 20, wherein: The plurality of sub-layers include first sub-layers and second sub-layers alternately stacked with each other, The first sublayer includes an inorganic film and the second sublayer includes an organic-inorganic hybrid material.

26. A display device comprising: a flexible substrate comprising a display area and a peripheral area surrounding the display area; a plurality of display elements, the plurality of display elements being arranged above the display area; a spacer disposed between the plurality of display elements, the spacer comprising a lateral side having a first slope; as well as a thin film encapsulation layer, the thin film encapsulation layer covering the display area, the thin film encapsulation layer comprising a buffer encapsulation layer disposed on the display area and an inorganic encapsulation layer disposed on the buffer encapsulation layer, the buffer encapsulation layer comprising an organic-inorganic hybrid material; The upper surface of the buffer encapsulation layer has a second slope, the inclination angle of the second slope is smaller than the inclination angle of the first slope, and the second slope overlaps with the first slope in the thickness direction of the substrate. The composite encapsulation layer comprises an organic-inorganic hybrid material and is the uppermost layer of the thin film encapsulation layer. The thickness of a portion of the organic encapsulation layer is greater than the thickness of the inorganic encapsulation layer.

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