Display apparatus

Abstract

The present invention provides a display device comprising: a lower substrate; a first light-emitting element disposed on the lower substrate and having a first light-emitting region; an upper substrate positioned on the upper portion of the lower substrate such that the first light-emitting element is interposed therein; a refractive layer positioned between the first light-emitting element and the upper substrate; a flattening layer positioned between the refractive layer and the upper substrate; a first color filter layer positioned on the lower portion of the upper substrate in the direction of the lower substrate; a bank having a first opening corresponding to the first light-emitting region; and a first quantum dot layer filling the first opening; wherein the upper surface of the refractive layer is provided in a shape that collects light emitted from the first light-emitting element.

Description

Technology Field

[0001] Embodiments of the present invention relate to a display device, and more specifically, to a display device with improved efficiency. Background Technology

[0002] A display device has a plurality of pixels. For a full-color display device, the plurality of pixels can emit light of different colors. To this end, at least some of the pixels of the display device have a color conversion unit. Accordingly, light of a first color generated from the light-emitting unit of some pixels can be converted into light of a second color by passing through the corresponding color conversion unit and emitted externally. The problem to be solved

[0003] However, these conventional display devices had the problem of low light efficiency.

[0004] The present invention aims to solve various problems, including those mentioned above, and provides a display device with improved efficiency. However, these problems are exemplary and do not limit the scope of the present invention. means of solving the problem

[0005] According to one aspect of the present invention, a display device is provided comprising: a lower substrate; a first light-emitting element disposed on the lower substrate and having a first light-emitting region; an upper substrate positioned on the upper portion of the lower substrate such that the first light-emitting element is interposed therein; a refractive layer positioned between the first light-emitting element and the upper substrate; a flattening layer positioned between the refractive layer and the upper substrate; a first color filter layer positioned on the lower portion of the upper substrate in the direction of the lower substrate; a bank having a first opening corresponding to the first light-emitting region; and a first quantum dot layer filling the first opening; wherein the upper surface of the refractive layer is provided in a shape that collects light emitted from the first light-emitting element.

[0006] In this embodiment, the upper surface of the refractive layer may include a concave portion concave in the direction of the lower surface of the lower substrate.

[0007] In this embodiment, the concave portion may be provided at least one or more times.

[0008] In this embodiment, the concave portion may overlap with the first light-emitting region.

[0009] In this embodiment, the planarization layer may be placed directly on the refractive layer.

[0010] In this embodiment, the planarization layer may have a refractive index greater than that of the refractive layer.

[0011] In this embodiment, the first color filter layer and the first quantum dot layer can each overlap with the first light-emitting region.

[0012] In the present embodiment, the apparatus may further include: a second light-emitting element disposed on the lower substrate and having a second light-emitting region; a second color filter layer having a fourth opening that overlaps with the first opening and is located on the lower surface of the upper substrate and overlaps with at least a portion of the second light-emitting region; and a second quantum dot layer located between the second light-emitting element and the second color filter layer.

[0013] In the present embodiment, the apparatus may further include: a third light-emitting element disposed on the lower substrate and having a third light-emitting region; a third color filter layer having a fifth opening that overlaps with the first opening and is located on the lower surface of the upper substrate and overlaps with at least a portion of the third light-emitting region; and a light-transmitting layer located between the third light-emitting element and the third color filter layer.

[0014] In this embodiment, the bank further includes a second opening corresponding to the second light-emitting region and a third opening corresponding to the third light-emitting region, and the second quantum dot layer can fill the second opening and the light-transmitting layer can fill the third opening.

[0015] In this embodiment, the first light-emitting element, the second light-emitting element, and the third light-emitting element can emit light belonging to the same wavelength band.

[0016] In the present embodiment, a thin film encapsulation layer located between the first light-emitting element and the refractive layer is further included, and the thin film encapsulation layer may include a first inorganic film layer, an organic film layer, and a second inorganic film layer sequentially stacked.

[0017] In this embodiment, the refractive layer may be directly disposed on the second inorganic film layer.

[0018] In this embodiment, the refractive layer may be integrally formed with the second inorganic film layer.

[0019] In this embodiment, a filler material located between the lower substrate and the upper substrate may be further included.

[0020] In this embodiment, the filler may be located between the refractive layer and the flattening layer.

[0021] In this embodiment, the filler may be located between the planarization layer and the first quantum dot layer.

[0022] In this embodiment, the filler may be located between the thin film encapsulation layer and the refractive layer.

[0023] In this embodiment, a protective layer located between the planarization layer and the first quantum dot layer may be further included.

[0024] In this embodiment, a column spacer located between the flattening layer and the bank may be further included.

[0025] According to another aspect of the present invention, a display device is provided comprising: a lower substrate; a first light-emitting element, a second light-emitting element, and a third light-emitting element disposed on the lower substrate and each having a first light-emitting region, a second light-emitting region, and a third light-emitting region; an upper substrate positioned on the upper portion of the lower substrate such that the first light-emitting element to the third light-emitting element are interposed therebetween; a refractive layer positioned between the first light-emitting element to the third light-emitting element and the upper substrate; a first color filter layer, a second color filter layer, and a third color filter layer positioned on the lower portion of the upper substrate in the direction of the lower substrate; and a first quantum dot layer, a second quantum dot layer, and a light-transmitting layer each overlapping with the first color filter layer, the second color filter layer, and the third color filter layer, respectively, wherein the upper surface of the refractive layer is provided in a shape that collects light emitted from the first light-emitting element, the second light-emitting element, and the third light-emitting element.

[0026] In this embodiment, the upper surface of the refractive layer may include a concave portion concave in the direction of the lower surface of the lower substrate.

[0027] In the present embodiment, the concave portion may be provided to correspond to each of the first light-emitting element, the second light-emitting element, and the third light-emitting element.

[0028] In this embodiment, a planarization layer located between the refractive layer and the upper substrate may be further included.

[0029] In this embodiment, the planarization layer may be placed directly on the refractive layer.

[0030] In this embodiment, the planarization layer may have a refractive index greater than that of the refractive layer.

[0031] In this embodiment, the first light-emitting element, the second light-emitting element, and the third light-emitting element can emit light belonging to the same wavelength band.

[0032] In the present embodiment, a thin film encapsulation layer located between the first light-emitting element and the refractive layer is further included, and the thin film encapsulation layer may include a first inorganic film layer, an organic film layer, and a second inorganic film layer sequentially stacked.

[0033] In this embodiment, the refractive layer may be directly disposed on the second inorganic film layer.

[0034] In this embodiment, the refractive layer may be integrally formed with the second inorganic film layer. Effects of the invention

[0035] According to one embodiment of the present invention as described above, a display device with improved efficiency can be implemented. Of course, the scope of the present invention is not limited by such effects. Brief explanation of the drawing

[0036] FIG. 1 is a perspective view schematically illustrating a display device according to one embodiment. FIG. 2 is a cross-sectional view schematically illustrating a display device according to one embodiment. FIG. 3 is a drawing for explaining a first quantum dot layer, a second quantum dot layer, and a light-transmitting layer included in a display device according to one embodiment. FIG. 4 is a cross-sectional view schematically illustrating a display device according to one embodiment. FIGS. 5, FIGS. 6 and FIGS. 7 are cross-sectional views schematically illustrating a display device according to one embodiment. FIG. 8 is a cross-sectional view schematically illustrating a display device according to one embodiment. FIG. 9 is a cross-sectional view schematically illustrating a display device according to one embodiment. FIG. 10 is a cross-sectional view schematically illustrating a display device according to one embodiment. Specific details for implementing the invention

[0037] The present invention is capable of various modifications and may have various embodiments; specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention, and the methods for achieving them, will become clear by referring to the embodiments described below in detail together with the drawings. However, the present invention is not limited to the embodiments disclosed below but can be implemented in various forms.

[0038] In the following embodiments, terms such as first, second, etc. are used not in a limiting sense, but for the purpose of distinguishing one component from another component.

[0039] In the following examples, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0040] In the following embodiments, terms such as "include" or "have" mean that the features or components described in the specification are present, and do not preclude the possibility that one or more other features or components may be added.

[0041] In the following embodiments, when a part such as a film, region, or component is described as being on or above another part, it includes not only cases where it is directly on top of another part, but also cases where another film, region, or component is interposed in between.

[0042] In the drawings, the size of components may be exaggerated or reduced for convenience of explanation. For example, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and therefore the present invention is not necessarily limited to what is illustrated.

[0043] In this specification, "A and / or B" indicates the case where it is A, B, or both A and B. Additionally, in this specification, "at least one of A and B" indicates the case where it is A, B, or both A and B.

[0044] In the following embodiments, the meaning of "the wiring extends in a first direction or a second direction" includes not only extending in a straight line shape, but also extending in a zigzag or curved shape along the first direction or the second direction.

[0045] In the following embodiments, "planar" refers to the view of the target part from above, and "cross-sectional" refers to the view of the cross-section obtained by vertically cutting the target part from the side. In the following embodiments, "superimposition" includes the superposition of the "planar" and "cross-sectional" views.

[0046] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings, and when describing with reference to the drawings, identical or corresponding components will be given the same reference numerals.

[0047] FIG. 1 is a perspective view schematically illustrating a display device according to one embodiment, FIG. 2 is a cross-sectional view schematically illustrating a display device according to one embodiment, and FIG. 3 is a drawing for explaining a first quantum dot layer, a second quantum dot layer, and a light-transmitting layer included in a display device according to one embodiment. FIG. 2 corresponds to a cross-sectional view taken along line II' of FIG. 1.

[0048] Referring to FIGS. 1, 2, and 3, a display device (1) may include a display area (DA) that implements an image and a non-display area (NDA) that does not implement an image. The display device (1) may provide an image through an array of multiple pixels (PX) arranged two-dimensionally in the display area (DA).

[0049] The non-display area (NDA) is an area that does not provide an image and may completely surround the display area (DA). Drivers or main power lines for providing electrical signals or power to pixel circuits may be placed in the non-display area (NDA). The non-display area (NDA) may include pads, which are areas where electronic components or printed circuit boards can be electrically connected.

[0050] The display area (DA) may have a polygonal shape including a rectangle, as illustrated in FIG. 1. For example, the display area (DA) may have a rectangular shape where the width is greater than the height, a rectangular shape where the width is smaller than the height, or a square shape. Alternatively, the display area (DA) may have various shapes such as an ellipse or a circle.

[0051] A display device (1) according to one embodiment may include a lower substrate (100), a light-emitting element, a thin film encapsulation layer (TFE), a refractive layer (340), a first quantum dot layer (370a), a second quantum dot layer (370b), a light-transmitting layer (370c), a first color filter layer (380a), a second color filter layer (380b), a third color filter layer (380c), and an upper substrate (400).

[0052] The lower substrate (100) may include glass, metal, or polymer resin. If the lower substrate (100) has flexible or bendable properties, the lower substrate (100) may include polymer resins such as polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, or cellulose acetate propionate. Of course, the lower substrate (100) may have a multilayer structure including two layers each containing such polymer resins and a barrier layer containing an inorganic material (such as silicon oxide, silicon nitride, silicon oxynitride, etc.) interposed between the layers, and various modifications are possible.

[0053] In one embodiment, a first light-emitting element including a first pixel electrode (311), a second light-emitting element including a second pixel electrode (321), and a third light-emitting element including a third pixel electrode (331) may be positioned on the lower substrate (100). Of course, in addition to the first to third light-emitting elements, a first thin-film transistor (210) electrically connected to the first light-emitting element, a second thin-film transistor (220) electrically connected to the second light-emitting element, and a third thin-film transistor (230) electrically connected to the third light-emitting element may also be positioned on the lower substrate (100).

[0054] As illustrated in FIG. 2, the first light-emitting element being electrically connected to the first thin-film transistor (210) means that the first pixel electrode (311) of the first light-emitting element is electrically connected to the first thin-film transistor (210). Additionally, the second light-emitting element being electrically connected to the second thin-film transistor (220) may mean that the second pixel electrode (321) of the second light-emitting element is electrically connected to the second thin-film transistor (220), and the third light-emitting element being electrically connected to the third thin-film transistor (230) may mean that the third pixel electrode (331) of the third light-emitting element is electrically connected to the third thin-film transistor (230).

[0055] The following description will focus on the first thin-film transistor (210) and the first pixel electrode (311). The second thin-film transistor (220) and the third thin-film transistor (230) may be provided with a structure identical or similar to that of the first thin-film transistor (210).

[0056] The first thin-film transistor (210) may include a first semiconductor layer (211) comprising amorphous silicon, polycrystalline silicon, an organic semiconductor material, or an oxide semiconductor material, a first gate electrode (213), a first source electrode (215a), and a first drain electrode (215b). The first gate electrode (213) may include various conductive materials and may have various layered structures, for example, may include a Mo layer and an Al layer. In this case, the first gate electrode (213) may have a Mo / Al / Mo layered structure. Alternatively, the first gate electrode (213) may include a TiNx layer, an Al layer, and / or a Ti layer. The first source electrode (215a) and the first drain electrode (215b) may also include various conductive materials and may have various layered structures, for example, may include a Ti layer, an Al layer, and / or a Cu layer. In this case, the first source electrode (215a) and the first drain electrode (215b) may have a layered structure of Ti / Al / Ti.

[0057] In order to ensure insulation between the first semiconductor layer (211) and the first gate electrode (213), a gate insulating film (121) containing an inorganic material such as silicon oxide, silicon nitride, and / or silicon oxynitride may be interposed between the first semiconductor layer (211) and the first gate electrode (213). Additionally, an interlayer insulating film (131) containing an inorganic material such as silicon oxide, silicon nitride, and / or silicon oxynitride may be disposed on the upper portion of the first gate electrode (213), and the first source electrode (215a) and the first drain electrode (215b) may be disposed on such an interlayer insulating film (131). An insulating film containing an inorganic material in this manner may be formed through CVD (chemical vapor deposition) or ALD (atomic layer deposition). This is also the case for the embodiments and variations described below.

[0058] A buffer layer (110) containing an inorganic material such as silicon oxide, silicon nitride and / or silicon oxynitride may be interposed between the first thin-film transistor (210) of this structure and the lower substrate (100). This buffer layer (110) may serve to increase the smoothness of the upper surface of the lower substrate (100) or to prevent or minimize the penetration of impurities from the lower substrate (100) into the first semiconductor layer (211) of the first thin-film transistor (210).

[0059] An organic insulating layer (140) may be disposed on the first thin-film transistor (210). For example, as shown in FIG. 2, when an organic light-emitting element is disposed as a first light-emitting element on top of the first thin-film transistor (210), the organic insulating layer (140) may serve to flatten the upper surface of the protective film covering the first thin-film transistor (210). This organic insulating layer (140) may include organic materials such as acrylic, BCB (Benzocyclobutene), or HMDSO (hexamethyldisiloxane). Although the organic insulating layer (140) is shown as a single layer in FIG. 2, various variations are possible, such as it being a multilayer.

[0060] A first light-emitting element, a second light-emitting element, and a third light-emitting element may be located on the organic insulating layer (140) of the lower substrate (100). In FIG. 2, the organic light-emitting element is shown as being located on the organic insulating layer (140) as the first to third light-emitting elements. The first light-emitting element may be located at the first pixel (PX1), the second light-emitting element may be located at the second pixel (PX2), and the third light-emitting element may be located at the third pixel (PX3).

[0061] A first light-emitting element located at a first pixel (PX1) may be an organic light-emitting element having a first pixel electrode (311), a counter electrode (305), and an intermediate layer (303) interposed between them and including a light-emitting layer, and a second light-emitting element located at a second pixel (PX2) may be an organic light-emitting element having a second pixel electrode (321), a counter electrode (305), and an intermediate layer (303) interposed between them and including a light-emitting layer, and a third light-emitting element located at a third pixel (PX3) may be an organic light-emitting element having a third pixel electrode (331), a counter electrode (305), and an intermediate layer (303) interposed between them and including a light-emitting layer.

[0062] The first pixel electrode (311) can be electrically connected to the first thin-film transistor (210) by contacting either the first source electrode (215a) or the first drain electrode (215b) through an opening formed in the organic insulating layer (140), as shown in FIG. 2. Additionally, the second pixel electrode (321) can be electrically connected to the second thin-film transistor (220) through an opening formed on the organic insulating layer (140), and the third pixel electrode (331) can be electrically connected to the third thin-film transistor (230) through an opening formed on the organic insulating layer (140).

[0063] The first pixel electrode (311) may include a transparent conductive layer formed of a transparent conductive oxide such as ITO, In2O3, or IZO, and a reflective layer formed of a metal such as Al or Ag. For example, the first pixel electrode (311) may have a three-layer structure of ITO / Ag / ITO. The second pixel electrode (321) and the third pixel electrode (331) may be provided with the same material as the first pixel electrode (311).

[0064] The intermediate layer (303) including the light-emitting layer may have a patterned shape corresponding to the first pixel electrode (311), but as shown in FIG. 2, it may also be located on the second pixel electrode (321) and the third pixel electrode (331) located on the lower substrate (100) and formed integrally across the first pixel electrode (311) to the third pixel electrode (331). The counter electrode (305) on the intermediate layer (303) may also be formed integrally across the first pixel electrode (311) to the third pixel electrode (331). The counter electrode (305) may include a light-transmitting conductive layer formed of ITO, In2O3, or IZO, and may also include a semi-transparent film containing a metal such as Al or Ag. For example, the counter electrode (305) may be a semi-transparent film containing MgAg.

[0065] A pixel defining film (150) may be disposed on the upper portion of the organic insulating layer (140). This pixel defining film (150) may serve to define pixels by having an opening corresponding to each pixel, that is, an opening that exposes the central portion of the first pixel electrode (311). For example, the first light-emitting element may have a first light-emitting region (EA1), and the first light-emitting region (EA1) of the first light-emitting element may be defined by the opening of the pixel defining film (150). At this time, the first light-emitting region (EA1) may correspond to the light-emitting region of the light emitted from the first light-emitting element.

[0066] The pixel defining film (150) can serve to define a pixel by having an opening that exposes the central portion of the second pixel electrode (321). For example, the second light-emitting element may have a second light-emitting region (EA2), and the second light-emitting region (EA2) of the second light-emitting element may be defined by the opening of the pixel defining film (150). At this time, the second light-emitting region (EA2) may correspond to the light-emitting region of the light emitted from the second light-emitting element.

[0067] The pixel defining film (150) can serve to define a pixel by having an opening that exposes the central portion of the third pixel electrode (331). For example, the third light-emitting element may have a third light-emitting region (EA3), and the third light-emitting region (EA3) of the third light-emitting element may be defined by the opening of the pixel defining film (150). At this time, the third light-emitting region (EA3) may correspond to the light-emitting region of the light emitted from the third light-emitting element.

[0068] In addition, as illustrated in FIG. 2, the pixel defining film (150) can prevent arcs from occurring at the edges of the first pixel electrode (311) to the third pixel electrode (331) by increasing the distance between the edge of the first pixel electrode (311) and the counter electrode (305), the distance between the edge of the second pixel electrode (321) and the counter electrode (305), and the distance between the edge of the third pixel electrode (331) and the counter electrode (305).

[0069] The pixel defining film (150) may include an organic insulating material. Alternatively, the pixel defining film (150) may include an inorganic insulating material such as silicon nitride, silicon oxynitride, or silicon oxide. Alternatively, the pixel defining film (150) may include both an organic insulating material and an inorganic insulating material. In one embodiment, the pixel defining film (150) may include a light-blocking material and may be provided in black. The light-blocking material may include carbon black, carbon nanotubes, a resin or paste containing a black dye, metal particles such as nickel, aluminum, molybdenum, and their alloys, metal oxide particles (e.g., chromium oxide), or metal nitride particles (e.g., chromium nitride). When the pixel defining film (150) includes a light-blocking material, it may reduce external light reflection by metal structures placed below the pixel defining film (150).

[0070] Although not shown in FIG. 2, a spacer may be disposed on the pixel defining film (150). The spacer may include an organic insulating material such as polyimide. Alternatively, the spacer may be silicon nitride (SiN X It may include an inorganic insulating material such as silicon oxide (SiO2) or an organic insulating material and an inorganic insulating material. In one embodiment, the spacer may include the same material as the pixel defining film (150). In this case, the pixel defining film (150) and the spacer may be formed together in a mask process using a halftone mask, etc. In one embodiment, the spacer and the pixel defining film (150) may include different materials.

[0071] An intermediate layer (303) including a light-emitting layer may be disposed on the first pixel electrode (311) to the third pixel electrode (331). The intermediate layer (303) may include a low-molecular-weight or high-molecular-weight material. If the intermediate layer (303) includes a low-molecular-weight material, the intermediate layer (303) may have a structure in which a hole injection layer (HIL), a hole transport layer (HTL), an emission layer (EML), an electron transport layer (ETL), an electron injection layer (EIL), etc., are stacked in a single or composite structure, and may be formed by a vacuum deposition method. If the intermediate layer (303) includes a high-molecular-weight material, the intermediate layer (303) may have a structure including a hole transport layer (HTL) and an emission layer (EML). At this time, the hole transport layer may include PEDOT, and the light-emitting layer may include polymer materials such as PPV (Poly-Phenylenevinylene) and polyfluorene. This intermediate layer (303) can be formed by screen printing, inkjet printing, deposition, or laser induced thermal imaging (LITI). Of course, the intermediate layer (303) is not necessarily limited to these methods and may have various structures.

[0072] As described above, the intermediate layer (303) may be provided as a layer that is integral across the first pixel electrode (311) to the third pixel electrode (331). However, the present invention is not limited thereto. For example, the intermediate layer (303) may be provided to be patterned to correspond to each of the first pixel electrode (311) to the third pixel electrode (331). In one embodiment, the intermediate layer (303) may include a light-emitting layer, and the light-emitting layer may emit light of a third wavelength band. For example, the light-emitting layer may emit light of a wavelength belonging to 450 nm to 495 nm. At this time, the light-emitting layer may be provided integrally across the first pixel electrode (311) to the third pixel electrode (331), or it may be patterned to correspond to each of the first pixel electrode (311) to the third pixel electrode (331).

[0073] The counter electrode (305) may be positioned on the intermediate layer (303) to correspond to the first pixel electrode (311) to the third pixel electrode (331). This counter electrode (305) may be formed as a single unit in a plurality of organic light-emitting elements.

[0074] The counter electrode (305) may be made of a conductive material with a low work function. For example, the counter electrode (305) may include a (semi)transparent layer comprising silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), lithium (Li), calcium (Ca), or alloys thereof. Alternatively, the counter electrode (305) may further include a layer such as ITO, IZO, ZnO, or In2O3 on the (semi)transparent layer comprising the aforementioned materials.

[0075] Although not illustrated, a capping layer may be further disposed on the counter electrode (305). The capping layer may include LiF, an inorganic material, or / and an organic material.

[0076] Since these organic light-emitting diodes can be easily damaged by external moisture or oxygen, an encapsulation layer may be provided to cover and protect them as needed. The encapsulation layer may be provided as a thin film encapsulation layer (TFE) comprising at least one inorganic film layer and at least one organic film layer. In this case, the thin film encapsulation layer (TFE) may include a first inorganic film layer (335), an organic film layer (337), and a second inorganic film layer (339) that are sequentially stacked.

[0077] The first inorganic film layer (335) can be placed directly on the counter electrode (305). The first inorganic film layer (335) can prevent or minimize external moisture or oxygen from penetrating into the first to third light-emitting elements.

[0078] The organic film layer (337) can be placed directly on the first inorganic film layer (335). The organic film layer (337) can provide a flat surface on the first inorganic film layer (335). Curvatures or particles formed on the upper surface of the first inorganic film layer (335) can be covered by the organic film layer (337), thereby blocking the influence of the surface condition of the upper surface of the first inorganic film layer (335) on the components formed on the organic film layer (337).

[0079] The second inorganic film layer (339) can be placed directly on the organic film layer (337). The second inorganic film layer (339) can prevent or minimize the release of moisture, etc., from the organic film layer (337) to the outside.

[0080] The first inorganic film layer (335) and the second inorganic film layer (339) may include one or more inorganic materials selected from aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide, silicon oxide, silicon nitride, and silicon oxynitride. The first inorganic film layer (335) and the second inorganic film layer (339) may be a single layer or a multilayer containing the aforementioned materials. The organic film layer (337) may include a polymer-based material. Polymer-based materials may include acrylic resin, epoxy resin, polyimide, and polyethylene. In one embodiment, the organic film layer (337) may include acrylate.

[0081] The upper substrate (400) is positioned above the lower substrate (100), and a first light-emitting element having a first pixel electrode (311), a second light-emitting element having a second pixel electrode (321), and a third light-emitting element having a third pixel electrode (331) may be interposed between the upper substrate (400) and the lower substrate (100).

[0082] The upper substrate (400) may include a polymer resin. The upper substrate (400) may include, for example, a polymer resin such as polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, or cellulose acetate propionate. Of course, the upper substrate (400) may have various modifications, such as having a multilayer structure comprising two layers each containing such a polymer resin and a barrier layer containing an inorganic material such as silicon oxide, silicon nitride, or silicon oxynitride interposed between the layers. The upper substrate (400) may have flexible or bendable properties.

[0083] In one embodiment, the lower substrate (100) may include an upper surface (100a) and a lower surface (100b), and the upper surface (100a) of the lower substrate (100) may mean a surface closer to the upper substrate (400) than the lower surface (100b) of the lower substrate (100). Additionally, the upper substrate (400) may include an upper surface (400a) and a lower surface (400b), and the lower surface (400b) of the upper substrate (400) may mean a surface closer to the lower substrate (100) than the upper surface (400a) of the upper substrate (400).

[0084] In one embodiment, a refractive layer (340) may be located between the lower substrate (100) and the upper substrate (400). For example, the refractive layer (340) may be placed on a thin film encapsulation layer (TFE). Specifically, the refractive layer (340) may be placed directly on the second inorganic film layer (339). The refractive layer (340) will be described later.

[0085] In one embodiment, a flattening layer (350) may be disposed between the lower substrate (100) and the upper substrate (400). For example, the flattening layer (350) may be disposed on the refractive layer (340). The flattening layer (350) will be described later.

[0086] In one embodiment, a bank (360) may be disposed between the lower substrate (100) and the upper substrate (400). The bank (360) may include various materials capable of absorbing light. The bank (360) may include the same material as the pixel defining film (150). Alternatively, the bank (360) may include a material different from the pixel defining film (150). For example, the bank (360) may include an opaque inorganic insulating material such as chromium oxide or molybdenum oxide, or an opaque organic insulating material such as black resin.

[0087] In one embodiment, the bank (360) may include an opening corresponding to a light-emitting region of each light-emitting element. Specifically, the bank (360) may be defined with a first opening (OP1) corresponding to a first light-emitting region (EA1) of a first light-emitting element, a second opening (OP2) corresponding to a second light-emitting region (EA2) of a second light-emitting element, and a third opening (OP3) corresponding to a third light-emitting region (EA3) of a third light-emitting element.

[0088] In one embodiment, the first opening (OP1), the second opening (OP2), and the third opening (OP3) defined in the bank (360) may each correspond to an opening defined in the pixel defining film (150). For example, the first opening (OP1) defined in the bank (360) may correspond to an opening in the pixel defining film (150) that defines a first light-emitting region (EA1), the second opening (OP2) defined in the bank (360) may correspond to an opening in the pixel defining film (150) that defines a second light-emitting region (EA2), and the third opening (OP3) defined in the bank (360) may correspond to an opening in the pixel defining film (150) that defines a third light-emitting region (EA3).

[0089] In one embodiment, the area of ​​the first opening (OP1) defined in the bank (360) may be larger than the area of ​​the opening of the pixel defining film (150) defining the first light-emitting region (EA1). That is, the fact that the first opening (OP1) of the bank (360) corresponds to the opening of the pixel defining film (150) defining the first light-emitting region (EA1) may mean that when viewed from a direction perpendicular to the upper surface (400a) of the upper substrate (400) (Z-axis direction), the shape of the edge of the first opening (OP1) of the bank (360) is identical or similar to the shape of the edge of the opening of the pixel defining film (150) defining the first light-emitting region (EA1).

[0090] In one embodiment, the area of ​​the second opening (OP2) defined in the bank (360) may be larger than the area of ​​the opening of the pixel defining film (150) defining the second light-emitting region (EA2). That is, the fact that the second opening (OP2) of the bank (360) corresponds to the opening of the pixel defining film (150) defining the second light-emitting region (EA2) may mean that when viewed from a direction perpendicular to the upper surface (400a) of the upper substrate (400) (Z-axis direction), the shape of the edge of the second opening (OP2) of the bank (360) is identical or similar to the shape of the edge of the opening of the pixel defining film (150) defining the second light-emitting region (EA2).

[0091] In one embodiment, the area of ​​the third opening (OP3) defined in the bank (360) may be larger than the area of ​​the opening of the pixel defining film (150) defining the third light-emitting region (EA3). That is, the fact that the third opening (OP3) of the bank (360) corresponds to the opening of the pixel defining film (150) defining the third light-emitting region (EA3) may mean that when viewed from a direction perpendicular to the upper surface (400a) of the upper substrate (400) (Z-axis direction), the shape of the edge of the third opening (OP3) of the bank (360) is identical or similar to the shape of the edge of the opening of the pixel defining film (150) defining the third light-emitting region (EA3).

[0092] In one embodiment, a first quantum dot layer (370a) may be disposed within a first opening (OP1) defined in the bank (360), a second quantum dot layer (370b) may be disposed within a second opening (OP2) defined in the bank (360), and a light-transmitting layer (370c) may be disposed within a third opening (OP3) defined in the bank (360).

[0093] In one embodiment, the first quantum dot layer (370a), the second quantum dot layer (370b), and the light-transmitting layer (370c) may be disposed on the flattening layer (350). For example, the first quantum dot layer (370a), the second quantum dot layer (370b), and the light-transmitting layer (370c) may be disposed directly on the flattening layer (350).

[0094] FIG. 3 is a drawing for explaining a first quantum dot layer, a second quantum dot layer, and a light-transmitting layer included in a display device according to one embodiment.

[0095] Referring to FIGS. 2 and 3, the first quantum dot layer (370a) can fill the first opening (OP1) defined in the bank (360). The first quantum dot layer (370a) can convert light of a third wavelength band generated in an intermediate layer (303) placed on the first pixel electrode (311) into light of a first wavelength band. For example, if light of a wavelength belonging to 450 nm to 495 nm is generated in the intermediate layer (303), the first quantum dot layer (370a) can convert this light into light of a wavelength belonging to 495 nm to 570 nm. Accordingly, light (Lg) of a wavelength belonging to 495 nm to 570 nm can be emitted to the outside through the upper substrate (400) from the first pixel (PX1).

[0096] In one embodiment, the first quantum dot layer (370a) may include a first photosensitive polymer (1151) in which first quantum dots (1152) and first scattering particles (1153) are dispersed. The first quantum dots (1152) may be excited by blue light (Lb) and emit green light (Lg) having a wavelength longer than the wavelength of blue light (Lb) isotropically. The first photosensitive polymer (1151) may be an organic material having light transmittance. The first scattering particles (1153) may increase color conversion efficiency by scattering blue light (Lb) that is not absorbed by the first quantum dots (1152), thereby causing more first quantum dots (1152) to be excited. The first scattering particles (1153) may be, for example, titanium oxide (TiO2) or metal particles. The first quantum dots (1152) can be selected from group II-VI compounds, group III-V compounds, group IV-VI compounds, group IV elements, group IV compounds and combinations thereof.

[0097] The second quantum dot layer (370b) can fill the second aperture (OP2) defined in the bank (360). The second quantum dot layer (370b) can convert light of the third wavelength band generated in the intermediate layer (303) placed on the second pixel electrode (321) into light of the second wavelength band. For example, if light of a wavelength belonging to 450 nm to 495 nm is generated in the intermediate layer (303), the second quantum dot layer (370b) can convert this light into light of a wavelength belonging to 630 nm to 780 nm. Accordingly, light of a wavelength belonging to 630 nm to 780 nm can be emitted to the outside through the upper substrate (400) from the second pixel (PX2).

[0098] In one embodiment, the second quantum dot layer (370b) may include a second photosensitive polymer (1161) in which second quantum dots (1162) and second scattering particles (1163) are dispersed. The second quantum dots (1162) may be excited by blue light (Lb) and emit red light (Lr) having a wavelength longer than the wavelength of blue light (Lb) isotropically. The second photosensitive polymer (1161) may be an organic material having light transmittance. The second scattering particles (1163) may increase color conversion efficiency by scattering blue light (Lb) that is not absorbed by the second quantum dots (1162), thereby causing more second quantum dots (1162) to be excited. The second scattering particles (1163) may be, for example, titanium oxide (TiO2) or metal particles. The second quantum dots (1162) may be selected from group II-VI compounds, group III-V compounds, group IV-VI compounds, group IV elements, group IV compounds, and combinations thereof. In one embodiment, the second quantum dots (1162) may be the same material as the first quantum dots (1152), wherein the size of the second quantum dots (1162) may be larger than the size of the first quantum dots (1152).

[0099] The light-transmitting layer (370c) can transmit blue light (Lb). The light-transmitting layer (370c) may include a third photosensitive polymer (1171) in which third scattering particles (1173) are dispersed. The third photosensitive polymer (1171) may be an organic material having light transmittance, such as silicone resin or epoxy resin, for example, and may be the same material as the first and second photosensitive polymers (1151, 1161) described above. The third scattering particles (1173) can scatter and emit blue light (Lb) and may be the same material as the first and second scattering particles (1153, 1163) described above.

[0100] In one embodiment, the first quantum dot layer (370a), the second quantum dot layer (370b), and the light-transmitting layer (370c) can be formed in the first opening (OP1), the second opening (OP2), and the third opening (OP3) of the bank (360), respectively, through an inkjet printing method.

[0101] In one embodiment, a first color filter layer (380a), a second color filter layer (380b), and a third color filter layer (380c) may be disposed on the lower surface (400b) of the upper substrate (400). The first color filter layer (380a) may be disposed directly on the first quantum dot layer (370a), the second color filter layer (380b) may be disposed directly on the second quantum dot layer (370b), and the third color filter layer (380c) may be disposed directly on the light-transmitting layer (370c). Accordingly, the light converted in the first quantum dot layer (370a) can be directly incident on the first color filter layer (380a), the light converted in the second quantum dot layer (370b) can be directly incident on the second color filter layer (380b), and the light passing through the light-transmitting layer (370c) can be directly incident on the third color filter layer (380c).

[0102] In one embodiment, the first color filter layer (380a), the second color filter layer (380b), and the third color filter layer (380c) can pass only light of wavelengths belonging to different wavelength bands. Specifically, the first color filter layer (380a) can pass only light of wavelengths belonging to the first wavelength band, the second color filter layer (380b) can pass only light of wavelengths belonging to the second wavelength band, and the third color filter layer (380c) can pass only light of wavelengths belonging to the third wavelength band. At this time, the first wavelength band may be 495nm to 570nm, the second wavelength band may be 630nm to 780nm, and the third wavelength band may be 450nm to 495nm. That is, the first color filter layer (380a) can pass only light of wavelengths ranging from 495 nm to 570 nm, the second color filter layer (380b) can pass only light of wavelengths ranging from 630 nm to 780 nm, and the third color filter layer (380c) can pass only light of wavelengths ranging from 450 nm to 495 nm.

[0103] In one embodiment, the first color filter layer (380a) may overlap (or at least partially overlap) with the first light-emitting element including the first pixel electrode (311). For example, the first color filter layer (380a) may overlap (or at least partially overlap) with the first light-emitting region (EA1) of the first light-emitting element. Accordingly, light emitted from the first light-emitting element can pass through the first color filter layer (380a). This will be explained in more detail below.

[0104] In one embodiment, the second color filter layer (380b) may overlap (or at least partially overlap) with the second light-emitting element including the second pixel electrode (321). For example, the second color filter layer (380b) may overlap (or at least partially overlap) with the second light-emitting region (EA2) of the second light-emitting element. Accordingly, light emitted from the second light-emitting element may pass through the second color filter layer (380b). This will be explained in more detail below.

[0105] In one embodiment, the third color filter layer (380c) may overlap (or at least partially overlap) with the third light-emitting element including the third pixel electrode (331). For example, the third color filter layer (380c) may overlap (or at least partially overlap) with the third light-emitting region (EA3) of the third light-emitting element. Accordingly, light emitted from the third light-emitting element can pass through the third color filter layer (380c). This will be explained in more detail below.

[0106] In one embodiment, a sixth opening (OP6) and an eighth opening (OP8) may be defined in the first color filter layer (380a). The sixth opening (OP6) defined in the first color filter layer (380a) may overlap (or at least partially overlap) with the second color filter layer (380b), and the eighth opening (OP8) defined in the first color filter layer (380a) may overlap (or at least partially overlap) with the third color filter layer (380c).

[0107] In one embodiment, a fourth opening (OP4) and a ninth opening (OP9) may be defined in the second color filter layer (380b). The fourth opening (OP4) defined in the first color filter layer (380a) may overlap (or at least partially overlap) with the first color filter layer (380a), and the ninth opening (OP9) defined in the second color filter layer (380b) may overlap (or at least partially overlap) with the third color filter layer (380c).

[0108] In one embodiment, a fifth opening (OP5) and a seventh opening (OP7) may be defined in the third color filter layer (380c). The fifth opening (OP5) defined in the third color filter layer (380c) may overlap (or at least partially overlap) with the first color filter layer (380a), and the seventh opening (OP7) defined in the third color filter layer (380c) may overlap (or at least partially overlap) with the second color filter layer (380b).

[0109] In one embodiment, at least a portion of the first color filter layer (380a) may be exposed through a fourth opening (OP4) defined in the second color filter layer (380b) and a fifth opening (OP5) defined in the third color filter layer (380c). The first color filter layer (380a) may come into direct contact with the lower surface (400b) of the upper substrate (400) through the fourth opening (OP4) and the fifth opening (OP5). Specifically, the first color filter layer (380a) can be in direct contact with the first quantum dot layer (370a) in the direction of the lower surface (100b) of the lower substrate (100) (e.g., -Z direction), and the first color filter layer (380a) can be in direct contact with the lower surface (400b) of the upper substrate (400) in the direction of the upper surface (400a) of the upper substrate (400) (e.g., +Z direction).

[0110] Accordingly, in the first pixel (PX1), light of a wavelength belonging to the first wavelength band can be emitted to the outside through the upper substrate (400). Specifically, light of the third wavelength band emitted from the first light-emitting element is converted into light of the first wavelength band while passing through the first quantum dot layer (370a) and is filtered while passing through the first color filter layer (380a), so that light of a wavelength belonging to the first wavelength band can be emitted to the outside through the upper substrate (400) in the first pixel (PX1). In addition, since the light emitted from the first light-emitting element passes through the first quantum dot layer (370a) and the first color filter layer (380a), the color purity of the light emitted through the upper substrate (400) can be improved.

[0111] In one embodiment, at least a portion of the second color filter layer (380b) may be exposed through a sixth opening (OP6) defined in the first color filter layer (380a) and a seventh opening (OP7) defined in the third color filter layer (380c). The second color filter layer (380b) may be in direct contact with the second quantum dot layer (370b) through the sixth opening (OP6), and the second color filter layer (380b) may be in direct contact with the lower surface (400b) of the upper substrate (400) through the seventh opening (OP7). Specifically, the second color filter layer (380b) can be in direct contact with the second quantum dot layer (370b) in the direction of the lower surface (100b) of the lower substrate (100) (e.g., -Z direction), and the second color filter layer (380b) can be in direct contact with the lower surface (400b) of the upper substrate (400) in the direction of the upper surface (400a) of the upper substrate (400) (e.g., +Z direction).

[0112] Accordingly, in the second pixel (PX2), light of a wavelength belonging to the second wavelength band can be emitted to the outside through the upper substrate (400). Specifically, light of the third wavelength band emitted from the second light-emitting element is converted into light of the second wavelength band while passing through the second quantum dot layer (370b) and is filtered while passing through the second color filter layer (380b), so that light of a wavelength belonging to the second wavelength band can be emitted to the outside through the upper substrate (400) in the second pixel (PX2). In addition, since the light emitted from the second light-emitting element passes through the second quantum dot layer (370b) and the second color filter layer (380b), the color purity of the light emitted through the upper substrate (400) can be improved.

[0113] In one embodiment, at least a portion of the third color filter layer (380c) may be exposed through the eighth opening (OP8) defined in the first color filter layer (380a) and the ninth opening (OP9) defined in the second color filter layer (380b). The third color filter layer (380c) may be in direct contact with the light-transmitting layer (370c) through the eighth opening (OP8) and the ninth opening (OP9). Specifically, the third color filter layer (380c) may be in direct contact with the light-transmitting layer (370c) in the direction of the lower surface (100b) of the lower substrate (100) (e.g., the -Z direction), and the third color filter layer (380c) may be in direct contact with the lower surface (400b) of the upper substrate (400) in the direction of the upper surface (400a) of the upper substrate (400) (e.g., the +Z direction).

[0114] Accordingly, in the third pixel (PX3), light of a wavelength belonging to the third wavelength band can be emitted to the outside through the upper substrate (400). Specifically, since the light of the third wavelength band emitted from the third light-emitting element passes through the light-transmitting layer (370c) and is filtered while passing through the third color filter layer (380c), light of a wavelength belonging to the third wavelength band can be emitted to the outside through the upper substrate (400) in the third pixel (PX3). In addition, since the light emitted from the third light-emitting element passes through the light-transmitting layer (370c) and the third color filter layer (380c), the color purity of the light emitted through the upper substrate (400) can be improved.

[0115] In one embodiment, at least two color filter layers may be superimposed between the first pixel (PX1), the second pixel (PX2), and the third pixel (PX3). In FIG. 2, the first color filter layer (380a), the second color filter layer (380b), and the third color filter layer (380c) are shown existing between the first pixel (PX1), the second pixel (PX2), and the third pixel (PX3). These superimposed color filter layers can function as a black matrix. For example, if the first color filter layer (380a) allows only light of a wavelength belonging to the first wavelength band to pass through, the second color filter layer (380b) allows only light of a wavelength belonging to the second wavelength band to pass through, and the third color filter layer (380c) allows only light of a wavelength belonging to the third wavelength band to pass through, then theoretically, no light of any wavelength can pass through these superimposed layers.

[0116] In one embodiment, a first color filter layer (380a), a second color filter layer (380b), and a third color filter layer (380c) may be superimposed between the upper substrate (400) and the bank (360). By superimposing the first color filter layer (380a), the second color filter layer (380b), and the third color filter layer (380c) between the upper substrate (400) and the bank (360), the step difference between the upper substrate (400) and the bank (360) can be maintained at a constant level.

[0117] For example, if the upper surface (340a) of the refractive layer (340) is provided flat, light emitted from the first light-emitting element of the first pixel (PX1) is incident on the second quantum dot layer (370b) or the light-transmitting layer (370c), and light is emitted from the upper substrate (400) of the second pixel (PX2) or the third pixel (PX3) by the incident light, which may cause a color mixing defect. Also, if the upper surface (340a) of the refractive layer (340) is provided flat, external light is incident on the pixel electrodes (311, 321, 331) of the light-emitting elements, and a reflected color may occur by the incident light.

[0118] In one embodiment, the upper surface (340a) of the refractive layer (340) may be provided in a shape that collects light emitted from the first light-emitting element, the second light-emitting element, and the third light-emitting element. In one embodiment, the upper surface (340a) of the refractive layer (340) may be provided in a concave shape toward the lower surface (100b) of the lower substrate (100) (e.g., the -Z direction). Hereinafter, the case in which the upper surface (340a) of the refractive layer (340) is provided in a concave shape toward the lower surface (100b) of the lower substrate (100) (e.g., the -Z direction) is described, but the present invention is not limited thereto. As long as it can collect light emitted from the first light-emitting element, the second light-emitting element, and the third light-emitting element, the upper surface (340a) of the refractive layer (340) may be provided in any shape.

[0119] In one embodiment, a concave portion (345a, 345b, 345c) that is concave in the direction of the lower surface (100b) of the lower substrate (100) (e.g., -Z direction) may be defined on the upper surface (340a) of the refractive layer (340). For example, a first concave portion (345a) corresponding to a first light-emitting element, a second concave portion (345b) corresponding to a second light-emitting element, and a third concave portion (345c) corresponding to a third light-emitting element may be defined on the upper surface (340a) of the refractive layer (340).

[0120] In one embodiment, a first concave portion (345a) defined on the upper surface (340a) of the refractive layer (340) may overlap (or at least partially overlap) with the first light-emitting region (EA1) of the first light-emitting element. The first concave portion (345a) defined on the upper surface (340a) of the refractive layer (340) may concentrate light emitted from the first light-emitting element positioned below it. Specifically, the first concave portion (345a) defined on the upper surface (340a) of the refractive layer (340) may direct (or collect) light emitted from the first light-emitting element positioned below it toward (or be gathered by) the first quantum dot layer (370a). Accordingly, by defining a first concave portion (345a) on the upper surface (340a) of the refractive layer (340), light emitted from the first light-emitting element may be prevented or minimized from being incident on the second quantum dot layer (370b) or the light-transmitting layer (370c), thereby improving the light efficiency of the display device.

[0121] In FIG. 2, a first concave portion (345a) is shown defined on the upper surface (340a) of the refractive layer (340) to correspond to the first light-emitting region (EA1) of the first light-emitting element, but the present invention is not limited thereto. At least one first concave portion (345a) may be provided. Two or more first concave portions (345a) may be provided. For example, a plurality of first concave portions (345a) may be defined on the upper surface (340a) of the refractive layer (340), and the plurality of first concave portions (345a) defined on the upper surface (340a) of the refractive layer (340) may overlap (or at least partially overlap) with the first light-emitting region (EA1) of the first light-emitting element.

[0122] In one embodiment, the second concave portion (345b) defined on the upper surface (340a) of the refractive layer (340) may overlap (or at least partially overlap) with the second light-emitting region (EA2) of the second light-emitting element. The second concave portion (345b) defined on the upper surface (340a) of the refractive layer (340) may concentrate light emitted from the second light-emitting element positioned below it. Specifically, the second concave portion (345b) defined on the upper surface (340a) of the refractive layer (340) may direct (or collect) light emitted from the second light-emitting element positioned below it toward (or be gathered by) the second quantum dot layer (370b). Accordingly, by defining a second concave portion (345b) on the upper surface (340a) of the refractive layer (340), light emitted from the second light-emitting element may be prevented or minimized from being incident on the first quantum dot layer (370a) or the light-transmitting layer (370c), thereby improving the light efficiency of the display device.

[0123] In FIG. 2, a second concave portion (345b) is shown defined on the upper surface (340a) of the refractive layer (340) to correspond to the second light-emitting region (EA2) of the second light-emitting element, but the present invention is not limited thereto. At least one second concave portion (345b) may be provided. Two or more second concave portions (345b) may be provided. For example, a plurality of second concave portions (345b) may be defined on the upper surface (340a) of the refractive layer (340), and the plurality of second concave portions (345b) defined on the upper surface (340a) of the refractive layer (340) may overlap (or at least partially overlap) with the second light-emitting region (EA2) of the second light-emitting element.

[0124] In one embodiment, the third concave portion (345c) defined on the upper surface (340a) of the refractive layer (340) may overlap (or at least partially overlap) with the third light-emitting region (EA3) of the third light-emitting element. The third concave portion (345c) defined on the upper surface (340a) of the refractive layer (340) may concentrate light emitted from the third light-emitting element positioned below it. Specifically, the third concave portion (345c) defined on the upper surface (340a) of the refractive layer (340) may direct (or collect) light emitted from the third light-emitting element positioned below it toward the light-transmitting layer (370c). Accordingly, by defining a third concave portion (345c) on the upper surface (340a) of the refractive layer (340), light emitted from the third light-emitting element may be prevented or minimized from being incident on the first quantum dot layer (370a) or the second quantum dot layer (370b), thereby improving the light efficiency of the display device.

[0125] In FIG. 2, a third concave portion (345c) is shown defined on the upper surface (340a) of the refractive layer (340) to correspond to the third light-emitting region (EA3) of the third light-emitting element, but the present invention is not limited thereto. At least one third concave portion (345c) may be provided. Two or more third concave portions (345c) may be provided. For example, a plurality of third concave portions (345c) may be defined on the upper surface (340a) of the refractive layer (340), and the plurality of third concave portions (345c) defined on the upper surface (340a) of the refractive layer (340) may overlap (or at least partially overlap) with the second light-emitting region (EA2) of the second light-emitting element.

[0126] In one embodiment, the refractive layer (340) may be provided with an inorganic material or a metal, and the flattening layer (350) may be provided with an organic material. For example, the refractive layer (340) may include one or more inorganic materials selected from aluminum oxide, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide, silicon oxide, silicon nitride, and silicon oxynitride, or may include a metal such as molybdenum (Mo), aluminum (Al), copper (Cu), and titanium (Ti). However, the present invention is not limited thereto.

[0127] When light travels from one medium to another, it can be refracted at the boundary between the two media. If we define the angle between the line perpendicular to the boundary surface of the two media and the incident light as the angle between the line perpendicular to the boundary surface and the refracted light as the angle of refraction, then when light travels from a medium with a lower refractive index to a medium with a higher refractive index, the angle of incidence is greater than the angle of refraction.

[0128] In one embodiment, the refractive layer (340) and the flattening layer (350) may have different refractive indices. The flattening layer (350) may have a refractive index greater than that of the refractive layer (340). Thus, by providing the flattening layer (350) with a refractive index greater than that of the refractive layer (340), light refracted at the interface between the refractive layer (340) and the flattening layer (350) can be concentrated.

[0129] For example, light emitted from the first light-emitting element may be refracted at the interface between the refractive layer (340) and the flattening layer (350). In this case, if the refractive index of the flattening layer (350) is greater than the refractive index of the refractive layer (340), the light refracted at the interface between the refractive layer (340) and the flattening layer (350) may be directed toward the first quantum dot layer (370a). Therefore, if the refractive index of the flattening layer (350) is greater than the refractive index of the refractive layer (340), the incident light emitted from the first light-emitting element on the second quantum dot layer (370b) or the light-transmitting layer (370c) may be prevented or minimized, thereby improving the light efficiency of the display device.

[0130] Additionally, light emitted from the second light-emitting element may be refracted at the interface between the refractive layer (340) and the flattening layer (350). In this case, if the refractive index of the flattening layer (350) is greater than the refractive index of the refractive layer (340), the light refracted at the interface between the refractive layer (340) and the flattening layer (350) may be directed toward the second quantum dot layer (370b). Therefore, if the refractive index of the flattening layer (350) is greater than the refractive index of the refractive layer (340), the incident light emitted from the second light-emitting element on the first quantum dot layer (370a) or the light-transmitting layer (370c) can be prevented or minimized, thereby improving the light efficiency of the display device.

[0131] Additionally, light emitted from the third light-emitting element may be refracted at the interface between the refractive layer (340) and the flattening layer (350). In this case, if the refractive index of the flattening layer (350) is greater than the refractive index of the refractive layer (340), the light refracted at the interface between the refractive layer (340) and the flattening layer (350) may be directed toward the light-transmitting layer (370c). Therefore, if the refractive index of the flattening layer (350) is greater than the refractive index of the refractive layer (340), the incident light emitted from the third light-emitting element on the first quantum dot layer (370a) or the second quantum dot layer (370b) may be prevented or minimized, thereby improving the light efficiency of the display device.

[0132] FIG. 4 is a cross-sectional view schematically illustrating a display device according to one embodiment. The embodiment of FIG. 4 differs from the embodiment of FIG. 2 in that a protective layer (410) is disposed between the flattening layer (350) and the first quantum dot layer (370a). In FIG. 4, the same reference numerals as in FIG. 2 refer to the same components, so a redundant description thereof is omitted.

[0133] Referring to FIG. 4, a protective layer (410) may be disposed between the flattening layer (350) and the first quantum dot layer (370a). The protective layer (410) may be disposed entirely on the flattening layer (350). For example, the protective layer (410) may be disposed between the flattening layer (350) and the first quantum dot layer (370a), between the flattening layer (350) and the second quantum dot layer (370b), and between the flattening layer (350) and the light-transmitting layer (370c).

[0134] A protective layer (410) placed between the flattening layer (350) and the first quantum dot layer (370a), between the flattening layer (350) and the second quantum dot layer (370b), and between the flattening layer (350) and the light-transmitting layer (370c) can serve to protect the first quantum dot layer (370a), the second quantum dot layer (370b), and the light-transmitting layer (370c).

[0135] In one embodiment, the protective layer (410) may be formed as a single layer or a multilayer film made of organic or inorganic material. In one embodiment, the protective layer (410) may include general-purpose polymers such as benzocyclobutene (BCB), polyimide (PI), hexamethyldisiloxane (HMDSO), polymethyl methacrylate (Poly(methyl 2-methylpropenoate) PMMA), or polystyrene (PS), polymer derivatives having phenolic groups, acrylic polymers, imide polymers, aryl ether polymers, amide polymers, fluorine polymers, p-xylene polymers, vinyl alcohol polymers, and blends thereof. In one embodiment, the protective layer (410) may be silicon oxide (SiO₂). X ), silicon nitride (SiN X ), silicon oxynitride (SiO₂ X N Y It may include aluminum oxide (Al2O3), titanium oxide (TiO2), tantalum oxide (Ta2O5), hafnium oxide (HfO2), or zinc oxide (ZnO), etc.

[0136] FIGS. 5, 6, and 7 are cross-sectional views schematically illustrating a display device according to one embodiment. The embodiments of FIGS. 5, 6, and 7 differ from the embodiment of FIG. 2 in that a filler material (420) is further provided between the lower substrate (100) and the upper substrate (400). In FIGS. 5, 6, and 7, the same reference numerals as in FIG. 2 refer to the same components, so a redundant description thereof is omitted.

[0137] Referring to FIGS. 5, 6, and 7, a filler material (420) may be further provided between the lower substrate (100) and the upper substrate (400). In one embodiment, as shown in FIG. 5, the filler material (420) may be interposed between the refractive layer (340) and the flattening layer (350). Alternatively, as shown in FIG. 6, the filler material (420) may be interposed between the flattening layer (350) and the first quantum dot layer (370a). Specifically, the filler material (420) may be interposed between the flattening layer (350) and the first quantum dot layer (370a), between the flattening layer (350) and the second quantum dot layer (370b), and between the flattening layer (350) and the light-transmitting layer (370c). Alternatively, as shown in FIG. 7, the filler (420) may be interposed between the thin film encapsulation layer (TFE) and the refractive layer (340). Specifically, the filler (420) may be interposed between the second inorganic film layer (339) and the refractive layer (340).

[0138] The filler (420) can act as a buffer against external pressure, etc. The filler (420) may be made of organic materials such as methyl silicone, phenyl silicone, and polyimide. However, it is not limited thereto, and the filler (420) may also be made of organic sealants such as urethane resin, epoxy resin, acrylic resin, or inorganic sealants such as silicone.

[0139] FIG. 8 is a cross-sectional view schematically illustrating a display device according to one embodiment. The embodiment of FIG. 8 differs from the embodiment of FIG. 2 in that the second inorganic film layer (339, FIG. 2) and the refractive layer (340) are integrally provided. In FIG. 8, the same reference numerals as in FIG. 2 refer to the same components, so a redundant description thereof is omitted.

[0140] Referring to FIG. 8, since organic light-emitting diodes can be easily damaged by external moisture or oxygen, an encapsulation layer may be provided to cover and protect these organic light-emitting diodes as needed. The encapsulation layer may be provided as a thin film encapsulation layer (TFE, FIG. 2) comprising at least one inorganic film layer and at least one organic film layer. In this case, the thin film encapsulation layer (TFE) may include a first inorganic film layer (335) and an organic film layer (337) that are sequentially stacked.

[0141] The first inorganic film layer (335) can be placed directly on the counter electrode (305). The first inorganic film layer (335) can prevent or minimize external moisture or oxygen from penetrating into the first to third light-emitting elements.

[0142] The organic film layer (337) can be placed directly on the first inorganic film layer (335). The organic film layer (337) can provide a flat surface on the first inorganic film layer (335). Curvatures or particles formed on the upper surface of the first inorganic film layer (335) can be covered by the organic film layer (337), thereby blocking the influence of the surface condition of the upper surface of the first inorganic film layer (335) on the components formed on the organic film layer (337).

[0143] In one embodiment, a refractive layer (340) may be located between the lower substrate (100) and the upper substrate (400). For example, the refractive layer (340) may be placed on a thin film encapsulation layer (TFE). Specifically, the refractive layer (340) may be placed directly on an organic film layer (337). That is, the refractive layer (340) can prevent or minimize the release of moisture, etc., emitted from the organic film layer (337) to the outside.

[0144] FIG. 9 is a cross-sectional view schematically illustrating a display device according to one embodiment. The embodiment of FIG. 9 differs from the embodiment of FIG. 2 in that a column spacer (365) is further disposed on the flattening layer (350). In FIG. 9, the same reference numerals as in FIG. 2 refer to the same components, so a redundant description thereof is omitted.

[0145] Referring to FIG. 9, in one embodiment, a column spacer (365) may be further interposed between the lower substrate (100) and the upper substrate (400). By placing the column spacer (365) between the lower substrate (100) and the upper substrate (400), the gap between the lower substrate (100) and the upper substrate (400) can be maintained at a constant level.

[0146] The column spacer (365) can be placed on the flattening layer (350). For example, the column spacer (365) can be placed directly on the flattening layer (350). Additionally, a bank (360) can be placed on the column spacer (365). For example, the bank (360) can be placed directly on the column spacer (365). Thus, the bank (360) and the column spacer (365) can overlap (or at least partially overlap).

[0147] In one embodiment, the column spacer (365) may overlap (or at least partially overlap) with the pixel defining film (150) disposed below it. For example, the column spacer (365) may not overlap with the light-emitting regions (EA1, EA2, EA3) of the light-emitting element.

[0148] In one embodiment, the column spacer (365) may be made of the same material as the bank (360). However, the present invention is not limited thereto. For example, the column spacer (365) may be made of a different material from the bank (360).

[0149] FIG. 10 is a cross-sectional view schematically illustrating a display device according to one embodiment. The embodiment of FIG. 10 differs from the embodiment of FIG. 2 in that the flattening layer (350) disposed on the refractive layer (340) is omitted. In FIG. 10, the same reference numerals as in FIG. 2 refer to the same components, so a redundant description thereof is omitted.

[0150] Referring to FIG. 10, a refractive layer (340) may be disposed between the lower substrate (100) and the upper substrate (400). The refractive layer (340) may be disposed on a thin film encapsulation layer (TFE). For example, the refractive layer (340) may be disposed directly on the second inorganic film layer (399).

[0151] In one embodiment, a first quantum dot layer (370a), a second quantum dot layer (370b), and a light-transmitting layer (370c) may be disposed on the refractive layer (340). For example, the first quantum dot layer (370a), the second quantum dot layer (370b), and the light-transmitting layer (370c) may be disposed directly on the refractive layer (340). Thus, light passing through the refractive layer (340) may be directly incident on the first quantum dot layer (370a), the second quantum dot layer (370b), and the light-transmitting layer (370c).

[0152] The present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims. Explanation of the symbols

[0153] 1: Display device 100, 400: Lower substrate, Upper substrate 340: Refractive layer 350: Leveling layer 370a, 370b, 370c: First quantum dot layer, second quantum dot layer, light-transmitting layer 380a, 380b, 380c: First color filter layer, second color filter layer, third color filter layer

Claims

Claim 1 A display device comprising: a lower substrate; a first light-emitting element disposed on the lower substrate and having a first light-emitting region; an upper substrate positioned on the upper portion of the lower substrate such that the first light-emitting element is interposed therein; a refractive layer positioned between the first light-emitting element and the upper substrate; a thin film encapsulation layer comprising a first inorganic film layer, an organic film layer, and a second inorganic film layer sequentially stacked between the first light-emitting element and the refractive layer; a planarization layer positioned between the refractive layer and the upper substrate; a first color filter layer positioned on the lower surface of the upper substrate in the direction of the lower substrate; a bank having a first opening corresponding to the first light-emitting region; and a first quantum dot layer filling the first opening; wherein the upper surface of the refractive layer is provided in a shape that concentrates light emitted from the first light-emitting element, and the refractive layer is provided integrally with the second inorganic film layer. Claim 2 A display device according to claim 1, wherein the upper surface of the refractive layer includes a concave portion concave in the direction of the lower surface of the lower substrate. Claim 3 In paragraph 2, the display device is provided with at least one concave portion. Claim 4 In paragraph 2, the above-mentioned concave portion overlaps with the above-mentioned first light-emitting region, a display device. Claim 5 A display device according to claim 1, wherein the planarization layer is directly disposed on the refractive layer. Claim 6 A display device according to claim 1, wherein the planarization layer has a refractive index greater than that of the refractive layer. Claim 7 A display device according to claim 1, wherein the first color filter layer and the first quantum dot layer each overlap with the first light-emitting region. Claim 8 A display device according to claim 1, further comprising: a second light-emitting element disposed on the lower substrate and having a second light-emitting region; a second color filter layer having a fourth opening that overlaps at least partially with the second light-emitting region, is located on the lower surface of the upper substrate, and overlaps with the first opening; and a second quantum dot layer located between the second light-emitting element and the second color filter layer. Claim 9 A display device according to claim 8, further comprising: a third light-emitting element disposed on the lower substrate and having a third light-emitting region; a third color filter layer having a fifth opening that overlaps at least partially with the third light-emitting region, is located on the lower surface of the upper substrate, and overlaps with the first opening; and a light-transmitting layer located between the third light-emitting element and the third color filter layer. Claim 10 A display device according to claim 9, wherein the bank further comprises a second opening corresponding to the second light-emitting region and a third opening corresponding to the third light-emitting region, wherein the second quantum dot layer fills the second opening and the light-transmitting layer fills the third opening. Claim 11 A display device according to claim 9, wherein the first light-emitting element, the second light-emitting element, and the third light-emitting element emit light belonging to the same wavelength band. Claim 12 delete Claim 13 delete Claim 14 delete Claim 15 A display device according to claim 1, further comprising a filler material located between the lower substrate and the upper substrate. Claim 16 In item 15, the above-mentioned filler is a display device located between the above-mentioned refractive layer and the above-mentioned flattening layer. Claim 17 In item 15, the above-mentioned filler is a display device located between the above-mentioned flattening layer and the above-mentioned first quantum dot layer. Claim 18 delete Claim 19 A display device according to claim 1, further comprising a protective layer located between the planarization layer and the first quantum dot layer. Claim 20 A display device according to claim 1, further comprising a column spacer located between the flattening layer and the bank. Claim 21 A lower substrate; a first light-emitting element, a second light-emitting element, and a third light-emitting element disposed on the lower substrate and each having a first light-emitting region, a second light-emitting region, and a third light-emitting region; an upper substrate positioned above the lower substrate such that the first light-emitting element to the third light-emitting element are interposed therebetween; a refractive layer positioned between the first light-emitting element to the third light-emitting element and the upper substrate; a thin film encapsulation layer comprising a first inorganic film layer, an organic film layer, and a second inorganic film layer positioned between the first light-emitting element to the third light-emitting element and the refractive layer and sequentially stacked; and a first color filter layer, a second color filter layer, and a third color filter layer positioned on the lower surface of the upper substrate in the direction of the lower substrate. A display device comprising: a first quantum dot layer, a second quantum dot layer, and a light-transmitting layer each overlapping with the first color filter layer, the second color filter layer, and the third color filter layer, wherein the upper surface of the refractive layer is provided in a shape that collects light emitted from the first light-emitting element, the second light-emitting element, and the third light-emitting element, and wherein the refractive layer is provided integrally with the second inorganic film layer. Claim 22 A display device according to claim 21, wherein the upper surface of the refractive layer includes a concave portion concave in the direction of the lower surface of the lower substrate. Claim 23 A display device according to claim 22, wherein the concave portion is provided to correspond to each of the first light-emitting element, the second light-emitting element, and the third light-emitting element. Claim 24 A display device according to claim 21, further comprising a planarization layer located between the refractive layer and the upper substrate. Claim 25 A display device according to claim 24, wherein the flattening layer is placed directly on the refractive layer. Claim 26 In paragraph 24, the display device having a refractive index greater than that of the refractive layer. Claim 27 A display device according to claim 21, wherein the first light-emitting element, the second light-emitting element, and the third light-emitting element emit light belonging to the same wavelength band. Claim 28 delete Claim 29 delete Claim 30 delete

Images