Color-converting substrate and display device including the same

Abstract

The disclosed color conversion substrate comprises a color conversion unit including wavelength conversion particles that excite incident light and emit light of a different color from the incident light, a color filter pattern that filters light emitted from the color conversion unit, and a light reflection layer disposed between the color conversion unit and the color filter pattern that selectively reflects light having a wavelength corresponding to the incident light.

Description

Technology Field

[0001] The present invention relates to a color conversion substrate, and more specifically, to a color conversion substrate and a display device including the same. Background Technology

[0002] Organic light-emitting display devices are self-emissive display devices capable of generating color images without a separate light source, such as a backlight.

[0003] Recently, organic light-emitting display devices including a color filter and a color conversion unit are being researched to improve display quality. The color conversion unit can convert the wavelength of light provided by a light-emitting element. Thus, it can emit light having a color different from the incident light. For example, the color conversion unit may include a wavelength conversion material such as quantum dots. The problem to be solved

[0004] The objective of the present invention is to provide a color conversion substrate with improved light efficiency.

[0005] Another objective of the present invention is to provide a display device with improved light efficiency.

[0006] However, the present invention is not limited to the purposes described above and may be extended in various ways without departing from the spirit and scope of the invention. means of solving the problem

[0007] To achieve the aforementioned objectives of the present invention, a color conversion substrate according to exemplary embodiments of the present invention comprises: a color conversion unit comprising wavelength conversion particles that excite incident light and emit light of a different color from the incident light; a color filter pattern that filters light emitted from the color conversion unit; and a light reflecting layer disposed between the color conversion unit and the color filter pattern that selectively reflects light having a wavelength corresponding to the incident light.

[0008] According to one embodiment, the light reflecting layer surrounds the light-emitting surface and side of the color conversion unit.

[0009] According to one embodiment, the light reflecting layer has a structure in which multiple layers having different refractive indices are alternately stacked.

[0010] According to one embodiment, the light reflecting layer includes a wire grid pattern.

[0011] According to one embodiment, the light reflecting layer comprises nanoparticles containing silver (Ag).

[0012] According to one embodiment, the nanoparticle comprises an oxide core and a metal shell containing silver (Ag).

[0013] According to one embodiment, the color conversion substrate further includes a compensation member that transmits the incident light without wavelength conversion, and the compensation member does not overlap with the light reflection layer.

[0014] According to one embodiment, the incident light is blue light.

[0015] According to one embodiment, the wavelength conversion particle includes a quantum dot.

[0016] According to one embodiment, the color conversion unit further includes a scatterer.

[0017] A display device according to exemplary embodiments of the present invention comprises a first substrate including a pixel array and a second substrate coupled to the first substrate. The second substrate comprises a color conversion unit including wavelength conversion particles that excite incident light and emit light of a different color from the incident light, a color filter pattern that filters light emitted from the color conversion unit, and a light reflection layer disposed between the color conversion unit and the color filter pattern that selectively reflects light having a wavelength corresponding to the incident light.

[0018] A display device according to exemplary embodiments of the present invention comprises a pixel array, an encapsulation layer covering the pixel array, a color conversion unit disposed on the encapsulation layer and including wavelength conversion particles that excite incident light and emit light of a different color from the incident light, a color filter pattern disposed on the color conversion unit and filtering light emitted from the color conversion unit, and a light reflection layer disposed between the color conversion unit and the color filter pattern and selectively reflecting light having a wavelength corresponding to the incident light. Effects of the invention

[0019] According to exemplary embodiments of the present invention, incident light that is not excited in the color conversion units can be reflected into the color conversion units. Thus, the incident light can be recycled as excitation light without being absorbed by the color filter patterns. Accordingly, the light efficiency of the color conversion substrate and the display device can be improved.

[0020] Accordingly, scatterers included in the color conversion units can be omitted or reduced.

[0021] In addition, as light efficiency is improved, the required thickness of the color conversion sections can be reduced. Accordingly, an additional photolithography process for forming a multilayer partition structure can be omitted.

[0022] In addition, as light efficiency is improved, the amount of dye or pigment included in the color filter can be reduced. Brief explanation of the drawing

[0023] FIG. 1 is a plan view showing an enlarged pixel area of ​​a display device according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of a display device according to one embodiment of the present invention, illustrated along the line I-I' of FIG. 1. FIGS. 3 to 5 are cross-sectional views showing enlarged area A of FIG. 2. FIGS. 6 to 9 are cross-sectional views illustrating a method for manufacturing a color conversion substrate according to an embodiment of the present invention. FIGS. 10 to 14 are cross-sectional views illustrating a display device according to embodiments of the present invention. Specific details for implementing the invention

[0024] Hereinafter, a color conversion substrate and a display device according to exemplary embodiments of the present invention will be described in detail with reference to the attached drawings.

[0025] FIG. 1 is a plan view showing an enlarged pixel area of ​​a display device according to one embodiment of the present invention. FIG. 2 is a cross-sectional view of a display device according to one embodiment of the present invention along the line I-I' of FIG. 1. FIG. 3 to 5 are cross-sectional views showing an enlarged area A of FIG. 2.

[0026] Referring to FIGS. 1 and 2, a display device according to one embodiment of the present invention includes a first substrate (100) and a second substrate (200). The first substrate (100) includes a pixel array. Each pixel of the pixel array may include a light-emitting element that generates light according to a driving signal.

[0027] The second substrate (200) includes a color conversion unit that converts the wavelength of light generated from the light-emitting element. Additionally, the second substrate (200) may further include a color filter that transmits light of a specific color.

[0028] Referring to FIG. 1, the display device may include a display area that generates an image and a surrounding area that surrounds the display area. The display area may include a plurality of pixel areas, and each pixel area may include a light-emitting area (LA1, LA2, LA3) that emits light and a light-blocking area (BA) that surrounds the light-emitting area (LA1, LA2, LA3). Light generated by the display device may be emitted to the outside through the light-emitting area.

[0029] The above-mentioned light-emitting regions may emit light of different colors. For example, the display device may include a first light-emitting region (LA1) that emits first color light, a second light-emitting region (LA2) that emits second color light, and a third light-emitting region (LA3) that emits third color light.

[0030] According to one embodiment, the first light-emitting region (LA1) may emit blue light, the second light-emitting region (LA2) may emit red light, and the third light-emitting region (LA3) may emit green light. However, embodiments of the present invention are not limited thereto. For example, the light-emitting regions may be combined to emit yellow, cyan, and magenta light.

[0031] In addition, the light-emitting regions may emit four or more colors of light. For example, the light-emitting regions may be combined to emit at least one of yellow, cyan, and crimson light in addition to red, green, and blue light. In addition, the light-emitting regions may be combined to emit white light.

[0032] According to one embodiment, the light-emitting regions (LA1, LA2, LA3) may each have a substantially rectangular shape. However, embodiments of the present invention are not limited thereto. For example, the light-emitting regions (LA1, LA2, LA3) may have different shapes. Additionally, the light-emitting regions (LA1, LA2, LA3) may have various shapes such as squares, rhombuses, triangles, circles, etc., and the edges or corners of each light-emitting region may have a rounded shape or a chamfered shape.

[0033] According to one embodiment, the light-emitting regions (LA1, LA2, LA3) may have different sizes. However, embodiments of the present invention are not limited thereto, and the light-emitting regions (LA1, LA2, LA3) may have the same size.

[0034] Referring to FIG. 2, the first substrate (100) includes driving elements (TR1, TR2, TR3) disposed on a base substrate (110). The driving elements (TR1, TR2, TR3) may be electrically connected to a light-emitting element. The light-emitting element may be an organic light-emitting diode. For example, the organic light-emitting diode may include a first electrode (EL1), a second electrode (EL2), and an organic light-emitting layer (OL) disposed between the first electrode (EL1) and the second electrode (EL2).

[0035] For example, the base substrate (110) may include glass, quartz, sapphire, polymer material, etc.

[0036] According to one embodiment, the driving elements (TR1, TR2, TR3) include thin-film transistors. For example, each driving element (TR1, TR2, TR3) may include a plurality of thin-film transistors.

[0037] For example, the channel layer of the thin-film transistor may include amorphous silicon, polycrystalline silicon, or a metal oxide semiconductor. The metal oxide semiconductor may include binary compounds (ABx), ternary compounds (ABxCy), quaternary compounds (ABxCyDz), etc. containing indium (In), zinc (Zn), gallium (Ga), tin (Sn), titanium (Ti), aluminum (Al), hafnium (Hf), zirconium (Zr), magnesium (Mg), etc. For example, the metal oxide semiconductor may include zinc oxide (ZnOx), gallium oxide (GaOx), titanium oxide (TiOx), tin oxide (SnOx), indium oxide (InOx), indium-gallium oxide (IGO), indium-zinc oxide (IZO), indium-tin oxide (ITO), gallium-zinc oxide (GZO), zinc-magnesium oxide (ZMO), zinc-tin oxide (ZTO), zinc-zirconium oxide (ZnZrxOy), indium-gallium-zinc oxide (IGZO), indium-zinc-tin oxide (IZTO), indium-gallium-hafnium oxide (IGHO), tin-aluminum-zinc oxide (TAZO), and indium-gallium-tin oxide (IGTO), etc.

[0038] The above driving element (TR) can be covered by an insulating structure (120). The insulating structure may include a combination of an inorganic insulating layer and an organic insulating layer.

[0039] The first electrode (EL1) can operate as an anode. For example, the first electrode (EL1) may be formed as a transmissive electrode or a reflective electrode depending on the light emission type. When the first electrode (EL1) is formed as a reflective electrode, it may include gold (Au), silver (Ag), aluminum (Al), copper (Cu), nickel (Ni), platinum (Pt), magnesium (Mg), chromium (Cr), tungsten (W), molybdenum (Mo), titanium (Ti), etc., and may further include a metal oxide layer such as indium tin oxide, indium zinc oxide, etc.

[0040] The pixel defining layer (PDL) is disposed on the insulating structure (120) and has an opening that exposes at least a portion of the first electrode (EL1). For example, the pixel defining layer (PDL) may comprise an organic insulating material. At least a portion of the light-emitting layer (OL) may be disposed within the opening of the pixel defining layer (PDL). In one embodiment, the light-emitting layer (OL) may extend continuously over a display area across a plurality of pixels. In another embodiment, the light-emitting layer (OL) may be separated from the light-emitting layer of an adjacent pixel.

[0041] The light-emitting layer (OL) may include at least one of the functional layers, such as a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, and an electron injection layer, in a single-layer or multi-layer structure. The light-emitting layer (OL) may include a low-molecular-weight organic compound or a high-molecular-weight organic compound.

[0042] According to one embodiment, the light-emitting layer (OL) may generate blue light. However, embodiments of the present invention are not limited thereto. In other embodiments, the light-emitting layer (OL) may generate red light or green light, or may generate light having different colors depending on the pixel.

[0043] The second electrode (EL2) may be formed as a transmissive electrode or a reflective electrode depending on the light emission type. For example, the second electrode (EL2) may include a metal, an alloy, a metal nitride, a metal fluoride, a conductive metal oxide, or a combination thereof. For example, the second electrode (EL2) may be continuously extended over a display area across a plurality of pixels.

[0044] The first substrate (100) may further include an encapsulation layer (130) covering the light-emitting element array. The encapsulation layer (130) may be continuously extended to cover the entire display area.

[0045] For example, the encapsulation layer (130) may include a stacked structure of an organic thin film and an inorganic thin film. For example, as shown in FIG. 2, it may include a first inorganic thin film (132), an organic thin film (134) disposed on the first inorganic thin film (132), and a second inorganic thin film (136) disposed on the organic thin film. However, embodiments of the present invention are not limited thereto, and the encapsulation layer (130) may have a structure comprising two or more organic thin films and three or more inorganic thin films.

[0046] For example, the organic thin film (134) may include a polymer cured material such as polyacrylate. For example, the polymer cured material may be formed by a cross-linking reaction of monomers. For example, the inorganic thin film (132, 136) may include silicon oxide, silicon nitride, silicon carbide, aluminum oxide, tantalum oxide, hafnium oxide, zirconium oxide, titanium oxide, etc.

[0047] The second substrate (200) includes a color conversion unit that converts the wavelength of light (L1) generated from a light-emitting element of the first substrate (100) and emits light of a different color from the incident light (L1). Additionally, the second substrate (200) may further include a color filter that overlaps with the color conversion unit.

[0048] The color filter may be placed between the base substrate (210) and the color conversion unit. The color filter may filter light passing through the color filter to transmit light of a specific color.

[0049] According to one embodiment, the color filter may include a first color filter pattern (222), a second color filter pattern (224), and a third color filter pattern (226). The color filter patterns overlap with corresponding light-emitting regions. Accordingly, the color of the light (L2R, L2B, L2G) emitted from the light-emitting regions can be determined by the color filter patterns.

[0050] According to one embodiment, the first color filter pattern (222) overlaps with the first light-emitting region (LA1). For example, the first color filter pattern (222) can transmit blue light. The second color filter pattern (224) overlaps with the second light-emitting region (LA2). For example, the second color filter pattern (224) can transmit red light. The third color filter pattern (226) overlaps with the third light-emitting region (LA3). For example, the third color filter pattern (226) can transmit green light.

[0051] In this application, terms such as "first," "second," etc., are not used to refer to specific components. For example, a light-emitting region emitting red light or a region emitting green light may be referred to as the first light-emitting region, and a red color filter pattern or a green color filter pattern may be referred to as the first color filter pattern.

[0052] The color filter may further include a light-blocking pattern (223) that overlaps with the light-blocking region (BA). The light-blocking pattern (223) may be formed in the same layer as the first color filter pattern (222) and may be connected to the first color filter pattern (222). According to one embodiment, the light-blocking pattern (223) may be formed entirely over the light-blocking region (BA). The light-blocking pattern (223) may serve to prevent color mixing between adjacent subpixel regions.

[0053] The second substrate (200) may include a first protective layer (240) covering the color filter. The first protective layer (240) may include an inorganic material such as silicon oxide, silicon nitride, etc.

[0054] The above color conversion unit overlaps with the corresponding light-emitting region. For example, the second substrate (200) may include a first color conversion unit (232) that overlaps with the second light-emitting region (LA2).

[0055] The first color conversion unit (232) may include wavelength conversion particles (232b) and a resin unit (232a).

[0056] For example, the wavelength conversion particle (232b) may include quantum dots. The quantum dots may be defined as semiconductor materials having nanocrystals. The quantum dots have a specific bandgap depending on their composition and size. Thus, they can absorb incident light and emit light having a wavelength different from the incident light. For example, the quantum dots may have a diameter of 100 nm or less, and preferably a diameter of 1 nm to 20 nm.

[0057] For example, the quantum dots may include group II-VI compounds, group III-V compounds, group IV-VI compounds, group IV elements, group IV compounds, and combinations thereof.

[0058] For example, group II-VI compounds are diatomic compounds selected from the group consisting of CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS, and mixtures thereof; ternary compounds selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS, and mixtures thereof; and may be selected from the group consisting of four-element compounds selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and mixtures thereof.

[0059] For example, III-V group compounds may be selected from the group consisting of diatomic compounds selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; ternary compounds selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and mixtures thereof; and quaternary compounds selected from the group consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof.

[0060] For example, group IV-VI compounds may be selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe and mixtures thereof; ternary compounds selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe and mixtures thereof; and quaternary compounds selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe and mixtures thereof.

[0061] For example, the Group IV element may be selected from the group consisting of Si, Ge, and mixtures thereof. The Group IV compound may be a binary compound selected from the group consisting of SiC, SiGe, and mixtures thereof.

[0062] For example, the quantum dot may have a core / shell structure comprising a core and a shell surrounding the core. For example, the core and the shell may comprise different materials.

[0063] The above quantum dots may be dispersed within the resin portion (232a). For example, the resin portion (232a) may include an epoxy resin, an acrylic resin, a phenolic resin, a melamine resin, a cardo resin, an imide resin, etc.

[0064] The first color conversion unit (232) may further include a scatterer (232c). The scatterer (232c) can increase the light path by scattering the incident light without substantially changing the wavelength of the light incident on the first color conversion unit (232).

[0065] The scattering body (232c) may include a metal oxide or an organic material. For example, the metal oxide may include titanium oxide (TiO2), zirconium oxide (ZrO2), aluminum oxide (Al2O3), indium oxide (In2O3), zinc oxide (ZnO), tin oxide (SnO2), etc., and the organic material may include an acrylic resin or a urethane resin, etc.

[0066] For example, the light-emitting element corresponding to the second light-emitting region (LA2) can emit blue light (L1) having a peak wavelength in the range of about 440 nm to about 480 nm. The first color conversion unit (232) can excite the incident blue light to emit red light. Blue light not excited by the first color conversion unit (232) is blocked by the second color filter pattern (224). Thus, the second light-emitting region (LA2) can emit red light (L2R). For example, the red light (L2R) can have a peak wavelength in the range of about 610 nm to 650 nm.

[0067] The second substrate (200) may further include a second color conversion unit (234) that overlaps with the third light-emitting region (LA3). The second color conversion unit (234) may include wavelength conversion particles (234b) and a resin unit (234a).

[0068] For example, the light-emitting element corresponding to the third light-emitting region (LA3) can emit blue light (L1). The second color conversion unit (234) can excite the incident blue light to emit green light. Blue light that is not excited by the second color conversion unit (234) is blocked by the third color filter pattern (226). Thus, the third light-emitting region (LA3) can emit green light (L2G). For example, the green light (L2G) can have a peak wavelength in the range of about 510 nm to 550 nm.

[0069] The second display substrate (200) may further include a compensation portion (238) that overlaps with the first light-emitting region (LA1). The compensation portion (238) may not include a wavelength conversion material. When a light-emitting element corresponding to the first light-emitting region (LA1) emits blue light (L1), the blue light may pass through the compensation portion (238) without wavelength conversion and be incident on the first color filter pattern (222). Accordingly, the first light-emitting region (LA1) may emit blue light (L2B).

[0070] The above compensation unit (238) may include a resin unit (238a). For example, the resin unit (238a) may include the same resin as the resin unit (232a, 234a) of the color conversion unit (232, 234). Additionally, the above compensation unit (238) may further include a scatterer (238c).

[0071] In another embodiment, the compensation unit (238) may further include a wavelength conversion material to improve color quality, increase color conversion efficiency, etc. For example, the wavelength conversion material may emit blue light by exciting ultraviolet light or light in a wavelength range close to ultraviolet light.

[0072] The second substrate (200) includes a partition wall (250) surrounding the sides of the color conversion unit (232, 234) and the compensation unit (238). The partition wall (250) can form a space capable of accommodating an ink composition during the process of forming the color conversion unit (232, 234) and the compensation unit (238). Accordingly, the partition wall (250) may have a grid shape or a matrix shape in a plan view.

[0073] For example, the above partition (250) may include organic materials such as epoxy resin, phenolic resin, acrylic resin, silicone resin, etc.

[0074] According to one embodiment, the partition (250) may include a light-blocking material to serve as a black matrix. For example, at least a portion of the partition (250) may include a light-blocking material such as a pigment, dye, carbon black, etc. For example, the partition (250) may overlap entirely with the light-blocking area (BA).

[0075] The above partition (250) may have a single-layer structure or a multi-layer structure. For example, in order for the above partition (250) to function as a partition capable of accommodating an ink composition, it may be designed to have a thickness greater than a certain amount, and for this purpose, a partition having a multi-layer structure may be formed.

[0076] The second substrate (200) includes a light reflecting layer (260) disposed between the color filter and the color conversion unit. The light reflecting layer (260) can selectively reflect incident light.

[0077] According to one embodiment, the light reflecting layer (260) may overlap with the second light-emitting region (LA2) and the third light-emitting region (LA3), and may not overlap with the first light-emitting region (LA1). For example, the light reflecting layer (260) may have an opening region corresponding to the first light-emitting region (LA1).

[0078] For example, the light reflecting layer (260) can selectively reflect blue light. Accordingly, red light or green light incident on the light reflecting layer (260) can pass through the light reflecting layer (260) and be emitted through the second light-emitting region (LA2) and the third light-emitting region (LA3).

[0079] According to one embodiment, the light reflecting layer (260) may have a dispersed Bragg reflection (DBR) structure. For example, the light reflecting layer (260) may have a stacked structure of layers having different refractive indices. For example, the light reflecting layer (260) may have a structure in which a first refractive layer (261, 263) having a first refractive index and a second refractive layer (262, 264) having a second refractive index smaller than the first refractive index are alternately stacked, as shown in FIG. 3. For example, the first refractive layer (261, 263) may include titanium oxide, and the second refractive layer (262, 264) may include silicon oxide.

[0080] However, embodiments of the present invention are not limited thereto, and the configuration of the light reflecting layer (260) may vary depending on the wavelength of the light to be reflected and the resulting dispersion Bragg reflection conditions.

[0081] According to one embodiment, the light reflecting layer may have a nano-pattern shape. For example, as shown in FIG. 4, the light reflecting layer (260') may include a wire grid pattern. The wire grid pattern may include an inorganic material such as silicon oxide, silicon nitride, etc., or a metal. The wire grid pattern may be formed on an incident surface where light is incident.

[0082] For example, the wire grid pattern may include a base layer (265a) and a protrusion (265b) protruding from the base layer (265a). The protrusion (265a) may have a linear shape extending in one direction and may be arranged in a direction perpendicular to the extension direction.

[0083] According to one embodiment, the wire grid pattern may reflect blue light. For example, the height (H1) of the protrusion (265b) may be about 50 nm to 70 nm, and the thickness (H2) of the base layer (265a) may be about 100 nm to 120 nm. Additionally, the pitch (P1) of the protrusions (265b) may be about 250 nm to 300 nm. The width (W1) of the protrusions (265b) may be the value obtained by multiplying the pitch (P1) by a fill factor. For example, the width (W1) of the protrusions (265b) may be 100 nm to 150 nm.

[0084] However, embodiments of the present invention are not limited thereto, and the wire grid pattern may have various configurations depending on the material constituting the pattern and the wavelength of light to be reflected.

[0085] According to one embodiment, the light reflecting layer may include nanoparticles. For example, as shown in FIG. 5, the light reflecting layer (260) may include nanoparticles (266a). The material and size of the nanoparticles (266a) may vary depending on the wavelength of the light to be reflected.

[0086] For example, nanoparticles for reflecting blue light may contain silver (Ag). Nanoparticles containing silver (Ag) have high scattering of blue light. According to one embodiment, the nanoparticles may have a core-shell structure to control the reflection wavelength. For example, the nanoparticles may include an oxide core containing silicon oxide, etc. and a metal shell containing silver (Ag). According to one embodiment, the diameter of the oxide core may be 1 nm to 2 nm, and the thickness of the metal shell may be 20 nm to 40 nm.

[0087] According to one embodiment, the light reflecting layer (260) may include a binder (266b) for dispersing nanoparticles (266a). The light reflecting layer (260) comprising the nanoparticles (266a) and the binder (266b) may serve as a low-refractive index layer to improve light extraction efficiency. For example, the binder (266b) may include an acrylic silicone resin, a silicone resin, etc.

[0088] However, embodiments of the present invention are not limited thereto, and for example, the nanoparticles (266a) may be provided with a solvent and then the solvent may be dried to be attached to the surface of the partition (250) and the first protective layer (240) without a binder.

[0089] The second substrate (200) may include a second protective layer (270) covering the color conversion unit (232, 234) and the compensation unit (238). The second protective layer (270) may include an inorganic material such as silicon oxide, silicon nitride, etc.

[0090] A filling member (300) may be disposed between the first substrate (100) and the second substrate (200). The filling member (300) may include an organic material such as a silicone-based resin or an epoxy-based resin. Additionally, the filling member (300) may include a material suitable for refractive index matching.

[0091] According to embodiments of the present invention, blue light that is not excited in the color conversion units (232, 234) can be reflected into the color conversion unit. Thus, the blue light can be recycled as excitation light without being absorbed by the color filter patterns. Thus, the light efficiency of the color conversion substrate and the display device can be improved.

[0092] In one embodiment, the color conversion units (232, 234) are described as including scatterers, but if the light efficiency is sufficiently improved by the light reflection layer (260), the amount of scatterers may be reduced or, if necessary, the scatterers may be omitted.

[0093] In addition, the light reflecting layer (260) can surround not only the output surface but also the side of the color conversion units (232, 234). Thus, the light efficiency of the color conversion substrate and the display device can be further improved.

[0094] Additionally, as light efficiency is improved, the thickness of the color conversion sections (232, 234) can be reduced. When the thickness of the color conversion sections (232, 234) is reduced, the required thickness of the partition (250) can be reduced. Therefore, an additional photolithography process for forming the partition (250) of the multilayer structure can be omitted.

[0095] In addition, as light efficiency is improved, the amount of dye or pigment included in the color filter can be reduced.

[0096] FIGS. 6 to 9 are cross-sectional views illustrating a method for manufacturing a color conversion substrate according to an embodiment of the present invention.

[0097] Referring to FIG. 6, a first color filter pattern (222) and a light-blocking pattern (223) are formed on a base substrate (210). The first color filter pattern (222) overlaps with a first light-emitting region (LA1). The light-blocking pattern (223) may overlap with a light-blocking region (BA) surrounding a second light-emitting region (LA2) and a third light-emitting region (LA3).

[0098] According to one embodiment, the first color filter pattern (222) and the light-blocking pattern (223) may be blue filters that transmit blue light. For example, the first color filter pattern (222) may be formed from a color filter composition comprising a blue pigment and / or a blue dye.

[0099] Referring to FIG. 7, a second color filter pattern (224) and a third color filter pattern (226) are formed on the base substrate (210).

[0100] The second color filter pattern (224) overlaps with the second light-emitting region (LA2). The third color filter pattern (226) overlaps with the third light-emitting region (LA3).

[0101] According to one embodiment, the second color filter pattern (224) may be a red filter that transmits red light. For example, the second color filter pattern (224) may be formed from a color filter composition comprising a red pigment and / or a red dye.

[0102] According to one embodiment, the third color filter pattern (226) may be a green filter that transmits green light. For example, the third color filter pattern (226) may be formed from a color filter composition comprising a green pigment and / or a green dye.

[0103] In embodiments of the present invention, the formation order and arrangement relationship of the color filters are not limited to those illustrated. For example, the second color filter pattern (224) or the third color filter pattern (226) may be formed before the first color filter pattern (222), and a portion of the light-blocking pattern (223) may be placed over the second color filter pattern (224) or the third color filter pattern (226).

[0104] Referring to FIG. 8, a first protective layer (240) covering the color filter patterns is formed. A partition (250) is formed on the first protective layer (240). The first protective layer (240) may be omitted if necessary. Accordingly, the partition (250) may be formed on the color filter.

[0105] The above partition (250) overlaps with the light-blocking area (BA) between the light-emitting areas (LA1, LA2, LA3). For example, the above partition (250) may have an opening area that overlaps with the light-emitting areas (LA1, LA2, LA3).

[0106] For example, the above partition (250) may include a first opening area (OP1) overlapping with the first light-emitting area (LA1), a second opening area (OP2) overlapping with the second light-emitting area (LA2), and a third opening area (OP3) overlapping with the third light-emitting area (LA3).

[0107] Next, a light-reflecting layer (260) is formed on the second color filter pattern (224), the third color filter pattern (226), and the partition wall (250). According to one embodiment, the light-reflecting layer (260) may overlap at least the second color filter pattern (224) and the third color filter pattern (226). Additionally, the light-reflecting layer (260) may cover the upper surface and the side surface of the partition wall (250).

[0108] The light reflecting layer (260) can be formed in various ways depending on the configuration.

[0109] For example, the light reflecting layer (260) having a dispersed Bragg reflection structure shown in FIG. 3 can be formed by forming an inorganic film having a multilayer structure and then removing the portion corresponding to the first light-emitting region (LA1).

[0110] The light-reflecting layer (260') having a wire grid pattern as illustrated in FIG. 4 can be formed by forming a preliminary film containing an inorganic material or a metal, removing the portion corresponding to the first light-emitting region (LA1), and partially etching the portions corresponding to the second light-emitting region (LA2), the third light-emitting region (LA3), and the light-blocking region (BA).

[0111] The light-reflecting layer (260) containing nanoparticles illustrated in FIG. 5 can be formed by removing the portion corresponding to the first light-emitting region (LA1) after forming a photoresist film containing the nanoparticles. Alternatively, it may be formed by selectively providing a photoresist composition containing the nanoparticles or an ink containing the nanoparticles to the areas corresponding to the second light-emitting region (LA2), the third light-emitting region (LA3), and the light-blocking region (BA).

[0112] Referring to FIG. 9, an ink containing wavelength-converting particles is provided within the opening region of the partition wall (250).

[0113] For example, an inkjet printing device may be used to provide the ink. The inkjet printing device may include a head comprising a plurality of nozzles (410). The inkjet printing device may provide the composition to the opening regions (OP1, OP2, OP3) of the partition wall (250) through the nozzles (410).

[0114] According to one embodiment, the second composition and the third composition may include wavelength-converting particles. For example, the second composition and the third composition may include wavelength-converting particles, a binder component, and a solvent.

[0115] For example, the wavelength-converting particles may include quantum dots. According to one embodiment, the second composition may include quantum dots that emit red light, and the third composition may include quantum dots that emit green light. The quantum dots may include organic ligands bonded to their surfaces.

[0116] The binder component may include a polymer, a polymerizable monomer, or a combination thereof. For example, the polymer may include an aromatic ring structure within its main chain. For example, the aromatic ring structure may include phenylene, biphenylene, fluorene, etc. The polymerizable monomer may have one or more carbon-carbon double bonds. For example, the polymerizable monomer may include a (meth)acrylate compound.

[0117] The above solvent may be appropriately selected or combined from among various known materials, taking into account the affinity with other components, the dispersibility of quantum dots, viscosity, boiling point, etc.

[0118] The second and third compositions may further include a scatterer, a photoinitiator, a polymer stabilizer, a leveling agent, a coupling agent, or a combination thereof, as needed.

[0119] The first composition may contain substantially the same components as the second composition or the third composition, except that it does not contain wavelength-converting particles. For example, the first composition may include a binder component and a solvent, and may further include a scatterer, a photoinitiator, a polymer stabilizer, a leveling agent, a coupling agent, or a combination thereof as needed.

[0120] The inkjet printing device provides ink droplets comprising a composition corresponding to the opening regions (OP1, OP2, OP3). Accordingly, the opening regions (OP1, OP2, OP3) can be filled.

[0121] The compositions filled in the above-mentioned opening regions (OP1, OP2, OP3) can be cured to form a color conversion section and a compensation section. For example, the compositions can be heat-cured and photo-cured.

[0122] Embodiments of the present invention may have various configurations depending on the manufacturing method of the display device, etc.

[0123] Referring to FIG. 10, the light reflecting layer (260) can be placed between the light-blocking matrix (252) and the base substrate (210).

[0124] For example, the light reflecting layer (260) may be formed on the first protective layer (240), and a compensation part (238), a first color conversion part (232), and a second color conversion part (234) may be formed on the first protective layer (240). The light-blocking matrix (252) may partially cover the lower surface of the compensation part (238), the first color conversion part (232), and the second color conversion part (234). The light-blocking matrix (252) may include a light-blocking material.

[0125] Referring to FIG. 11, the display device may have a single substrate structure. For example, the first color conversion unit (152), the second color conversion unit (154), and the compensation unit (158) may be formed on the encapsulation layer (130). The first color conversion unit (152), the second color conversion unit (154), and the compensation unit (158) may each be formed using a photoresist composition.

[0126] For example, the first color conversion unit (152) may include a resin part (152a), a wavelength conversion particle (152b), and a scatterer (152c). The second color conversion unit (154) may include a resin part (154a), a wavelength conversion particle (154b), and a scatterer (154c). The compensation unit (158) may include a resin part (158a) and a scatterer (158c).

[0127] The above display device includes a light reflecting layer (140) covering the first color conversion unit (152) and the second color conversion unit (154). For example, the light reflecting layer (140) may cover the upper surface and the side surface of the first color conversion unit (152) and the second color conversion unit (154). The light reflecting layer (140) may have the same configuration as the previously described light reflecting layer (260).

[0128] The display device may include a low-refractive index layer (160) disposed on the light reflection layer (140) and the compensation unit (158). The low-refractive index layer (160) has a lower refractive index than the color conversion unit (152, 154) and the compensation unit (158). The low-refractive index layer (160) can improve light extraction efficiency, thereby increasing the brightness and lifespan of the display device. For example, the low-refractive index layer (160) may have a refractive index of 1.3 or less.

[0129] The low refractive index layer (160) may include hollow particles to have a desirable refractive index. According to one embodiment, the low refractive index layer (160) may include hollow particles dispersed in a resin matrix.

[0130] The above hollow particles may contain inorganic materials. For example, the hollow particles may contain silica (SiO2), magnesium fluoride (MgF2), iron oxide (Fe3O4), or a combination thereof.

[0131] For example, the resin matrix of the low-refractive index layer (160) may include acrylic resin, siloxane resin, urethane resin, imide resin, etc., and may be selected considering the refractive index and processability.

[0132] A color filter may be disposed on the low-refractive index layer (160). According to one embodiment, the color filter may include a first color filter pattern (182), a second color filter pattern (184), and a third color filter pattern (186). The color filter patterns overlap with corresponding light-emitting regions (LA1, LA2, LA3). If necessary, the color filter pattern overlapping with the compensation unit (158) may be omitted.

[0133] The above display device may further include a light-blocking matrix (170). The light-blocking matrix (170) may have a shape that surrounds the first light-emitting region (LA1), the second light-emitting region (LA2), and the third light-emitting region (LA3), and a light-blocking region (BA) may be defined by the light-blocking matrix (170).

[0134] The light-blocking matrix (170) may be placed on the low-refractive index layer (160). For example, the light-blocking matrix (170) may partially cover the color filter patterns (182, 184, 186). However, embodiments of the present invention are not limited thereto, and a light-blocking matrix (170) having openings may be formed first, and the color filter patterns (182, 184, 186) may be formed within the openings.

[0135] The display device may further include a protective layer (190) covering the light-blocking matrix (170) and the color filter patterns (182, 184, 186). For example, the protective layer (190) may include an inorganic material, an organic material, or a combination thereof. According to one embodiment, the protective layer (190) may include an inorganic material such as silicon oxide, silicon nitride, etc.

[0136] Referring to FIG. 12, a light-blocking pattern (183) formed from the same layer as the first color filter pattern (182) may be included, and the light-blocking pattern (183) may serve as a light-blocking matrix.

[0137] Referring to FIG. 13, the first color conversion unit (152), the second color conversion unit (154), and the compensation unit (158) can be formed through an inkjet process.

[0138] For example, a partition (172) is formed on the encapsulation layer (130). The partition (172) has an opening area corresponding to the light-emitting regions. A composition is provided in the opening area to form the compensation part (158) overlapping with the first light-emitting region (LA1), the first color conversion part (152) overlapping with the second light-emitting region (LA2), and the second color conversion part (154) overlapping with the third light-emitting region (LA3).

[0139] A light reflection layer (140) is formed on the above partition (172), the above first color conversion unit (152), and the above second color conversion unit (154).

[0140] A low-refractive index layer (160) is formed on the light reflection layer (140) and the compensation part (158), and color filter patterns (182, 184, 186) and a protective layer (190) are formed on the low-refractive index layer (160).

[0141] Referring to FIG. 14, a display device according to one embodiment includes a display panel and a backlight assembly (600). The display panel includes a first substrate (100) and a second substrate (200).

[0142] The first substrate (100) includes a pixel array. A liquid crystal layer (500) is disposed between the first substrate (100) and the second substrate (200).

[0143] Each pixel of the pixel array comprises driving elements (TR1, TR2, TR3) and pixel electrodes (PE) electrically connected to the driving elements (TR1, TR2, TR3). The second substrate (200) comprises a common electrode (CE). However, embodiments of the present invention are not limited thereto, and the common electrode (CE) may be included in the first substrate (100).

[0144] A first alignment layer (AL1) may be disposed on the pixel electrode (PE). A second alignment layer (AL2) may be disposed on the second substrate (200). The first alignment layer (AL1) and the second alignment layer (AL2) may include a polymer such as polyimide and may be processed to have a certain orientation and tilt by rubbing, photo-alignment, etc.

[0145] The second substrate (200) may have the same configuration as the color conversion substrate shown in FIG. 2, except that it further includes the common electrode (CE) and the second alignment layer (AL2).

[0146] According to the operation of the driving element (TR), a pixel voltage is applied to the pixel electrode (PE). A common voltage is applied to the common electrode (CE). The arrangement of liquid crystal molecules of the liquid crystal layer (500) is controlled by the electric field generated by the voltage difference between the pixel voltage and the common voltage. Accordingly, the transmittance of the light (L1) provided from the backlight assembly can be controlled.

[0147] The second substrate (200) may include a color conversion unit (232, 234) that converts the wavelength of light (L1) passing through the liquid crystal layer (500) and emits light of a color different from the incident light (L1), and a compensation unit (238) that transmits the incident light (L1). Additionally, the second substrate (200) includes a color filter that overlaps with the color conversion unit (232, 234) and the compensation unit (234).

[0148] For example, the second substrate (200) includes a color filter disposed on one side of the base substrate (210). The color filter can filter light passing through the color filter to emit light of a specific color.

[0149] According to one embodiment, the color filter may include a first color filter pattern (222), a second color filter pattern (224), and a third color filter pattern (226). The color filter overlaps with corresponding light-emitting regions (LA1, LA2, LA3). Accordingly, the color of the light (L2R, L2B, L2G) emitted from the light-emitting regions can be determined by the color filter.

[0150] According to one embodiment, the first color filter pattern (222) overlaps with the first light-emitting region (LA1) and can transmit blue light. The second color filter pattern (224) overlaps with the second light-emitting region (LA2) and can transmit red light. The third color filter pattern (226) overlaps with the third light-emitting region (LA3) and can transmit green light.

[0151] According to one embodiment, the second substrate (200) includes a light-reflecting layer (260) disposed between the color filter and the color conversion unit (232, 234). Thus, the light efficiency can be improved by increasing the recycling of the incident light (L1).

[0152] According to one embodiment, the incident light (L1) may be blue light. However, embodiments of the present invention are not limited thereto, and the incident light (L1) may include light of various wavelengths. For example, the incident light (L1) may include ultraviolet light. If the incident light (L1) includes ultraviolet light, a color conversion unit including wavelength conversion particles that emit blue light may be added instead of the compensation unit (238).

[0153] As described, the color conversion substrate according to the embodiments of the present invention can be used in a liquid crystal display device. In addition, the embodiments of the present invention can be applied to various display devices capable of utilizing the color conversion substrate, such as electroluminescent display devices, micro LED display devices, etc.

[0154] Although the foregoing description refers to exemplary embodiments of the present invention, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the invention as set forth in the following claims. Industrial applicability

[0155] The present invention can be applied to various display devices. For example, the present invention can be applied to various display devices such as display devices for vehicles, ships, and aircraft, portable communication devices, display devices for exhibition or information transmission, medical display devices, etc.

Claims

Claim 1 A color conversion unit comprising wavelength conversion particles that excite incident light and emit light of a different color from the incident light; a color filter pattern that filters light emitted from the color conversion unit; and a light reflection layer disposed between the color conversion unit and the color filter pattern and selectively reflecting light having a wavelength corresponding to the incident light, wherein the color conversion unit comprises a first color conversion unit and a second color conversion unit that emit light of different colors, and the light reflection layer comprises a first portion that overlaps the first color conversion unit and a second portion that overlaps the second color conversion unit, and the first portion and the second portion are formed as a continuous identical layer to selectively reflect light of the same wavelength range. Claim 2 A color conversion substrate according to claim 1, wherein the light reflecting layer surrounds the light-emitting surface and side of the color conversion unit. Claim 3 A color conversion substrate according to claim 1, wherein the light reflecting layer has a structure in which a plurality of layers having different refractive indices are alternately stacked. Claim 4 A color conversion substrate according to claim 1, wherein the light reflective layer comprises a wire grid pattern. Claim 5 A color conversion substrate according to claim 1, characterized in that the light reflecting layer comprises nanoparticles containing silver (Ag). Claim 6 A color conversion substrate according to claim 5, characterized in that the nanoparticle comprises an oxide core and a metal shell containing silver (Ag). Claim 7 A color conversion substrate according to claim 1, further comprising a compensation member that transmits the incident light without wavelength conversion, wherein the compensation member does not overlap with the light reflection layer. Claim 8 A color conversion substrate characterized in that, in claim 7, the incident light is blue light. Claim 9 A color conversion substrate according to claim 1, wherein the wavelength conversion particles include quantum dots. Claim 10 A color conversion substrate according to claim 1, wherein the color conversion unit further comprises a scatterer. Claim 11 A display device comprising: a first substrate including a pixel array; and a second substrate coupled to the first substrate, wherein the second substrate includes: a color conversion unit including wavelength conversion particles that excite incident light and emit light of a different color from the incident light; a color filter pattern that filters light emitted from the color conversion unit; and a light reflection layer disposed between the color conversion unit and the color filter pattern and selectively reflecting light having a wavelength corresponding to the incident light, wherein the color conversion unit includes a first color conversion unit and a second color conversion unit that emit light of different colors, and the light reflection layer includes a first portion that overlaps the first color conversion unit and a second portion that overlaps the second color conversion unit, and the first portion and the second portion are formed as a continuous identical layer to selectively reflect light of the same wavelength range. Claim 12 A display device according to claim 11, wherein the light reflecting layer surrounds the light-emitting surface and side of the color conversion unit. Claim 13 A display device according to claim 11, characterized in that the light reflecting layer has a structure in which multiple layers having different refractive indices are alternately stacked. Claim 14 A display device according to claim 11, wherein the light reflective layer comprises a wire grid pattern. Claim 15 A display device according to claim 11, characterized in that the light reflecting layer comprises nanoparticles containing silver (Ag). Claim 16 A display device according to claim 11, further comprising a compensation member that transmits the incident light without wavelength conversion, wherein the compensation member does not overlap with the light reflection layer. Claim 17 A display device comprising: a pixel array; an encapsulation layer covering the pixel array; a color conversion unit disposed on the encapsulation layer and including wavelength conversion particles that excite incident light and emit light of a different color from the incident light; a color filter pattern disposed on the color conversion unit and filtering light emitted from the color conversion unit; and a light reflection layer disposed between the color conversion unit and the color filter pattern and selectively reflecting light having a wavelength corresponding to the incident light, wherein the color conversion unit includes a first color conversion unit and a second color conversion unit that emit light of different colors, and the light reflection layer includes a first portion that overlaps the first color conversion unit and a second portion that overlaps the second color conversion unit, and the first portion and the second portion are formed as a continuous identical layer to selectively reflect light of the same wavelength range. Claim 18 A display device according to claim 17, characterized in that the light reflecting layer has a structure in which multiple layers having different refractive indices are alternately stacked. Claim 19 A display device according to claim 17, characterized in that the light reflective layer includes a wire grid pattern. Claim 20 A display device according to claim 17, characterized in that the light reflecting layer comprises nanoparticles containing silver (Ag).

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