Display device

Abstract

A display device includes a color conversion layer disposed over a light emitting element and including a first quantum dot and a second quantum dot. The core of the first quantum dot includes a group I-III-VI semiconductor compound, and the core of the second quantum dot includes a group III-V semiconductor compound.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0079700 filed in the Korean Intellectual Property Office (KIPO) on June 21, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to display devices. Background Art

[0004] Recently, as interest in information display increases, research and development of display devices have been continuously conducted. Summary of the invention

[0005] Embodiments provide a display device having improved efficiency of a color conversion layer.

[0006] According to an embodiment of the present disclosure, a display device may include: a color conversion layer disposed above a light-emitting element and including a first quantum dot and a second quantum dot. The core of the first quantum dot may include a I-III-VI semiconductor compound, and the core of the second quantum dot may include a III-V semiconductor compound.

[0007] Group I-III-VI semiconductor compounds may include AgInS, AgInS 2 、CuInS、CuInS 2 、CuGaO 2 、CuInGaS、AgGaO 2 , AgInGaS or a combination thereof.

[0008] The III-V semiconductor compound may include InP, InAs, GaP, GaAs, GaN, AlP, AlAs, AlN, or combinations thereof.

[0009] The content of the second quantum dots may be greater than the content of the first quantum dots.

[0010] The color conversion layer may include a first layer and a second layer.

[0011] The first layer may include first quantum dots, and the second layer may include second quantum dots.

[0012] The thickness of the second layer may be greater than the thickness of the first layer.

[0013] The color conversion layer may also include light scattering particles.

[0014] The light emitting element may include a first electrode, a second electrode, and a light emitting layer between the first electrode and the second electrode.

[0015] The display device may further include: a color filter layer on the color conversion layer.

[0016] According to an embodiment of the present disclosure, a display device may include: a first color conversion layer and a second color conversion layer, which are arranged above a light-emitting element. The first color conversion layer may include a first quantum dot and a second quantum dot, the second color conversion layer may include a third quantum dot, the core of the first quantum dot may include a I-III-VI semiconductor compound, and the core of the second quantum dot and the core of the third quantum dot may include a III-V semiconductor compound.

[0017] Group I-III-VI semiconductor compounds may include AgInS, AgInS 2 、CuInS、CuInS 2 、CuGaO 2 、CuInGaS、AgGaO 2 , AgInGaS or a combination thereof.

[0018] The III-V semiconductor compound may include InP, InAs, GaP, GaAs, GaN, AlP, AlAs, AlN, or combinations thereof.

[0019] The content of the second quantum dots may be greater than the content of the first quantum dots.

[0020] The first color conversion layer may include a first layer and a second layer.

[0021] The first layer may include first quantum dots, and the second layer may include second quantum dots.

[0022] The thickness of the second layer may be greater than the thickness of the first layer.

[0023] The thickness of the second color conversion layer may be greater than the thickness of the second layer.

[0024] The first color conversion layer and the second color conversion layer may further include light scattering particles.

[0025] The light emitting element may include a first electrode, a second electrode, and a light emitting layer between the first electrode and the second electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Exemplary embodiments will now be described more fully below with reference to the accompanying drawings; however, they may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the exemplary embodiments to those skilled in the art.

[0027] In the accompanying drawings, dimensions may be exaggerated for clarity of illustration. It will be understood that when an element is referred to as being "between" two elements, it may be the only element between the two elements, or one or more intervening elements may also be present. The same reference numerals always refer to the same elements.

[0028] Figure 1 is a schematic cross-sectional view of a display device according to an embodiment of the present disclosure.

[0029] Figure 2 is a schematic cross-sectional view of a display device according to an embodiment of the present disclosure.

[0030] Figures 3 to 7 2 is a schematic cross-sectional view showing process steps of a method of manufacturing a display device according to an embodiment of the present disclosure.

[0031] Figures 8 to 10 2 is a schematic cross-sectional view showing process steps of a method of manufacturing a display device according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0032] By referring to the embodiments described in detail below in conjunction with the accompanying drawings, the effects and features of the present disclosure and the methods for achieving the effects and features will be clear. However, the present disclosure is not limited to the embodiments disclosed herein, but can be implemented in various forms. The embodiments are provided only by way of example so that those of ordinary skill in the art can fully understand the features and scope of the present disclosure. Therefore, the present disclosure can be limited by the scope of the appended claims.

[0033] The terms used herein are only for the purpose of describing specific embodiments, and are not interpreted as limiting the present disclosure. The terms used herein are used for the purpose of describing specific embodiments, and are not intended to be limited. As used herein, the singular forms "one", "a kind of" and "the" are intended to also include plural forms, unless the context clearly indicates otherwise. In addition, when used in this specification, the terms "comprise", "comprises", "includes" and / or "includes" specify the existence of stated features, integral bodies, steps, operations, elements, components and / or its groups, but do not exclude the existence or addition of one or more other features, integral bodies, steps, operations, elements, components and / or its groups. It should also be noted that, as used herein, the terms "substantially", "about" and other similar terms are used as approximate terms, and are not used as degree terms, and therefore, are used to explain the inherent deviations in the values ​​measured, calculated and / or provided that will be recognized by those of ordinary skill in the art.

[0034] When an element, such as a layer, is referred to as being "on," "connected to," or "coupled to" another element or layer, it may be directly on, directly connected to, or directly coupled to the other element or layer, or there may be intervening elements or layers. However, when an element or layer is referred to as being "directly on," "directly connected to," or "directly coupled to" another element or layer, there are no intervening elements or layers. For this purpose, the term "connected" may refer to a physical connection, an electrical connection, and / or a fluid connection with or without intervening elements.

[0035] For descriptive purposes, spatially relative terms such as "below," "below," "under," "down," "above," "up," "above," "higher," "side" (e.g., as in "sidewall"), etc. may be used herein and thereby describe the relationship of one element to another element(s) as shown in the accompanying drawings. In addition to the orientations depicted in the accompanying drawings, spatially relative terms are intended to encompass different orientations of the device in use, operation, and / or manufacture. For example, if the device in the accompanying drawings is flipped, an element described as being "below" or "below" other elements or features will then be oriented "above" the other elements or features. Thus, the exemplary term "below" may encompass both above and below orientations. Additionally, the device may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and therefore, the spatially relative descriptors used herein are interpreted accordingly. Throughout the specification, the same reference numerals generally represent the same elements.

[0036] For the purpose of this disclosure, "at least one of A and B" may be interpreted 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 interpreted as only X, only Y, only Z, or any combination of two or more of X, Y, and Z. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0037] It will be understood that although the terms "first", "second", etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Therefore, without departing from the teachings of the present disclosure, the "first" element discussed below may also be referred to as the "second" element.

[0038] Unless otherwise defined or implied herein, all terms (including technical and scientific terms) used 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 terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted as an idealized or overly formal meaning unless clearly defined in this specification.

[0039] Hereinafter, embodiments of the present disclosure will be described in more detail with reference to the accompanying drawings.

[0040] Figure 1 and Figure 2 is a schematic cross-sectional view of a display device according to an embodiment of the present disclosure.

[0041] refer to Figure 1 and Figure 2 , the pixel PXL may include a first pixel PXG, a second pixel PXR and / or a third pixel PXB. Hereinafter, when at least one of the first pixel PXG, the second pixel PXR and the third pixel PXB is arbitrarily specified, or when two or more of the first pixel PXG, the second pixel PXR and the third pixel PXB are inclusively specified, each of the first pixel PXG, the second pixel PXR and the third pixel PXB or the first pixel PXG, the second pixel PXR and the third pixel PXB will be referred to as a “pixel (pixel) PXL” or “pixels (pixels) PXL”.

[0042] The first pixel PXG may emit light of a first color, the second pixel PXR may emit light of a second color, and the third pixel PXB may emit light of a third color. The first pixel PXG may be a green pixel that emits green light, the second pixel PXR may be a red pixel that emits red light, and the third pixel PXB may be a blue pixel that emits blue light. However, the present disclosure is not limited thereto. At least one first pixel PXG, at least one second pixel PXR, and at least one third pixel PXB that are disposed adjacent to each other may constitute a pixel unit that can emit light of various colors.

[0043] In an embodiment, the first pixel PXG, the second pixel PXR, and the third pixel PXB may have a light emitting element 120 that emits light of the same color, and include color conversion layers 230G, 230R, 230W of different colors and / or color filters of different colors disposed above the corresponding light emitting elements 120 to emit light of the first color, the second color, and the third color, respectively. In another embodiment, the first pixel PXG, the second pixel PXR, and the third pixel PXB may have a light emitting element of the first color, a light emitting element of the second color, and a light emitting element of the third color as a light source to emit light of the first color, the second color, and the third color, respectively. However, the color, type, and / or quantity of each pixel PXL are not particularly limited. For example, the color of the light emitted by each pixel PXL may be variously changed.

[0044] The display device may be formed into a structure in which a first substrate 110 on which a light emitting element 120 is disposed and a second substrate 210 on which a color conversion layer 230G, 230R, 230W and / or a color filter layer 220G, 220R, and 220B is disposed are bonded together and a filling material 300 is interposed between the first substrate 110 and the second substrate 210. However, the present disclosure is not necessarily limited thereto. In an embodiment, the color conversion layer 230G, 230R, 230W and / or the color filter layer 220G, 220R, and 220B may be stacked on the light emitting element 120 (e.g., directly on the light emitting element 120).

[0045] The first substrate 110 may constitute a base member and may be a rigid substrate or a rigid film or a flexible substrate or a flexible film. For example, the first substrate 110 may be a rigid substrate made of glass or tempered glass, a flexible substrate (or a film) made of plastic or metal, or at least one insulating layer. The material and / or properties of the first substrate 110 are not particularly limited.

[0046] The pixel circuit 121 may be disposed on the first substrate 110 . The pixel circuit 121 may include at least one thin film transistor, at least one capacitor, various signal lines, etc. The pixel circuit 121 may be electrically connected to the first electrode 122 of the light emitting element 120 .

[0047] The light emitting element 120 may be disposed above the pixel circuit 121. The light emitting element 120 may include a first electrode 122, a second electrode 124, and a light emitting layer 123 between the first electrode 122 and the second electrode 124. The light emitting element 120 may generate light using a principle that holes and electrons injected from the first electrode 122 and the second electrode 124 are recombined in the light emitting layer 123 to emit light. In an embodiment, the light emitting layer 123 may generate light having a wavelength in a range of about 430 nm to about 500 nm, and the light emitted from the light emitting layer 123 may be converted into light of the first color, the second color, and the third color in the corresponding color conversion layers 230G, 230R, and 230W.

[0048] The second electrode 124 may be disposed on the light emitting layer 123. The second electrode 124 may be configured with a metal layer including silver (Ag), magnesium (Mg), aluminum (Al), platinum (Pt), palladium (Pd), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr) or any alloy thereof and / or a transparent conductive layer including indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO) or indium tin zinc oxide (ITZO). In an embodiment, the second electrode 124 may be configured as a multilayer including at least two layers including a metal thin layer. For example, the second electrode 124 may be configured as three layers of ITO / Ag / ITO.

[0049] The thin film encapsulation layer 130 may be disposed throughout the light emitting element 120. The thin film encapsulation layer 130 may have a single layer structure or a multi-layer structure. The thin film encapsulation layer 130 may include a plurality of insulating layers covering the light emitting element 120. The thin film encapsulation layer 130 may include at least one inorganic layer and at least one organic layer. For example, the thin film encapsulation layer 130 may have a structure in which inorganic layers and organic layers are alternately stacked with each other.

[0050] The filling material 300 may be disposed on the thin film encapsulation layer 130. The filling material 300 may be interposed between the first substrate 110 and the second substrate 210 to perform the function of bonding the first substrate 110 and the second substrate 210 together and maintaining an appropriate distance between the first substrate 110 and the second substrate 210. Therefore, the filling material 300 may be applied between the first substrate 110 and the second substrate 210, and the first substrate 110 and the second substrate 210 may be bonded together, so that the filling material 300 may be used to firmly bond the first substrate 110 and the second substrate 210 together while appropriately maintaining the distance between the first substrate 110 and the second substrate 210.

[0051] The bank 240 and the color conversion layers 230G, 230R, and 230W may be disposed on the filling material 300. The bank 240 may be disposed between the first pixel PXG, the second pixel PXR, and the third pixel PXB or at the boundary of the first pixel PXG, the second pixel PXR, and the third pixel PXB, and include an opening that overlaps the first pixel PXG, the second pixel PXR, and the third pixel PXB, respectively, in a plan view. The opening of the bank 240 may provide a space in which the color conversion layers 230G, 230R, and 230W may be disposed.

[0052] Color conversion layers 230G, 230R, and 230W may be disposed on light emitting element 120 in the opening of bank 240. Color conversion layers 230G, 230R, and 230W may include a first color conversion layer 230G disposed in first pixel PXG, a second color conversion layer 230R disposed in second pixel PXR, and a light scattering layer 230W disposed in third pixel PXB.

[0053] First color conversion layer 230G may include first and second quantum dots QD1 and QD2 that convert light emitted from light emitting element 120 into light of the first color. For example, first and second quantum dots QD1 and QD2 of first color conversion layer 230G may be dispersed in a matrix material such as a base resin.

[0054] In an embodiment, when the light emitting element 120 is a blue light emitting element that emits blue light and the first pixel PXG is a green pixel, the first color conversion layer 230G may include a first quantum dot QD1 and a second quantum dot QD2 that converts the blue light emitted from the blue light emitting element into green light. The first quantum dot QD1 and the second quantum dot QD2 may absorb blue light and emit green light by shifting the wavelength of the blue light according to energy transition. When the first pixel PXG is a pixel of another color, the first color conversion layer 230G may include a first quantum dot QD1 and a second quantum dot QD2 corresponding to the color of the first pixel PXG.

[0055] Each of the first quantum dot QD1 and the second quantum dot QD2 may have a core-shell structure including a core comprising a semiconductor compound and a shell comprising an oxide of a metal, a metalloid or a non-metal, a semiconductor compound or any combination thereof. For example, the material included in the core and the material included in the shell may be different from each other. The shell of each of the first quantum dot QD1 and the second quantum dot QD2 may be used as a protective layer for maintaining semiconductor properties by preventing chemical modification of the core and / or a charging layer for providing electrophoretic properties. The shell may be a single layer or a multilayer.

[0056] The core of the first quantum dot QD1 may include a Group I-III-VI semiconductor compound. The Group I-III-VI semiconductor compound may include AgInS, AgInS 2 、CuInS、CuInS 2 、CuGaO 2 、CuInGaS、AgGaO 2 The shell of the first quantum dot QD1 may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or a combination thereof.

[0057] The core of the second quantum dot QD2 may include a III-V semiconductor compound. The III-V semiconductor compound may include InP, InAs, GaP, GaAs, GaN, AlP, AlAs, AlN, or a combination thereof. The shell of the second quantum dot QD2 may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or a combination thereof.

[0058] In an embodiment, each of the first quantum dot QD1 and the second quantum dot QD2 may be provided in the form of nanoparticles, nanotubes, nanowires, nanofibers, planar nanoparticles, etc., having a spherical shape, a pyramid shape, a multi-arm shape, or a cubic shape. However, the present disclosure is not necessarily limited thereto.

[0059] In an embodiment, the first color conversion layer 230G may be formed as follows Figure 1 In the case where the first color conversion layer 230G is formed as a single layer, the first quantum dot QD1 and the second quantum dot QD2 may be mixed together and arranged in the same layer. In an embodiment, the content of the first quantum dot QD1 of the first color conversion layer 230G and the content of the second quantum dot QD2 of the first color conversion layer 230G may be different from each other. For example, the content of the second quantum dot QD2 may be greater than the content of the first quantum dot QD1, but the present disclosure is not necessarily limited thereto.

[0060] In an embodiment, the first color conversion layer 230G may be formed as a multi-layer. For example, the first color conversion layer 230G may be formed as Figure 2 The first layer L1 and the second layer L2 are shown in FIG. Figure 2, a structure in which the first layer L1 is disposed on the second layer L2 is shown, but the present disclosure is not limited thereto, and the stacking order of the first layer L1 and the second layer L2 may be variously changed. In the case where the first color conversion layer 230G is formed as a multilayer, the first quantum dot QD1 and the second quantum dot QD2 may be disposed in different layers, respectively. For example, the first layer L1 may include the first quantum dot QD1, and the second layer L2 may include the second quantum dot QD2. In an embodiment, the thickness of the first layer L1 and the second layer L2 may vary according to the content of the first quantum dot QD1 and the second quantum dot QD2. For example, the thickness of the first layer L1 and the thickness of the second layer L2 may be different from each other. The thickness of the second layer L2 may be greater than the thickness of the first layer L1, but the present disclosure is not necessarily limited thereto.

[0061] As described above, when the first quantum dots QD1 of the I-III-VI group and the second quantum dots QD2 of the III-V group are mixed together and applied at the same time, the efficiency can be improved and the reflectivity can be reduced compared to the case where the III-V group quantum dots are applied alone. Compared to the case where the I-III-VI group quantum dots are applied alone, the material cost can be saved and the wavelength conversion efficiency can be improved.

[0062] In an embodiment, the first color conversion layer 230G may further include at least one light scattering particle SCT in order to effectively utilize the light emitted from the light emitting element 120. For example, the light scattering particle SCT may include barium sulfate (BaSO 4 ), calcium carbonate (CaCO 3 ), titanium oxide (TiO 2 ), silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ) and at least one of zinc oxide (ZnO).

[0063] Second color conversion layer 230R may include third quantum dots QD3 that convert light emitted from light emitting element 120 into light of a second color. For example, third quantum dots QD3 of second color conversion layer 230R may be dispersed in a matrix material such as a base resin.

[0064] In an embodiment, when the light emitting element 120 is a blue light emitting element that emits blue light and the second pixel PXR is a red pixel, the second color conversion layer 230R may include a third quantum dot QD3 that converts the blue light emitted from the blue light emitting element into red light. The third quantum dot QD3 may absorb blue light and emit red light by shifting the wavelength of the blue light according to energy transition. When the second pixel PXR is a pixel of another color, the second color conversion layer 230R may include a third quantum dot QD3 corresponding to the color of the second pixel PXR.

[0065] The third quantum dot QD3 may have a core-shell structure including a core comprising a semiconductor compound and a shell comprising an oxide of a metal, a metalloid or a non-metal, a semiconductor compound or any combination thereof. For example, the material included in the core and the material included in the shell may be different from each other. The shell of the third quantum dot QD3 may be used as a protective layer for maintaining semiconductor properties by preventing chemical modification of the core and / or a charging layer for providing electrophoretic properties. The shell may be a single layer or a multilayer.

[0066] The core of the third quantum dot QD3 may include a III-V semiconductor compound. The III-V semiconductor compound may include InP, InAs, GaP, GaAs, GaN, AlP, AlAs, AlN, or a combination thereof. The shell of the third quantum dot QD3 may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or a combination thereof. The third quantum dot QD3 and the second quantum dot QD2 may include the same material, but the core size of the third quantum dot QD3 and the core size of the second quantum dot QD2 may be different from each other.

[0067] In an embodiment, the third quantum dot QD3 may be provided in the form of nanoparticles, nanotubes, nanowires, nanofibers, planar nanoparticles, etc., which have a spherical shape, a pyramid shape, a multi-arm shape, or a cubic shape. However, the present disclosure is not necessarily limited thereto.

[0068] In an embodiment, the second color conversion layer 230R may further include at least one light scattering particle SCT in order to effectively utilize the light emitted from the light emitting element 120. For example, the light scattering particle SCT may include barium sulfate (BaSO 4 ), calcium carbonate (CaCO 3 ), titanium oxide (TiO 2 ), silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), aluminum oxide (Al2 O 3 ), zirconium oxide (ZrO 2 ) and at least one of zinc oxide (ZnO).

[0069] In an embodiment, blue light having a relatively short wavelength in the visible light band may be incident into the quantum dots QD1, QD2, and QD3 of the first color conversion layer 230G and the second color conversion layer 230R, so that the absorption coefficients of the quantum dots QD1, QD2, and QD3 may be increased. Therefore, the efficiency of the light finally emitted from the first pixel PXG and the second pixel PXR may be improved, and excellent color reproduction may be ensured. The first pixel PXG, the second pixel PXR, and the third pixel PXB may be configured by using the light emitting element 120 of the same color (e.g., a blue light emitting element), so that the manufacturing efficiency of the display device may be improved.

[0070] The light scattering layer 230W may be configured to effectively utilize the light emitted from the light emitting element 120. For example, in the case where the light emitting element 120 is a blue light emitting element that emits blue light and the third pixel PXB is a blue pixel, the light scattering layer 230W may include at least one light scattering particle SCT to effectively utilize the light emitted from the light emitting element 120. For example, the light scattering particles SCT of the light scattering layer 230W may include barium sulfate (BaSO 4 ), calcium carbonate (CaCO 3 ), titanium oxide (TiO 2 ), silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), aluminum oxide (Al 2 O 3 ), zirconium oxide (ZrO 2 ) and at least one of zinc oxide (ZnO). In an embodiment, the light scattering particles SCT may be omitted, and a light scattering layer 230W configured with a transparent polymer may be provided.

[0071] In an embodiment, a capping layer 270 may be disposed between the color conversion layers 230G, 230R, and 230W and the filling material 300. The capping layer 270 may be disposed throughout the first pixel PXG, the second pixel PXR, and the third pixel PXB. The capping layer 270 may cover the color conversion layers 230G, 230R, and 230W. The capping layer 270 may prevent the color conversion layers 230G, 230R, and 230W from being damaged or contaminated due to impurities such as moisture or air penetrating from the outside. The capping layer 270 may include a silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiO x Ny ), aluminum nitride (AlN x ), aluminum oxide (AlO x ), zirconium oxide (ZrO x ), hafnium oxide (HfO x ) and titanium oxide (TiO x ) of an inorganic insulating material. In an embodiment, the capping layer 270 may be formed to have a thickness of about to about The thickness may be within the range of , but the present disclosure is not necessarily limited thereto.

[0072] The optical layer 260 may be disposed between the dam 240 and the color conversion layers 230G, 230R, and 230W. The optical layer 260 may be used to improve light extraction efficiency by recycling light provided from the color conversion layers 230G, 230R, and 230W through total reflection. To this end, the optical layer 260 may have a relatively lower refractive index than the refractive index of the color conversion layers 230G, 230R, and 230W. For example, the refractive index of the color conversion layers 230G, 230R, and 230W may be in the range of about 1.6 to about 2.0, and the refractive index of the optical layer 260 may be in the range of about 1.1 to about 1.3.

[0073] Color filter layers 220G, 220R, and 220B may be disposed on the optical layer 260. The color filter layers 220G, 220R, and 220B may include a first color filter 220G, a second color filter 220R, and a third color filter 220B that are consistent with the color of the corresponding pixel PXL. The first color filter 220G, the second color filter 220R, and the third color filter 220B that are consistent with the color of the corresponding first pixel PXG, the second pixel PXR, and the third pixel PXB may be disposed so that a full-color image may be displayed.

[0074] The color filter layers 220G, 220R, and 220B may include a first color filter 220G disposed in the first pixel PXG to allow light emitted from the first pixel PXG to be selectively transmitted therethrough, a second color filter 220R disposed in the second pixel PXR to allow light emitted from the second pixel PXR to be selectively transmitted therethrough, and a third color filter 220B disposed in the third pixel PXB to allow light emitted from the third pixel PXB to be selectively transmitted therethrough.

[0075] In an implementation, the first color filter 220G, the second color filter 220R, and the third color filter 220B may be a green color filter, a red color filter, and a blue color filter, respectively, but the present disclosure is not necessarily limited thereto.

[0076] The first color filter 220G may overlap the first color conversion layer 230G in the thickness direction (Z-axis direction). The first color filter 220G may include a color filter material for allowing light of the first color (or green) to selectively transmit therethrough. For example, in the case where the first pixel PXG is a green pixel, the first color filter 220G may include a green color filter material.

[0077] The second color filter 220R may overlap the second color conversion layer 230R in the thickness direction (Z-axis direction). The second color filter 220R may include a color filter material for allowing light of the second color (or red) to selectively transmit therethrough. For example, in the case where the second pixel PXR is a red pixel, the second color filter 220R may include a red color filter material.

[0078] The third color filter 220B may overlap the light scattering layer 230W in the thickness direction (Z-axis direction). The third color filter 220B may include a color filter material for allowing light of a third color (or blue) to selectively transmit therethrough. For example, in the case where the third pixel PXB is a blue pixel, the third color filter 220B may include a blue color filter material.

[0079] In an embodiment, the first color filter 220G, the second color filter 220R, and the third color filter 220B may overlap each other between the first pixel PXG, the second pixel PXR, and the third pixel PXB in the thickness direction (Z-axis direction). Therefore, when the first color filter 220G, the second color filter 220R, and the third color filter 220B are formed to overlap each other between the first pixel PXG, the second pixel PXR, and the third pixel PXB, a color mixing defect observed at the front or side of the display device can be prevented.

[0080] The second substrate 210 may be disposed on the color filter layers 220G, 220R, and 220B. The second substrate 210 may protect the display device from external impacts and provide an input surface and / or a display surface to a user. The second substrate 210 may have a multilayer structure including a glass substrate, a plastic film, a plastic substrate, or a combination thereof. The multilayer structure may be formed by a continuous process or an adhesive process using an adhesive layer. The entirety or a portion of the second substrate 210 may be flexible.

[0081] A method of manufacturing a display device according to an embodiment will be described.

[0082] Figures 3 to 7 is a schematic cross-sectional view showing the process steps of a method for manufacturing a display device according to an embodiment of the present disclosure. Figure 1 Components that are substantially the same as those shown in are denoted by the same reference numerals, and overlapping descriptions are omitted.

[0083] refer to Figure 3 , a light emitting element 120 may be formed on the first substrate 110, and a thin film encapsulation layer 130 may be formed throughout the light emitting element 120. The first electrode 122 may be formed to overlap each of the pixels PXG, PXR, and PXB in the thickness direction (Z-axis direction). The light emitting layer 123 may also include a hole transport region adjacent to the first electrode 122 and an electron transport region adjacent to the second electrode 124. In an embodiment, the light emitting layer 123 may also include a plurality of light emitting units sequentially stacked between the first electrode 122 and the second electrode 124 and a charge generation layer disposed between the light emitting units. Therefore, in the case where the light emitting layer 123 includes a light emitting unit and a charge generation layer, the light emitting element 120 may be a tandem light emitting element. In an embodiment, the light emitting layer 123 may be a blue light emitting layer that emits light having a wavelength in the range of about 430 nm to about 500 nm, but the present disclosure is not necessarily limited thereto.

[0084] refer to Figure 4 , color filter layers 220G, 220R, and 220B may be formed on the second substrate 210, and an optical layer 260 may be formed on the color filter layers 220G, 220R, and 220B. In an embodiment, the first color filter 220G, the second color filter 220R, and the third color filter 220B may be formed to overlap each other between the first pixel PXG, the second pixel PXR, and the third pixel PXB in the thickness direction (Z-axis direction). Therefore, in the case where the first color filter 220G, the second color filter 220R, and the third color filter 220B overlap each other between the first pixel PXG, the second pixel PXR, and the third pixel PXB, a color mixing defect observed at the front or side of the display device may be prevented.

[0085] The optical layer 260 may be formed throughout the first pixel PXG, the second pixel PXR, and the third pixel PXB. The optical layer 260 may planarize a step difference due to the color filter layers 220G, 220R, and 220B, but the present disclosure is not necessarily limited thereto.

[0086] refer to Figure 5 , a bank 240 may be formed on the optical layer 260. The bank 240 may be disposed between the first pixel PXG, the second pixel PXR, and the third pixel PXB or at a boundary of the first pixel PXG, the second pixel PXR, and the third pixel PXB, and include an opening that overlaps the first pixel PXG, the second pixel PXR, and the third pixel PXB in a thickness direction (Z-axis direction), respectively. The opening of the bank 240 may provide a space in which the color conversion layers 230G, 230R, and 230W may be disposed.

[0087] refer to Figure 6, color conversion layers 230G, 230R, and 230W may be formed in the openings of bank 240 , and capping layer 270 may be formed over color conversion layers 230G, 230R, and 230W.

[0088] The first color conversion layer 230G may be formed in the first pixel PXG, the second color conversion layer 230R may be formed in the second pixel PXR, and the light scattering layer 230W may be formed in the third pixel PXB.

[0089] The first color conversion layer 230G may be formed by inkjet printing a first ink composition including first quantum dots QD1 and second quantum dots QD2. For example, the first ink composition may include a monomer, a first quantum dot QD1, a second quantum dot QD2, light scattering particles SCT, an initiator, a dispersant, and / or a viscosity control agent. The content of the first quantum dot QD1 of the first ink composition and the content of the second quantum dot QD2 of the first ink composition may be different from each other. For example, the content of the second quantum dot QD2 may be greater than the content of the first quantum dot QD1, but the present disclosure is not necessarily limited thereto.

[0090] The core of the first quantum dot QD1 may include a Group I-III-VI semiconductor compound. The Group I-III-VI semiconductor compound may include AgInS, AgInS 2 、CuInS、CuInS 2 、CuGaO 2 、CuInGaS、AgGaO 2 The shell of the first quantum dot QD1 may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or a combination thereof.

[0091] The core of the second quantum dot QD2 may include a III-V semiconductor compound. The III-V semiconductor compound may include InP, InAs, GaP, GaAs, GaN, AlP, AlAs, AlN, or a combination thereof. The shell of the second quantum dot QD2 may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or a combination thereof.

[0092] In an embodiment, each of the first quantum dot QD1 and the second quantum dot QD2 may be provided in the form of nanoparticles, nanotubes, nanowires, nanofibers, planar nanoparticles, etc., having a spherical shape, a pyramid shape, a multi-arm shape, or a cubic shape. However, the present disclosure is not necessarily limited thereto.

[0093] As described above, when the first quantum dots QD1 of the I-III-VI group and the second quantum dots QD2 of the III-V group are mixed together and applied at the same time, the efficiency can be improved and the reflectivity can be reduced compared to the case where the III-V group quantum dots are applied alone. Compared to the case where the I-III-VI group quantum dots are applied alone, the material cost can be saved and the wavelength conversion efficiency can be improved, which has been described above.

[0094] The second color conversion layer 230R may be formed by inkjet printing a second ink composition including third quantum dots QD 3. For example, the second ink composition may include a monomer, third quantum dots QD 3, light scattering particles SCT, an initiator, a dispersant, and / or a viscosity controller.

[0095] The core of the third quantum dot QD3 may include a III-V semiconductor compound. The III-V semiconductor compound may include InP, InAs, GaP, GaAs, GaN, AlP, AlAs, AlN, or a combination thereof. The shell of the third quantum dot QD3 may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or a combination thereof. The third quantum dot QD3 and the second quantum dot QD2 may include the same material, but the core size of the third quantum dot QD3 and the core size of the second quantum dot QD2 may be different from each other.

[0096] In an embodiment, the third quantum dot QD3 may be provided in the form of nanoparticles, nanotubes, nanowires, nanofibers, planar nanoparticles, etc., which have a spherical shape, a pyramid shape, a multi-arm shape, or a cubic shape. However, the present disclosure is not necessarily limited thereto.

[0097] In an embodiment, blue light having a relatively short wavelength in the visible light band may be incident on the quantum dots QD1, QD2, and QD3 of the first color conversion layer 230G and the second color conversion layer 230R, so that the absorption coefficients of the quantum dots QD1, QD2, and QD3 may be increased. Therefore, the efficiency of the light finally emitted from the first pixel PXG and the second pixel PXR may be improved, and excellent color reproduction may be ensured. The first pixel PXG, the second pixel PXR, and the third pixel PXB may be configured by using the light emitting element 120 of the same color (e.g., a blue light emitting element), so that the manufacturing efficiency of the display device may be improved, which has been described above.

[0098] The light scattering layer 230W may be formed by inkjet printing a third ink composition including light scattering particles SCT. The light scattering particles SCT may include barium sulfate (BaSO 4 ), calcium carbonate (CaCO 3 ), titanium oxide (TiO 2 ), silicon oxide (SiO 2 ), silicon nitride (Si 3 N 4 ), aluminum oxide (Al 2 O 3 )、ZrO 2 ) and at least one of zinc oxide (ZnO). The color conversion layers 230G, 230R, and 230W may be cured by irradiating ultraviolet (UV) light onto the printed first to third ink compositions.

[0099] Subsequently, a capping layer 270 may be formed throughout the color conversion layers 230G, 230R, and 230W. The capping layer 270 may be disposed throughout the first pixel PXG, the second pixel PXR, and the third pixel PXB. The capping layer 270 may cover the color conversion layers 230G, 230R, and 230W. The capping layer 270 may prevent the color conversion layers 230G, 230R, and 230W from being damaged or contaminated due to impurities such as moisture or air penetrating from the outside. The capping layer 270 may include a silicon oxide (SiO x ), silicon nitride (SiN x ), silicon oxynitride (SiO x N y ), aluminum nitride (AlN x ), aluminum oxide (AlO x ), zirconium oxide (ZrO x ), hafnium oxide (HfO x ) and titanium oxide (TiO x ) of inorganic insulating materials.

[0100] refer to Figure 7, then, the first substrate 110 and the second substrate 210 may be bonded together, thereby completing the display device. A filling material 300 may be provided between the first substrate 110 and the second substrate 210. The filling material 300 may be interposed between the thin film encapsulation layer 130 on the first substrate 110 and the capping layer 270 on the second substrate 210 to perform the function of bonding the first substrate 110 and the second substrate 210 together and maintaining an appropriate distance between the first substrate 110 and the second substrate 210.

[0101] Hereinafter, another embodiment will be described. In the following embodiment, the same components as those already described are denoted by the same reference numerals, and overlapping descriptions will be omitted or simplified.

[0102] Figures 8 to 10 is a schematic cross-sectional view showing the process steps of a method for manufacturing a display device according to an embodiment of the present disclosure. Figure 2 Components that are substantially the same as those shown in are denoted by the same reference numerals, and overlapping descriptions are omitted.

[0103] refer to Figure 8 , the color filter layers 220G, 220R, and 220B and the optical layer 260 may be formed on the second substrate 210, and the dam 240 may be formed on the optical layer 260. Figures 4 to 5 The process of forming the color filter layers 220G, 220R, and 220B, the optical layer 260, and the bank 240 is described, and thus, an overlapping description will be omitted.

[0104] refer to Fig. 9 , color conversion layers 230G, 230R, and 230W may be formed in the openings of bank 240 , and capping layer 270 may be formed over color conversion layers 230G, 230R, and 230W.

[0105] The first color conversion layer 230G may be formed in the first pixel PXG, the second color conversion layer 230R may be formed in the second pixel PXR, and the light scattering layer 230W may be formed in the third pixel PXB.

[0106] The first color conversion layer 230G may be formed by sequentially inkjet printing a first composition including a first quantum dot QD1 and a second composition including a second quantum dot QD2 and curing the printed first and second compositions. Therefore, the first color conversion layer 230G may be formed as a multilayer. For example, the first color conversion layer 230G may be formed with a first layer L1 and a second layer L2. The first layer L1 may be formed by inkjet printing a first composition including a first quantum dot QD1 and curing the printed first composition. The second layer L2 may be formed by inkjet printing a second composition including a second quantum dot QD2 on the first layer L1 and curing the printed second composition. Therefore, the first quantum dot QD1 and the second quantum dot QD2 of the first color conversion layer 230G may be respectively arranged in different layers. In an embodiment, the thickness of the first layer L1 and the second layer L2 may vary according to the content of the first quantum dot QD1 and the second quantum dot QD2. For example, the thickness of the first layer L1 and the thickness of the second layer L2 may be different from each other. The thickness of the second layer L2 may be greater than the thickness of the first layer L1, but the present disclosure is not necessarily limited thereto.

[0107] In an embodiment, the first composition may include a monomer, a first quantum dot QD1, a light scattering particle SCT, an initiator, a dispersant and / or a viscosity control agent. The second composition may include a monomer, a second quantum dot QD2, a light scattering particle SCT, an initiator, a dispersant and / or a viscosity control agent. The content of the first quantum dot QD1 of the first composition and the content of the second quantum dot QD2 of the second composition may be different from each other. For example, the content of the second quantum dot QD2 may be greater than the content of the first quantum dot QD1, but the present disclosure is not necessarily limited to this.

[0108] The core of the first quantum dot QD1 may include a Group I-III-VI semiconductor compound. The Group I-III-VI semiconductor compound may include AgInS, AgInS 2 、CuInS、CuInS 2 、CuGaO 2 、CuInGaS、AgGaO 2 The shell of the first quantum dot QD1 may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or a combination thereof.

[0109] The core of the second quantum dot QD2 may include a III-V semiconductor compound. The III-V semiconductor compound may include InP, InAs, GaP, GaAs, GaN, AlP, AlAs, AlN, or a combination thereof. The shell of the second quantum dot QD2 may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, or a combination thereof.

[0110] As described above, when the first quantum dots QD1 of the I-III-VI group and the second quantum dots QD2 of the III-V group are mixed together and applied at the same time, the efficiency can be improved and the reflectivity can be reduced compared to the case where the III-V group quantum dots are applied alone. Compared to the embodiment in which the I-III-VI group quantum dots are applied alone, the material cost can be saved and the wavelength conversion efficiency can be improved, which has been described above.

[0111] Already referenced Figure 6 The processes of forming the second color conversion layer 230R, the light scattering layer 230W, and the capping layer 270 are described, and thus, overlapping descriptions will be omitted.

[0112] refer to Fig.10 Subsequently, the first substrate 110 and the second substrate 210 may be bonded together, thereby completing the display device. A filling material 300 may be disposed between the first substrate 110 and the second substrate 210 .

[0113] According to the present disclosure, group I-III-VI quantum dots and group III-V quantum dots may be applied to a color conversion layer while being mixed together, so that efficiency may be improved and reflectivity may be reduced.

[0114] The above description is an example of the technical features of the present disclosure, and a person skilled in the art to which the present disclosure belongs will be able to make various modifications and changes.Therefore, the embodiments of the present disclosure described above can be implemented separately or in combination with each other.

[0115] 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 it should be understood that all technical spirits within the equivalent scope are included in the scope of the present disclosure.

Claims

1. A display device, comprising: A color conversion layer is disposed above the light emitting element and includes a first quantum dot and a second quantum dot, wherein the core of the first quantum dot comprises a Group I-III-VI semiconductor compound, and The core of the second quantum dot includes a Group III-V semiconductor compound.

2. The display device according to claim 1, wherein: The Group I-III-VI semiconductor compound includes AgInS, AgInS2, CuInS, CuInS2, CuGaO2, CuInGaS, AgGaO2, AgInGaS or a combination thereof.

3. The display device according to claim 1, wherein: The III-V semiconductor compound includes InP, InAs, GaP, GaAs, GaN, AlP, AlAs, AlN or a combination thereof.

4. The display device according to claim 1, wherein: The content of the second quantum dots is greater than the content of the first quantum dots.

5. The display device according to claim 1, wherein: The color conversion layer includes a first layer and a second layer.

6. The display device according to claim 5, wherein: The first layer includes the first quantum dots, and The second layer includes the second quantum dots.

7. The display device according to claim 6, wherein: The thickness of the second layer is greater than the thickness of the first layer.

8. The display device according to claim 1, wherein: The color conversion layer also includes light scattering particles.

9. The display device according to claim 1, wherein: The light emitting element includes a first electrode, a second electrode, and a light emitting layer between the first electrode and the second electrode.

10. The display device according to claim 1, further comprising: A color filter layer is on the color conversion layer.

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