Light-emitting device and preparation method thereof

Abstract

The invention belongs to the field of electroluminescence, and relates to a light-emitting device which comprises a light-emitting unit. The light extraction layer covers the light emitting unit and is used for extracting the light rays emitted by the light emitting unit; the light emitted by the light emitting unit is extracted; the light extraction layer is covered with the spacing layer, and the spacing layer is used for refracting light rays emitted by the light emitting unit; wherein the refractive index of the spacing layer is smaller than that of the light extraction layer. The invention also relates to a preparation method of the light-emitting device. According to the technical scheme provided by the invention, the visual angle deviation generated when the light-emitting device emits light can be effectively weakened, and the light-emitting effect and the light-emitting visual angle of the light-emitting device are improved.

Description

Technical Field

[0001] The present application relates to the field of electroluminescence technology, and more specifically, to a light-emitting device and a method for preparing the same. Background Art

[0002] An electroluminescent diode is a light-emitting device excited by electrons. It has the advantages of self-luminescence, fast response, high brightness, and light weight, and has become one of the main directions of current display research. Among them, the top-emitting electroluminescent diode is conducive to achieving a higher aperture ratio and improving the display effect because each film layer can refract light. In this technology, the anode far away from the light-emitting side has the characteristic of total reflection of light, while the cathode located on the light-emitting side has the characteristic of semi-refraction and semi-reflection of light. In this case, the light emitted by the light-emitting layer inside the device will continue to reflect and refract between the anode and the cathode, so the device often has a strong optical microcavity effect. Under the optical microcavity effect, although the luminous brightness is enhanced in the vertical direction, the corresponding light output becomes weaker at the side angle. Moreover, the greater the angle of deviation from the vertical direction of the device, the greater the difference in luminous brightness or chromaticity, resulting in the phenomenon of viewing angle deviation. Summary of the invention

[0003] The technical problem to be solved by the embodiments of the present application is to provide a light-emitting device and a method for preparing the same, so as to solve the viewing angle deviation of the top-emitting device caused by the microcavity structure.

[0004] In order to solve the above technical problems, the embodiment of the present application provides a light emitting device, which adopts the following technical solution:

[0005] Light emitting unit;

[0006] A light extraction layer, the light extraction layer covers the light emitting unit and is used to extract light emitted by the light emitting unit;

[0007] a spacing layer, the spacing layer covering the light extraction layer and used for refracting the light emitted by the light emitting unit;

[0008] Wherein, the refractive index of the spacing layer is smaller than the refractive index of the light extraction layer.

[0009] Further, the refractive index of the light extraction layer is 1.8-2.0, and the refractive index of the spacer layer is 1.45-1.55;

[0010] And / or, the thickness of the spacer layer is greater than the thickness of the light emitting unit.

[0011] Furthermore, the thickness of the spacer layer is 8um-14um;

[0012] And / or, the material of the spacer layer is organic glue;

[0013] Optionally, the organic glue includes one or more of acrylate, epoxy resin, and silicone;

[0014] And / or, the material of the light extraction layer includes one or more of indium tin oxide, indium zinc oxide, and indium gallium zinc oxide;

[0015] The thickness of the light extraction layer is 50nm-70nm.

[0016] Furthermore, the light emitting device further comprises:

[0017] substrate;

[0018] A pixel definition layer is located on the substrate and defines a pixel area and a non-pixel area; wherein the light-emitting unit is arranged in the pixel area, and the spacer layer covers the pixel area and the non-pixel area.

[0019] Furthermore, the light emitting device also includes: an encapsulation layer and a scattering layer, wherein the encapsulation layer and the scattering layer are sequentially stacked on the spacing layer from bottom to top, and the surface of the scattering layer away from the encapsulation layer is a rough surface for scattering the light refracted by the spacing layer.

[0020] Furthermore, the encapsulation layer is at least one of silicon nitride or silicon oxynitride, and the thickness of the encapsulation layer is 0.8um-1um;

[0021] And / or, the scattering layer is silicon oxycarbide, the thickness of the scattering layer is 1 um-2 um, and the roughness of the rough surface is greater than or equal to 8 um.

[0022] In order to solve the above technical problems, the embodiment of the present application further provides a method for preparing a light-emitting device, which adopts the following technical solution:

[0023] Providing a light-emitting unit to be packaged;

[0024] Covering the light emitting unit with a metal oxide to form a light extraction layer;

[0025] Covering the pixel area and the non-pixel area with organic glue to form a spacer layer;

[0026] Wherein, the refractive index of the spacing layer is smaller than the refractive index of the light extraction layer.

[0027] Further, the refractive index of the light extraction layer is 1.8-2.0, and the refractive index of the spacer layer is 1.45-1.55;

[0028] And / or, the thickness of the spacer layer is 8um-14um;

[0029] And / or, the material of the spacer layer is organic glue;

[0030] Optionally, the organic glue includes one or more of acrylate, epoxy resin, and silicone;

[0031] And / or, the material of the light extraction layer includes one or more of indium tin oxide, indium zinc oxide, and indium gallium zinc oxide;

[0032] The thickness of the light extraction layer is 50nm-70nm.

[0033] Furthermore, the method further comprises the following steps:

[0034] Forming a pixel definition layer on the substrate, wherein the pixel definition layer defines a pixel area and a non-pixel area;

[0035] preparing the light-emitting unit in the pixel area;

[0036] And / or, a packaging layer and a scattering layer are sequentially prepared on the spacer layer, and the scattering layer is roughened.

[0037] Furthermore, the step of covering the pixel area and the non-pixel area with organic glue to form a spacer layer specifically includes:

[0038] Evenly spraying an organic glue layer on the light extraction layer and the non-pixel area;

[0039] Detecting whether the thickness of the organic glue layer reaches a predetermined threshold;

[0040] If the thickness of the organic glue layer reaches the predetermined threshold, using the organic glue layer as the spacing layer; and

[0041] If the thickness of the organic glue layer does not reach the predetermined threshold, continue spraying until the thickness of the organic glue layer reaches the predetermined threshold;

[0042] And / or, the step of sequentially preparing the encapsulation layer and the scattering layer on the spacer layer specifically comprises:

[0043] Depositing silicon nitride or silicon oxynitride or a mixture of silicon nitride and silicon oxynitride on the spacer layer using a chemical vapor deposition method to form an encapsulation layer;

[0044] Silicon oxycarbide is deposited on the packaging layer using a chemical vapor deposition method to form a scattering layer.

[0045] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects: the embodiments cover the light-emitting unit with a light extraction layer for extracting light emitted by the light-emitting unit, and cover the light extraction layer with a spacing layer whose refractive index is smaller than that of the light extraction layer, thereby effectively refracting the light emitted by the light-emitting unit through the spacing layer to change the light emission angle of the light-emitting device, thereby improving the viewing angle deviation caused by the microcavity structure of the light-emitting unit and effectively improving the light emission effect of the light-emitting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the scheme of the present application, a brief introduction is given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0047] Figure 1 is a schematic diagram of a layered structure of an optional embodiment of the light-emitting device of the present application;

[0048] Figure 2 It is a schematic diagram of a layered structure of pixel pits arranged on a substrate in an optional embodiment of the light-emitting device of the present application;

[0049] Figure 3 is a flow chart of an optional embodiment of the method for preparing a light-emitting device of the present application;

[0050] Figure 4 yes Figure 3 A flowchart of a specific implementation of step S40;

[0051] Figure 5 yes Figure 3 A flowchart of a specific implementation of step S50 in FIG.

[0052] Figure numerals: light-emitting unit 1, anode layer 11, hole functional layer 12, light-emitting layer 13, electron functional layer 14, cathode layer 15, light extraction layer 2, spacer layer 3, substrate 4, pixel definition layer 5, pixel area 51, non-pixel area 52, encapsulation layer 6, scattering layer 7, red light-emitting layer 131, green light-emitting layer 132, blue light-emitting layer 133, red sub-light-emitting unit 1a, green sub-light-emitting unit 1b, blue sub-light-emitting unit 1c. DETAILED DESCRIPTION

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by technicians in the technical field of this application; the terms used in the specification of the application herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, not to describe a specific order.

[0054] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0055] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0056] refer to Figure 1 , the embodiment of the present application provides a light emitting device, including:

[0057] Light emitting unit 1;

[0058] A light extraction layer 2, the light extraction layer 2 is covered on the light emitting unit 1 and is used to extract light emitted by the light emitting unit 1;

[0059] a spacer layer 3, the spacer layer 3 being covered on the light extraction layer 2 and being used for refracting the light emitted by the light emitting unit 1;

[0060] The refractive index of the spacer layer 3 is smaller than the refractive index of the light extraction layer 2 .

[0061] Also includes: a substrate 4;

[0062] The pixel definition layer 5 is located on the substrate 4 and defines a pixel area 51 and a non-pixel area 52 ; wherein the light emitting unit 1 is disposed in the pixel area 51 , and the spacer layer 3 covers the pixel area 51 and the non-pixel area 52 .

[0063] The encapsulation layer 6 and the scattering layer 7 are stacked on the spacing layer 3 from bottom to top, and the surface of the scattering layer 7 away from the encapsulation layer 6 is a rough surface for scattering the light refracted by the spacing layer 3.

[0064] In this embodiment, a light extraction layer 2 for extracting light emitted by the light emitting unit 1 is covered on the light emitting unit 1, and a spacer layer 3 whose refractive index is smaller than that of the light extraction layer 2 is covered on the light extraction layer 2, thereby effectively refracting the light emitted by the light emitting unit 2 through the spacer layer 3 to change the light emission angle of the light emitting device, thereby improving the viewing angle deviation caused by the microcavity structure of the light emitting unit 1 and effectively improving the light emission effect of the light emitting device.

[0065] The light extraction layer 2 is made of metal oxide with a thickness of 50nm-70nm. The metal oxide includes doped or undoped metal oxide, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, IGZO and AMO, preferably one or more of ITO, IZO, IGZO, or includes a composite electrode of metal sandwiched between doped or undoped transparent metal oxides, and the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2 and TiO2 / Al / TiO2.

[0066] In an optional embodiment of the present embodiment, the refractive index of the light extraction layer 2 is 1.8-2.0, and the refractive index of the spacer layer 3 is 1.45-1.55.

[0067] This embodiment adopts the refractive index of the light extraction layer 2 and the spacer layer 3 mentioned above, so that the light emitted through the light extraction layer 2 can be refracted at a larger angle, thereby improving the viewing angle deviation and enhancing the side light emission effect.

[0068] In some optional embodiments of the present embodiment, the refractive index of the light extraction layer 2 is any one of 1.8, 1.9, 2.0, etc., or a range between any two of them; the refractive index of the spacer layer 3 is any one of 1.45, 1.46, 1.47, 1.48, 1.49, 1.5, 1.51, 1.52, 1.53, 1.54, 1.55, etc., or a range between any two of them, wherein the refractive index of the spacer layer 3 may preferably be 1.5.

[0069] refer to Figure 2 In an optional embodiment of the present embodiment, the thickness of the spacer layer 3 is 8um-14um;

[0070] And / or, the material of the spacer layer 3 is organic glue;

[0071] Optionally, the organic glue includes one or more of acrylate, epoxy resin, and silicone.

[0072] In some optional embodiments of the present embodiment, the thickness of the spacer layer 3 is any one of 8um, 9um, 10um, 11um, 12um, 13um, 14um, etc., or a range between any two of them.

[0073] In this embodiment, the light emitting unit is covered with organic glue of the above thickness, so that the light emitted by the light emitting unit 1 can be further refracted effectively, thereby effectively ensuring the light emitting effect of the device.

[0074] In this embodiment, the organic glue includes an organic material, and the organic material includes one or more of acrylate, epoxy resin, and silicone.

[0075] In this embodiment, since the light extraction layer 2 is formed by vacuum sputtering of metal oxide, a large amount of foreign matter is attached to the film layer during the film formation process. By setting the spacer layer 3 to cover the top of the light extraction layer 2, it can also play the role of covering the foreign matter and avoid failure of the subsequent packaging layer.

[0076] In an optional embodiment of the present embodiment, the light-emitting unit 1 includes an anode layer 11, a hole functional layer 12, a light-emitting layer 13, an electron functional layer 14, and a cathode layer 15 which are stacked in sequence;

[0077] The light-emitting layer 13 includes: a red light-emitting layer 131, a green light-emitting layer 132, and a blue light-emitting layer 133; the light-emitting unit 1 includes a red sub-light-emitting unit 1a, a green sub-light-emitting unit 1b, and a blue sub-light-emitting unit 1c corresponding to the red light-emitting layer 131, the green light-emitting layer 132, and the blue light-emitting layer 133; the red sub-light-emitting unit 1a, the green sub-light-emitting unit 1b, and the blue sub-light-emitting unit 1c are arranged in different pixel areas on the substrate 4 in a predetermined arrangement manner;

[0078] Optionally, the thickness of the red light-emitting layer 131 is 30nm-70nm, the thickness of the green light-emitting layer 132 is 30nm-70nm, and the thickness of the blue light-emitting layer 133 is 30nm-50nm.

[0079] In this embodiment, the pixel area 51 opened on the substrate 4 includes a plurality of pixel pits, which are arranged in a matrix. The red sub-light-emitting unit 1a, the green sub-light-emitting unit 1b, and the blue sub-light-emitting unit 1c are arranged in the pixel pits according to a predetermined rule. The color of the light-emitting layer in any pixel pit in the same row is different from the color of the light-emitting layer in the adjacent interval pixel pits, and the color of the light-emitting layer in any pixel pit in the same column is the same as the color of the light-emitting layer in the adjacent interval pixel pits; or, the color of the light-emitting layer in any pixel pit in the same row is the same as the color of the light-emitting layer in the adjacent interval pixel pits, and the color of the light-emitting layer in any pixel pit in the same column is different from the color of the light-emitting layer in the adjacent interval pixel pits.

[0080] In this embodiment, the light-emitting layer 13 is a quantum dot light-emitting layer or an organic light-emitting layer; the material of the quantum dot light-emitting layer includes at least one of a single structure quantum dot and a core-shell structure quantum dot, and the material of the single structure quantum dot is selected from at least one of a II-VI group compound, a IV-VI group compound, a III-V group compound and a I-III-VI group compound, wherein the II-VI group compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSe At least one of S, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, and the IV-VI group compound is selected from SnS, SnSe, SnTe, PbS, PbSe , PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe and SnPbSTe, and the III-V group compound is selected from GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, A At least one of lPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs or InAlPSb, and the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2 and AgInS2; and / or

[0081] The core of the core-shell structure quantum dot includes any one of the single structure quantum dots, and the shell material of the core-shell structure quantum dot includes at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS and the single structure quantum dot; the material of the organic light-emitting layer includes at least one of 4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridine-C2,N)iridium(III), 4,4',4"-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridine-C2,N)iridium, diaromatic anthracene derivatives, distyrene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials and DBP fluorescent materials, polyacetylene and its derivatives, polyparaphenylene and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives;

[0082] The material of the hole function layer 12 includes at least one of TFB, CuPc, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, T·APC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxide, transition metal sulfide, transition metal tinide, doped graphene, undoped graphene and C60;

[0083] The material of the electronic functional layer 14 includes inorganic materials and / or organic materials; the inorganic material is selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, aluminum zinc oxide, manganese zinc oxide, zinc tin oxide, lithium zinc oxide, indium tin oxide, cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, zinc tin, indium phosphide, gallium phosphide, copper indium sulfide, copper gallium sulfide, and barium titanate, and the doped elements include one or more of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium;

[0084] The material of the anode layer 11 and / or the transparent cathode layer 15 includes one or more of metal, carbon material and metal oxide, wherein the metal includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb and Mg; the carbon material includes one or more of graphite, carbon nanotubes, graphene and carbon fiber; the metal oxide includes doped or undoped metal oxide, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO, or includes a composite electrode in which a metal is sandwiched between doped or undoped transparent metal oxides, wherein the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2 and TiO2 / Al / TiO2;

[0085] In some optional embodiments of the present embodiment, the thickness of the red light-emitting layer 131 is any one of 30nm, 40nm, 50nm, 60nm, 70nm, etc. or a range between any two of them; the thickness of the green light-emitting layer 132 is any one of 30nm, 40nm, 50nm, 60nm, 70nm, etc. or a range between any two of them; the thickness of the blue light-emitting layer 133 is any one of 30nm, 40nm, 50nm, etc. or a range between any two of them.

[0086] In this embodiment, since the corresponding lights emitted by the red sub-light-emitting unit 1a, the green sub-light-emitting unit 1b, and the blue sub-light-emitting unit 1c have different wavelengths, different thicknesses of the red light-emitting layer 131, the green light-emitting layer 132, and the blue light-emitting layer 133 need to be set. In addition, the thicknesses of the red sub-light-emitting unit 1a, the green sub-light-emitting unit 1b, and the blue sub-light-emitting unit 1c are also different. Specifically, the thicknesses of the anode layer 11 of the red sub-light-emitting unit 1a, the green sub-light-emitting unit 1b, and the blue sub-light-emitting unit 1c are all 10nm-70nm, the thickness of the hole functional layer 12 of the red sub-light-emitting unit 1a is 140nm-240nm, the thickness of the hole functional layer 12 of the green sub-light-emitting unit 1b is 110nm-190nm, the thickness of the hole functional layer 12 of the blue sub-light-emitting unit 1c is 100nm-150nm, the sum of the thicknesses of the electronic functional layer 14 and the cathode 15 of the red sub-light-emitting unit 1a, the green sub-light-emitting unit 1b, and the blue sub-light-emitting unit 1c are all 30nm-55nm, and the thicknesses of the light extraction layer 2 of the red sub-light-emitting unit 1a, the green sub-light-emitting unit 1b, and the blue sub-light-emitting unit 1c are all 50nm-70nm. By setting the red sub-light emitting unit 1a, the green sub-light emitting unit 1b and the blue sub-light emitting unit 1c with the above thickness, a good light emitting effect of the RGB pixels of the device can be effectively guaranteed.

[0087] In other embodiments, the light emitting device may also be a monochromatic light emitting device.

[0088] In an optional embodiment of this embodiment, the encapsulation layer 6 is at least one of silicon nitride or silicon oxynitride, and the thickness of the encapsulation layer 6 is 0.8um-1um;

[0089] And / or, the scattering layer 7 is silicon oxycarbide, the thickness of the scattering layer 7 is 1 um-2 um, and the roughness of the rough surface is greater than or equal to 8 um.

[0090] In some optional embodiments of this embodiment, the thickness of the encapsulation layer 6 is any one of 0.8um, 0.9um, 1um, etc. or a range between any two thereof. The thickness of the scattering layer 7 is any one of 1um, 1.2um, 1.4um, 1.6um, 1.8um, 2um, etc. or a range between any two thereof; the roughness can be an integer value such as 8um, 9um, 10um, etc., and can be 8.5um, 9.5um, 10.5um, etc.

[0091] This embodiment can effectively block water and oxygen by providing the encapsulation layer 6 of the above material and thickness, thereby preventing the inside of the device from being corroded and aged by oxygen.

[0092] In this embodiment, by providing the scattering layer 7 with the above-mentioned material, thickness and surface roughness, the light refracted by the spacing layer 3 can be effectively scattered, so as to improve the viewing angle deviation and effectively enhance the light output effect.

[0093] refer to Figure 3 Based on the above-mentioned light-emitting device, the embodiment of the present application further provides a method for preparing a light-emitting device, comprising the following steps:

[0094] Step S10, forming a pixel definition layer 5 on the substrate 4, wherein the pixel definition layer 5 defines a pixel area 51 and a non-pixel area 52;

[0095] Step S20, preparing a light-emitting unit 1 in the pixel area 51;

[0096] Step S30, covering the light emitting unit 1 with a metal oxide to form a light extraction layer 2;

[0097] Step S40, covering the pixel area 51 and the non-pixel area 52 with organic glue to form a spacer layer 3; and

[0098] Step S50 , preparing an encapsulation layer 6 and a scattering layer 7 on the spacer layer 3 in sequence, and roughening the scattering layer 7 .

[0099] In this embodiment, the preparation method of each film layer of the light-emitting unit 1 is as follows: the hole functional layer 12 is filled in the pixel area 51 by inkjet printing using the above-mentioned corresponding materials, and then reduced pressure drying and baking are performed to form a uniform hole functional layer 12; the light-emitting layer 13 is filled in the pixel area 51 by inkjet printing using the above-mentioned corresponding materials, and then reduced pressure drying and baking are performed to form a uniform light-emitting layer 13; the electronic functional layer 14 is filled in the pixel area 51 by evaporation using the above-mentioned corresponding materials; the transparent cathode layer 15 is filled in the pixel area 51 by a vacuum sputtering process using the above-mentioned metal oxide material, and the light extraction layer 2 is filled in the pixel area 51 by a vacuum sputtering process using the above-mentioned metal oxide material.

[0100] The spacer layer 3 is formed by using organic glue in a solution method on the substrate 4 to obtain a uniform spacer layer 3 . The spacer layer 3 can also be formed by spraying organic glue on the substrate 4 .

[0101] By adopting the above method to prepare the light-emitting device, the microcavity structure of the prepared light-emitting device can be improved to cause the viewing angle deviation generated when emitting light, thereby effectively improving the light emission effect of the light-emitting device.

[0102] refer to Figure 4 In an optional embodiment of this embodiment, step S40 includes the following steps:

[0103] Step S401, spraying an organic glue layer uniformly on the light extraction layer 2 and the non-pixel area 51;

[0104] Step S402, detecting whether the thickness of the organic glue layer reaches a predetermined threshold;

[0105] Step S403, if the thickness of the organic glue layer reaches the predetermined threshold, use the organic glue layer as the spacer layer 3; and

[0106] Step S404: if the thickness of the organic glue layer does not reach the predetermined threshold, continue spraying until the thickness of the organic glue layer reaches the predetermined threshold.

[0107] In this embodiment, the predetermined threshold is 8 um, which can be adjusted according to actual conditions.

[0108] refer to Figure 5 In an optional embodiment of this embodiment, step S50 includes the following steps:

[0109] Step S501, depositing silicon nitride or silicon oxynitride or a mixture of silicon nitride and silicon oxynitride on the spacer layer 3 using a chemical vapor deposition method to form an encapsulation layer 6;

[0110] Step S502 : depositing silicon oxycarbide on the packaging layer 6 by using chemical vapor deposition to form a scattering layer 7 .

[0111] This embodiment adopts the above materials and methods to prepare the encapsulation layer 6 and the spacer layer 7, so as to effectively isolate water and oxygen and scatter the light to optimize the brightness and viewing angle of the light-emitting device and effectively improve the viewing angle deviation of the light-emitting device.

[0112] Table 1: Comparison of brightness and viewing angle between common light emitting devices and the light emitting devices of the present application

[0113]

[0114] Referring to Table 1, a common light-emitting device includes a top-emitting device, a light extraction layer and an encapsulation layer, and the top-emitting device includes a reflective anode layer, a hole injection layer, a hole transport layer, a light-emitting material layer, an electron transport layer, an electron injection layer, and a transparent cathode which are stacked in sequence;

[0115] The reflective anode layer material is silver (Ag) and indium tin oxide (ITO), and is set as a stack of silver / indium tin oxide / silver, with a thickness of 100nm / 1000nm / 100nm, and the preparation method is to sputter the reflective anode layer material on a glass substrate to form a reflective anode layer;

[0116] The hole injection layer material is copper phthalocyanine (Cupc), and the corresponding thicknesses of the three pixels of red, green and blue are 115nm / 60nm / 40nm respectively. The preparation method is to fill the hole injection layer material in the pixel pit by inkjet printing, and then reduce the pressure to dry and bake to form a uniform hole injection layer (the material used is in the form of ink);

[0117] The hole transport layer material is polyvinyl carbazole (PVK), and the corresponding thicknesses of the three pixels of red, green and blue are 120nm / 116nm / 100nm respectively. The preparation method is to fill the hole transport layer material in the pixel pit by inkjet printing, and then perform reduced pressure drying and baking to form a uniform hole transport layer (the material used is in the form of ink);

[0118] The luminescent material layer is made of zinc sulfide (ZnS), and the corresponding thicknesses of the three pixels of red, green and blue are 60nm / 60nm / 38nm respectively. The preparation method is to fill the luminescent layer material in the pixel pit (corresponding to the red, green and blue sub-pixels) by inkjet printing, and then perform reduced pressure drying and baking to form a uniform red / green / blue luminescent layer (the material used is in the form of ink);

[0119] The electron transport layer material is lithium titanium oxide (Li2TiO3) with a thickness of 23nm. The preparation method is to fill the electron transport layer material into the pixel pit by evaporation (the material used is in solid form);

[0120] The electron injection layer material is aluminum oxide (Al2O3) with a thickness of 1 nm. The preparation method is to fill the electron injection layer material into the pixel pit by evaporation (the material used is in solid form);

[0121] The transparent cathode material is indium tin oxide (ITO) with a thickness of 16 nm, and the preparation method is to fill the transparent cathode material into the pixel pit by a vacuum sputtering process or to fill the transparent cathode material into the pixel pit by an evaporation process;

[0122] The light extraction layer material is indium zinc oxide (IZO), with a thickness of 60nm and a refractive index of 2.0. The preparation method is to fill the light extraction layer material into the pixel pit using a vacuum sputtering process;

[0123] The encapsulation layer material is silicon nitride (Si3N4) and aluminum oxide (Al2O3), and is arranged as a stack of silicon nitride / aluminum oxide / silicon nitride, with a thickness of 0.7um / 15nm / 1.0um and a refractive index of 1.79 / 1.5 / 1.79. The preparation method is to deposit a mixture of silicon nitride and aluminum oxide on the light extraction layer using chemical vapor deposition;

[0124] The light-emitting device of the present application includes a top-emitting device, a light extraction layer, a spacer layer, an encapsulation layer, and a scattering layer. The materials and thicknesses of the top-emitting device, the light extraction layer, and the encapsulation layer are consistent with those of the above-mentioned ordinary light-emitting device. The materials and thicknesses of the spacer layer and the scattering layer are as follows:

[0125] The spacer layer material is acrylic acid ester, with a thickness of 12 nm and a refractive index of 1.5, and is prepared by spraying the spacer layer material using an inkjet printing process;

[0126] The scattering layer material is silicon oxycarbide (Sioc), with a thickness of 0.5 um and a refractive index of 1.55. The preparation method is to deposit the scattering layer material on the packaging layer 6 using a chemical vapor deposition method.

[0127] This embodiment adopts the above-mentioned materials, thicknesses and preparation methods to prepare the light-emitting device of the present application. Compared with ordinary light-emitting devices, it is possible to effectively optimize the brightness viewing angle of the electroluminescent device when the device emits light and improve the viewing angle deviation of the light-emitting device.

[0128] Obviously, the embodiments described above are only some embodiments of the present application, rather than all embodiments. The preferred embodiments of the present application are given in the accompanying drawings, but they do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present application more thorough and comprehensive. Although the present application is described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions recorded in the aforementioned specific implementation methods, or to perform equivalent replacement of some of the technical features therein. Any equivalent structure made using the contents of the specification and drawings of this application, directly or indirectly used in other related technical fields, is similarly within the scope of patent protection of this application.

Claims

1. A light emitting device, characterized in that: include: Light emitting unit; A light extraction layer, the light extraction layer covers the light emitting unit and is used to extract light emitted by the light emitting unit; a spacing layer, the spacing layer covering the light extraction layer and used for refracting the light emitted by the light emitting unit; Wherein, the refractive index of the spacing layer is smaller than the refractive index of the light extraction layer.

2. The light emitting device according to claim 1, characterized in that: The refractive index of the light extraction layer is 1.8-2.0, and the refractive index of the spacer layer is 1.45-1.55; And / or, the thickness of the spacer layer is greater than the thickness of the light emitting unit.

3. The light emitting device according to claim 1, characterized in that: The thickness of the spacer layer is 8um-14um; And / or, the material of the spacer layer is organic glue; Optionally, the organic glue includes one or more of acrylate, epoxy resin, and silicone; And / or, the material of the light extraction layer includes one or more of indium tin oxide, indium zinc oxide, and indium gallium zinc oxide; The thickness of the light extraction layer is 50nm-70nm.

4. The light emitting device according to claim 1, characterized in that: Also includes: substrate; A pixel definition layer is located on the substrate and defines a pixel area and a non-pixel area; wherein the light-emitting unit is arranged in the pixel area, and the spacer layer covers the pixel area and the non-pixel area.

5. The light emitting device according to claim 1, characterized in that: Also includes: The encapsulation layer and the scattering layer are stacked on the spacing layer in sequence from bottom to top, and the surface of the scattering layer away from the encapsulation layer is a rough surface for scattering the light refracted by the spacing layer.

6. The light emitting device according to claim 5, characterized in that: The encapsulation layer is at least one of silicon nitride or silicon oxynitride, and the thickness of the encapsulation layer is 0.8um-1um; And / or, the scattering layer is silicon oxycarbide, the thickness of the scattering layer is 1 um-2 um, and the roughness of the rough surface is greater than or equal to 8 um.

7. A method for preparing a light emitting device, characterized in that: The method comprises the following steps: Providing a light-emitting unit to be packaged; Covering the light emitting unit with a metal oxide to form a light extraction layer; Covering the light extraction layer with organic glue to form a spacer layer; Wherein, the refractive index of the spacing layer is smaller than the refractive index of the light extraction layer.

8. The method for preparing a light emitting device according to claim 7, characterized in that: The refractive index of the light extraction layer is 1.8-2.0, and the refractive index of the spacer layer is 1.45-1.55; And / or, the thickness of the spacer layer is 8um-14um; And / or, the material of the spacer layer is organic glue; Optionally, the organic glue includes one or more of acrylate, epoxy resin, and silicone; And / or, the material of the light extraction layer includes one or more of indium tin oxide, indium zinc oxide, and indium gallium zinc oxide; The thickness of the light extraction layer is 50nm-70nm.

9. The method for preparing a light emitting device according to claim 7, characterized in that: The method further comprises the steps of: Forming a pixel definition layer on the substrate, wherein the pixel definition layer defines a pixel area and a non-pixel area; preparing the light-emitting unit in the pixel area; And / or, a packaging layer and a scattering layer are sequentially prepared on the spacer layer, and the scattering layer is roughened.

10. The method for preparing a light emitting device according to claim 9, characterized in that: The step of covering the pixel area and the non-pixel area with organic glue to form a spacer layer specifically includes: Evenly spraying an organic glue layer on the light extraction layer and the non-pixel area; Detecting whether the thickness of the organic glue layer reaches a predetermined threshold; If the thickness of the organic glue layer reaches the predetermined threshold, using the organic glue layer as the spacing layer; and If the thickness of the organic glue layer does not reach the predetermined threshold, continue spraying until the thickness of the organic glue layer reaches the predetermined threshold; And / or, the step of sequentially preparing the encapsulation layer and the scattering layer on the spacer layer specifically comprises: Depositing silicon nitride or silicon oxynitride or a mixture of silicon nitride and silicon oxynitride on the spacer layer using a chemical vapor deposition method to form an encapsulation layer; Silicon oxycarbide is deposited on the packaging layer using a chemical vapor deposition method to form a scattering layer.

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