Display device and method for manufacturing same

Abstract

A display device of an embodiment comprises: a base layer where a pixel area and a peripheral area adjacent to the pixel area are defined; a pixel defining film, which is disposed on the base layer and in which a pixel opening corresponding to the pixel area is defined; a light emitting element disposed in the pixel opening and generating light of a first color; and an encapsulation layer disposed on the light emitting element, wherein the encapsulation layer comprises: a first encapsulation inorganic layer disposed on the light emitting element; a polymer layer disposed on the first encapsulation inorganic layer and containing a base resin and an organic acid derivative; an encapsulation organic layer disposed on the polymer layer; and a second encapsulation inorganic layer disposed on the encapsulation organic layer.

Description

Display device and method for manufacturing the display device

[0001] The present invention relates to a display device and a method for manufacturing the display device.

[0002] A variety of display devices are being developed for use in multimedia devices such as televisions, mobile phones, tablet computers, navigation systems, and game consoles. These display devices utilize so-called self-luminous display elements that display information by emitting light from a luminescent material containing an organic compound.

[0003] In addition, development of light-emitting devices using quantum dots as light-emitting materials is in progress to improve the color reproducibility of display devices, and there is a need to improve the light-emitting efficiency and lifespan of light-emitting devices using quantum dots.

[0004] The purpose of the present invention is to provide a display device having excellent luminous efficiency by introducing a polymer layer containing an organic acid derivative into a sealing layer.

[0005] In addition, an object of the present invention is to provide a method for manufacturing a display device capable of forming a sealing layer capable of increasing the current injection characteristics and luminous efficiency of a light-emitting element.

[0006] A display device according to one embodiment of the present invention includes a base layer defining a pixel area and a peripheral area adjacent to the pixel area, a pixel defining film disposed on the base layer and defining a light-emitting opening corresponding to the pixel area, a light-emitting element disposed in the light-emitting opening and generating a first color light, and an encapsulating layer disposed on the light-emitting element, wherein the encapsulating layer includes a first encapsulating inorganic layer disposed on the light-emitting element, a polymer layer disposed on the first encapsulating inorganic layer and including a base resin and an organic acid derivative, an encapsulating organic layer disposed on the polymer layer, and a second encapsulating inorganic layer disposed on the encapsulating organic layer.

[0007] The above base resin may include at least one of polyacrylic acid, polymethyl methacrylate, polystyrene, and polyvinylpyrrolidone.

[0008] The above organic acid derivative may include a carboxylic acid compound or a carboxylic acid ester compound.

[0009] The organic acid derivative may include at least one of citric acid, methacrylic acid, acrylic acid, isobutyric acid, alkyl (meth)acrylate, and hydroxyalkyl (meth)acrylate.

[0010] The thickness of the polymer layer may be 100 nm or more and 1000 nm or less.

[0011] The content of the organic acid derivative may be 2 wt% to 50 wt% or less based on the total content of the polymer layer.

[0012] The polymer layer may overlap the pixel area and the peripheral area and have a constant thickness.

[0013] The polymer layer may be directly disposed on the first encapsulating inorganic layer, the encapsulating organic layer may be directly disposed on the polymer layer, and the second encapsulating inorganic layer may be directly disposed on the encapsulating organic layer.

[0014] The light-emitting element includes a first electrode, a second electrode, and a light-emitting layer disposed between the first electrode and the second electrode and emitting the first color light, and the first color light can be emitted from the first electrode in the direction of the second electrode.

[0015] The light-emitting element may further include a hole transport region disposed between the first electrode and the light-emitting layer, and an electron transport region disposed between the second electrode and the light-emitting layer.

[0016] The light-emitting element may further include an electron transport region disposed between the first electrode and the light-emitting layer, and a hole transport region disposed between the second electrode and the light-emitting layer.

[0017] The above light-emitting layer may include quantum dots.

[0018] It may further include an optical layer disposed between the second electrode and the sealing layer.

[0019] The present invention further includes a color filter layer disposed on the sealing layer, and the color filter layer may include a first filter that transmits the first color light, a second filter that transmits the second color light in a longer wavelength region than the first color light, and a third filter that transmits the third color light in a longer wavelength region than the second color light.

[0020] The color filter layer further includes a buffer layer disposed between the sealing layer and the first to third filters, and the sealing layer can be covered by the buffer layer.

[0021] The above color filter layer can be placed directly on the sealing layer.

[0022] The color filter layer further includes a light-shielding portion disposed between the first filter, the second filter, and the third filter, and the second sealing inorganic layer may be directly disposed on one surface of the first filter, the second filter, the third filter, and the light-shielding portion.

[0023] A method for manufacturing a display device according to one embodiment of the present invention comprises the steps of preparing a light-emitting element, forming a first encapsulating inorganic layer on the light-emitting element, forming a preliminary polymer layer by applying a coating solution containing a first base resin and an organic acid derivative on the first encapsulating inorganic layer, forming a polymer layer by drying or heat-treating the preliminary polymer layer at a first temperature, forming an encapsulating organic layer on the polymer layer, and forming a second encapsulating inorganic layer on the encapsulating organic layer.

[0024] The above first temperature may be 25°C or higher and 200°C or lower.

[0025] The step of forming the above-mentioned bag organic layer may include the step of applying and curing a second base resin on the above-mentioned polymer layer.

[0026] A display device of one embodiment may include a polymer layer including an organic acid derivative as an encapsulating layer disposed on a light-emitting element, so that the current efficiency characteristics and luminous efficiency of the light-emitting element can be improved.

[0027] A method for manufacturing a display device according to one embodiment can form an encapsulating layer that can improve the current efficiency characteristics and luminous efficiency of a light-emitting element, thereby providing improved reliability.

[0028] FIG. 1 is a perspective view showing a display device according to one embodiment of the present invention.

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

[0030] Figure 3 is a cross-sectional view of a display panel according to one embodiment of the present invention.

[0031] FIG. 4a is a cross-sectional view of a light-emitting device according to one embodiment of the present invention.

[0032] FIG. 4b is a cross-sectional view of a light-emitting device according to one embodiment of the present invention.

[0033] FIG. 5a and FIG. 5b are enlarged views of a portion of a cross-section of a display device according to one embodiment of the present invention.

[0034] FIG. 6a and FIG. 6b are enlarged views of a portion of a cross-section of a display device according to one embodiment of the present invention.

[0035] Figure 7 is a flowchart of a method for manufacturing a display device according to one embodiment of the present invention.

[0036] FIGS. 8A to 8G are drawings schematically illustrating some of the steps of a method for manufacturing a display device according to one embodiment of the present invention.

[0037] The present invention is susceptible to various modifications and takes various forms. Specific embodiments are illustrated in the drawings and described in detail herein. However, this is not intended to limit the present invention to specific disclosed forms, but rather to encompass all modifications, equivalents, and alternatives falling within the spirit and technical scope of the present invention.

[0038] In this specification, when it is said that a component (or region, layer, portion, etc.) is “on,” “connected to,” or “coupled to” another component, it means that it can be directly disposed / connected / coupled to the other component, or a third component may be disposed between them.

[0039] Identical drawing numbers indicate identical components. Furthermore, in the drawings, the thicknesses, proportions, and dimensions of the components are exaggerated for the purpose of effectively illustrating the technical content. "And / or" encompasses any combination of one or more of the associated components.

[0040] While terms such as "first" and "second" may be used to describe various components, these components should not be limited by these terms. These terms are used solely to distinguish one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a "second component," and similarly, a second component may also be referred to as a "first component." Singular expressions include plural expressions unless the context clearly indicates otherwise.

[0041] Additionally, terms such as "below," "lower," "above," and "upper" are used to describe the relationships between components depicted in the drawings. These terms are relative concepts and are described based on the directions indicated in the drawings.

[0042] It should be understood that terms such as "include" or "have" are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0043] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by those skilled in the art to which this invention pertains. Furthermore, terms defined in commonly used dictionaries should be interpreted to have a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an overly idealistic or overly formal sense unless explicitly defined herein.

[0044] Hereinafter, a display device according to one embodiment of the present invention and a manufacturing method of the display device according to one embodiment will be described with reference to the drawings.

[0045] Fig. 1 is a perspective view showing a display device according to one embodiment. Fig. 2 is a cross-sectional view of a display device according to one embodiment. Fig. 2 illustrates a cross-section corresponding to line I-I' of Fig. 1. Fig. 3 is a cross-sectional view of a display panel according to one embodiment of the present invention. Figs. 4a and 4b are cross-sectional views of a light-emitting element according to one embodiment of the present invention.

[0046] The display device (DD) of one embodiment may be a device activated by an electrical signal. For example, the display device (DD) may be a large-scale device such as a television, monitor, or outdoor billboard. Furthermore, the display device (DD) may be a small- to medium-sized device such as a personal computer, laptop computer, personal digital assistant, car navigation unit, game console, smartphone, tablet, or camera. Furthermore, these are merely examples and may be employed in other electronic devices without departing from the scope of the present invention.

[0047] A display device (DD) can display an image (or video) through a display surface (DD-IS). The display device (DD) can include a plurality of light-emitting areas (PXA) and a peripheral area (NPXA). The display surface (DD-IS) can be parallel to a plane defined by a first direction (DR1) and a second direction (DR2). The display surface (DD-IS) can include a display area (DA) and a non-display area (NDA). The plurality of light-emitting areas (PXA) can be arranged in the display area (DA). The light-emitting areas (PXA) can be referred to as pixel areas.

[0048] A non-display area (NDA) may be defined along the edge of the display area (DD-IS). The non-display area (NDA) may surround the display area (DA). However, the embodiment is not limited thereto, and the non-display area (NDA) may be omitted, or the non-display area (NDA) may be positioned only on one side of the display area (DA).

[0049] Although Fig. 1 illustrates a display device (DD) having a flat display surface (DD-IS), the embodiment is not limited thereto. The display device (DD) may include a curved display surface or a three-dimensional display surface. The three-dimensional display surface may include a plurality of display areas pointing in different directions.

[0050] In FIG. 1 and the drawings below, the first direction (DR1) to the third direction (DR3) are illustrated, and the directions indicated by the first to third directions (DR1, DR2, DR3) described in this specification are relative concepts and can be converted into other directions. In this specification, the first direction (DR1) and the second direction (DR2) are orthogonal to each other, and the third direction (DR3) may be a normal direction with respect to a plane defined by the first direction (DR1) and the second direction (DR2). In this specification, a 'plane' means a plane defined by the first direction (DR1) and the second direction (DR2), and a 'cross-section' means a plane that is perpendicular to the plane defined by the first direction (DR1) and the second direction (DR2) and parallel to the third direction (DR3). The thickness direction of the display device (DD) may be parallel to a third direction (DR3), which is a normal direction to a plane defined by the first direction (DR1) and the second direction (DR2).

[0051] In this specification, the upper surface (or front surface) and the lower surface (or back surface) of the members constituting the display device (DD) may be defined with reference to the third direction (DR3). More specifically, among two surfaces of one member facing each other with reference to the third direction (DR3), the surface that is relatively close to the display surface (DD-IS) may be defined as the front surface (or upper surface), and the surface that is relatively spaced from the display surface (DD-IS) may be defined as the back surface (or lower surface). In addition, in this specification, the upper surface (or upper side) and the lower surface (or lower side) may be defined with reference to the third direction (DR3), and the upper surface (or upper side) may be defined in a direction approaching the display surface (DD-IS), and the lower surface (or lower side) may be defined in a direction away from the display surface (DD-IS).

[0052] In this specification, when a component is "directly disposed / directly formed" on another component, it means that no third component is disposed between the component and the other component. In other words, when a component is "directly disposed / directly formed" on another component, it means that the component and the other component are in "contact."

[0053] Referring to FIGS. 2 and 3, a display device (DD) may include a display panel (DP) and an optical member (PP) disposed on the display panel (DP). The display panel (DP) may include a display layer (EDL). The display panel (DP) may include a base layer (BS), a circuit layer (DP-CL) disposed on the base layer (BS), and a display layer (EDL) disposed on the circuit layer (DP-CL). The display layer (EDL) may include light-emitting elements (ED-R, ED-G, ED-B, see FIGS. 5A to 6B). In addition, the display panel (DP) may include an encapsulation layer (TFE) disposed on the display layer (EDL). In one embodiment, the encapsulation layer (TFE) may be directly disposed on the display layer (EDL). However, the embodiment is not limited thereto, and the encapsulation layer (TFE) may be coupled to the display layer (EDL) through a separate member.

[0054] The display panel (DP) may be a configuration that actually generates an image. In one embodiment of the display device (DD), the display panel (DP) may be an emissive display panel. For example, the display panel (DP) may be a quantum dot emissive display panel including a quantum dot emissive element. However, the embodiment is not limited thereto.

[0055] A display area (DA) and a non-display area (NDA) corresponding to the display area (DA) and the non-display area (NDA) illustrated in FIG. 1 may be defined in a display panel (DP). In the display panel (DP), the display area (DA) may be defined as an area where pixels are arranged. In the display panel (DP), the non-display area (NDA) may be defined as an area where pixels are not arranged and where signal lines supporting pixel operation are arranged. In this specification, "areas correspond to each other" means "overlapping each other" and is not limited to having the same area.

[0056] An optical member (PP) is arranged on a display panel (DP) to control light reflected from the display panel (DP) due to external light.

[0057] FIG. 4A is a drawing showing a light-emitting element (ED) according to one embodiment. Referring to FIG. 4A, the light-emitting element (ED) according to one embodiment includes a first electrode (AE), a second electrode (CE) facing the first electrode (AE), and a plurality of functional layers disposed between the first electrode (AE) and the second electrode (CE) and including a light-emitting layer (EL).

[0058] The plurality of functional layers may include a hole transport region (HTR) disposed between a first electrode (AE) and an emitting layer (EL) and an electron transport region (ETR) disposed between the emitting layer (EL) and a second electrode (CE).

[0059] The hole transport region (HTR) and the electron transport region (ETR) may each include a plurality of sub-functional layers. For example, the hole transport region (HTR) may include a hole injection layer (HIL) and a hole transport layer (HTL) as sub-functional layers, and the electron transport region (ETR) may include an electron injection layer (EIL) and an electron transport layer (ETL) as sub-functional layers. Meanwhile, the embodiment is not limited thereto, and the hole transport region (HTR) may further include an electron blocking layer (not shown) or a hole buffer layer (not shown) as sub-functional layers, and the electron transport region (ETR) may further include a hole blocking layer (not shown) or an electron buffer layer (not shown) as sub-functional layers.

[0060] In a light-emitting element (ED) according to one embodiment, a first electrode (AE) has conductivity. The first electrode (AE) may be formed of a metal alloy or a conductive compound. The first electrode (AE) may be an anode. The first electrode (AE) may be a pixel electrode.

[0061] In a light emitting element (ED) according to one embodiment, the first electrode (AE) may be a reflective electrode. However, the embodiment is not limited thereto. For example, the first electrode (AE) may be a transmissive electrode or a semi-transmissive electrode. When the first electrode (AE) is a semi-transmissive electrode or a reflective electrode, the first electrode (AE) may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, or a compound or mixture thereof (for example, a mixture of Ag and Mg). Alternatively, the first electrode (AE) may have a multi-layer structure including a reflective film or a semi-transmissive film formed of the above-mentioned materials and a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), or the like. For example, the first electrode (AE) may be a multilayer metal film and may have a structure in which metal films of ITO / Ag / ITO are laminated.

[0062] A hole transport region (HTR) is provided on the first electrode (AE). The hole transport region (HTR) may include a hole injection layer (HIL) and a hole transport layer (HTL). In addition to the hole injection layer (HIL) and the hole transport layer (HTL), the hole transport region (HTR) may further include at least one of a hole buffer layer (not shown) and an electron blocking layer (not shown). The hole buffer layer (not shown) may compensate for a resonance distance according to a wavelength of light emitted from the light emitting layer (EL) to increase light emission efficiency. A material that can be included in the hole transport region (HTR) may be used as a material included in the hole buffer layer (not shown). The electron blocking layer (not shown) is a layer that serves to prevent electron injection from the electron transport region (ETR) to the hole transport region (HTR).

[0063] The hole transport region (HTR) may have a multilayer structure having a single layer made of a single material, a single layer made of multiple different materials, or multiple layers made of multiple different materials. For example, the hole transport region (HTR) may have a structure of single layers made of multiple different materials, or a structure of a hole injection layer (HIL) / hole transport layer (HTL), a hole injection layer (HIL) / hole transport layer (HTL) / hole buffer layer (not shown), a hole injection layer (HIL) / hole buffer layer (not shown), a hole transport layer (HTL) / hole buffer layer (not shown), or a hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (not shown) sequentially stacked from the first electrode (AE), but the embodiments are not limited thereto.

[0064] The hole transport region (HTR) can be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0065] The hole injection layer (HIL) is, for example, a phthalocyanine compound such as copper phthalocyanine, DNTPD (N,N'-diphenyl-N,N'-bis-[4-(phenyl-m-tolyl-amino)-phenyl]-biphenyl-4,4'-diamine), m-MTDATA(4,4',4"-[tris(3-methylphenyl)phenylamino] triphenylamine), TDATA(4,4'4"-Tris(N,N-diphenylamino)triphenylamine), 2-TNATA(4,4',4"-tris{N,-(2-naphthyl)-N-phenylamino}-triphenylamine), PEDOT / PSS(Poly(3,4-ethylenedioxythiophene) / Poly(4-styrenesulfonate)), PANI / DBSA(Polyaniline / Dodecylbenzenesulfonic acid), It may also include PANI / CSA (Polyaniline / Camphor sulfonicacid), PANI / PSS (Polyaniline / Poly(4-styrenesulfonate)), NPD (N,N'-di(naphthalene-l-yl)-N,N'-diphenyl-benzidine), polyether ketone containing triphenylamine (TPAPEK), 4-Isopropyl-4'-methyldiphenyliodonium [Tetrakis(pentafluorophenyl)borate], HAT-CN (dipyrazino[2,3-f: 2',3'-h] quinoxaline-2,3,6,7,10,11-hexacarbonitrile), etc.

[0066] The hole transport layer (HTL) may comprise any of common materials known in the art. For example, it may further include carbazole derivatives such as N-phenylcarbazole and polyvinylcarbazole, fluorene derivatives, triphenylamine derivatives such as TPD (N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1-biphenyl]-4,4'-diamine), TCTA (4,4',4"-tris(N-carbazolyl)triphenylamine), NPD (N,N'-di(naphthalene-l-yl)-N,N'-diphenyl-benzidine), TAPC (4,4′-Cyclohexylidene bis[N,N-bis(4-methylphenyl)benzenamine]), HMTPD (4,4'-Bis[N,N'-(3-tolyl)amino]-3,3'-dimethylbiphenyl), mCP (1,3-Bis(N-carbazolyl)benzene), etc.

[0067] The thickness of the hole transport region (HTR) may be about 5 nm to about 1,500 nm, for example, about 10 nm to about 500 nm. The thickness of the hole injection layer (HIL) may be about 3 nm to about 100 nm, and the thickness of the hole transport layer (HTL) may be about 3 nm to about 100 nm. For example, the thickness of the electron blocking layer (not shown) may be about 1 nm to about 100 nm. When the thicknesses of the hole transport region (HTR), the hole injection layer (HIL), the hole transport layer (HTL), and the electron blocking layer (not shown) satisfy the ranges described above, a satisfactory degree of hole transport characteristics can be obtained without a substantial increase in driving voltage.

[0068] An emitting layer (EL) is provided on the hole transport region (HTR). The emitting layer (EL) includes a plurality of quantum dots (QDs).

[0069] Quantum dots (QDs) included in the light-emitting layer (EL) can be stacked to form layers. In FIG. 4A, quantum dots (QDs) having a circular cross-section are arranged to roughly form three layers, but the embodiment is not limited thereto. For example, the arrangement of quantum dots (QDs) can vary depending on the thickness of the light-emitting layer (EL), the shape of the quantum dots (QDs) included in the light-emitting layer (EL), the average diameter of the quantum dots (QDs), etc. Specifically, the quantum dots (QDs) in the light-emitting layer (EL) can be aligned adjacent to each other to form one layer, or can be aligned to form multiple layers, such as two or three layers.

[0070] Additionally, in the light-emitting device (ED) of one embodiment, the light-emitting layer (EL) may include a host and a dopant. In one embodiment, the light-emitting layer (EL) may include quantum dots (QDs) as a dopant material. Furthermore, in one embodiment, the light-emitting layer (EL) may further include a host material.

[0071] Meanwhile, in the light-emitting element (ED) of one embodiment, the light-emitting layer (EL) may emit fluorescent light. For example, quantum dots (QDs) may be used as a fluorescent dopant material.

[0072] Quantum dots are crystals of semiconductor compounds. Depending on the size of the crystal, quantum dots can emit light of various wavelengths. Quantum dots can also emit light of various wavelengths by adjusting the element ratio within the quantum dot compound.

[0073] The diameter of the quantum dots may be, for example, about 1 nm to 10 nm. The quantum dots may be synthesized by wet chemical processes, organometallic chemical vapor deposition processes, molecular beam epitaxy processes, or similar processes.

[0074] Among the quantum dot manufacturing processes, the wet chemical process involves mixing an organic solvent with a precursor material and then growing quantum dot crystals. As the quantum dot crystals grow, the organic solvent naturally acts as a dispersant coordinated to the quantum dot crystal surface, controlling the growth of the crystals. Therefore, the wet chemical process is easier and less expensive than vapor deposition methods such as metal-organic chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE), allowing for controlled growth of quantum dots.

[0075] The core of the quantum dot can be selected from a group II-VI compound, a group III-V compound, a group III-VI compound, a group I-III-VI compound, a group IV-VI compound, a group IV element, a group IV compound, and a combination thereof.

[0076] The group II-VI compound is a binary compound selected from the group consisting of CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, MgSe, MgS and mixtures thereof; a ternary compound 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 it may be selected from the group consisting of a four-element compound selected from the group consisting of HgZnTeS, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe and mixtures thereof. Meanwhile, the II-VI group semiconductor compound may further include a Group I metal and / or a Group IV element. The Group I-II-VI compound may be selected from CuSnS or CuZnS, and the Group II-IV-VI compound may be selected from ZnSnS, etc. The Group I-II-IV-VI compound may be selected from a four-element compound selected from the group consisting of Cu2ZnSnS2, Cu2ZnSnS4, Cu2ZnSnSe4, Ag2ZnSnS2 and mixtures thereof.

[0077] The III-VI group compounds may include binary compounds such as In2S3, In2Se3, etc., ternary compounds such as InGaS3, InGaSe3, etc., or any combination thereof.

[0078] Group I-III-VI compounds are ternary compounds selected from the group consisting of AgInS, AgInS2, CuInS, CuInS2, AgGaS2, CuGaS2CuGaO2, AgGaO2, AgAlO2 and mixtures thereof, or AgInGaS2, It can be selected from four-element compounds such as CuInGaS2.

[0079] The group III-V compound may be selected from the group consisting of binary compounds selected from the group consisting of 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, InGaP, InAlP, InNP, InNAs, InNSb, InPAs, InPSb, and mixtures thereof, and quaternary compounds selected from the group consisting of GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof. Meanwhile, the group III-V compound may further include a group II metal. For example, InZnP may be selected as the group III-II-V compound.

[0080] The group IV-VI compound may be selected from the group consisting of binary compounds 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.

[0081] Examples of group II-IV-V semiconductor compounds may be ternary compounds selected from the group consisting of ZnSnP, ZnSnP2, ZnSnAs2, ZnGeP2, ZnGeAs2, CdSnP2, and CdGeP2 and mixtures thereof.

[0082] 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.

[0083] Each element contained in a multi-element compound, such as a binary compound, a ternary compound, or a quaternary compound, can exist in the particle in a uniform or non-uniform concentration. In other words, the chemical formula indicating a quantum dot indicates the type of element contained in the quantum dot compound, and the element ratio within the compound may be different. For example, AgInGaS2 is AgIn x Ga 1-x It can mean S2 (where x is a real number between 0 and 1).

[0084] Here, binary, ternary, or quaternary compounds may exist within the particle at a uniform concentration, or may exist within the same particle with partially different concentration distributions. Furthermore, one quantum dot may have a core / shell structure, where one quantum dot surrounds another. In a core / shell structure, the concentration of the element present in the shell may have a concentration gradient, decreasing toward the core.

[0085] In some embodiments, quantum dots may have a core-shell structure comprising a core comprising the aforementioned nanocrystals and a shell surrounding the core. The shell of the quantum dot may function as a protective layer to maintain semiconductor properties by preventing chemical modification of the core and / or as a charging layer to impart electrophoretic properties to the quantum dot. The shell may be a single layer or a multilayer. Examples of the shell of the quantum dot include a metal or non-metal oxide, a semiconductor compound, or a combination thereof.

[0086] For example, oxides of metals or non-metals may be binary compounds such as SiO2, Al2O3, TiO2, ZnO, MnO, Mn2O3, Mn3O4, CuO, FeO, Fe2O3, Fe3O4, CoO, Co3O4, NiO, or ternary compounds such as MgAl2O4, CoFe2O4, NiFe2O4, CoMn2O4, but the present invention is not limited thereto.

[0087] In addition, semiconductor compounds may include, but are not limited to, CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnSeS, ZnTeS, GaAs, GaP, GaSb, HgS, HgSe, HgTe, InAs, InP, InGaP, InSb, AlAs, AlP, AlSb, etc.

[0088] Quantum dots can have a full width of half maximum (FWHM) of an emission wavelength spectrum of about 45 nm or less, preferably about 40 nm or less, and more preferably about 30 nm or less, and color purity and color reproducibility can be improved within this range. In addition, since light emitted by these quantum dots is emitted in all directions, a wide viewing angle can be improved.

[0089] In addition, the shape of the quantum dot is not particularly limited to a shape commonly used in the field, but more specifically, a shape such as a spherical, pyramidal, multi-arm, or cubic nanoparticle, nanotube, nanowire, nanofiber, or nanoplatelet particle can be used.

[0090] Quantum dots allow for the control of their energy band gaps by adjusting their size or the element ratio within the quantum dot compound, allowing for the generation of light of various wavelengths from the quantum dot emitting layer. Therefore, by employing quantum dots of different sizes or varying the element ratio within the quantum dot compound, light-emitting devices capable of emitting light of various wavelengths can be realized.

[0091] Referring again to FIG. 4A, in the light-emitting element (ED) of one embodiment, an electron transport region (ETR) is provided on the light-emitting layer (EL). The electron transport region (ETR) may include at least one of a hole blocking layer (not shown), an electron transport layer (ETL), and an electron injection layer (EIL), but the embodiment is not limited thereto.

[0092] The electron transport region (ETR) may have a multilayer structure having a single layer made of a single material, a single layer made of multiple different materials, or multiple layers made of multiple different materials.

[0093] For example, the electron transport region (ETR) may have a single-layer structure of an electron injection layer (EIL) or an electron transport layer (ETL), or may have a single-layer structure composed of an electron injection material and an electron transport material. In addition, the electron transport region (ETR) may have a single-layer structure composed of a plurality of different materials, or may have an electron transport layer (ETL) / electron injection layer (EIL), hole blocking layer (not shown) / electron transport layer (ETL) / electron injection layer (EIL) structure sequentially stacked from an emitting layer (EL), but is not limited thereto. The thickness of the electron transport region (ETR) may be, for example, about 20 nm to about 150 nm.

[0094] The electron transport region (ETR) can be formed using various methods such as vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) method, inkjet printing, laser printing, and laser induced thermal imaging (LITI).

[0095] When the electron transport region (ETR) includes an electron transport layer (ETL), the electron transport region (ETR) may include an anthracene compound. However, the electron transport region is not limited thereto, and examples thereof include Alq3(Tris(8-hydroxyquinolinato)aluminum), 1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, 2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine, DPEPO(bis[2-(diphenylphosphino)phenyl]ether oxide), 2-(4-(N-phenylbenzoimidazolyl-1-ylphenyl)-9,10-dinaphthylanthracene, TPBi(1,3,5-Tri(1-phenyl-1H-benzo[d]imidazol-2-yl)phenyl), BCP(2,9-Dimethyl-4,7-diphenyl-1,10-phenanthroline), Bphen(4,7-Diphenyl-1,10-phenanthroline), It may include TAZ(3-(4-Biphenylyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole), NTAZ(4-(Naphthalen-1-yl)-3,5-diphenyl-4H-1,2,4-triazole), tBu-PBD(2-(4-Biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole), BAlq(Bis(2-methyl-8-quinolinolato-N1,O8)-(1,1'-Biphenyl-4-olato)aluminum), Bebq2(berylliumbis(benzoquinolin-10-olate), ADN(9,10-di(naphthalene-2-yl)anthracene) or a mixture thereof. The thickness of the electron transport layers (ETLs) may be about 10 nm to about 100 nm, for example, about 15 nm to about 50 nm. there is.When the thickness of the electron transport layers (ETLs) satisfies the range described above, satisfactory electron transport characteristics can be obtained without a substantial increase in operating voltage.

[0096] When the electron transport region (ETR) includes an electron injection layer (EIL), the ETR may be formed of, but is not limited to, a metal halide such as LiF, NaCl, CsF, RbCl, RbI, a lanthanide metal such as Yb, a metal oxide such as Li2O, BaO, or lithium quinolate (LiQ). The electron injection layer (EIL) may also be formed of a material in which an electron transport material and an insulating organometallic salt are mixed. For example, the organometallic salt may include a metal acetate, a metal benzoate, a metal acetoacetate, a metal acetylacetonate, or a metal stearate. The thickness of the electron injection layers (EILs) can be from about 0.1 nm to about 10 nm, or from about 0.3 nm to about 9 nm. When the thickness of the electron injection layers (EILs) satisfies the range described above, satisfactory electron injection characteristics can be obtained without a substantial increase in driving voltage.

[0097] The electron transport region (ETR) may include a hole blocking layer (not shown), as previously mentioned. The hole blocking layer (not shown) may include, for example, but is not limited to, at least one of BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline) and Bphen (4,7-diphenyl-1,10-phenanthroline).

[0098] The second electrode (CE) is provided on the electron transport region (ETR). The second electrode (CE) may be a common electrode or a cathode. The second electrode (CE) may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode. When the second electrode (CE) is a transmissive electrode, the second electrode (CE) may be made of a transparent metal oxide, such as ITO (indium tin oxide), IZO (indium zinc oxide), ZnO (zinc oxide), or ITZO (indium tin zinc oxide).

[0099] When the second electrode (CE) is a semi-transmissive electrode or a reflective electrode, the second electrode (CE) may include Ag, Mg, Cu, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, Li, Ca, LiF / Ca, LiF / Al, Mo, Ti, Yb or a compound containing them (e.g., AgYb, AgMg and MgAg compounds depending on the content, etc.) or a mixture thereof (e.g., a mixture of Ag and Mg). Alternatively, the second electrode (CE) may have a multi-layer structure including a reflective film or semi-transmissive film formed of the above materials and a transparent conductive film formed of indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium tin zinc oxide (ITZO), etc.

[0100] Although not shown, the second electrode (CE) may be connected to an auxiliary electrode. When the second electrode (CE) is connected to the auxiliary electrode, the resistance of the second electrode (CE) may be reduced.

[0101] The light emitting element (ED) may further include an optical layer (CPL) disposed on the second electrode (CE). The optical layer (CPL) may include a multilayer or a single layer.

[0102] In one embodiment, the optical layer (CPL) may be an organic layer or an inorganic layer. For example, when the optical layer (CPL) includes an inorganic material, the inorganic material may be an alkali metal compound such as LiF, an alkaline earth metal compound such as MgF2, SiON, SiN. X , SiOy, etc.

[0103] For example, when the optical layer (CPL) includes an organic material, the organic material may include α-NPD, NPB, TPD, m-MTDATA, Alq3, CuPc, TPD15 (N4,N4,N4',N4'-tetra (biphenyl-4-yl) biphenyl-4,4'-diamine), TCTA (4,4',4"- Tris (carbazol sol-9-yl) triphenylamine), etc., or may include an acrylate such as an epoxy resin or a methacrylate. However, the embodiment is not limited thereto, and the optical layer (CPL) may include at least one of the following compounds P1 to P5.

[0104]

[0105]

[0106] Meanwhile, the refractive index of the optical layer (CPL) may be 1.6 or greater. Specifically, the refractive index of the optical layer (CPL) may be 1.6 or greater for light in the wavelength range of 550 nm or greater and 660 nm or less.

[0107] Fig. 4b is a cross-sectional view showing another embodiment of a light-emitting element according to one embodiment of the present invention. In the description of Fig. 4b, any content that overlaps with that described with reference to Figs. 1 to 4a will not be described again, and differences will be mainly described.

[0108] Compared to the light-emitting element (ED) illustrated in FIG. 4a, the light-emitting element (ED-a) illustrated in FIG. 4b has a difference in the arrangement positions of the hole transport region (HTR) and the electron transport region (ETR). Referring to FIG. 4b, the light-emitting element (ED-a) may include a first electrode (AE), an electron transport region (ETR) disposed on the first electrode, an emission layer (EL) disposed on the electron transport region (ETR), a hole transport region (HTR) disposed on the emission layer (EL), and a second electrode (CE) disposed on the hole transport region (HTR). The electron transport region (ETR) may be disposed between the first electrode (AE) and the emission layer (EL), and the hole transport region (HTR) may be disposed between the second electrode (CE) and the emission layer (EL).

[0109] FIGS. 5A and 5B are enlarged views of a portion of a cross-section of a display device according to one embodiment of the present invention. FIGS. 5A and 5B each illustrate a cross-section corresponding to line II-II' of FIG. 1.

[0110] Referring to FIG. 5A, a display device (DD) of one embodiment may include a display panel (DP) and an optical member (PP) disposed on the display panel (DP). The display panel (DP) may include a base layer (BS), a circuit layer (DP-CL) disposed on the base layer (BS), and a display layer (EDL) disposed on the circuit layer (DP-CL).

[0111] Referring to FIGS. 1 and 5A, a plurality of light-emitting areas (PXAs) may be arranged in a display area (DA) of a display device (DD) of one embodiment. Each of the plurality of light-emitting areas (PXAs) may be an area where light generated from each of the light-emitting elements (ED-R, ED-G, ED-B) is emitted.

[0112] In one embodiment, the light-emitting areas (PXA) in the display device (DD) may be arranged in a stripe shape. Referring to FIG. 1, a plurality of light-emitting areas (PXAs) may be aligned along a first direction (DR1) or a second direction (DR2). However, the embodiment is not limited thereto, and the arrangement of the light-emitting areas (PXAs) may have a pentile (PENTILE™) arrangement shape or a diamond (Diamond Pixel™) arrangement shape. PENTILE™ and DIAMOND PIXEL™ are official registered trademarks of Samsung Display Co., Ltd.

[0113] In addition, although the areas of the light-emitting areas (PXAs) are all shown as being similar in FIG. 1, the embodiment is not limited thereto, and the areas of the light-emitting areas (PXAs) may be different from each other depending on the wavelength region of the light emitted.

[0114] The light-emitting areas (PXA) may include first to third light-emitting areas (PXA-R, PXA-G, PXA-B). The display device (DD) may include a plurality of light-emitting areas (PXA-R, PXA-G, PXA-B) repeatedly arranged throughout the display area (DA). The display device (DD) of one embodiment may include first to third light-emitting areas (PXA-R, PXA-G, PXA-B) that are distinct from each other. In addition, the display device (DD) may include a non-light-emitting area (NPXA) arranged around the first to third light-emitting areas (PXA-R, PXA-G, PXA-B). The peripheral area (NPXA) sets a boundary between the first to third light-emitting areas (PXA-R, PXA-G, PXA-B). The peripheral region (NPXA) may surround the first to third light-emitting regions (PXA-R, PXA-G, PXA-B). A structure that prevents color mixing between the first to third light-emitting regions (PXA-R, PXA-G, PXA-B), such as a pixel defining layer (PDL), may be disposed in the peripheral region (NPXA).

[0115] Each of the first to third light-emitting regions (PXA-R, PXA-G, PXA-B) may be a region defined by a pixel defining layer (PDL). The peripheral regions (NPXA) may be regions between the neighboring first to third light-emitting regions (PXA-R, PXA-G, PXA-B) and may be regions corresponding to the pixel defining layer (PDL).

[0116] Each of the first to third light-emitting regions (PXA-R, PXA-G, PXA-B) may be a region in which light generated from each of the first to third light-emitting elements (ED-R, ED-G, ED-B) is emitted. The first to third light-emitting regions (PXA-R, PXA-G, PXA-B) may be spaced apart from each other on a plane.

[0117] Meanwhile, in the present specification, each of the first to third light-emitting regions (PXA-R, PXA-G, PXA-B) may correspond to a pixel. A pixel defining layer (PDL) may distinguish the first to third light-emitting elements (ED-R, ED-G, ED-B). The light-emitting layers (EL-R, EL-G, EL-B) of the first to third light-emitting elements (ED-R, ED-G, ED-B) may be arranged and distinguished within an opening (OH) defined in the pixel defining layer (PDL).

[0118] The pixel defining layer (PDL) may be formed of a polymer resin. For example, the pixel defining layer (PDL) may be formed by including a polyacrylate-based resin or a polyimide-based resin. In addition, the pixel defining layer (PDL) may be formed by including an inorganic material in addition to the polymer resin. Meanwhile, the pixel defining layer (PDL) may be formed by including a light absorbing material, or may be formed by including a black pigment or a black dye. A pixel defining layer (PDL) formed by including a black pigment or a black dye can implement a black pixel defining layer. Carbon black or the like may be used as the black pigment or black dye when forming the pixel defining layer (PDL), but the embodiment is not limited thereto.

[0119] Additionally, the pixel defining layer (PDL) can be formed of an inorganic material. For example, the pixel defining layer (PDL) can be formed of silicon nitride (SiN x ), silicon oxide (SiO x ), silicon nitride (SiO x N y ) can be formed from inorganic substances such as (where x and y are each integers greater than or equal to 1. For example, x and y are each integers greater than or equal to 1 and less than or equal to 4).

[0120] The first to third light-emitting regions (PXA-R, PXA-G, PXA-B) can be distinguished according to the color of light generated from the first to third light-emitting elements (ED-R, ED-G, ED-B). In the display device (DD) of one embodiment illustrated in FIG. 5A, three light-emitting regions (PXA-R, PXA-G, PXA-B) that emit red light, green light, and blue light are exemplarily illustrated. For example, in the display device (DD) of one embodiment, the first light-emitting region (PXA-R) may correspond to a red light-emitting region, the second light-emitting region (PXA-G) may correspond to a green light-emitting region, and the third light-emitting region (PXA-B) may correspond to a blue light-emitting region.

[0121] In a display device (DD) according to one embodiment, the light-emitting elements (ED-R, ED-G, ED-B) may emit light in different wavelength regions. For example, in the display device (DD) according to one embodiment, the first light-emitting element (ED-R) may be a red light-emitting element that emits red light, the second light-emitting element (ED-G) may be a green light-emitting element that emits green light, and the third light-emitting element (ED-B) may be a blue light-emitting element that emits blue light. That is, the red light-emitting region (PXA-R), the green light-emitting region (PXA-G), and the blue light-emitting region (PXA-B) of the display device (DD) may correspond to the first light-emitting element (ED-R), the second light-emitting element (ED-G), and the third light-emitting element (ED-B), respectively.

[0122] Meanwhile, although FIG. 5A illustrates three distinct light-emitting regions (PXA-R, PXA-G, PXA-B), the embodiment is not limited thereto, and the display device (DD) of one embodiment may include four or more light-emitting regions having different light-emitting characteristics.

[0123] In a display panel (DP), a base layer (BS) may be a member that provides a base surface on which a display layer (EDL) is placed. The base layer (BS) may be a glass substrate, a metal substrate, a plastic substrate, or the like. However, the embodiment is not limited thereto, and the base layer (BS) may be an inorganic layer, an organic layer, or a composite material layer.

[0124] In one embodiment, the circuit layer (DP-CL) is disposed on the base layer (BS), and the circuit layer (DP-CL) may include a plurality of transistors (not shown). The transistors (not shown) may each include a control electrode, an input electrode, and an output electrode. For example, the circuit layer (DP-CL) may include a switching transistor and a driving transistor for driving the light-emitting elements (ED-R, ED-G, ED-B) of the display layer (EDL).

[0125] Each of the plurality of light-emitting elements (ED-R, ED-G, ED-B) of one embodiment may include a first electrode (AE), a second electrode (CE) facing the first electrode (AE), and a light-emitting layer (EL-R, EL-G, EL-B) disposed between the first electrode (AE) and the second electrode (CE). A hole transport region (HTR) may be disposed between the first electrode (AE) and the light-emitting layer (EL-R, EL-G, EL-B). An electron transport region (ETR) may be disposed between the second electrode (CE) and the light-emitting layer (EL-R, EL-G, EL-B). In one embodiment, the plurality of light-emitting elements (ED-R, ED-G, ED-B) may emit light in a direction from the first electrode (AE) to the second electrode (CE).

[0126] An encapsulation layer (TFE) may be disposed on the display layer (EDL). The encapsulation layer (TFE) may be disposed on the light-emitting elements (ED-R, ED-G, ED-B). The encapsulation layer (TFE) may seal the light-emitting elements (ED-R, ED-G, ED-B). The encapsulation layer (TFE) may be provided as a common layer throughout the first to third light-emitting regions (PXA-R, PXA-G, PXA-B). The encapsulation layer (TFE) may be disposed as a common layer so as to overlap the first to third light-emitting regions (PXA-R, PXA-G, PXA-B) and the peripheral region (NPXA). The encapsulation layer (TFE) may be disposed on the second electrode (CE). The encapsulation layer (TFE) may be directly disposed on the second electrode (CE). Additionally, when the display layer (EDL) of one embodiment includes the optical layer (CPL), the encapsulation layer (TFE) may be directly disposed on the optical layer (CPL). The encapsulation layer (TFE) may cover the light-emitting elements (ED-R, ED-G, ED-B). The encapsulation layer (TFE) may seal the display layer (EDL). The encapsulation layer (TFE) may be a thin film encapsulation layer.

[0127] The encapsulation layer (TFE) may be a laminate of multiple layers. In one embodiment, the encapsulation layer (TFE) may include at least one organic layer (hereinafter, “encapsulation organic layer”) and at least one inorganic layer (hereinafter, “encapsulation inorganic layer”). In addition, in one embodiment, the encapsulation layer (TFE) may include a polymer layer (AL) disposed between the encapsulation organic layer and the encapsulation inorganic layer.

[0128] The encapsulating layer (TFE) may include a first encapsulating inorganic layer (IOL1), a polymer layer (AL), an encapsulating organic layer (OL), and a second encapsulating inorganic layer (IOL2). The first encapsulating inorganic layer (IOL1), the polymer layer (AL), the encapsulating organic layer (OL), and the second encapsulating inorganic layer (IOL2) may be sequentially arranged along a third direction (DR3).

[0129] The first encapsulating inorganic layer (IOL1) may be disposed on the second electrode (CE). The first encapsulating inorganic layer (IOL1) may be disposed directly on the second electrode (CE). As illustrated in FIG. 5A, when the display panel (DP) further includes an optical layer (CPL), the first encapsulating inorganic layer (IOL1) may be disposed on the optical layer (CPL). The first encapsulating inorganic layer (IOL1) may be disposed directly on the optical layer (CPL). The first encapsulating inorganic layer (IOL1) may have a substantially constant thickness on the light-emitting elements (ED-R, ED-G, ED-B) and the pixel defining layer (PDL) that separates the light-emitting elements (ED-R, ED-G, ED-B).

[0130] The first encapsulating inorganic layer (IOL1) can have a function of protecting the display layer (EDL) from moisture / oxygen. The first encapsulating inorganic layer (IOL1) can have a high film density by including an inorganic material and can have a high bonding strength with a functional layer disposed under the first encapsulating inorganic layer (IOL1). Accordingly, penetration of moisture or oxygen into the interface between the first encapsulating inorganic layer (IOL1) and a functional layer disposed under the first encapsulating inorganic layer (IOL1), for example, an optical layer (CPL), can be prevented, and peeling of the first encapsulating inorganic layer (IOL1) can be prevented. The first encapsulating inorganic layer (IOL1) can include at least one of silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, and aluminum oxide.

[0131] The polymer layer (AL) may be disposed on the first encapsulating inorganic layer (IOL1). The polymer layer (AL) may be disposed directly on the first encapsulating inorganic layer (IOL1). The polymer layer (AL) may have a substantially constant thickness on the light-emitting elements (ED-R, ED-G, ED-B) and the pixel defining layer (PDL) that separates the light-emitting elements (ED-R, ED-G, ED-B).

[0132] The polymer layer (AL) may include a first base resin and an organic acid derivative. The polymer layer (AL) may be a layer that improves the current efficiency characteristics of a light-emitting device and increases luminous efficiency by including the organic acid derivative. The polymer layer (AL) may be a layer that functions to increase the current efficiency and luminous efficiency of a light-emitting device including a quantum dot luminous layer. The polymer layer (AL) may be disposed on a light-emitting device (ED-R, ED-G, ED-B) to improve the stability of the light-emitting layer (EL-R, EL-G, EL-B) including quantum dots, thereby allowing the light-emitting device (ED-R, ED-G, ED-B) to exhibit excellent luminous efficiency.

[0133] The polymer layer (AL) may be a single layer or may have multiple layers. When the polymer layer (AL) has multiple layers, the multiple layers may contain the same material or different materials.

[0134] The first base resin included in the polymer layer (AL) may be selected from the group consisting of polyacrylic acid (PAA), polymethyl methacrylate (PMMA), polystyrene (PS), polyvinyl pyrrolidone (PVP), polydimethylsiloxane (PDMS), polycarbonate (PC), polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and polyvinyl alcohol (PVA). In one embodiment, the first base resin may include at least one of polyacrylic acid (PAA), poly(methyl methacrylate) (PMMA), polystyrene (PS), and polyvinyl pyrrolidone (PVP).

[0135] In one embodiment, the first base resin may include at least one of polyacrylic acid (PAA), poly(methyl methacrylate) (PMMA), polystyrene (PS), and polyvinyl pyrrolidone (PVP). As the first base resin includes the aforementioned materials, the optical properties and mechanical reliability of the polymer layer (AL) may be improved, and the thin film stability and processability may be improved due to the high affinity with the organic acid derivative.

[0136] The organic acid derivative may include a carboxylic acid compound or a carboxylic acid ester compound. The polymer layer (AL) may include one type alone or two or more types of organic acid derivatives.

[0137] In one embodiment, the organic acid derivative has a pK of 1.0 or greater. a may have a pK of 3.0 or more, preferably a can have pK of organic acid derivatives a When the value satisfies the above-mentioned range, the effect of improving the luminous efficiency of the light-emitting element (ED-R, ED-G, ED-B) by the polymer layer (AL) can be increased. Meanwhile, in the present specification, pK a means the acid dissociation constant at 25℃, and the pK of the compound when it contains two or more acid dissociation functional groups in the molecule a is pK a The value of the lowest functional group, i.e., the first acid dissociation constant (pK a1 ) can be determined.

[0138] A carboxylic acid compound may refer to a compound containing one or more carboxyl groups within its molecule. The carboxylic acid compound may include monocarboxylic acids, dicarboxylic acids, and polycarboxylic acids having 1 to 20, or 1 to 10, carbon atoms. For example, carboxylic acid compounds may include formic acid, acetic acid, propionic acid, acrylic acid, methacrylic acid, butyric acid, isobutyric acid, crotonic acid, valeric acid, isovaleric acid, citric acid, lactic acid, glycolic acid, oxalic acid, malonic acid, succinic acid, adipic acid, pimelic acid, maleic acid, fumaric acid, and tartaric acid.

[0139] A carboxylic acid ester compound refers to a compound derived from an ester of an unsaturated carboxylic acid such as acrylic acid or methacrylic acid and an alcohol having 1 to 20 carbon atoms. In one embodiment, the carboxylic acid ester compound may be an alkyl (meth)acrylate comprising an alkyl group having 1 to 30, 1 to 20, or 1 to 10 carbon atoms, or a hydroxyalkyl (meth)acrylate comprising a hydroxyalkyl group having 1 to 30, 1 to 20, or 1 to 10 carbon atoms and having 1 or 2 hydroxyl groups.

[0140] Examples of carboxylic acid ester compounds include alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, i-propyl (meth)acrylate, n-butyl (meth)acrylate, i-butyl (meth)acrylate, sec-butyl (meth)acrylate, t-butyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, and isobornyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, and Examples include hydroxyalkyl (meth)acrylates such as 2-hydroxybutyl (meth)acrylate.

[0141] In one embodiment, the organic acid derivative may include at least one of citric acid, methacrylic acid, acrylic acid, isobutyric acid, an alkyl (meth)acrylate, and a hydroxyalkyl (meth)acrylate. In this case, the alkyl (meth)acrylate may be isobornyl (meth)acrylate, and the hydroxyalkyl (meth)acrylate may be, but is not limited to, 2-hydroxyethyl (meth)acrylate.

[0142] In one embodiment, the thickness of the polymer layer (AL) may be 100 nm or more and 1000 nm or less. If the thickness of the polymer layer (AL) is less than 100 nm, the function of protecting the light-emitting layer (EL) is insufficient, so that the improvement of light-emitting efficiency is not effective. If the thickness of the polymer layer (AL) exceeds 1000 nm, the light-emitting efficiency may be reduced due to the large thickness, and the mechanical reliability of the thin film may be deteriorated.

[0143] An encapsulating organic layer (OL) may be disposed on a polymer layer (AL). The encapsulating organic layer (OL) may be directly disposed on the polymer layer (AL). The encapsulating organic layer (OL) may function to protect the display layer (EDL) from foreign substances such as dust particles. The encapsulating organic layer (OL) may have a flat upper surface. The encapsulating organic layer (OL) may reduce a step difference of the polymer layer (AL). The encapsulating organic layer (OL) may be provided to reduce a step difference of the upper surface of the polymer layer (AL) so that a functional layer to be disposed thereon may be uniformly disposed. In one embodiment, the thickness of the encapsulating organic layer (OL) may be greater than the thickness of the polymer layer (AL). In addition, the thickness of the encapsulating organic layer (OL) may be greater than the thicknesses of the first and third encapsulating inorganic layers (IOL1, IOL2). For example, the thickness of the encapsulating organic layer (OL) may be 1 μm or more and 30 μm or less. However, the embodiment is not limited thereto.

[0144] The encapsulating organic layer (OL) may include a second base resin. In one embodiment, the first base resin included in the polymer layer (AL) and the second base resin included in the encapsulating organic layer (OL) may be different from each other. The second base resin may include an acrylic resin, a urethane resin, a fluorine resin, an epoxy resin, a polyester resin, a polyamide resin, a silicone resin, or a combination thereof.

[0145] The second encapsulating inorganic layer (IOL2) may be disposed on the encapsulating organic layer (OL). The second encapsulating inorganic layer (IOL2) may be disposed directly on the encapsulating organic layer (OL). In one embodiment, the second encapsulating inorganic layer (IOL2) may define the top surface of the encapsulating layer (TFE).

[0146] The second encapsulating inorganic layer (IOL2) can have a function of protecting the display layer (EDL) from moisture / oxygen. The second encapsulating inorganic layer (IOL2) can have a substantially uniform thickness on the encapsulating organic layer (OL) and can have a dense film quality. Accordingly, the second encapsulating inorganic layer (IOL2) can have a strong bonding force with the encapsulating organic layer (OL) and can prevent moisture and oxygen from penetrating into the interface between the encapsulating organic layer (OL) and the second encapsulating inorganic layer (IOL2). In one embodiment, the second encapsulating inorganic layer (IOL2) can include at least one of silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, and aluminum oxide.

[0147] Although not shown, the encapsulation layer (TFE) may further include an additional encapsulation organic layer and an additional encapsulation inorganic layer disposed on the second encapsulation inorganic layer (IOL2). The encapsulation layer (TFE) may further include n (wherein n is a natural number greater than or equal to 1) additional encapsulation organic layers and n additional encapsulation inorganic layers. The n additional encapsulation organic layers and the n additional encapsulation inorganic layers may be disposed alternately. The n additional encapsulation organic layers may have a thickness greater than that of the n additional encapsulation inorganic layers on average, but the embodiment is not limited thereto. The same descriptions of the encapsulation organic layer (OL) and the first and second encapsulation inorganic layers (IOL1, IOL2) may be applied to the materials of the additional encapsulation organic layer and the additional encapsulation inorganic layer.

[0148] An optical member (PP) may be disposed on the display panel (DP). The optical member (PP) may be a reflection reduction layer that reduces reflectance due to external light. For example, the optical member (PP) may include a polarizing film including a phase retarder and / or a polarizer, multilayer reflective layers that destructively interfere with reflected light, or color filters that are disposed in response to the pixel arrangement and emission color of the display panel (DP). When the optical member (PP) includes color filters, the color filters may be arranged in consideration of the emission colors of pixels included in the display panel (DP). Additionally, in one embodiment, the optical member (PP) may be omitted.

[0149] In one embodiment, the optical member (PP) may include a base substrate (BL) and a color filter layer (CFL).

[0150] The base substrate (BL) may be a member that provides a base surface on which a color filter layer (CFL) or the like is placed. The base substrate (BL) may be a glass substrate, a metal substrate, a plastic substrate, or the like. However, the embodiment is not limited thereto, and the base substrate (BL) may be an inorganic layer, an organic layer, or a composite material layer.

[0151] The color filter layer (CFL) may include filters (CF-R, CF-G, CF-B). The color filter layer (CFL) may include first to third filters (CF-R, CF-G, CF-B). Each of the first to third filters (CF-R, CF-G, CF-B) may be arranged to correspond to the first to third light-emitting elements (ED-R, ED-G, ED-B). For example, the first filter (CF-R) may be a red filter, the second filter (CF-G) may be a green filter, and the third filter (CF-B) may be a blue filter. Each of the first to third filters (CF-R, CF-G, CF-B) may be arranged to correspond to the first to third pixel areas (PXA-R, PXA-G, PXA-B).

[0152] In addition, a plurality of filters (CF-R, CF-G, CF-B) that transmit different types of light can be overlapped and arranged in response to the non-emissive region (NPXA) arranged between the emissive regions (PXA-R, PXA-G, PXA-B). The plurality of filters (CF-R, CF-G, CF-B) can be overlapped and arranged in the third direction (DR3), which is the thickness direction, to distinguish the boundaries between adjacent emissive regions (PXA-R, PXA-G, PXA-B). Accordingly, the light blocking effect of external light increases, and the plurality of filters (CF-R, CF-G, CF-B) can have a function like a black matrix. The overlapping structure of the plurality of filters (CF-R, CF-G, CF-B) can have a function of preventing color mixing.

[0153] Each of the first to third filters (CF-R, CF-G, CF-B) may include a polymer photosensitive resin and a pigment or dye. The first filter (CF-R) may include a red pigment or a blue dye, the second filter (CF-G) may include a green pigment or a green dye, and the third filter (CF-B) may include a blue pigment or a red dye. However, the embodiment is not limited thereto, and the third filter (CF-B) may not include a pigment or a dye. The third filter (CF-B) may include a polymer photosensitive resin and not include a pigment or a dye. The third filter (CF-B) may be transparent. The third filter (CF-B) may be formed of a transparent photosensitive resin.

[0154] The color filter layer (CFL) may further include a buffer layer (BFL). For example, the buffer layer (BFL) may be a protective layer that protects the first to third filters (CF-R, CF-G, CF-B). The buffer layer (BFL) may be an inorganic layer containing at least one inorganic material selected from the group consisting of silicon nitride, silicon oxide, and silicon oxynitride. The buffer layer (BFL) may be formed of a single layer or multiple layers.

[0155] Additionally, the first filter (CF-R) and the second filter (CF-G) may be yellow filters. The first filter (CF-R) and the second filter (CF-G) may be provided as a single unit without being distinguished from each other.

[0156] Although not shown, the color filter layer (CFL) may further include a shading portion (not shown). The shading portion may be a black matrix. The shading portion may be formed by including an organic shading material or an inorganic shading material including a black pigment or a black dye. The shading portion may prevent light leakage and demarcate boundaries between adjacent filters (CF-R, CF-G, CF-B).

[0157] In addition, unlike that shown in FIG. 5a, etc., the optical member (PP) of the display device (DD) of one embodiment may not include a color filter layer (CFL).

[0158] In a display device (DD) of one embodiment, each of the first to third light-emitting elements (ED-R, ED-G, ED-B) may include the aforementioned first electrode (AE), a hole transport region (HTR), an emitting layer (EL-R, EL-G, EL-B), an electron transport region (ETR), and a second electrode (CE). In addition, each of the light-emitting elements (ED-R, ED-G, ED-B) may include an optical layer (CPL) disposed on the second electrode (CE).

[0159] The first electrode (AE) may be exposed in the pixel opening (OH) of the pixel defining layer (PDL). The first electrode (AE) has conductivity. The first electrode (AE) may be formed of a metal material, a metal alloy, or a conductive compound. The first electrode (AE) may be an anode or a cathode. In addition, the first electrode (AE) may be a pixel electrode. However, the embodiment is not limited thereto.

[0160] The second electrode (CE) may be disposed on the first electrode (AE). The second electrode (CE) may be a cathode or an anode. In one embodiment, when the first electrode (AE) is an anode, the second electrode (CE) may be a cathode, and when the first electrode (AE) is a cathode, the second electrode (CE) may be an anode. The second electrode (CE) may be a common electrode. However, the embodiment is not limited thereto.

[0161] A hole transport region (HTR) may be arranged between the first electrode (AE) and the light-emitting layer (EL-R, EL-G, EL-B), and an electron transport region (ETR) may be arranged between the light-emitting layer (EL-R, EL-G, EL-B) and the second electrode (CE).

[0162] In one embodiment illustrated in FIG. 5A, the hole transport region (HTR), the light-emitting layer (EL-R, EL-G, EL-B), and the electron transport region (ETR) of each of the first to third light-emitting elements (ED-R, ED-G, ED-B) may be disposed within the pixel opening (OH) and may be separated from the hole transport regions (HTR), the light-emitting layers (EL-R, EL-G, EL-B), and the electron transport regions (ETR) of the neighboring light-emitting regions. That is, in one embodiment, the hole transport region (HTR), the light-emitting layer (EL-R, EL-G, EL-B), and the electron transport region (ETR) may be patterned and disposed within each pixel opening (OH).

[0163] In the display device (DD) of one embodiment, the hole transport region (HTR), the light-emitting layer (EL-R, EL-G, EL-B), and the electron transport region (ETR) of each of the first to third light-emitting elements (ED-R, ED-G, ED-B) may be provided and formed by an inkjet printing method according to a display device manufacturing method of one embodiment described below. However, the embodiment is not limited thereto. The hole transport region (HTR), the light-emitting layer (EL-R, EL-G, EL-B), and the electron transport region (ETR) may be provided and formed by a method other than the inkjet printing method, and further, in another embodiment, at least a portion of the hole transport region (HTR) or the electron transport region (ETR) may be arranged to extend above the pixel defining layer (PDL), or at least a portion may be connected to each other.

[0164] In the display device (DD) of one embodiment, the second electrode (CE) and the optical layer (CPL) may be provided as a common layer for all of the first to third light-emitting elements (ED-R, ED-G, ED-B), respectively. However, the embodiment is not limited thereto, and at least one of the second electrode (CE) and the optical layer (CPL) may be provided to be separated from each other in the neighboring light-emitting regions (PXA-R, PXA-G, PXA-B).

[0165] In a display device (DD) of one embodiment, at least one of the first to third light-emitting elements (ED-R, ED-G, ED-B) may be a quantum dot light-emitting element including a quantum dot. In one embodiment, each of the first to third light-emitting elements (ED-R, ED-G, ED-B) may be a quantum dot light-emitting element including a quantum dot. However, the embodiment is not limited thereto, and at least one selected from the first to third light-emitting elements (ED-R, ED-G, ED-B) may be a quantum dot light-emitting element including a quantum dot, and the rest may be organic light-emitting elements including an organic light-emitting material.

[0166] The display device (DD-a) illustrated in FIG. 5b has a difference in the arrangement positions of the hole transport region (HTR) and the electron transport region (ETR) compared to the display device (DD) illustrated in FIG. 5a.

[0167] Referring to FIG. 5B, each of the plurality of light-emitting elements (ED-R, ED-G, ED-B) of one embodiment may include a first electrode (AE), a second electrode (CE) facing the first electrode (AE), and a light-emitting layer (EL-R, EL-G, EL-B) disposed between the first electrode (AE) and the second electrode (CE). An electron transport region (ETR) may be disposed between the first electrode (AE) and the light-emitting layer (EL-R, EL-G, EL-B). A hole transport region (HTR) may be disposed between the second electrode (CE) and the light-emitting layer (EL-R, EL-G, EL-B). In one embodiment, the plurality of light-emitting elements (ED-R, ED-G, ED-B) may emit light in a direction from the first electrode (AE) to the second electrode (CE).

[0168] Figures 6a and 6b are enlarged views of a portion of a cross-section of a display device according to one embodiment of the present invention. Figures 6a and 6b each illustrate a cross-section corresponding to line II-II' of Figure 1.

[0169] Referring to FIG. 6A, a display device (DD-1) according to one embodiment may include a display panel (DP) and an optical member (PP-1) disposed on the display panel (DP). In the display device (DD-1) according to one embodiment, the optical member (PP-1) may include a color filter layer (CFL-1) and a base substrate (BL-1) sequentially laminated on an encapsulation layer (TFE).

[0170] The color filter layer (CFL-1) may include a plurality of filters (CF-R, CF-G, CF3-B) and a light-shielding portion (BM).

[0171] Compared to the display device (DD) illustrated in FIG. 5A, the display device (DD-1) according to an embodiment illustrated in FIG. 6A is an example in which the color filter layer (CFL-1) is arranged with the upper surface of the encapsulation layer (TFE) as the base surface. That is, the filters (CF-R, CF-G, CF-B) of the color filter layer (CFL-1) may be formed on the encapsulation layer (TFE) in a continuous process. The color filter layer (CFL-1) may be formed with the upper surface of the second encapsulation inorganic layer (IOL2) included in the encapsulation layer (TFE) as the base surface, and thus may have a different shape from that illustrated in FIG. 5A.

[0172] In one embodiment of the color filter layer (CFL-1), the light-shielding portion (BM) may be a black matrix. The light-shielding portion (BM) may be formed by including an organic light-shielding material or an inorganic light-shielding material including a black pigment or black dye. The light-shielding portion (BM) may prevent light leakage and demarcate boundaries between adjacent filters (CF-R, CF-G, CF-B).

[0173] The display device (DD-1a) illustrated in FIG. 6b has a difference in the arrangement positions of the hole transport region (HTR) and the electron transport region (ETR) compared to the display device (DD-1) illustrated in FIG. 6a.

[0174] Referring to FIG. 6B, each of the plurality of light-emitting elements (ED-R, ED-G, ED-B) of one embodiment may include a first electrode (AE), a second electrode (CE) facing the first electrode (AE), and a light-emitting layer (EL-R, EL-G, EL-B) disposed between the first electrode (AE) and the second electrode (CE). An electron transport region (ETR) may be disposed between the first electrode (AE) and the light-emitting layer (EL-R, EL-G, EL-B). A hole transport region (HTR) may be disposed between the second electrode (CE) and the light-emitting layer (EL-R, EL-G, EL-B). In one embodiment, the plurality of light-emitting elements (ED-R, ED-G, ED-B) may emit light in a direction from the first electrode (AE) to the second electrode (CE).

[0175] In a display device (DD, DD-a, DD-1, DD-1a) of one embodiment, the encapsulation layer (TFE) includes a first encapsulation inorganic layer (IOL1), an encapsulation organic layer (OL), and a second encapsulation inorganic layer (IOL2) sequentially stacked in the thickness direction, and includes a polymer layer (AL) disposed between the first encapsulation inorganic layer (IOL1) and the encapsulation organic layer (OL) and including an organic acid derivative, thereby increasing the current efficiency and luminous efficiency of a light-emitting element (ED-R, ED-G, ED-B) including quantum dots. Accordingly, the display device (DD, DD-a) including the encapsulation layer (TFE) of one embodiment can exhibit excellent luminous efficiency.

[0176] FIG. 7 is a flowchart illustrating a method for manufacturing a display device according to one embodiment. Referring to FIG. 7, the method for manufacturing a display device according to one embodiment of the present invention includes a step of preparing a light-emitting element (S100), a step of forming a first encapsulating inorganic layer on the light-emitting element (S200), a step of forming a preliminary polymer layer by applying a coating solution on the first encapsulating inorganic layer (S300), a step of forming a polymer layer by drying or heat-treating the preliminary polymer layer at a first temperature (S400), a step of forming an encapsulating organic layer on the polymer layer (S500), and a step of forming a second encapsulating inorganic layer on the encapsulating organic layer (S600).

[0177] FIGS. 8A to 8G are cross-sectional views illustrating some of the steps of a method for manufacturing a display device according to an embodiment of the present invention. FIGS. 8A to 8G are cross-sectional views illustrating a process for forming an encapsulation layer (TFE) according to an embodiment. A display device manufactured by the method for manufacturing a display device according to an embodiment described with reference to FIGS. 8A to 8G and the like may have the structure of the display device according to an embodiment described with reference to FIGS. 1 to 6B and the like. Therefore, in the following description of a method for manufacturing a display device according to an embodiment of the present invention with reference to FIGS. 8A to 8G, the same reference numerals will be given to the same components as the display device configurations of FIGS. 1 to 6B described above, and redundant descriptions will be omitted.

[0178] Referring to FIG. 8a, a method for manufacturing a display device according to one embodiment of the present invention may include a step of preparing a light-emitting element (ED-R, ED-G, ED-B).

[0179] Referring to FIG. 8A, light-emitting elements (ED-R, ED-G, ED-B) may be formed on a circuit layer (DP-CL). The light-emitting elements (ED-R, ED-G, ED-B) may be provided and disposed within pixel openings (OH-1, OH-2, OH-3) defined in a pixel defining layer (PDL). The first light-emitting element (ED-R) may be provided and disposed within the first pixel opening (OH-1), the second light-emitting element (ED-G) may be provided and disposed within the second pixel opening (OH-2), and the third light-emitting element (ED-B) may be provided and disposed within the third pixel opening (OH-3). Each of the pixel openings (OH-1, OH-2, OH-3) may be a portion corresponding to each of the first to third light-emitting regions (PXA-R, PXA-G, PXA-B) described in FIG. 5A, etc.

[0180] The step of preparing a light-emitting element (ED-R, ED-G, ED-B) may include a step of forming a first electrode (AE) on a circuit layer (DP-CL), a step of forming a hole transport region (HTR) on the first electrode (AE), a step of forming a light-emitting layer (EL-R, EL-G, EL-B) on the hole transport region (HTR), a step of forming an electron transport region (ETR) on the light-emitting layer (EL-R, EL-G, EL-B), and a step of forming a second electrode (CE) on the electron transport region (ETR).

[0181] The step of providing a light-emitting element (ED-R, ED-G, ED-B) can be performed through an inkjet process. In one embodiment, the light-emitting element (ED-R, ED-G, ED-B) includes a hole transport region (HTR), a light-emitting layer (EL-R, EL-G, EL-B), and an electron transport region (ETR), and at least one of the hole transport region (HTR), the light-emitting layer (EL-R, EL-G, EL-B), and the electron transport region (ETR) may be formed through an inkjet process. For example, among the hole transport region (HTR), the light-emitting layer (EL-R, EL-G, EL-B), and the electron transport region (ETR), the light-emitting layer (EL-R, EL-G, EL-B) may be formed through an inkjet process. Additionally, the hole transport region (HTR), the emitting layers (EL-R, EL-G, EL-B), and the electron transport region (ETR) may all be formed through an inkjet process.

[0182] In a method for manufacturing a display device according to an embodiment of the present invention, the step of preparing a light-emitting element (ED-R, ED-G, ED-B) may further include a step of forming an optical layer (CPL). The optical layer (CPL) may be formed on the light-emitting element (ED-R, ED-G, ED-B). The optical layer (CPL) may be formed on the second electrode (CE). The optical layer (CPL) may be formed using various methods such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, a laser induced thermal imaging (LITI) method, etc.

[0183] Referring to FIG. 8b, a method for manufacturing a display device according to one embodiment of the present invention may include a step of forming a first encapsulating inorganic layer (IOL1) on a light-emitting element (ED-R, ED-G, ED-B).

[0184] A first encapsulating inorganic layer (IOL1) can be formed on a light-emitting element (ED-R, ED-G, ED-B). The step of forming the first encapsulating inorganic layer (IOL1) can be performed by a deposition process. The first encapsulating inorganic layer (IOL1) can be formed by providing an inorganic material onto the light-emitting element (ED-R, ED-G, ED-B) by a deposition process. The inorganic material forming the first encapsulating inorganic layer (IOL1) can include at least one of silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, and aluminum oxide.

[0185] Referring to FIGS. 8C to 8E, a method for manufacturing a display device according to an embodiment of the present invention may include a step of forming a polymer layer (AL) on a first encapsulating inorganic layer (IOL1). The step of forming the polymer layer (AL) of one embodiment may include a step of forming a preliminary polymer layer (P-AL) by applying a coating solution (IK-A) on the first encapsulating inorganic layer (IOL1), and a step of forming the polymer layer (AL) by drying or heat-treating the preliminary polymer layer (P-AL) at a first temperature.

[0186] Referring to FIG. 8c, a coating solution (IK-A) including a first base resin and an organic acid derivative may be applied onto a first encapsulating inorganic layer (IOL1) to form a preliminary polymer layer (P-AL). The coating solution (IK-A) may be formed by coating using a known coating method such as spin coating, slit coating, or inkjet printing. For example, as illustrated in FIG. 8c, the coating solution (IK-A) including a first base resin and an organic acid derivative may be provided onto the first inorganic encapsulating layer (IOL1). The coating solution (IK-A) may be provided through a nozzle (NZ). The coating solution (IK-A) may be provided entirely on the pixel openings (OH-1, OH-2, OH-3) and the pixel defining layer (PDL).

[0187] Referring to FIGS. 8d and 8e, a polymer layer (AL, FIG. 8e) can be formed by drying or heat-treating a pre-polymer layer (P-AL) at a first temperature. Through the step of drying or heat-treating the pre-polymer layer (P-AL), the solvent remaining in the pre-polymer layer (P-AL) can be removed. In one embodiment, the first temperature is not particularly limited, but may be, for example, 25°C or higher and 200°C or lower. As illustrated in FIG. 8d, a polymer layer (AL) can be formed through a step of heat-treating the pre-polymer layer (P-AL) by applying heat (h).

[0188] The polymer layer (AL) can be formed to have a substantially constant thickness on the light-emitting elements (ED-R, ED-G, ED-B) and the pixel defining layer (PDL). The polymer layer (AL) can have a constant thickness along the upper surface of the first encapsulating inorganic layer (IOL1). That is, the polymer layer (AL) overlaps the first to third light-emitting regions (PXA-R, PXA-G, PXA-B) and the peripheral region (NPXA) and can be formed to have a substantially constant thickness in the first to third light-emitting regions (PXA-R, PXA-G, PXA-B) and the peripheral region (NPXA). The polymer layer (AL) can be arranged to follow the step of the upper surface of the first encapsulating inorganic layer (IOL1). As the light emitting elements (ED-R, ED-G, ED-B) and the optical layer (CPL) are arranged within the pixel apertures (OH-1, OH-2, OH-3), a step may be formed on the upper surface of the first encapsulating inorganic layer (IOL1). The polymer layer (AL) is arranged to follow the step of the upper surface of the first encapsulating inorganic layer (IOL1), and a step may also be formed on the upper surface of the polymer layer (AL).

[0189] Referring to FIG. 8F, a method for manufacturing a display device according to an embodiment of the present invention may include a step of forming an encapsulating organic layer (OL) on a polymer layer (AL). The encapsulating organic layer (OL) may be formed using various methods, such as a vacuum deposition method, a spin coating method, a casting method, a Langmuir-Blodgett (LB) method, an inkjet printing method, a laser printing method, a laser induced thermal imaging (LITI) method, etc.

[0190] In one embodiment, the encapsulation organic layer (OL) may be formed by applying a second base resin on the polymer layer (AL) and then curing it. Specifically, the second base resin may be provided on the polymer layer (AL) to form a preliminary encapsulation organic layer. The second base resin forming the encapsulation organic layer (OL) may include at least one of an epoxy resin, a phenolic resin, and an acrylic resin. Thereafter, the preliminary encapsulation organic layer may be thermally cured or photocured to form the encapsulation organic layer (OL). In one embodiment, the encapsulation organic layer (OL) may be formed by photocuring the preliminary encapsulation organic layer.

[0191] The encapsulating organic layer (OL) may have a flat upper surface. The encapsulating organic layer (OL) may reduce the step height of the polymer layer (AL). The encapsulating organic layer (OL) may be provided to reduce the step height of the upper surface of the polymer layer (AL), thereby allowing the functional layer to be disposed thereon to be uniformly disposed. In one embodiment, the thickness of the encapsulating organic layer (OL) may be greater than the thickness of the polymer layer (AL).

[0192] Referring to FIG. 8g, a method for manufacturing a display device according to one embodiment of the present invention may include a step of forming a second encapsulating inorganic layer (IOL2) on an encapsulating organic layer (OL).

[0193] A second encapsulating inorganic layer (IOL2) can be formed on an encapsulating organic layer (OL). The step of forming the second encapsulating inorganic layer (IOL2) can be performed by a deposition process. The second encapsulating inorganic layer (IOL2) can be formed by providing an inorganic material onto the encapsulating organic layer (OL) by a deposition process. The inorganic material forming the second encapsulating inorganic layer (IOL2) can include at least one of silicon nitride, silicon oxynitride, silicon oxide, titanium oxide, and aluminum oxide. Through the step of forming the second encapsulating inorganic layer (IOL2), an encapsulating layer (TFE) can be formed on the light emitting elements (ED-R, ED-G, ED-B). The contents described above with reference to FIG. 5A, etc., can be equally applied to the encapsulating layer (TFE).

[0194] Meanwhile, in the method for manufacturing a display panel of the above-described FIGS. 8a to 8g, the method for forming a display device (DD, DD-1) including light-emitting elements (ED-R, ED-G, ED-B) having a laminated structure as shown in FIGS. 5a and 6a is exemplarily shown, but the embodiment is not limited thereto, and a display panel (DD-a, DD-1a) including light-emitting elements (ED-R, ED-G, ED-B) having a laminated structure as shown in FIGS. 5b and 6b can also be formed by the same method as the method for forming the above-described display panel. For example, a method for manufacturing a display device (DD-a, DD-1a) illustrated in FIGS. 5b and 6b may include a step of sequentially providing a first electrode (AE), an electron transport region (ETR), an emission layer (EL-R, EL-G, EL-B), a hole transport region (HTR), a second electrode (CE), and an optical layer (CPL) to form a light-emitting element (ED-R, ED-G, ED-B), and a step of forming an encapsulating layer (TFE) on the light-emitting element (ED-R, ED-G, ED-B). Here, the contents described with reference to FIGS. 8a and 8g may be equally applied to the step of forming the encapsulating layer (TFE).

[0195] A method for manufacturing a display device according to one embodiment includes a step of forming a polymer layer including an organic acid derivative between an encapsulating inorganic layer and an encapsulating organic layer adjacent to a light-emitting element in a step of forming an encapsulating layer, thereby improving current injection characteristics and luminous efficiency characteristics of a light-emitting element including quantum dots, thereby providing a display device having excellent display efficiency.

[0196] In addition, the method for manufacturing a display device according to an embodiment of the present invention can reduce the defect rate compared to the pressure bonding process by directly providing a coating solution on the first encapsulating inorganic layer to form a polymer layer. Therefore, the process efficiency and process reliability of the display device can be improved. In order to form a polymer layer on the display layer, a process of applying a coating solution to one surface of an encapsulating substrate and then pressurizing and bonding the encapsulating substrate and the display layer can be used. However, since this method compresses the encapsulating substrate and the display layer with a pressure exceeding a certain level, the coating solution may penetrate between the interfaces of the functional layers included in the display layer, resulting in defects. In particular, if a coating solution containing a weakly acidic organic acid derivative comes into contact with an electrode film, it may cause corrosion of the electrode film. According to the present invention, the first encapsulating inorganic layer is formed on the display layer, and the coating solution for forming the polymer layer is directly coated on the first encapsulating inorganic layer, so that a pressing process, etc. can be omitted. Accordingly, defects such as those due to interfacial penetration of the coating solution that may occur during the pressing process of the display layer and the encapsulation substrate can be prevented, thereby improving the process reliability and process efficiency of the display device.

[0197] Although the present invention has been described above with reference to preferred embodiments thereof, it will be understood by those skilled in the art or having ordinary knowledge in the art that various modifications and changes to the present invention can be made without departing from the spirit and technical scope of the present invention as set forth in the claims to be described below.

[0198] Therefore, the technical scope of the present invention should not be limited to the contents described in the detailed description of the specification, but should be defined by the claims.

[0199] To improve the color reproducibility of display devices, development of light-emitting devices using quantum dots as light-emitting materials is in progress, and there is a need to improve the luminous efficiency and lifespan of light-emitting devices using quantum dots. According to one embodiment of the present invention, a display device can improve the current efficiency and luminous efficiency characteristics of a light-emitting device including quantum dots by including a polymer layer including an organic acid derivative as an encapsulating layer disposed on the light-emitting device. Therefore, the present invention, which provides a display device according to one embodiment, has high industrial applicability.

Claims

1. A base layer in which a pixel area and a peripheral area adjacent to the pixel area are defined; A pixel defining film disposed on the base layer and having a light-emitting opening corresponding to the pixel area defined therein; A light-emitting element disposed in the above light-emitting opening and generating first color light; and Including a sealing layer disposed on the above light-emitting element, The above encapsulation layer A first encapsulating inorganic layer disposed on the light-emitting element; A polymer layer disposed on the first bag inorganic layer and containing a base resin and an organic acid derivative; A bagging organic layer disposed on the polymer layer; and A display device comprising a second inorganic layer disposed on the organic layer of the packaging.

2. In paragraph 1, A display device wherein the base resin comprises at least one of polyacrylic acid, polymethyl methacrylate, polystyrene, and polyvinyl pyrrolidone.

3. In paragraph 1, The above organic acid derivative is a display device comprising a carboxylic acid compound or a carboxylic acid ester compound.

4. In paragraph 1, A display device wherein the organic acid derivative comprises at least one of citric acid, methacrylic acid, acrylic acid, isobutyric acid, alkyl (meth)acrylate, and hydroxyalkyl (meth)acrylate.

5. In paragraph 1, A display device wherein the thickness of the polymer layer is 100 nm or more and 1000 nm or less.

6. In paragraph 1, A display device wherein the content of the organic acid derivative is 2 wt% to 50 wt% or less based on the total content of the polymer layer.

7. In paragraph 1, A display device in which the polymer layer overlaps the pixel area and the peripheral area and has a constant thickness.

8. In paragraph 1, The above polymer layer is directly disposed on the first bag inorganic layer, The above-mentioned bag organic layer is directly disposed on the above-mentioned polymer layer, A display device in which the second bag inorganic layer is directly disposed on the bag organic layer.

9. In paragraph 1, The light-emitting element includes a first electrode, a second electrode, and a light-emitting layer disposed between the first electrode and the second electrode and emitting light of the first color, A display device in which the first color light is emitted from the first electrode toward the second electrode.

10. In paragraph 9, The above light emitting element a hole transport region disposed between the first electrode and the light-emitting layer; and A display device further comprising an electron transport region disposed between the second electrode and the light-emitting layer.

11. In paragraph 9, The above light emitting element an electron transport region disposed between the first electrode and the light-emitting layer; and A display device further comprising a hole transport region disposed between the second electrode and the light-emitting layer.

12. In paragraph 9, A display device wherein the above light-emitting layer includes quantum dots.

13. In paragraph 9, A display device further comprising an optical layer disposed between the second electrode and the sealing layer.

14. In paragraph 1, Further comprising a color filter layer disposed on the above-mentioned sealing layer, The above color filter layer A first filter transmitting the first color light; A second filter that transmits second color light of a longer wavelength range than the first color light; and A display device including a third filter that transmits third color light having a longer wavelength range than the second color light.

15. In paragraph 14, The color filter layer further includes a buffer layer disposed between the sealing layer and the first to third filters, A display device in which the above-mentioned sealing layer is covered by the above-mentioned buffer layer.

16. In paragraph 14, A display device in which the color filter layer is directly disposed on the sealing layer.

17. In paragraph 14, The color filter layer further includes a light-shielding portion disposed between the first filter, the second filter, and the third filter, A display device in which the second bag weapon layer is directly disposed on one surface of the first filter, the second filter, the third filter, and the light-shielding portion.

18. Step of preparing a light-emitting element; A step of forming a first encapsulating inorganic layer on the light-emitting element; A step of forming a preliminary polymer layer by applying a coating solution containing a first base resin and an organic acid derivative on the first bag inorganic layer; A step of forming a polymer layer by drying or heat treating the above preliminary polymer layer at a first temperature; A step of forming a sealing organic layer on the polymer layer; and A method for manufacturing a display device, comprising the step of forming a second encapsulating inorganic layer on the encapsulating organic layer.

19. In paragraph 18, A method for manufacturing a display device, wherein the first temperature is 25°C or higher and 200°C or lower.

20. In paragraph 18, A method for manufacturing a display device, wherein the step of forming the above-mentioned encapsulating organic layer includes the step of applying and curing a second base resin on the above-mentioned polymer layer.

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