Display device and method of manufacturing same

Abstract

The invention relates to a display device and a method of manufacturing the same. The display device includes: a first electrode; a second electrode on the first electrode and facing the first electrode; an intermediate layer between the first electrode and the second electrode and including an emission layer including quantum dots; a first pixel defining layer covering at least a portion of the first electrode and exposing an upper surface of the first electrode; a reflective film on the first pixel defining layer; and a second pixel defining layer on the reflective film.

Description

Technical Field

[0001] The present disclosure relates to a display device, and more particularly to a display device including quantum dots and a method of manufacturing the display device. Background Art

[0002] As information technology develops, the importance of display devices as a connection medium between users and information is becoming increasingly prominent. For example, the use of display devices such as liquid crystal display (LCD) devices, organic light emitting display (OLED) devices, plasma display devices (PDD) and quantum dot display devices is increasing.

[0003] The quantum dot display device includes a quantum dot light emitting element, and the quantum dot light emitting element has the advantages of high chromaticity, high luminous efficiency, and multi-coloring. Summary of the invention

[0004] The embodiment provides a display device having improved element characteristics.

[0005] The embodiment provides a method of manufacturing a display device.

[0006] According to an embodiment, a display device includes: a first electrode; a second electrode on the first electrode and facing the first electrode; an intermediate layer between the first electrode and the second electrode and including an emission layer containing quantum dots; a first pixel defining layer, the first pixel defining layer covering at least a portion of the first electrode and exposing an upper surface of the first electrode; a reflective film on the first pixel defining layer; and a second pixel defining layer on the reflective film.

[0007] In an embodiment, the reflective film may include a metallic material.

[0008] In an embodiment, the reflective film may include aluminum or an aluminum alloy.

[0009] In an embodiment, the reflective film may be electrically disconnected from the first electrode.

[0010] In an embodiment, the emissive layer may further include a cross-linking agent activated by ultraviolet light.

[0011] In an embodiment, a structure in which the first pixel defining layer, the reflective film, and the second pixel defining layer are sequentially stacked may define a pixel opening exposing the upper surface of the first electrode, and the intermediate layer may be disposed in the pixel opening.

[0012] In an embodiment, a structure in which the first pixel defining layer, the reflective film, and the second pixel defining layer are sequentially stacked may surround the intermediate layer in a plan view.

[0013] In an embodiment, the intermediate layer may further include a metal oxide layer adjacent to the emission layer and including a metal oxide.

[0014] In an embodiment, the reflective film may directly contact the intermediate layer.

[0015] In an embodiment, at least a portion of the reflective film may be exposed from the second pixel defining layer.

[0016] In an embodiment, the second pixel defining layer may include a light blocking material.

[0017] According to an embodiment, a method for manufacturing a display device includes: forming a first pixel defining layer, the first pixel defining layer covers at least a portion of a first electrode and exposes an upper surface of the first electrode; forming a reflective film on the first pixel defining layer; forming a second pixel defining layer on the reflective film; forming an emission layer including quantum dots on the first electrode; and curing the emission layer with ultraviolet rays.

[0018] In an embodiment, the emitting layer may further include a cross-linking agent activated by the ultraviolet rays.

[0019] In an embodiment, when the emitting layer is cured with the ultraviolet rays, at least some of the ultraviolet rays are reflected by the reflective film and reach the emitting layer.

[0020] In an embodiment, curing the emissive layer with the ultraviolet rays may be performed at a temperature below about 180°C.

[0021] In an embodiment, the forming the reflective film may include: forming a preliminary reflective film including a metal material on the first electrode and the first pixel defining layer; and patterning the preliminary reflective film.

[0022] In an embodiment, the preliminary reflective film includes aluminum or an aluminum alloy.

[0023] In an embodiment, the method may further include: forming a metal oxide layer including a metal oxide on the first electrode; and radiating ultraviolet rays to the metal oxide layer.

[0024] In an embodiment, when the ultraviolet rays are radiated toward the metal oxide layer, at least some of the ultraviolet rays may be reflected by the reflective film and reach the metal oxide layer.

[0025] In an embodiment, the emission layer and the metal oxide layer may be formed adjacent to each other.

[0026] The display device according to the embodiment may include a first pixel defining layer covering at least a portion of the first electrode of the light emitting element, a reflective film on the first pixel defining layer, and a second pixel defining layer on the reflective film. For example, in the display device according to the embodiment, a structure in which the first pixel defining layer, the reflective film, and the second pixel defining layer are stacked in sequence may define a pixel opening exposing the upper surface of the first electrode of the light emitting element.

[0027] Furthermore, in the method of manufacturing the display device according to the embodiment, the emission layer included in the light emitting element may be cured with ultraviolet rays, and the surface of the metal oxide layer included in the light emitting element may be modified by irradiating ultraviolet rays to the metal oxide layer.

[0028] Therefore, in the process of curing the emission layer formed in the pixel opening with ultraviolet rays, at least some of the radiated ultraviolet rays can be reflected by the reflective film and reach the emission layer. For example, in addition to the ultraviolet rays that directly reach the emission layer, the ultraviolet rays reflected by the reflective film can also additionally reach the emission layer. Therefore, the amount of ultraviolet rays reaching the emission layer can be increased, and the degree of film curing of the emission layer by radiating ultraviolet rays can be increased. Therefore, the phenomenon that the material included in the emission layer and the material included in the metal oxide layer are mixed at the interface between the emission layer and the metal oxide layer can be further reduced or prevented. Therefore, the element characteristics of the light-emitting element can be improved.

[0029] In addition, in the process of modifying the surface of the metal oxide layer by radiating ultraviolet rays to the metal oxide layer formed in the pixel opening, at least some of the radiated ultraviolet rays can be reflected by the reflective film and reach the metal oxide layer. For example, in addition to the ultraviolet rays directly reaching the metal oxide layer, the ultraviolet rays reflected by the reflective film can also additionally reach the metal oxide layer. Therefore, the amount of ultraviolet rays reaching the metal oxide layer can be increased, and the surface modification effect of the metal oxide layer by radiating ultraviolet rays can be increased. Therefore, the element characteristics of the light-emitting element can be improved.

[0030] It is to be understood that both the foregoing general description and the following detailed description are explanatory and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Illustrative, non-limiting embodiments will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings.

[0032] Figure 1 is a schematic plan view showing a display device according to an embodiment of the present disclosure.

[0033] Figure 2 is along Figure 1 Schematic cross-sectional view taken along line II'.

[0034] Figures 3 to 13 is a schematic cross-sectional view illustrating a method of manufacturing a display device according to an embodiment of the present disclosure.

[0035] Figures 14 to 17 is shown along Figure 1 Schematic cross-sectional views of various embodiments taken along line II'. DETAILED DESCRIPTION

[0036] Hereinafter, a display device according to an embodiment will be described in more detail with reference to the accompanying drawings. In the accompanying drawings, the same reference numerals are used for the same components, and redundant descriptions of the same components will be omitted.

[0037] The terms "about" or "approximately" as used herein include the stated value and mean within the range of acceptable deviations for the particular value as determined by one of ordinary skill in the art, taking into account the measurement in question and the errors associated with the measurement of the particular quantity (i.e., the limitations of the measurement system). For example, "about" can mean within one or more standard deviations, or within ±30%, ±20%, ±10%, or ±5% of the stated value.

[0038] The term "and / or" includes all combinations that can be defined by one or more related configurations. For example, "A and / or B" can be understood to mean "A, B, or A and B".

[0039] For the purpose of the present disclosure, the phrase "at least one of A and B" may be understood as only A, only B, or any combination of A and B. In addition, "at least one of X, Y, and Z" and "at least one selected from the group consisting of X, Y, and Z" may be understood as only X, only Y, only Z, or any combination of two or more of X, Y, and Z.

[0040] Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which the present disclosure belongs. It will also be understood that, unless explicitly defined as such herein, terms (such as those defined in general dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology and the present disclosure, and should not be interpreted in an idealized or overly formal sense.

[0041] Figure 1 is a schematic plan view showing a display device DD according to an embodiment of the present disclosure.

[0042] refer to Figure 1, the display device DD according to an embodiment of the present disclosure may include a display area DA and a peripheral area PA. The display area DA may be an area that can display an image by generating light or adjusting the transmittance of light provided from an external light source. The peripheral area PA may be an area where an image is not displayed. The peripheral area PA may be located around the display area DA. For example, the peripheral area PA may completely surround the display area DA.

[0043] The display area DA may include pixel areas PXA. The pixel areas PXA may be arranged in a matrix form on a plane defined by a first direction DR1 and a second direction DR2 intersecting the first direction DR1.

[0044] The third direction DR3 may be a normal direction of a plane defined by the first direction DR1 and the second direction DR2. For example, the third direction DR3 may be perpendicular to the first direction DR1 and the second direction DR2.

[0045] The pixel area PXA may refer to an area where light emitted from a light emitting element is emitted to the outside of the display device DD. Each of the plurality of pixel areas PXA may have a triangular planar shape, a square planar shape, a circular planar shape, an elliptical planar shape, or the like. In an embodiment, each of the plurality of pixel areas PXA may have a rectangular planar shape. However, the present disclosure is not limited thereto, and each of the plurality of pixel areas PXA may have a planar shape other than a rectangular planar shape.

[0046] Figure 2 is along Figure 1 Schematic cross-sectional view taken along line II'.

[0047] Specifically, Figure 2 It is shown Figure 1 A schematic cross-sectional view of one pixel area PXA among a plurality of pixel areas PXA.

[0048] refer to Figure 1 and Figure 2 , the display device DD may include a substrate SUB, a pixel circuit layer PCL, a light emitting element LED, a first pixel defining layer PDL1 , a reflective film MTL, and a second pixel defining layer PDL2 .

[0049] The substrate SUB may include, for example, a transparent material, a semi-transparent material, and / or an opaque material. In an embodiment, examples of materials that may be used as the substrate SUB may include glass, quartz, or plastic, etc. These may be used alone or in combination with each other.

[0050] The pixel circuit layer PCL may be disposed on the substrate SUB and may include first, second, third, fourth, fifth, and sixth insulating layers IL1, IL2, IL3, IL4, IL5, IL6, at least one transistor TR, at least one capacitor CST, and at least one connection electrode CNE.

[0051] The transistor TR may include an active pattern ACT, a first gate electrode GAT1, a first contact electrode CE1, and a second contact electrode CE2. The capacitor CST may include a first gate electrode GAT1 and a second gate electrode GAT2. The light emitting element LED may include a first electrode E1, an intermediate layer ML, and a second electrode E2. The intermediate layer ML may include a hole transport region HTA, an emission layer EML, and an electron transport region ETA.

[0052] The first insulating layer IL1 may be disposed on the substrate SUB. The first insulating layer IL1 may prevent impurities such as oxygen and moisture from diffusing into an upper portion of the substrate SUB. The first insulating layer IL1 may include an inorganic insulating material such as a silicon compound or a metal oxide.

[0053] The active pattern ACT may be disposed on the first insulating layer IL1. In an embodiment, the active pattern ACT may include a silicon semiconductor material or an oxide semiconductor material.

[0054] In an embodiment, the second insulating layer IL2 may be disposed on the first insulating layer IL1. The second insulating layer IL2 may cover the active pattern ACT (or overlap the active pattern ACT). In an embodiment, the second insulating layer IL2 may be arranged in a pattern on the active pattern ACT to expose a portion of the active pattern ACT. For example, the second insulating layer IL2 may be disposed in a pattern on the active pattern ACT so as to overlap the first gate electrode GAT1. The second insulating layer IL2 may include an inorganic insulating material.

[0055] The first gate electrode GAT1 may be disposed on the second insulating layer IL2. In an embodiment, the first gate electrode GAT1 may include a metal, an alloy, a conductive metal oxide, a transparent conductive material, or the like.

[0056] The third insulating layer IL3 may be disposed on the second insulating layer IL2. In an embodiment, the third insulating layer IL3 may cover the first gate electrode GAT1. The third insulating layer IL3 may include an inorganic insulating material.

[0057] The second gate electrode GAT2 may be disposed on the third insulating layer IL3. In an embodiment, the second gate electrode GAT2 may overlap the first gate electrode GAT1. In an embodiment, the second gate electrode GAT2 may include a metal, an alloy, a conductive metal oxide, or a transparent conductive material, etc. The first gate electrode GAT1 and the second gate electrode GAT2 may form a capacitor CST.

[0058] The fourth insulating layer IL4 may be disposed on the third insulating layer IL3. In an embodiment, the fourth insulating layer IL4 may cover the second gate electrode GAT2. The fourth insulating layer IL4 may include an inorganic insulating material.

[0059] The first contact electrode CE1 and the second contact electrode CE2 may be disposed on the fourth insulating layer IL4. The first contact electrode CE1 and the second contact electrode CE2 may be electrically connected to the active pattern ACT through a contact hole formed in the second insulating layer IL2, the third insulating layer IL3, and the fourth insulating layer IL4. For example, the first contact electrode CE1 and the second contact electrode CE2 may contact the active pattern ACT. Each of the first contact electrode CE1 and the second contact electrode CE2 may include a metal, an alloy, a conductive metal oxide, a transparent conductive material, or the like.

[0060] The fifth insulating layer IL5 may be disposed on the fourth insulating layer IL4. The fifth insulating layer IL5 may cover the first contact electrode CE1 and the second contact electrode CE2. The fifth insulating layer IL5 may include an organic insulating material.

[0061] The connection electrode CNE may be disposed on the fifth insulating layer IL5. The connection electrode CNE may be electrically connected to at least one of the first contact electrode CE1 and the second contact electrode CE2 through a contact hole formed in the fifth insulating layer IL5. The connection electrode CNE may include metal, alloy, conductive metal oxide, transparent conductive material, or the like.

[0062] The sixth insulating layer IL6 may be disposed on the fifth insulating layer IL5. The sixth insulating layer IL6 may cover the connection electrode CNE. The sixth insulating layer IL6 may include an organic insulating material.

[0063] Figure 2 The structure of the pixel circuit layer PCL shown in FIG. 1 is merely an example and may be changed in various ways depending on the embodiment.

[0064] The first electrode E1 may be disposed on the sixth insulating layer IL6. The first electrode E1 may be electrically connected to the connection electrode CNE through a contact hole formed in the sixth insulating layer IL6. For example, the first electrode E1 may be electrically connected to the transistor TR through the connection electrode CNE. The first electrode E1 may include metal, alloy, conductive metal oxide, or transparent conductive material, etc.

[0065] The first pixel defining layer PDL1 may be disposed on the sixth insulating layer IL6. For example, the first pixel defining layer PDL1 and the first electrode E1 may be disposed at the same height from the substrate SUB. The first pixel defining layer PDL1 may cover at least a portion of the first electrode E1 and expose another portion of the first electrode E1. Specifically, the first pixel defining layer PDL1 may expose an upper surface of the first electrode E1. For example, the first pixel defining layer PDL1 may cover an edge of the first electrode E1 and expose a central portion of the first electrode E1. However, the present disclosure is not limited thereto.

[0066] In an embodiment, the first pixel defining layer PDL1 may include an organic material. Examples of organic materials that may be used as the first pixel defining layer PDL1 may include photoresists, polyacrylic resins, polyimide resins, or acrylic resins, etc. These may be used alone or in combination with each other. For example, in a plan view, the first pixel defining layer PDL1 may have a grid shape.

[0067] In an embodiment, the thickness of the first pixel defining layer PDL1 in the third direction DR3 may be about 100 mm / s. to about within the range of, for example, about to about In the case where the thickness of the first pixel defining layer PDL1 satisfies the above range, the reflective film MTL and the first electrode E1 may be electrically insulated (electrically disconnected) from each other without substantially increasing the thickness of the display device DD in the third direction DR3.

[0068] The reflective film MTL may be disposed on the first pixel defining layer PDL1. For example, the reflective film MTL may have a mesh shape in a plan view.

[0069] In an embodiment, the reflective film MTL may include a metal material. For example, the metal material included in the reflective film MTL may have low resistance and high reflectivity. For example, the reflective film MTL may include aluminum (Al) or an aluminum alloy. The aluminum alloy may include a metal such as nickel (Ni), lanthanum (La), titanium (Ti), or molybdenum (Mo), but the present disclosure is not limited thereto.

[0070] In an embodiment, the thickness of the reflective film MTL in the third direction DR3 may be about to about within the range of, for example, about to about In the case where the thickness of the reflective film MTL satisfies the above range, in the process of irradiating ultraviolet rays described below, the amount of ultraviolet rays irradiated to the middle layer ML (for example, the emission layer EML) can be more effectively increased. For example, the thickness of the reflective film MTL can be about

[0071] In an embodiment, the reflective film MTL may be electrically insulated from the first electrode E1. For example, the reflective film MTL may not contact the first electrode E1. Specifically, the reflective film MTL may be disposed on the first pixel defining layer PDL1 and electrically insulated from the first electrode E1 by the first pixel defining layer PDL1. Therefore, the reflective film MTL may not affect the electrical characteristics of the light emitting element LED.

[0072] In an embodiment, the reflective film MTL may completely cover the upper surface of the first pixel defining layer PDL1. However, the present disclosure is not limited thereto. Figure 2 , the reflective film MTL is shown as not being disposed on the side surface of the first pixel defining layer PDL1, but the present disclosure is not limited thereto. For example, the reflective film MTL may also cover a portion of the side surface of the first pixel defining layer PDL1 (or overlap a portion of the side surface of the first pixel defining layer PDL1).

[0073] The second pixel defining layer PDL2 may be disposed on the reflective film MTL. The second pixel defining layer PDL2 may include, for example, an organic insulating material. Examples of organic insulating materials that may be used as the second pixel defining layer PDL2 include photoresists, polyacrylic resins, polyimide resins, or acrylic resins, etc. These may be used alone or in combination with each other. For example, the second pixel defining layer PDL2 may have a grid shape in a plan view.

[0074] Therefore, the structure in which the first pixel defining layer PDL1, the reflective film MTL, and the second pixel defining layer PDL2 are sequentially stacked may define a pixel opening PO exposing the upper surface of the first electrode E1. For example, the structure in which the first pixel defining layer PDL1, the reflective film MTL, and the second pixel defining layer PDL2 are sequentially stacked may have a grid shape in a plan view.

[0075] In an embodiment, the second pixel defining layer PDL2 may have liquid repellency. Specifically, the upper surface of the second pixel defining layer PDL2 may have liquid repellency. In the present specification, liquid repellency may mean a property of repelling a solution (e.g., a predetermined solution or an optional solution) and preventing the solution from completely penetrating. For example, the surface bonding force of the solution with the surface having liquid repellency may be relatively small, and the surface tension of the solution disposed on the surface having liquid repellency may increase.

[0076] Since the second pixel defining layer PDL2 may have liquid repellency, in the process of forming the intermediate layer ML in the pixel opening PO, the phenomenon that the material discharged into the pixel opening PO by inkjet printing overflows to the upper surface of the second pixel defining layer PDL2 may be reduced or prevented. Therefore, defects in the manufacturing process of the display device DD may be reduced or prevented.

[0077] The second pixel defining layer PDL2 may expose at least a portion of the reflective film MTL. Therefore, the reflective film MTL may directly contact the middle layer ML in the pixel opening PO. For example, the second pixel defining layer PDL2 may expose at least a portion of the side surface of the reflective film MTL, and the side surface of the reflective film MTL may directly contact the middle layer ML.

[0078] In an embodiment, the second pixel defining layer PDL2 may completely cover the upper surface of the reflective film MTL (or overlap with the upper surface of the reflective film MTL). However, the present disclosure is not limited thereto, and the second pixel defining layer PDL2 may also expose at least a portion of the upper surface of the reflective film MTL. This will be described below with reference to Fig.14 Describe in more detail.

[0079] exist Figure 2 , the second pixel defining layer PDL2 is shown as not being disposed on the side surface of the reflective film MTL, but the present disclosure is not limited thereto, and the second pixel defining layer PDL2 may also cover a portion of the side surface of the reflective film MTL. For example, the second pixel defining layer PDL2 may expose a portion of the side surface of the reflective film MTL and cover another portion of the side surface of the reflective film MTL.

[0080] The middle layer ML may be disposed in the pixel opening PO. For example, the middle layer ML may be disposed on the first electrode E1. In an embodiment, the middle layer ML may include a material that emits light.

[0081] For example, a structure in which the first pixel defining layer PDL1, the reflective film MTL, and the second pixel defining layer PDL2 are stacked in sequence may surround the middle layer ML in a plan view. Specifically, the first pixel defining layer PDL1 may surround the middle layer ML in a plan view, the reflective film MTL may surround the middle layer ML in a plan view, and the second pixel defining layer PDL2 may surround the middle layer ML in a plan view.

[0082] As described above, the middle layer ML may include a hole transport region HTA, an emission layer EML, and an electron transport region ETA. In an embodiment, the hole transport region HTA, the emission layer EML, and the electron transport region ETA may be sequentially stacked on the first electrode E1. The light emitting element LED may be a conventional structure light emitting element in which the first electrode E1 is an anode and the second electrode E2 is a cathode.

[0083] The hole transport area HTA may have i) a single-layer structure formed as a single-material single-layer, ii) a single-layer structure formed as a single-layer of different materials, or iii) a multi-layer structure having layers of different materials.

[0084] The hole transport area HTA may include at least one of a hole injection layer, a hole transport layer, a light emission auxiliary layer, and an electron blocking layer.

[0085] For example, the hole transport region HTA may have a single-layer structure formed as a single layer of different materials, or a multilayer structure of a hole injection layer / hole transport layer, a hole injection layer / hole transport layer / light emission auxiliary layer, a hole injection layer / light emission auxiliary layer, a hole transport layer / light emission auxiliary layer, or a hole injection layer / hole transport layer / electron blocking layer sequentially stacked on the first electrode E1. However, the present disclosure is not limited thereto.

[0086] The hole transport region HTA may include an amorphous inorganic material or an amorphous organic material. The thickness of the hole transport region HTA may be about to about within the range of, for example, about to about If the hole transport region HTA includes at least one of a hole injection layer and a hole transport layer, the thickness of the hole injection layer may be in the range of about to about within the range of, for example, about to about and the thickness of the hole transport layer can be in the range of about to about within the range of, for example, about to about In the case where the thickness of the hole transport area HTA, the thickness of the hole injection layer, and the thickness of the hole transport layer satisfy the above ranges, satisfactory hole transport characteristics can be obtained without substantially increasing the driving voltage.

[0087] The emission layer EML may include a material that emits light. For example, the emission layer EML may include quantum dots. The quantum dots may emit light when stimulated by light. For example, the light emitting element LED may be a quantum dot light emitting element.

[0088] For example, quantum dots may include II-VI semiconductor compounds, III-VI semiconductor compounds, III-V semiconductor compounds, IV-VI semiconductor compounds, IV elements or compounds, or I-III-VI semiconductor compounds, etc. These may be used alone or in combination with each other.

[0089] Examples of II-VI semiconductor compounds may include binary compounds such as CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgS, MgSe, etc.; ternary compounds such as CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZ nSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnS, MgZnSe, etc.; quaternary compounds such as CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, etc.; or any combination thereof.

[0090] Examples of III-VI semiconductor compounds may include binary compounds such as In 2 S 3 , Ga 2 S 3 etc.; ternary compounds such as InGaS 3 ,InGaSe 3 etc.; or any combination thereof.

[0091] Examples of III-V semiconductor compounds may include binary compounds such as GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, etc.; ternary compounds such as GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InAsP, InGaP, InGaAs, InAlP, InNP, InNAs, InNSb, InPAs, InPSb, etc.; quaternary compounds such as GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, etc.; or any combination thereof. III-V semiconductor compounds may also include Group II metals (e.g., InZnP).

[0092] Examples of IV-VI semiconductor compounds may include: binary compounds such as SnS, SnSe, SnTe, PbS, PbSe, PbTe, etc.; ternary compounds such as SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, etc.; quaternary compounds such as SnPbSSe, SnPbSeTe, SnPbSTe, etc.; or any combination thereof.

[0093] Examples of Group IV elements or compounds may include: Si and / or Ge; binary compounds such as SiC, SiGe, etc.; or any combination thereof.

[0094] Examples of Group I-III-VI semiconductor compounds may include: ternary compounds such as AgInS, AgInS 2 、CuInS、CuInS 2 、CuGaO 2 、AgGaO 2 、AgAlO 2 or any combination thereof. The Group I-III-VI semiconductor compound may also include a Group II element. For example, the Group I-III-VI semiconductor compound may include a quaternary compound such as CuInZnS.

[0095] Quantum dots can have a single structure with homogeneous components and composition or a complex structure such as a core-shell structure or a gradient structure.

[0096] In an embodiment, the quantum dot may have a core-shell structure including a core including a first semiconductor crystal and a shell including a second semiconductor crystal. The core and the shell may include materials different from each other.

[0097] The shell may be used as a protective layer to maintain semiconductor properties by preventing chemical denaturation of the core, and / or as a charging layer to impart electrophoretic properties to the quantum dot. The shell may have a single layer structure or a multilayer structure. The interface between the core and the shell may have a concentration gradient in which the concentration of the element in the shell decreases toward the center. Examples of the shell of the quantum dot may include metal oxides or non-metal oxides, semiconductor compounds, or combinations thereof.

[0098] For example, in a core-shell structure, each material forming the core and the shell may be selected from the above-mentioned semiconductor compounds.

[0099] The emission layer EML may include a photoreactive material. For example, the emission layer EML may include a photocrosslinker. Specifically, the emission layer EML may further include a crosslinker activated by ultraviolet rays.

[0100] Examples of crosslinking agents that may be included in the emission layer EML may include crosslinkable monomers or urethane monomers having ethylene unsaturated groups, etc. Examples of crosslinkable monomers having ethylene unsaturated groups may include 1,4-butanediol diacrylate, 1,3-butanediol diacrylate, ethylene glycol diacrylate, pentaerythritol tetraacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, dipentaerythritol diacrylate, sorbitol triacrylate, bisphenol A diacrylate derivatives, trimethylolpropane triacrylate, dipentaerythritol polyacrylate or dipentaerythritol hexaacrylate, etc. These may be used alone or in combination with each other. The urethane monomer may be a general crosslinking monomer having a urethane structure, and its type is not particularly limited.

[0101] The emission layer EML can be formed by coating (applying) a composition for forming the emission layer EML in which quantum dots and a crosslinking agent are dispersed in a solvent onto the first electrode E1 and drying the composition for forming the emission layer EML. After drying the composition for forming the emission layer EML, the degree of film curing of the emission layer EML can be improved by curing the emission layer EML with ultraviolet rays. This will be referred to below. Fig.10 Describe in more detail.

[0102] The composition for forming the emission layer EML can be applied by spin coating, casting, micro gravure coating, gravure coating, rod coating, roller coating, wire bar coating, dip coating, spray coating, screen printing, flexographic printing, offset printing or inkjet printing, etc. The composition for forming the emission layer EML can be applied by inkjet printing.

[0103] The solvent may be water, hexane, chloroform, toluene, or the like, but is not particularly limited as long as it is a dissolving material for forming the emission layer EML.

[0104] The electron transport region ETA may have i) a single layer structure formed of (or formed as) a single layer of a single material, ii) a single layer structure formed of single layers of different materials, or iii) a multilayer structure having layers of different materials.

[0105] The electron transport area ETA may include at least one of a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer, but the present disclosure is not limited thereto.

[0106] The thickness of the buffer layer, the thickness of the hole blocking layer, or the thickness of the electron control layer may be independently about to about within the range of, for example, about to about In the case where the thickness of the buffer layer, the thickness of the hole blocking layer or the thickness of the electron control layer satisfies the above range, excellent hole blocking characteristics or electron control characteristics can be obtained without substantially increasing the driving voltage.

[0107] The electron transport region ETA may include a metal oxide layer. For example, the metal oxide layer may be at least one selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer. In an embodiment, the metal oxide layer may be an electron transport layer. However, the present disclosure is not limited thereto.

[0108] The metal oxide layer may include a conductive metal oxide, a fullerene derivative, or a combination thereof. For example, the metal oxide layer may include Mg-doped ZnO (ZnMgO), Al-doped ZnO (AZO), Ga-doped ZnO (GZO), In-doped Indium ZnO (IZO), Al-doped SnO (ZnMgO), or 2 , Ga-doped SnO 2 , In-doped SnO 2 , Al-doped TiO 2 , Ga-doped TiO 2 , In-doped TiO 2 、In 2 O 3 , Nb 2 O 5 , Fe 2 O 3 、CeO 2 、SrTiO 3 、Zn 2 SnO 4 、BaSnO 3 、In 2 S 3 , ZnSiO, PC60BM, PC70BM, Mg-doped In 2 O 3 , Al-doped In 2 O 3 , Ga-doped In 2 O 3 , Nb-doped 2 O 5 , Al-doped Nb 2 O 5 , Ga-doped Nb 2 O 5 , Mg-doped Fe 2 O 3 , Al-doped Fe 2 O 3 , Ga-doped Fe 2 O 3 , In-doped Fe2 O3, Mg-doped CeO 2 , Al-doped CeO 2 , Ga-doped CeO 2 , In-doped CeO 2 , Mg-doped SrTiO3, Al-doped SrTiO 3 , Ga-doped SrTiO 3 , In-doped SrTiO 3 , Mg-doped Zn 2 SnO 4 , Al-doped Zn 2 SnO 4 , Ga-doped Zn 2 SnO 4 , In-doped Zn 2 SnO 4 , Mg-doped BaSnO 3 , Al-doped BaSnO 3 , Ga-doped BaSnO 3 , In-doped BaSnO 3 , Mg-doped In 2 S 3 , Al-doped In 2 S 3 , Ga-doped In 2 S 3 , In doped In 2 S 3 , Mg-doped ZnSiO, or a combination thereof. Specifically, the metal oxide layer may include a zinc-containing oxide. For example, the metal oxide layer may include Mg-doped ZnO (ZnMgO).

[0109] In an embodiment, the metal oxide layer may be adjacent to the emission layer EML. For example, the metal oxide layer may form an interface with the emission layer EML. For example, in a conventional structure light-emitting element in which the electron transport region ETA is disposed on the emission layer EML, the metal oxide layer may be a lower layer or a lowermost layer of the electron transport region ETA. In other words, the metal oxide layer may be disposed on the emission layer EML so as to directly contact the emission layer EML.

[0110] Oxygen vacancies may be generated inside the metal oxide layer. If excessive oxygen vacancies are generated inside the metal oxide layer, the electrical properties of the metal oxide layer may change, and thus the charge transfer characteristics (e.g., current characteristics) of the metal oxide layer may deteriorate. Therefore, the characteristics of the light emitting element LED may deteriorate.

[0111] Therefore, during the manufacturing process of the display device DD, a process of modifying the surface of the metal oxide layer may be required to control the oxygen vacancies of the metal oxide layer. According to an embodiment, the surface of the metal oxide layer may be modified by irradiating ultraviolet rays to the metal oxide layer. For example, the oxygen vacancies of the metal oxide layer may be controlled by irradiating ultraviolet rays to the metal oxide layer. This will be described below with reference to Fig.12 Describe in more detail.

[0112] The electron transport area ETA may further include a metal-containing material in addition to the above-mentioned materials.

[0113] The metal-containing material may include at least one of an alkali metal complex and an alkaline earth metal complex. The metal ions of the alkali metal complex may be selected from Li ions, Na ions, K ions, Rb ions and Cs ions, and the metal ions of the alkaline earth metal complex may be selected from Be ions, Mg ions, Ca ions, Sr ions and Ba ions. The ligand coordinated with the metal ions of the alkali metal complex and the alkaline earth metal complex may be selected (independently of each other) from hydroxyquinoline, hydroxyisoquinoline, hydroxybenzoquinoline, hydroxyacridine, hydroxyphenanthridine, hydroxybenzooxazole, hydroxyphenylthiazole, hydroxydiphenyloxadiazole, hydroxydiphenylthiadiazole, hydroxyphenylpyridine, hydroxyphenylbenzimidazole, hydroxyphenylbenzothiazole, bipyridine, phenanthroline or cyclopentadiene, but is not limited thereto.

[0114] The second electrode E2 may be disposed on the middle layer ML. The second electrode E2 may include a conductive material such as a metal, an alloy, a conductive metal nitride, a conductive metal oxide, or a transparent conductive material, etc. In an embodiment, the second electrode E2 may extend continuously through the pixel area PXA. As a result, the light emitting element LED may emit light.

[0115] Although not shown, a packaging member may be additionally provided on the light emitting element LED. The packaging member may protect the light emitting element LED from external moisture, heat, impact, or the like.

[0116] In an embodiment, the encapsulation member may be a glass substrate. The encapsulation member may be bonded to the substrate SUB by a sealing member or the like, and may be spaced apart from the light emitting element LED in the third direction DR3. The space between the encapsulation member and the light emitting element LED may be filled with air or filler.

[0117] In an embodiment, the encapsulation member may have a structure in which an encapsulation layer is stacked on the second electrode E2. For example, the encapsulation member may include a first inorganic encapsulation layer disposed on the second electrode E2, an organic encapsulation layer disposed on the first inorganic encapsulation layer, and a second inorganic encapsulation layer disposed on the organic encapsulation layer.

[0118] According to an embodiment, the display device DD may include a first pixel defining layer PDL1 covering at least a portion of the first electrode E1 of the light emitting element LED, a reflective film MTL on the first pixel defining layer PDL1, and a second pixel defining layer PDL2 on the reflective film MTL. For example, in the display device DD according to the embodiment, a structure in which the first pixel defining layer PDL1, the reflective film MTL, and the second pixel defining layer PDL2 are stacked in sequence may define a pixel opening PO exposing an upper surface of the first electrode E1 of the light emitting element LED.

[0119] In the process of curing the emission layer EML formed in the pixel opening PO with ultraviolet rays, at least some of the radiated ultraviolet rays can be reflected by the reflective film MTL and reach the emission layer EML. For example, in addition to the ultraviolet rays directly reaching the emission layer EML, the ultraviolet rays reflected by the reflective film MTL can additionally reach the emission layer EML. Therefore, the amount of ultraviolet rays reaching the emission layer EML can be increased, and the degree of film curing of the emission layer EML cured by ultraviolet rays can be increased. Therefore, the phenomenon that the material included in the emission layer EML and the material included in the metal oxide layer are mixed at the interface between the emission layer EML and the metal oxide layer can be reduced or prevented. Therefore, the element characteristics of the light-emitting element LED can be improved.

[0120] In the process of modifying the surface of the metal oxide layer by radiating ultraviolet rays to the metal oxide layer formed in the pixel opening PO, at least some of the radiated ultraviolet rays can be reflected by the reflective film MTL and reach the metal oxide layer. For example, in addition to the ultraviolet rays directly reaching the metal oxide layer, the ultraviolet rays reflected by the reflective film MTL can additionally reach the metal oxide layer. Therefore, the amount of ultraviolet rays reaching the metal oxide layer can be increased, and the surface modification effect of the metal oxide layer by ultraviolet radiation can be increased. For example, the oxygen vacancies of the metal oxide layer can be more easily controlled. Therefore, the element characteristics of the light-emitting element LED can be improved.

[0121] Since the first pixel defining layer PDL1 is disposed below the reflective film MTL, the reflective film MTL and the first electrode E1 may be electrically insulated from each other. Therefore, the reflective film MTL may not affect the electrical characteristics of the light emitting element LED. At the same time, since the second pixel defining layer PDL2 is disposed on the reflective film MTL, in the process of forming the intermediate layer ML, the material discharged into the pixel opening by inkjet printing may be reduced or prevented from overflowing toward other pixel openings around the pixel opening. Therefore, the intermediate layer ML may be formed more easily without substantially degrading the element characteristics of the light emitting element LED.

[0122] Figures 3 to 13 is a schematic cross-sectional view illustrating a method of manufacturing a display device according to an embodiment of the present disclosure.

[0123] Specifically, Figures 3 to 13 For reference only Figure 2 Schematic cross-sectional view of a method for manufacturing a display device described in the following. In the following, the description of the components of the display device DD may be the same as that of the reference Figure 1 and Figure 2 Therefore, if the detailed description of a component is omitted or simplified, it can be understood that it is the same as the description of reference Figure 1 and Figure 2 The corresponding components described in detail are substantially the same.

[0124] For convenience of description, illustration of components included in the pixel circuit layer PCL is omitted and may be Figure 2 The diagrams are basically the same.

[0125] refer to Figure 3 , a pixel circuit layer PCL may be formed on a substrate SUB. The pixel circuit layer PCL may be formed by coating one or more insulating layers and one or more conductive layers on the substrate SUB and performing a process of patterning each of the insulating layer and the conductive layer multiple times.

[0126] The first electrode E1 may be formed on the pixel circuit layer PCL. The first electrode E1 may be formed by coating a conductive layer on the pixel circuit layer PCL and patterning the conductive layer.

[0127] refer to Figure 4 , a first pixel defining layer PDL1 may be formed on the pixel circuit layer PCL and the first electrode E1. The first pixel defining layer PDL1 may be formed by a process of coating an insulating layer on the pixel circuit layer PCL and the first electrode E1 and patterning the insulating layer. The first pixel defining layer PDL1 may be formed to cover at least a portion of the first electrode E1 and expose an upper surface of the first electrode E1. For example, the first pixel defining layer PDL1 may be formed to have a grid shape in a plan view. In an embodiment, the first pixel defining layer PDL1 may be formed of an organic material.

[0128] refer to Figure 5 and Figure 6 , a reflective film MTL may be formed on the first pixel defining layer PDL1. Figure 5 As shown in , a preliminary reflective film MTL-A may be formed on the first electrode E1 and the first pixel defining layer PDL1. The preliminary reflective film MTL-A may be formed of a metal material. For example, the preliminary reflective film MTL-A may be formed by coating a metal material on the first electrode E1 and the first pixel defining layer PDL1 via a spin coating method, a casting method, a micro gravure coating method, a gravure coating method, a rod coating method, a roller coating method, a wire bar coating method, a dip coating method, or a spray coating method. However, the present disclosure is not limited thereto.

[0129] The metal material that can be used as the preliminary reflective film MTL-A may have low resistance and high reflectivity. For example, the preliminary reflective film MTL-A may be formed of aluminum (Al) or an aluminum alloy. The aluminum alloy may include materials such as nickel (Ni), lanthanum (La), titanium (Ti), or molybdenum (Mo), but the present disclosure is not limited thereto.

[0130] like Figure 6 As shown in , the preliminary reflective film MTL-A may be patterned to form the reflective film MTL. For example, the reflective film MTL may be formed by removing the other portions of the preliminary reflective film MTL-A except for the portion overlapping with the first pixel defining layer PDL1 in a plan view. For example, the reflective film MTL may be formed to have a grid shape in a plan view.

[0131] In an embodiment, the process of patterning the preliminary reflective film MTL-A may be performed through an etching process, an exposure process, a development process, etc. The process of patterning the preliminary reflective film MTL-A may be performed through a dry etching process using an etching gas.

[0132] refer to Figure 7 , a second pixel defining layer PDL2 may be formed on the reflective film MTL. The second pixel defining layer PDL2 may be formed by a process of coating an insulating layer on the first electrode E1, the first pixel defining layer PDL1, and the reflective film MTL and patterning the insulating layer. For example, the second pixel defining layer PDL2 may be formed to have a grid shape in a plan view. In an embodiment, the second pixel defining layer PDL2 may be formed of an organic material.

[0133] A structure in which the first pixel defining layer PDL1, the reflective film MTL, and the second pixel defining layer PDL2 are stacked in sequence may be formed on the pixel circuit layer PCL. The structure may define a pixel opening PO exposing the upper surface of the first electrode E1. For example, the structure in which the first pixel defining layer PDL1, the reflective film MTL, and the second pixel defining layer PDL2 are stacked in sequence may be formed to have a grid shape in a plan view.

[0134] refer to Figure 8 , the hole transport region HTA may be formed on the first electrode E1 exposed by the pixel opening PO. In an embodiment, the hole transport region HTA may be formed by inkjet printing. For example, an organic composition may be provided in the pixel opening PO by inkjet printing. The organic composition may be a material for forming the hole transport region HTA. Thereafter, the organic composition may be dried to form the hole transport region HTA.

[0135] refer to Fig. 9, an emission layer EML can be formed on the hole transport area HTA in the pixel opening PO. In an embodiment, the emission layer EML can be formed by inkjet printing. For example, a composition for forming the emission layer EML can be provided by inkjet printing on the hole transport area HTA in the pixel opening PO. The composition for forming the emission layer EML may include a solvent, quantum dots, and a cross-linking agent activated by ultraviolet rays. The composition for forming the emission layer EML can be dried to form the emission layer EML.

[0136] refer to Fig.10 , the emission layer EML can be cured with ultraviolet rays UV. Since the emission layer EML includes a cross-linking agent activated by ultraviolet rays, when the emission layer EML is irradiated with ultraviolet rays UV, film curing of the emission layer EML can occur. Therefore, the phenomenon that the material of the metal oxide layer formed on the emission layer EML is mixed with the material of the emission layer EML in the subsequent process can be reduced or prevented.

[0137] In an embodiment, in the process of curing the emission layer EML with ultraviolet rays UV, at least some of the radiated ultraviolet rays UV can be reflected by the reflective film MTL and reach the emission layer EML. For example, in addition to the ultraviolet rays UV directly reaching the emission layer EML, the ultraviolet rays UV reflected by the reflective film MTL can also additionally reach the emission layer EML. Therefore, the amount of ultraviolet rays UV reaching the emission layer EML can be increased, and the degree of film curing of the emission layer EML can be increased.

[0138] In an embodiment, the emission layer EML may be cured with ultraviolet light UV at a temperature lower than about 180° C. (e.g., equal to or lower than about 140° C.). If the temperature for performing the curing process using ultraviolet light UV is equal to or higher than about 180° C., the quantum dots may be damaged and the light emitting element LED (see Figure 2 ) may deteriorate the characteristics of the components.

[0139] According to an embodiment, by curing the emission layer EML with ultraviolet rays UV, a separate thermal curing process may be omitted. Since the thermal curing process needs to be performed at a high temperature equal to or higher than about 180°C, the element characteristics of the emission layer EML may deteriorate. Therefore, according to an embodiment, by omitting the thermal curing process, the film curing of the emission layer EML may be performed without substantially degrading the element characteristics of the emission layer EML. The amount of ultraviolet rays UV reaching the emission layer EML may be increased by the reflective film MTL, and the degree of film curing of the emission layer EML may be increased.

[0140] refer to Fig.11, an electron transport region ETA may be formed on the emission layer EML in the pixel opening PO. In an embodiment, the electron transport region ETA may be formed by inkjet printing. As a result, an intermediate layer ML including a hole transport region HTA, an emission layer EML, and an electron transport region ETA may be formed in the pixel opening PO.

[0141] Specifically, in a conventional structure light emitting element in which the electron transport region ETA is disposed on the emission layer EML, the electron transport region ETA may include a metal oxide layer, and the metal oxide layer may be the lowermost layer of the electron transport region ETA. Therefore, the metal oxide layer may be formed in the pixel opening PO to be adjacent to the emission layer EML.

[0142] In the following, for the convenience of description, Fig.11 Taking the case where the electron transport region ETA shown in FIG. 1 has a single-layer structure of a metal oxide layer as an example, a method of forming the metal oxide layer will be described in more detail.

[0143] In an embodiment, the metal oxide layer may be formed by inkjet printing. For example, a composition for forming a metal oxide layer may be provided on the emission layer EML in the pixel opening PO by inkjet printing. The composition for forming the metal oxide layer may include a solvent and a metal oxide. Thereafter, the composition for forming the metal oxide layer may be dried to form the metal oxide layer.

[0144] refer to Fig.12 , ultraviolet UV can be radiated to the metal oxide layer. By radiating ultraviolet UV to the metal oxide layer, the surface of the metal oxide layer can be modified. For example, the oxygen vacancies of the metal oxide layer can be controlled by radiating ultraviolet UV to the metal oxide layer. Therefore, the light emitting element LED (see Figure 2 ) characteristics.

[0145] In an embodiment, in the process of radiating ultraviolet rays UV to the metal oxide layer, at least some of the radiated ultraviolet rays UV can be reflected by the reflective film MTL and reach the metal oxide layer. For example, in addition to the ultraviolet rays UV directly reaching the metal oxide layer, the ultraviolet rays UV reflected by the reflective film MTL can also additionally reach the metal oxide layer. Therefore, the amount of ultraviolet rays UV reaching the metal oxide layer can be increased, and the surface modification effect of the metal oxide layer can be increased.

[0146] In an embodiment, the metal oxide layer may be irradiated with ultraviolet light UV at a temperature lower than about 180° C. (specifically, equal to or lower than about 140° C.). If the temperature for irradiating ultraviolet light UV is equal to or higher than about 180° C., the quantum dots may be damaged and the light emitting element LED (see Figure 2 ) may deteriorate the characteristics of the components.

[0147] According to an embodiment, by modifying the surface of the metal oxide layer by irradiating ultraviolet rays UV to the metal oxide layer, a separate aging process may be omitted. The aging process may be performed during the manufacture of the display device DD (see Figure 1 ) after leaving or heating the display device DD so that an aging element such as acid reaches the metal oxide layer. Therefore, for the aging process, a separate acid-containing coating may be required in the display device DD. This coating may have a problem in that it is difficult to form a uniform film, resulting in a display area DA (see Figure 1 ) and makes it difficult to store for a long time. Therefore, according to the embodiment, by omitting the aging process, the surface modification of the metal oxide layer can be performed without substantially deteriorating the display quality of the display device DD. In addition, the amount of ultraviolet rays UV reaching the metal oxide layer can be increased by the reflective film MTL, and the surface modification effect of the metal oxide layer is increased.

[0148] refer to Fig.13 , the second electrode E2 may be formed on the second pixel defining layer PDL2 and the middle layer ML. Therefore, a light emitting element LED including the first electrode E1, the middle layer ML, and the second electrode E2 and being a quantum dot light emitting element may be formed.

[0149] Thereafter, although not shown, an encapsulation member may be additionally formed on the second electrode E2. In an embodiment, the encapsulation member may be bonded to the substrate SUB by a sealing member, etc. However, the present disclosure is not limited thereto.

[0150] Figures 14 to 17 is shown along Figure 1 Schematic cross-sectional views of various embodiments taken along line II'. Specifically, Figures 14 to 17 Can correspond to Figure 2 Schematic cross-sectional view of .

[0151] In reference Figures 14 to 17 The display device DD described (see Figure 1 ) in the embodiment, if with reference Figure 2 The detailed description of the components of the embodiment of the display device DD described above is omitted or simplified, and it can be understood that it is the same as the reference numerals. Figure 1 and Figure 2 The corresponding components described in detail are substantially the same.

[0152] refer to Fig.14In an embodiment, the second pixel defining layer PDL2 may expose at least a portion of the upper surface of the reflective film MTL. For example, the second pixel defining layer PDL2 may expose the side of the upper surface of the reflective film MTL. However, the present disclosure is not limited thereto. The second pixel defining layer PDL2 may expose at least a portion of the upper surface of the reflective film MTL, thereby increasing the reflectivity of the reflective film MTL relative to the radiated ultraviolet rays. Therefore, the amount of ultraviolet rays reflected by the reflective film MTL and reaching the emission layer EML or the metal oxide layer may be further increased. Therefore, the element characteristics of the light emitting element LED may be further improved.

[0153] refer to Fig.14 The manufacturing method of the display device DD described can be distinguished from the reference Figures 3 to 13 The manufacturing method of the display device described in the present invention is at least that when forming the second pixel defining layer PDL2 (see Figure 7 ), the second pixel defining layer PDL2 is formed to expose a portion of the upper surface of the reflective film MTL.

[0154] refer to Fig.15 In an embodiment, the second pixel defining layer PDL2 may include a light blocking material. Examples of light blocking materials that can be used as the second pixel defining layer PDL2 may include black dyes or black pigments such as carbon black, etc. These may be used alone or in combination with each other. Since the second pixel defining layer PDL2 includes a light blocking material, the visibility of external light (e.g., visible light) caused by the reflective film MTL may be reduced. Therefore, the visible degradation of the display quality of the display device DD due to external light may be reduced or prevented.

[0155] refer to Fig.14 The manufacturing method of the display device DD described in the reference Figures 3 to 13 The difference between the manufacturing methods of the display device described above may be at least that: when forming the second pixel defining layer PDL2 (see Figure 7 ), the second pixel defining layer PDL2 is formed by coating an insulating layer including a light blocking material in addition to an organic material and patterning the insulating layer.

[0156] refer to Fig.16 In the embodiment where the second pixel defining layer PDL2 includes a light blocking material, the second pixel defining layer PDL2 may expose at least a portion of the upper surface of the reflective film MTL. Therefore, the reflectivity of the reflective film MTL with respect to the radiated ultraviolet light may be further increased without substantially deteriorating the display quality of the display device DD due to visibly external light.

[0157] refer to Fig.17In an embodiment, the electron transport region ETA, the emission layer EML, and the hole transport region HTA may be sequentially stacked on the first electrode E1. The light emitting element LED may be an inverted structure light emitting element in which the first electrode E1 is a cathode and the second electrode E2 is an anode.

[0158] As described above, the electron transport region ETA may include a metal oxide layer. For example, in an inverted structure light-emitting element in which the electron transport region ETA is disposed below the emission layer EML, the metal oxide layer may be the uppermost layer of the electron transport region ETA. In other words, the metal oxide layer may be disposed below the emission layer EML so as to directly contact the emission layer EML.

[0159] In an embodiment, the metal oxide layer may include a photoreactive material. For example, the metal oxide layer may include a photocrosslinker. Specifically, the metal oxide layer may also include a crosslinker activated by ultraviolet rays.

[0160] Examples of crosslinking agents that may be included in the metal oxide layer may include crosslinkable monomers or urethane monomers with ethylene unsaturated groups, etc. Examples of crosslinkable monomers with ethylene unsaturated groups may include 1,4-butanediol diacrylate, 1,3-butanediol diacrylate, ethylene glycol diacrylate, pentaerythritol tetraacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, dipentaerythritol diacrylate, sorbitol triacrylate, bisphenol A diacrylate derivatives, trimethylolpropane triacrylate, dipentaerythritol polyacrylate or dipentaerythritol hexaacrylate, etc. These may be used alone or in combination with each other. Urethane monomers may be general crosslinking monomers with urethane structures, and their types are not particularly limited.

[0161] Since the metal oxide layer includes a crosslinking agent activated by ultraviolet rays, film curing of the metal oxide layer can occur when ultraviolet rays are radiated to the metal oxide layer, and the material of the emission layer EML formed on the metal oxide layer in a subsequent process can be reduced or prevented from mixing with the material of the metal oxide layer.

[0162] For example, in the process of forming an inverted structure light emitting element, by irradiating ultraviolet rays to the metal oxide layer, surface modification of the metal oxide layer and film curing of the metal oxide layer can be performed simultaneously. Therefore, the characteristics of the light emitting element LED can be further improved, and the display device DD can be simplified (see Figure 1 ) manufacturing process.

[0163] refer to Fig.17 The manufacturing method of the display device DD described herein refers to Figures 3 to 13 The manufacturing methods of the display devices described may differ at least in that the formation of the hole transport area HTA is changed (see Figure 8 ) and the formation of the electron transport region ETA and the irradiation of ultraviolet light to the electron transport region ETA (see Fig.11 and Fig.12 ) in the order of .

[0164] Although not shown, even in the embodiment where the light emitting element LED has an inverted structure, the second pixel defining layer PDL2 may be exposed as shown in FIG. Fig.14 At least a portion of the upper surface of the reflective film MTL shown in FIG. Fig.15 As shown in , the second pixel defining layer PDL2 may further include a light blocking material. Fig.16 As shown in , the second pixel defining layer PDL2 may further include a light blocking material and expose at least a portion of the upper surface of the reflective film MTL. Figures 14 to 16 The description is repeated, so the detailed description will be omitted.

[0165] The above description is an example of the technical features of the present disclosure, and those skilled in the art to which the present disclosure belongs will be able to make various modifications and changes.Therefore, the above embodiments of the present disclosure can be implemented separately or in combination with each other.

[0166] Therefore, the embodiments disclosed in the present disclosure are not intended to limit the technical spirit of the present disclosure, but are intended to describe the technical spirit of the present disclosure, and the scope of the technical spirit of the present disclosure is not limited by these embodiments. The protection scope of the present disclosure should be interpreted by the attached claims, and should be interpreted as all technical spirits within the equivalent scope are included in the scope of the present disclosure.

Claims

1. A display device, wherein: The display device comprises: a first electrode; a second electrode on the first electrode and facing the first electrode; an intermediate layer between the first electrode and the second electrode and including an emission layer including quantum dots; a first pixel defining layer, the first pixel defining layer covering at least a portion of the first electrode and exposing an upper surface of the first electrode; a reflective film on the first pixel defining layer; and The second pixel defining layer is on the reflective film.

2. The display device according to claim 1, wherein: The reflective film includes aluminum or an aluminum alloy.

3. The display device according to claim 1, wherein: The reflective film is electrically disconnected from the first electrode.

4. The display device according to claim 1, wherein: The emissive layer also includes a cross-linking agent activated by ultraviolet light.

5. The display device according to claim 1, wherein: A structure in which the first pixel defining layer, the reflective film, and the second pixel defining layer are stacked in sequence defines a pixel opening exposing the upper surface of the first electrode, and The intermediate layer is disposed in the pixel opening.

6. The display device according to claim 1, wherein: A structure in which the first pixel defining layer, the reflective film, and the second pixel defining layer are sequentially stacked surrounds the intermediate layer in a plan view.

7. The display device according to claim 1, wherein: The intermediate layer further includes a metal oxide layer adjacent to the emission layer and including a metal oxide.

8. The display device according to claim 1, wherein: The reflective film directly contacts the intermediate layer.

9. The display device according to claim 1, wherein: At least a portion of the reflective film is exposed from the second pixel defining layer.

10. The display device according to claim 1, wherein: The second pixel defining layer includes a light blocking material.

11. A method for manufacturing a display device, wherein: The method comprises: forming a first pixel defining layer, wherein the first pixel defining layer covers at least a portion of the first electrode and exposes an upper surface of the first electrode; forming a reflective film on the first pixel defining layer; forming a second pixel defining layer on the reflective film; forming an emission layer including quantum dots on the first electrode; and The emissive layer is cured using ultraviolet light.

12. The method according to claim 11, wherein: The emissive layer also includes a cross-linking agent activated by the ultraviolet rays.

13. The method according to claim 11, wherein: When the emitting layer is cured by the ultraviolet rays, At least some of the ultraviolet rays are reflected by the reflective film and reach the emitting layer.

14. The method according to claim 11, wherein: The forming of the reflective film comprises: forming a preliminary reflective film including a metal material on the first electrode and the first pixel defining layer; and The preliminary reflective film is patterned, and Wherein, the preliminary reflective film includes aluminum or aluminum alloy.

15. The method according to claim 11, wherein: The method further comprises: forming a metal oxide layer including a metal oxide on the first electrode; and irradiating ultraviolet rays to the metal oxide layer, wherein, when the ultraviolet rays are radiated toward the metal oxide layer, at least some of the ultraviolet rays are reflected by the reflective film and reach the metal oxide layer, and Wherein, the emission layer and the metal oxide layer are formed adjacent to each other.

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