Composite layer and preparation method thereof, photoelectric device and display device

Abstract

The invention discloses a composite layer and a preparation method thereof, a photoelectric device and a display device, and relates to the technical field of display. The composite layer comprises a first refraction layer, a second refraction layer and a third refraction layer which are sequentially arranged in a stacked mode, the material of the first refraction layer comprises a first material, the refractive index of the first material is N1, the material of the second refraction layer comprises a second material, the refractive index of the second material is N2, the material of the third refraction layer comprises a third material, the refractive index of the third material is N3, and the refractive index of the third material is N3. N1, N2 and N3 meet the following relational expressions: N1 is greater than N2, and N3 is greater than N2. The light extraction efficiency of the composite layer provided by the invention is high.

Description

Technical Field

[0001] The present application relates to the field of display technology, and in particular to a composite layer and a preparation method thereof, an optoelectronic device, and a display device. Background Art

[0002] Light is emitted from the light-emitting side of the optoelectronic device, and some light with a large incident angle will be reflected back into the optoelectronic device, reducing the luminous efficiency. Usually, a light extraction layer is added to the outside of the light-emitting side of the optoelectronic device to change the path of the light and suppress the extinction reaction caused by the movement of surface plasma.

[0003] In the prior art, the light extraction efficiency of the light extraction layer is relatively low and needs to be further improved. Summary of the invention

[0004] In view of this, the present application provides a composite layer and a preparation method thereof, an optoelectronic device, and a display device.

[0005] The embodiment of the present application is implemented as follows: a composite layer includes a first refractive layer, a second refractive layer and a third refractive layer which are stacked in sequence, wherein the material of the first refractive layer includes a first material, and the refractive index of the first material is N1; the material of the second refractive layer includes a second material, and the refractive index of the second material is N2; the material of the third refractive layer includes a third material, and the refractive index of the third material is N3, wherein N1, N2 and N3 satisfy the following relationship: N1>N2, N3>N2.

[0006] Accordingly, the present invention also provides a method for preparing a composite layer, comprising the following steps:

[0007] Providing a first material, wherein the refractive index of the first material is N1, and depositing the first material to form a first refractive layer;

[0008] Providing a second material, wherein the refractive index of the second material is N2, N1>N2, and depositing the second material on the first refractive layer to form a second refractive layer;

[0009] A third material is provided, wherein the refractive index of the third material is N3, where N3>N2. The third material is deposited on the second refractive layer to form a third refractive layer, thereby obtaining a composite layer.

[0010] Accordingly, an embodiment of the present application further provides an optoelectronic device, comprising a light emitting unit and a light extraction unit; the light extraction unit is arranged on the light emitting side of the light emitting unit;

[0011] The light extraction unit includes a composite layer, the composite layer includes a first refractive layer, a second refractive layer and a third refractive layer which are sequentially stacked, the first refractive layer is arranged between the light emitting unit and the second refractive layer; the material of the first refractive layer includes a first material, the refractive index of the first material is N1, the material of the second refractive layer includes a second material, the refractive index of the second material is N2, the material of the third refractive layer includes a third material, the refractive index of the third material is N3, wherein N1, N2 and N3 satisfy the following relationship: N1>N2, N3>N2.

[0012] Correspondingly, an embodiment of the present application further provides a display device, which includes the above-mentioned optoelectronic device.

[0013] The composite layer provided in the present application has high light extraction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without paying any creative work.

[0015] Figure 1 is a schematic diagram of the structure of the composite layer provided in an embodiment of the present application;

[0016] Figure 2 is a schematic diagram of the structure of another composite layer provided in an embodiment of the present application;

[0017] Figure 3 is a flow chart of a method for preparing a composite layer provided in an embodiment of the present application;

[0018] Figure 4 is a schematic diagram of the structure of the optoelectronic device provided in an embodiment of the present application;

[0019] Figure 5 It is a schematic diagram of the structure of another optoelectronic device provided in an embodiment of the present application.

[0020] Reference numerals:

[0021] Optoelectronic device 100;

[0022] Composite layer 10; first refractive layer 11; second refractive layer 12; third refractive layer 13;

[0023] Light-emitting unit 20; first electrode 21; light-emitting layer 22; second electrode 23; first carrier functional layer 24; second carrier functional layer 25;

[0024] Encapsulation unit 30 ; first encapsulation film layer 31 ; second encapsulation film layer 32 ; third encapsulation film layer 33 . DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0026] In this application, unless otherwise stated, directional words such as "upper" and "lower" generally refer to the upper and lower parts of the device in actual use or working state, specifically the drawing direction in the accompanying drawings; while "inner" and "outer" refer to the outline of the device. In addition, in the description of this application, the term "including" means "including but not limited to". The terms first, second, third, etc. are used only as labels and do not impose numerical requirements or establish an order.

[0027] In this application, "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0028] In the present application, "at least one" means one or more, and "plurality" means two or more. "One or several", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0029] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0030] The light-emitting principle of optoelectronic devices is to apply direct current to the positive and negative electrodes, and electrons and holes are injected into the device from the cathode and anode respectively. Under the action of the electric field, the carriers migrate in the auxiliary transport material and meet in the light-emitting layer to produce excitons. The excitons radiatively transition back to the ground state and emit light. In existing optoelectronic devices, only about 20% of the light is emitted to the outside of the device, about 30% of the light is lost in the substrate waveguide mode and about 50% of the light is lost in the ITO / organic layer waveguide mode. In addition, the purity of the light emitted by the current optoelectronic devices is low and the appearance is not good. Therefore, how to maximize the light extraction, increase the transmitted light, and improve the purity of the emitted light is the research focus of improving the performance of optoelectronic devices.

[0031] The technical solution of this application is as follows:

[0032] First, see Figure 1 The embodiment of the present application provides a composite layer 10, comprising a first refractive layer 11, a second refractive layer 12 and a third refractive layer 13 arranged in sequence, wherein the material of the first refractive layer 11 comprises a first material, and the refractive index of the first material is N1, the material of the second refractive layer 12 comprises a second material, and the refractive index of the second material is N2, the material of the third refractive layer 13 comprises a third material, and the refractive index of the third material is N3, wherein N1, N2 and N3 satisfy the following relationship: N1>N2, N3>N2.

[0033] It should be noted that the refractive index is the ratio of the speed of light in a vacuum to the speed of light in the medium. The higher the refractive index of a material, the stronger its ability to refract incident light. For example, the refractive index of the first material represents the speed of light in a vacuum (3×10 8 m / s) to the propagation speed of light in the first material.

[0034] The composite layer 10 provided in the present application can form a secondary microcavity structure by first reducing and then increasing the refraction of the first refraction layer 11, the second refraction layer 12 and the third refraction layer 13. By adjusting the refractive index of each film, the films work together to control the resonance intensity of the microcavity structure, which is beneficial to adjust the optical interference distance, suppress external light reflection, and promote light emission, thereby improving the light extraction efficiency and the color purity of the emitted light.

[0035] In some embodiments, N1 and N2 satisfy the following relationship: N1-N2≥0.5. For example, N1-N2 can be 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, etc. Within the range, it is beneficial for light to be efficiently transmitted from the first refractive layer 11 to the second refractive layer 12.

[0036] In some embodiments, N2 and N3 satisfy the following relationship: N3-N2≥0.5, for example, N1-N2 can be 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, etc. Within the range, it is beneficial for light to be efficiently transmitted from the second refractive layer 12 to the third refractive layer 13.

[0037] In some embodiments, N1 is 1.9 to 2.4, for example, 1.92, 1.94, 1.96, 1.98, 2, 2.02, 2.04, 2.06, 2.08, 2.1, 2.2, 2.3, etc. Within the range, it is beneficial for light to be emitted from the normal viewing angle of the first refractive layer 11 and transmitted to the second refractive layer 12 as much as possible.

[0038] In some embodiments, N2 is 1.38 to 1.55, for example, 1.39, 1.40, 1.41, 1.42, 1.44, 1.46, 1.48, 1.5, 1.52, 1.54, etc. Within the range, it is beneficial to optically adjust the light transmitted from the first refractive layer 11 to the second refractive layer 12 to avoid total reflection of light.

[0039] In some embodiments, the N3 is 1.9 to 2.4, for example, it can be 1.92, 1.94, 1.96, 1.98, 2, 2.02, 2.04, 2.06, 2.08, 2.1, 2.2, 2.3, etc. Within the range, it is beneficial for light to be emitted from the third refractive layer 13 at a normal viewing angle, thereby improving the light extraction efficiency of the composite layer 10.

[0040] It can be understood that the N1 and the N3 are the same or different.

[0041] It should be noted that when N1=1.9, N2=1.55, and N3=1.9, N1-N2=0.35<0.5, and N3-N2=0.35<0.5, and at this time, the composite layer 10 also has a certain light extraction effect.

[0042] In some embodiments, the first material includes one or more of a first inorganic material and an organic material.

[0043] Furthermore, the first inorganic material includes a first metal oxide, and the first metal oxide includes one or more of IZO, ITO, FTO, ATO, AZO, GZO, MZO, MoO3, and AMO.

[0044] The organic material includes one or more of N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine (NPB), tri(4-carbazolyl-9-ylphenyl)amine (TCTA), 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi), 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP), 4-[1-[4-[di(4-methylphenyl)amino]phenyl]cyclohexyl]-N-(3-methylphenyl)-N-(4-methylphenyl)aniline (TAPC), and 9,9'-(1,3-phenyl)di-9H-carbazole (mCP).

[0045] In some embodiments, the second material includes a second inorganic material.

[0046] Furthermore, the second inorganic material includes LiF, NaF, MgF2, SiO x1 The second inorganic material can effectively block the erosion of water and oxygen, and will not have an adverse effect on the underlying film when depositing the film during the preparation process, and can effectively protect the underlying film from erosion.

[0047] In some embodiments, the third material includes a third inorganic material.

[0048] Furthermore, the third inorganic material includes a third metal oxide, and the third metal oxide includes ZnO, TiO2, MoO x2 、ZnMgO x3 It can be understood that the second material and the third material are both inorganic materials, which have high compatibility and good interface contact performance.

[0049] It should be noted that SiO x1 x1, MoO x2 x2, and ZnMgO x3The value of x3 can be determined according to the actual situation, such as x1 can be 2, x2 can be 1.5, x3 can be 0.5, etc.

[0050] In some embodiments, the thickness of the first refractive layer 11 is 50 nm to 70 nm, for example, 52 nm, 54 nm, 56 nm, 58 nm, 60 nm, 62 nm, 64 nm, 66 nm, 68 nm, etc.

[0051] In some embodiments, the thickness of the second refractive layer 12 is 80 nm to 150 nm, for example, 85 nm, 90 nm, 95 nm, 100 nm, 105 nm, 110 nm, 115 nm, 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, etc.

[0052] In some embodiments, the third refractive layer 13 includes a plurality of island-shaped units.

[0053] Furthermore, the surface of the island-shaped unit away from the second refractive layer 12 is a curved surface. Compared with a planar structure, the curved surface can make more light rays with incident angles within the critical angle range be emitted from the third refractive layer 13 without being absorbed, thereby improving the light extraction efficiency and further reducing the light extraction loss caused by the light waveguide effect when the light enters the film layer with a changing refractive index.

[0054] See also Figure 2 , the structure of the island-shaped unit may include a hemispherical shape. It can be understood that in the process of depositing the island-shaped unit, the material of the third refractive layer 13 is easily accumulated to form a columnar structure at the beginning of deposition, and then a structure with a curved surface is formed above the columnar structure, so the structure of the island-shaped unit also includes the columnar unit and the hemispherical shape above the columnar unit.

[0055] It should be noted that, in the present application, “island-like unit” refers to the material of the third refractive layer 13 presenting an island-like structure on the second refractive layer 12 at a microscopic level. The island-like units are not connected to each other and are independently dispersed on the surface of the second refractive layer 12 away from the first refractive layer 11.

[0056] In some embodiments, the average height of the island unit is 200nm to 500nm, for example, it can be 220nm, 240nm, 260nm, 280nm, 300nm, 320nm, 340nm, 360nm, 380nm, 400nm, 420nm, 440nm, 460nm, 480nm, etc.

[0057] In some embodiments, the average diameter of the island-shaped unit is 0.1 μm to 0.5 μm, for example, 0.15 μm, 0.2 μm, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm, etc. It should be noted that the shape of the orthographic projection of the island-shaped unit on the second refractive layer 12 can be a circle, an ellipse, an oval, a rounded square, a rounded diamond, etc. The diameter of the island-shaped unit is the ratio of the circumference of the orthographic projection of the island-shaped unit on the second refractive layer 12 to π, and the average diameter of the island-shaped unit refers to the ratio of the sum of the diameters of all the island-shaped units in the third refractive layer 13 to the total number of the island-shaped units.

[0058] In some embodiments, the average interval between adjacent island-shaped units is 0.2 μm to 0.5 μm, for example, 0.25 μm, 0.3 μm, 0.35 μm, 0.4 μm, 0.45 μm, etc.

[0059] Thus, within the size range of the island-shaped unit, the third refractive layer 13 can make the incident angle of more light within the critical angle range, thereby reducing total reflection and absorption of light, lowering light loss, and improving light extraction efficiency.

[0060] Second, see Figure 3 The present application also provides a method for preparing a composite layer 10, comprising the following steps:

[0061] S11, providing a first material, wherein the refractive index of the first material is N1, and depositing the first material to form a first refractive layer 11;

[0062] S12, providing a second material, wherein the refractive index of the second material is N2, N1>N2, and depositing the second material on the first refractive layer 11 to form a second refractive layer 12;

[0063] S13 , providing a third material, wherein the refractive index of the third material is N3, N3>N2, and depositing the third material on the second refractive layer 12 to form a third refractive layer 13 , thereby obtaining a composite layer 10 .

[0064] The relationship and range of the first material, the second material, the third material, and N1, N2 and N3 are as described above and will not be repeated here.

[0065] It should be noted that the composite layer 10 may also be prepared by first preparing the third refractive layer 13 , then preparing the second refractive layer 12 , and finally preparing the first refractive layer 11 .

[0066] It can be understood that the formation method of the first refractive layer 11, the second refractive layer 12 and the third refractive layer 13 can be realized by conventional techniques in the art, such as chemical method or physical method. Among them, the chemical method includes chemical vapor deposition, continuous ion layer adsorption and reaction method, anodization method, electrolytic deposition method, and coprecipitation method. The physical method includes physical coating method and solution method, among which the physical coating method includes: thermal evaporation coating method, electron beam evaporation coating method, magnetron sputtering method, multi-arc ion coating method, physical vapor deposition method, atomic layer deposition method, pulsed laser deposition method, etc.; the solution method can be spin coating method, printing method, inkjet printing method, doctor blade method, printing method, dip pulling method, immersion method, spray coating method, roll coating method, casting method, slit coating method and strip coating method, etc.

[0067] In the S11:

[0068] Preferably, in some embodiments, the method of depositing the first material includes evaporation deposition method and vapor deposition method.

[0069] In at least one embodiment, when the first material is the organic material, the method of depositing the first material may be an evaporation deposition method, and when the first material is the first inorganic material, the method of depositing the first material may be a vapor deposition method.

[0070] Specifically, the speed of the evaporation deposition method is For example, it can be

[0071] etc.; vacuum degree is 10 -4 Pa~3×10 -4 Pa, for example, can be 1.2×10 -4 Pa, 1.4×10 -4 Pa, 1.6×10 -4 Pa, 1.8×10 -4 Pa, 2×10 -4 Pa, 2.2×10 -4 Pa, 2.4×10 -4 Pa, 2.6×10 -4 Pa, 2.8×10 -4 Pa, etc. In this way, under the above-mentioned evaporation deposition conditions, it is beneficial to prepare the organic first refractive layer 11 with good film-forming properties.

[0072] The target power of the vapor deposition method is 5 kW to 10 kW, for example, 5.5 kW, 6 kW, 6.5 kW, 7 kW, 7.5 kW, 8 kW, 8.5 kW, 9 kW, 9.5 kW, etc. The pressure is 0.1 Pa to 0.6 Pa, for example, 0.15 Pa, 0.2 Pa, 0.25 Pa, 0.3 Pa, 0.35 Pa, 0.4 Pa, 0.45 Pa, 0.5 Pa, 0.55 Pa, etc. In this way, under the conditions of the evaporation deposition, it is conducive to preparing the inorganic first refractive layer 11 with good film-forming properties.

[0073] In S12:

[0074] Preferably, in some embodiments, the method of depositing the second material comprises an evaporation deposition method or a vapor deposition method. The specific parameters of the evaporation deposition method and the vapor deposition method can be referred to above and will not be described in detail here.

[0075] In S13:

[0076] In some embodiments, after forming the second refractive layer 12 and before depositing the third material, the method further includes: treating the second refractive layer 12 with plasma.

[0077] In some embodiments, the plasma includes CF4.

[0078] In some embodiments, the gas flow rate of the plasma is 200 sccm to 500 sccm, for example, 220 sccm, 250 sccm, 280 sccm, 300 sccm, 320 sccm, 350 sccm, 380 sccm, 400 sccm, 420 sccm, 450 sccm, 480 sccm, etc.

[0079] In some embodiments, the plasma treatment time is 30s to 300s, for example, 50s, 80s, 100s, 120s, 150s, 180s, 200s, 220s, 250s, 280s, etc.; the temperature is 50°C to 100°C.

[0080] In this way, by performing plasma treatment on the second refractive layer 12 under the above conditions, the hydrophobicity of the surface of the second refractive layer 12 can be improved, which is beneficial for forming the third refractive layer 13 on the second refractive layer 12 .

[0081] Preferably, in some embodiments, the method of depositing the third material comprises an inkjet printing method.

[0082] Specifically, the viscosity of the ink used in the inkjet printing method is 3cp to 15cp, such as 3cp, 4cp, 5cp, 6cp, 7cp, 8cp, 9cp, 10cp, 11cp, 12cp, 13cp, 14cp, 15cp, etc. The concentration of the ink is 40mg / mL to 80mg / mL, such as 45mg / mL, 50mg / mL, 55mg / mL, 60mg / mL, 65mg / mL, 70mg / mL, 75mg / mL, etc. In this way, within the viscosity and concentration range of the ink, the film-forming property of the third refractive layer 13 is improved.

[0083] The preparation method described in the present application is simple to operate. By sequentially arranging the first refractive layer 11, the second refractive layer 12 and the third refractive layer 13, the composite layer 10 is prepared, which is beneficial to the synergistic effect of the first refractive layer 11, the second refractive layer 12 and the third refractive layer 13, thereby improving the light extraction efficiency and reducing the light loss.

[0084] Third, see Figure 4 , the embodiment of the present application further provides an optoelectronic device 100, comprising a light emitting unit 20 and a light extraction unit; the light extraction unit is arranged on the light emitting side of the light emitting unit;

[0085] Wherein, the light extraction unit includes a composite layer 10, the composite layer includes a first refractive layer, a second refractive layer and a third refractive layer which are stacked in sequence, the first refractive layer is arranged between the light emitting unit and the second refractive layer; the material of the first refractive layer includes a first material, the refractive index of the first material is N1, the material of the second refractive layer includes a second material, the refractive index of the second material is N2, the material of the third refractive layer includes a third material, the refractive index of the third material is N3, wherein N1, N2 and N3 satisfy the following relationship: N1>N2, N3>N2.

[0086] The optoelectronic device 100 provided in the present application is provided with the light extraction unit described in the present application on the light emitting side of the light emitting unit 20. The light extraction unit can adjust the optical interference distance, suppress the reflection of external light, reduce the loss of light, and improve the light emission rate and purity, thereby improving the luminous efficiency and luminous purity of the optoelectronic device 100.

[0087] The refractive layers of the composite layer 10 are described above and will not be described again here.

[0088] In some embodiments, the light emitting unit 20 includes a first electrode 21 , a light emitting layer 22 , and a second electrode 23 which are sequentially stacked, and the second electrode 23 is located between the light emitting layer 22 and the light extraction unit.

[0089] Specifically, the formula of the refractive index of light generated from the light emitting layer 22 from the second electrode 23 to the light extraction unit is as follows:

[0090]

[0091] Where R represents the refractive index, n H represents the refractive index of the first refractive layer 11 in the composite layer 10, n L represents the refractive index of the second refractive layer 12 in the composite layer 10, n s represents the refractive index of the second electrode 23, p represents the number of groups of alternating layers of high and low refractive indices, and in this solution, p=1.

[0092] By adjusting the refractive index of the first refractive layer 11 and the second refractive layer 12 and then emitting light through the third refractive layer 13 , the emission efficiency of the light generated by the light emitting layer 22 after passing through the second electrode 23 can be promoted, thereby improving the luminous efficiency of the optoelectronic device 100 .

[0093] In some embodiments, the first electrode 21 and the second electrode 23 each independently include one or more of a metal, a carbon material and a metal oxide; 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 a metal oxide electrode or a composite electrode in which a metal is arranged between doped or undoped transparent metal oxides, and the material of the metal oxide electrode includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, MoO3 and AMO, 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. Here, “ / ” represents a stacked structure. For example, AZO / Ag / AZO represents a composite electrode including an AZO layer, an Ag layer and an AZO layer stacked in sequence.

[0094] In some embodiments, the material of the light-emitting layer 22 includes one or more of an organic light-emitting material and a quantum dot light-emitting material.

[0095] The organic light-emitting material can be selected from but not limited to CBP:Ir(mppy)3(4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridine iridium(III)]), TCTX:Ir(mmpy)(4,4",4"-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridine iridium]), diaromatic anthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, TTA materials, TADF (thermally activated delay) materials, polymers containing covalent bonds of BN, HLCT (hybridized localized charge transfer excited state) materials, and Exciplex (exciplex) light-emitting materials.

[0096] The quantum dot light-emitting material may be selected from, but not limited to, one or more of single structure quantum dots, core-shell structure quantum dots and perovskite semiconductor materials.

[0097] The material of the single structure quantum dot, the core material of the core-shell structure quantum dot and the shell material of the core-shell structure quantum dot can be selected from but not limited to one or more of II-VI group compounds, IV-VI group compounds, III-V group compounds and I-III-VI group compounds. The shell of the core-shell structure quantum dot includes one or more layers. The II-VI group compound can be selected from but not limited to one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe. The IV-VI group compound can be selected from but not limited to one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compound may be selected from, but not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compound may be selected from, but not limited to, one or more of CuInS2, CuInSe2, and AgInS2.

[0098] As an example, the core-shell structure quantum dots can be selected from but not limited to one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS and InP / ZnSe / ZnS. The “ / ” in the above expressions such as CdSe / ZnS means that the substance after the “ / ” (as a shell layer) covers the substance before the “ / ” (as a core layer).

[0099] The perovskite semiconductor material may be selected from, but not limited to, doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors. The inorganic perovskite semiconductor has a general structural formula of AMX3, wherein A is Cs + ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ One or more of, X is a halogen anion selected from Cl - Br - ,I - The general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, wherein B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ One or more of, X is a halogen anion selected from Cl - Br - ,I -One or more of the .

[0100] In some embodiments, the light-emitting unit 20 also includes one or more of a first carrier functional layer 24 and a second carrier functional layer 25, wherein the first carrier functional layer 24 is arranged between the first electrode 21 and the light-emitting layer 22, and the second carrier functional layer 25 is arranged between the second electrode 23 and the light-emitting layer 22.

[0101] In some embodiments, the first carrier functional layer 24 is a hole functional layer, and the second carrier functional layer 25 is an electron functional layer. Accordingly, the first electrode 21 is an anode, and the second electrode 23 is a cathode.

[0102] In some other embodiments, the second carrier functional layer 25 is a hole functional layer, and the first carrier functional layer 24 is an electron functional layer. Accordingly, the second electrode 23 is an anode, and the first electrode 21 is a cathode.

[0103] The hole functional layer includes one or more of a hole injection layer and a hole transport layer.

[0104] The electronic functional layer includes one or more of an electron injection layer and an electron transport layer.

[0105] In some embodiments, the material of the hole functional layer includes 4,4'-N,N'-dicarbazolyl-biphenyl, N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tri(N-carbazolyl)-triphenylamine, 4,4',4'-tri(carbazol-9-yl)triphenylamine, trichloroisocyanuric acid, terbium-doped phosphate-based green emission Optical materials, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 4,4',4'-tri(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(4-butylphenyl-diphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], polyaniline, polypyrrole, poly(p-phenylene vinylene), poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)- 1,4-phenylene vinylene], copper phthalocyanine, aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraaryl benzidine, PEDOT, PEDOT:PSS and its derivatives, PEDOT:PSS derivatives doped with s-MoO3, poly(N-vinyl carbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-di(naphthalene-1-yl)-N,N'-diphenyl benzidine, spiro NPB, nano-polycrystalline diamond, microcrystalline cellulose and tetracyanoquinodimethane, doped graphene, undoped graphene, second doped metal oxide The invention relates to a method for preparing an aqueous solution of at least one doped metal oxide particle, a second non-doped metal oxide particle, a metal sulfide, a metal selenide and a metal nitride, wherein the metal oxide in the second doped metal oxide particle and the metal oxide in the second non-doped metal oxide particle independently include one or more of MoO3, WO3, NiO, CrO3, CuO and V2O5, the doping element in the second doped metal oxide particle includes one or more of Mo, W, Ni, Cr, Cu and V, the metal sulfide includes one or more of CuS, MoS3 and WS3, the metal selenide includes one or more of MoSe3 and WSe3, and the metal nitride includes P-type gallium nitride.

[0106] In some embodiments, the material of the electronic functional layer includes 8-hydroxyquinoline aluminum, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 4,7-diphenyl-1,10-phenanthroline, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum, bis(2-methyl-8-hydroxyquinoline-N1,O8)- (1,1'-biphenyl-4-hydroxy)aluminum, 2,2'-(1,3-phenyl)bis[5-(4-tert-butylphenyl)-1,3,4-oxadiazole], tris[2,4,6-trimethyl-3-(3-pyridyl)phenyl]borane, tetrakis[(m-pyridyl)-phenyl-3-yl]biphenyl, 3,3'-[5'-[3-(3-pyridyl)phenyl][1,1':3',1"-terphenyl]-3,3"-diyl]bipyridine, 1,3-bis(3,5-bipyridin-3-ylphenyl)benzene, n,n'-bis(naphthalene-1-yl)-n,n'-bis(phenyl)biphenyl Aniline, diphenyl [4- (triphenylsilyl) phenyl] phosphine oxide, octahydroxyquinoline lithium first doped metal oxide particles, first non-doped metal oxide particles, IIB-VIA semiconductor materials, IIIA-VA semiconductor materials and IB-IIIA-VIA semiconductor materials One or more of the materials of the first non-doped metal oxide particles include one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5, and the metal oxide in the first doped metal oxide particles includes ZnO, TiO2, SnO2 , ZrO2, Ta2O5, Al2O3, the doping elements in the first doped metal oxide particles include one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, the IIB-VIA group semiconductor materials include one or more of ZnS, ZnSe, CdS, the IIIA-VA group semiconductor materials include one or more of InP, GaP, the IB-IIIA-VIA group semiconductor materials include one or more of CuInS, CuGaS.

[0107] In some embodiments, see Figure 5 The optoelectronic device 100 further includes a packaging unit 30 , and the packaging unit 30 is located on a side of the light extraction unit away from the light emitting unit 20 .

[0108] Furthermore, the encapsulation unit 30 includes a first encapsulation film layer 31 , a second encapsulation film layer 32 and a third encapsulation film layer 33 which are stacked in sequence, and the first encapsulation film layer 31 is located between the light extraction unit and the second encapsulation film layer 32 .

[0109] In some embodiments, the material of the first packaging film layer 31 includes a first packaging material, the material of the second packaging film layer 32 includes a second packaging material, and the material of the third packaging film layer 33 includes a third packaging material.

[0110] It should be noted that when the third refractive layer 13 is a plurality of island-shaped unit structures, the first packaging material will also fill the gaps between adjacent island-shaped units, thereby improving the structural stability of the optoelectronic device 100 and facilitating the continuity of light emission.

[0111] In some embodiments, the first packaging material includes a first inorganic packaging material, and the first inorganic packaging material includes SiNO x4 、SiN x5 、AlO x6 One or more of the .

[0112] In some embodiments, the third packaging material comprises a third inorganic packaging material, and the first inorganic packaging material comprises SiNO x4 、SiN x5 、AlO x6 One or more of the .

[0113] Understandably, SiNO x4 x4, SiN x5 x5 and AlO x6 The value of x6 in the formula may be determined according to actual conditions. The first packaging material and the third packaging material may be the same or different.

[0114] In some embodiments, the second packaging material includes an organic packaging material, and the organic packaging material includes one or more of acrylic, epoxy resin, and polyimide.

[0115] The packaging unit 30 can protect the light emitting unit 20 and the light extraction unit from being corroded by water and oxygen, thereby extending the service life of the optoelectronic device 100 .

[0116] In a fourth aspect, an embodiment of the present application further provides a display device, which includes the above-mentioned optoelectronic device 100.

[0117] The display device can be any electronic product with a display function, including but not limited to smart phones, tablet computers, laptops, digital cameras, digital video cameras, smart wearable devices, smart weighing electronic scales, car displays, televisions or e-book readers, among which smart wearable devices can be, for example, smart bracelets, smart watches, virtual reality (VR) helmets, etc.

[0118] The present application is described in detail below through specific embodiments. The following embodiments are only partial embodiments of the present application and are not limitations of the present application.

[0119] Example 1

[0120] This embodiment provides a composite layer, and the preparation method is as follows:

[0121] Providing a first material IZO, the refractive index of IZO is about 2.1, depositing the first material by PVD deposition method, the target power is 8 kW, the pressure is 0.4 Pa, and forming a first refractive layer with a thickness of 60 nm;

[0122] Providing the second material SiO x , SiO x The refractive index is about 1.46. The second material is deposited on the first refractive layer by CVD process. The target power is 8kW and the vacuum degree is 2×10 -4 Pa, forming a second refractive layer with a thickness of 90nm;

[0123] A third material ZnO is provided, the refractive index of ZnO is about 2.0, and the third material is inkjet printed on the second refractive layer. The viscosity of the ink is 8 cp, and the concentration of the ink is 50 mg / mL, for example, it can be 45 mg / mL, forming a regularly arranged hemispherical island unit structure and a third refractive layer with a thickness of 300 nm to obtain a composite layer.

[0124] Example 2

[0125] Example 2 is substantially the same as Example 1, except that the first material IZO is replaced by NPB, and the refractive index of NPB is approximately 1.43.

[0126] Example 3

[0127] Example 3 is substantially the same as Example 1, except that the second material IZO is replaced by LiF, and the refractive index of LiF is approximately 1.39.

[0128] Example 4

[0129] Example 4 is basically the same as Example 1, except that the third material ZnO is replaced by TiO y , TiOy The refractive index is about 2.4.

[0130] Example 5

[0131] Embodiment 5 is substantially the same as Embodiment 1, except that the thickness of the first refractive layer is 70 nm.

[0132] Example 6

[0133] Embodiment 6 is substantially the same as Embodiment 1, except that the thickness of the first refractive layer is 50 nm.

[0134] Example 7

[0135] Embodiment 7 is substantially the same as Embodiment 1, except that the thickness of the second refractive layer is 150 nm.

[0136] Example 8

[0137] Embodiment 8 is substantially the same as Embodiment 1, except that the thickness of the second refractive layer is 80 nm.

[0138] Example 9

[0139] Embodiment 9 is substantially the same as Embodiment 1, except that the thickness of the third refractive layer is 500 nm.

[0140] Example 10

[0141] Embodiment 10 is substantially the same as Embodiment 1, except that the thickness of the third refractive layer is 200 nm.

[0142] Embodiment 11

[0143] Embodiment 11 is substantially the same as Embodiment 1, except that after the second refractive layer is formed, the surface of the second refractive layer is treated with CF4 plasma, and then the third refractive layer is prepared on the treated second refractive layer.

[0144] Comparative Example 1

[0145] Comparative Example 1 is the first refractive layer of Example 1.

[0146] Comparative Example 2

[0147] Comparative Example 2 is the second refractive layer of Example 1.

[0148] Comparative Example 3

[0149] Comparative Example 3 is the third refractive layer of Example 1.

[0150] Comparative Example 4

[0151] Comparative Example 4 is basically the same as Example 1, except that the second material SiOx Replaced with organic material epoxy resin.

[0152] Device Example 1

[0153] This device embodiment provides a photoelectric device, and the preparation method is as follows:

[0154] The ITO conductive glass was cleaned with a detergent to preliminarily remove the stains on the surface, and then ultrasonically cleaned in deionized water, acetone, anhydrous ethanol, and deionized water for 20 minutes to remove impurities on the surface, and finally dried with high-purity nitrogen to obtain an ITO anode;

[0155] MnO3 was evaporated on the ITO anode at a rate of The vacuum degree is 2×10 -4 Pa, forming a hole injection layer with a thickness of 10 nm;

[0156] CPB was evaporated on the hole injection layer at a rate of The vacuum degree is 2×10 -4 Pa, forming a hole transport layer with a thickness of 30 nm;

[0157] CBP:FIrpic was co-evaporated on the hole transport layer, where the doping ratio of FIrpic was 8wt%, and the evaporation rates of the two were controlled as follows: and The vacuum degree is 2×10 -4 Pa, forming a first light-emitting layer with a thickness of 20 nm; then evaporating CBP:Ir(ppy)3 on the first light-emitting layer, wherein the doping ratio of Ir(ppy)3 is 6wt%, and the evaporation rates of the two are controlled as follows: and The vacuum degree is 2×10 -4 Pa, forming a second light-emitting layer with a thickness of 40 nm; CBP:Ir(piq)3 was evaporated on the second light-emitting layer, wherein the doping ratio of Ir(piq)3 was 5wt%, and the evaporation rates of the two were controlled as follows: and The vacuum degree is 2×10 -4 Pa, forming a third light-emitting layer with a thickness of 55 nm;

[0158] On the third light-emitting layer, diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide and lithium octahydroxyquinoline are co-deposited by doping, with a mass ratio of 1:1. The evaporation rates of both are controlled at The vacuum degree is 2×10 -4 Pa, forming an electron transport layer with a thickness of 35 nm;

[0159] Mg:Ag alloy was evaporated on the electron transport layer, where the weight ratio of Mg:Ag was 1:9, and the evaporation rates of the two were controlled as follows: and The vacuum degree is 2×10 -4 Pa, forming a semi-transparent cathode with a thickness of 15 nm to form a light-emitting unit;

[0160] Prepare a light extraction unit on the light-emitting unit according to the preparation method of the composite layer in Example 1;

[0161] 0.7 μm SiNO was sequentially prepared on the light extraction unit. x1 The first packaging film layer, 12μm epoxy resin The second packaging film layer, 1μm SiNO x1 The third packaging film layer forms a packaging unit to obtain a photoelectric device.

[0162] Device Examples 2 to 11

[0163] Device Examples 2 to 11 are substantially the same as Device Example 1, with the only difference being that the light extraction units in Device Examples 2 to 11 are prepared with reference to Examples 2 to 11, respectively.

[0164] Device Example 12

[0165] Device Example 12 is basically the same as Device Example 1, with the only difference being that the light-emitting unit in Device Example 12 is an inverted structure, and the preparation order is cathode, electron transport layer, light-emitting layer, hole transport layer, hole injection layer and anode, and a light extraction unit is formed on the anode.

[0166] Device Comparison Examples 1 to 4

[0167] Device comparative examples 1 to 4 are substantially the same as device embodiment 1, except that the light extraction units in device comparative examples 1 to 4 are prepared with reference to embodiments 1 to 4, respectively.

[0168] Device Comparison Example 5

[0169] Device Comparative Example 4 is substantially the same as Device Example 1, except that Device Comparative Example 5 does not include a light extraction unit.

[0170] Referring to each device embodiment 1 to 12 and device comparative examples 1 to 5, a red light photoelectric device (R), a green light emitting device (G) and a blue light photoelectric device (B) were prepared respectively, and the external quantum efficiency EQE of each photoelectric device was tested respectively, and the results were shown in Table 1.

[0171] Among them, the test method of external quantum efficiency EQE is: the ratio of the number of electron-hole pairs injected into quantum dots to the number of emitted photons, the unit is %, which is an important parameter to measure the quality of electroluminescent devices, and can be obtained by measuring with EQE optical testing instruments. The specific calculation formula is as follows:

[0172]

[0173] Among them, η e is the light output coupling efficiency, η r is the ratio of the number of recombined carriers to the number of injected carriers, χ is the ratio of the number of photon-generating excitons to the total number of excitons, K R is the radiation process rate, K NR is the rate of the non-radiative process.

[0174] Test conditions: carried out at room temperature, air humidity is 30-60%.

[0175] Table 1

[0176]

[0177]

[0178] From Table 1, we can see that:

[0179] It can be seen from device embodiments 1 to 4 and device comparison examples 1 to 4 that, whether it is a red light optoelectronic device, a green light optoelectronic device, or a blue light optoelectronic device, the composite layer provided in the present application is used as the light extraction unit of the optoelectronic device, which can effectively improve the external quantum efficiency of the optoelectronic device. The composite layer provided in the present application can utilize the synergistic effect of the first film layer with a high refractive index / the second film layer with a low refractive index / the third film layer with a high refractive index to effectively emit the light of the light-emitting unit; among which device comparison examples 1 to 3 have only one thin film as the light extraction unit, and the external quantum efficiency of the optoelectronic device is low. In device comparison example 4, three thin films are used together as the light extraction unit, and its external quantum efficiency is higher than that of other device comparison examples, but the intermediate film is an organic material, and the performance of the optoelectronic device is still worse than that of the device embodiment;

[0180] It can be seen from device embodiments 1, 5 to 10 and device comparative example 1 that changes in the thickness of any thin film of the light extraction unit will affect the light emission path, thereby affecting the external quantum efficiency of the optoelectronic device; within the thickness range of each thin film in the composite layer provided in the present application, the light emission efficiency can be effectively improved, thereby improving the external quantum efficiency of the optoelectronic device and reducing light loss;

[0181] It can be seen from device embodiments 1, 11 to 12 and device comparative examples 1 and 5 that in device embodiment 11, when forming the light extraction unit, the second refractive layer is subjected to hydrophobic treatment, and then the third refractive layer of the hemispherical island unit is arranged, which is conducive to the close contact between the third refractive layer and the second refractive layer, thereby improving the performance of the light extraction unit; arranging the light extraction unit outside the anode of the inverted optoelectronic device can also effectively improve the external quantum efficiency of the optoelectronic device; in device comparative example 5, no light extraction unit is arranged, and most of the light is lost and cannot be emitted, resulting in a low external quantum efficiency of the optoelectronic device.

[0182] The composite layer and its preparation method, optoelectronic device, and display device provided in the embodiments of the present application are introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A composite layer, characterized in that: The invention comprises a first refractive layer, a second refractive layer and a third refractive layer which are sequentially stacked, wherein the material of the first refractive layer comprises a first material, the refractive index of the first material is N1, the material of the second refractive layer comprises a second material, the refractive index of the second material is N2, the material of the third refractive layer comprises a third material, the refractive index of the third material is N3, wherein N1, N2 and N3 satisfy the following relationship: N1>N2, N3>N2.

2. The composite layer according to claim 1, characterized in that N1 and N2 satisfy the following relationship: N1-N2≥0.5; and / or N2 and N3 satisfy the following relationship: N3-N2≥0.5; and / or The N1 is 1.9 to 2.4; and / or The N2 is 1.38 to 1.55; and / or The N3 is 1.9 to 2.4; and / or The N1 and the N3 are the same or different.

3. The composite layer according to claim 1, characterized in that The first material includes one or more of a first inorganic material and an organic material; and / or The second material comprises a second inorganic material; and / or The third material includes a third inorganic material; and / or The thickness of the first refractive layer is 50nm to 70nm; and / or The thickness of the second refractive layer is 80nm to 150nm; and / or The third refractive layer includes a plurality of island-shaped units; further, the surface of the island-shaped unit away from the second refractive layer is a curved surface.

4. The composite layer according to claim 3, characterized in that The first inorganic material includes a first metal oxide, and the first metal oxide includes one or more of IZO, ITO, FTO, ATO, AZO, GZO, MZO, MoO3, and AMO; and / or The organic material includes one or more of N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, tri(4-carbazolyl-9-ylphenyl)amine, 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene, 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, 4-[1-[4-[di(4-methylphenyl)amino]phenyl]cyclohexyl]-N-(3-methylphenyl)-N-(4-methylphenyl)aniline, and 9,9'-(1,3-phenyl)di-9H-carbazole; and / or The second inorganic material includes LiF, NaF, MgF2, SiO x One or more of; and / or The third inorganic material includes a third metal oxide, and the third metal oxide includes ZnO, TiO2, MoO y 、ZnMgO z One or more of; and / or The average height of the island-shaped units is 200nm to 500nm; and / or The average diameter of the island-shaped units is 0.1 μm to 0.5 μm; and / or The average interval between adjacent island-shaped units is 0.2 μm to 0.5 μm; and / or The structure of the island-shaped unit includes a hemispherical shape.

5. A method for preparing a composite layer, characterized in that: The steps include: Providing a first material, wherein the refractive index of the first material is N1, and depositing the first material to form a first refractive layer; Providing a second material, wherein the refractive index of the second material is N2, N1>N2, and depositing the second material on the first refractive layer to form a second refractive layer; A third material is provided, wherein the refractive index of the third material is N3, where N3>N2. The third material is deposited on the second refractive layer to form a third refractive layer, thereby obtaining a composite layer.

6. The preparation method according to claim 5, characterized in that: N1 and N2 satisfy the following relationship: N1-N2≥0.5; and / or N2 and N3 satisfy the following relationship: N3-N2≥0.5; and / or The N1 is 1.9 to 2.4; and / or The N2 is 1.38 to 1.55; and / or The N3 is 1.9 to 2.4; and / or The N1 and the N3 are the same or different; and / or The first material includes one or more of a first inorganic material and an organic material; optionally, the first inorganic material includes a first metal oxide, and the first metal oxide includes one or more of IZO, ITO, FTO, ATO, AZO, GZO, MZO, MoO3, and AMO; optionally, the organic material includes one or more of N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, tris(4-carbazolyl-9-ylphenyl)amine, 1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene, 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline, 4-[1-[4-[di(4-methylphenyl)amino]phenyl]cyclohexyl]-N-(3-methylphenyl)-N-(4-methylphenyl)aniline, and 9,9'-(1,3-phenyl)di-9H-carbazole; and / or The second material includes a second inorganic material; optionally, the second inorganic material includes LiF, NaF, MgF2, SiO x1 One or more of; and / or The third material includes a third inorganic material; optionally, the third inorganic material includes a third metal oxide, and the third metal oxide includes ZnO, TiO2, MoO x2 、ZnMgO x3 One or more of the .

7. The preparation method according to claim 5, characterized in that: The method of depositing the first material comprises an evaporation deposition method, a vapor deposition method; and / or The method of depositing the second material comprises an evaporation deposition method, a vapor deposition method; and / or The method of depositing the third material comprises inkjet printing; and / or After forming the second refractive layer and before depositing the third material, the method further includes: treating the second refractive layer with plasma.

8. The preparation method according to claim 7, characterized in that: The speed of the evaporation deposition method is Vacuum degree is 10 -4 Pa~3×10 -4 Pa; and / or The target power of the vapor deposition method is 5kW to 10kW; the pressure is 0.1Pa to 0.6Pa; and / or The inkjet printing ink has a viscosity of 3 cp to 15 cp; a concentration of 40 mg / mL to 80 mg / mL; and / or The plasma comprises CF4; and / or The gas flow rate of the plasma is 200 sccm to 500 sccm; and / or The temperature of the plasma treatment is 50° C. to 100° C., and the time is 30s to 300s.

9. A photoelectric device, characterized in that: It comprises a light emitting unit and a light extraction unit; the light extraction unit is arranged on the light emitting side of the light emitting unit; The light extraction unit includes a composite layer, the composite layer includes a first refractive layer, a second refractive layer and a third refractive layer which are sequentially stacked, the first refractive layer is arranged between the light emitting unit and the second refractive layer; the material of the first refractive layer includes a first material, the refractive index of the first material is N1, the material of the second refractive layer includes a second material, the refractive index of the second material is N2, the material of the third refractive layer includes a third material, the refractive index of the third material is N3, wherein N1, N2 and N3 satisfy the following relationship: N1>N2, N3>N2.

10. The optoelectronic device according to claim 9, characterized in that The light-emitting unit includes a first electrode, a light-emitting layer, and a second electrode which are sequentially stacked, and the second electrode is located between the light-emitting layer and the light extraction unit; Optionally, the first electrode and the second electrode each independently include one or more of a metal, a carbon material and a metal oxide; 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 a metal oxide electrode or a composite electrode in which a metal is arranged between doped or undoped transparent metal oxides, the material of the metal oxide electrode includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, MoO3 and AMO, 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; Optionally, the material of the light-emitting layer includes one or more of an organic light-emitting material and a quantum dot light-emitting material; the organic light-emitting material is selected from 4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridine iridium(III)], 4,4',4"-tris(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridine iridium], diaromatic anthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, T One or more of TA materials, TADF materials, polymers containing BN covalent bonding, HLCT materials, and Exciplex luminescent materials; the quantum dot luminescent material is selected from one or more of single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials; the material of the single-structure quantum dots, the core material of the core-shell structure quantum dots, and the shell material of the core-shell structure quantum dots are selected from one or more of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds; the shell of the core-shell structure quantum dots comprising one or more layers; the II-VI group compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSe Te, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe; the IV-VI group compound is selected from one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe and SnPbSTe;The III-V group compound is selected from one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs and InAlPSb or Several; the I-III-VI group compound is selected from one or more of CuInS2, CuInSe2 and AgInS2; the core-shell structure quantum dots are selected from one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS and InP / ZnSe / ZnS; the perovskite semiconductor material is selected from one or more of doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors; the general structural formula of the inorganic perovskite semiconductor is AMX3, wherein A is Cs; + ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ One or more of, X is a halogen anion selected from Cl - Br - ,I - One or more of the following; the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, wherein B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ One or more of, X is a halogen anion selected from Cl - Br - ,I - One or more of the following; Optionally, the light-emitting unit further includes one or more of a first carrier functional layer and a second carrier functional layer, wherein the first carrier functional layer is arranged between the first electrode and the light-emitting layer, and the second carrier functional layer is arranged between the second electrode and the light-emitting layer; the first carrier functional layer is a hole functional layer, and the second carrier functional layer is an electron functional layer; or, the second carrier functional layer is a hole functional layer, and the first carrier functional layer is an electron functional layer; optionally, the material of the electronic functional layer includes 8-hydroxyquinoline aluminum, 1,3,5-tri(1-phenyl-1H-benzimidazol-2-yl)benzene, 4,7-diphenyl-1,10-phenanthroline, 2, 9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole, bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum, bis(2-methyl-8-hydroxyquinoline-N1,O8)-(1,1'-biphenyl-4-hydroxy)aluminum, 2,2'-(1,3-phenyl)bis[5-(4-tert-butylphenyl)-1,3,4-oxadiazole], tris[2,4,6-trimethyl-3-(3-pyridyl)phenyl]borane, tetrakis[(m-pyridyl)-phenyl-3-yl]biphenyl, 3,3'-[5'-[3-(3-pyridyl)phenyl] [1,1':3',1"-terphenyl]-3,3"-diyl]bipyridine, 1,3-bis(3,5-bipyridin-3-ylphenyl)benzene, n,n'-bis(naphthalene-1-yl)-n,n'-bis(phenyl)benzidine, diphenyl[4-(triphenylsilyl)phenyl]phosphine oxide, lithium octahydroxyquinoline, first doped metal oxide particles, first undoped metal oxide particles, IIB-VIA semiconductor materials, IIIA-VA semiconductor materials and IB-IIIA-VIA semiconductor materials, wherein the material of the first undoped metal oxide particles includes one of ZnO, TiO2, SnO2, ZrO2, and Ta2O5 or several, the metal oxide in the first doped metal oxide particles includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3, the doping element in the first doped metal oxide particles includes one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga, the IIB-VIA group semiconductor material includes one or more of ZnS, ZnSe, and CdS, the IIIA-VA group semiconductor material includes one or more of InP and GaP, and the IB-IIIA-VIA group semiconductor material includes one or more of CuInS and CuGaS;Optionally, the material of the hole functional layer includes 4,4'-N,N'-dicarbazolyl-biphenyl, N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tri(N-carbazolyl)-triphenylamine, 4,4',4'-tri(carbazolyl-9-yl)triphenylamine, trichloroisocyanuric acid, terbium-doped phosphate-based green light-emitting material 、2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene、4,4',4'-tri(N-3-methylphenyl-N-phenylamino)triphenylamine、poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))]、poly(4-butylphenyl-diphenylamine)、poly[bis(4-phenyl)(4-butylphenyl)amine]、polyaniline、polypyrrole、poly(p-phenylenevinylene)、poly(phenylenevinylene)、poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]、poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1, 4-phenylene vinylene], copper phthalocyanine, aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraaryl benzidine, PEDOT, PEDOT:PSS and its derivatives, PEDOT:PSS derivatives doped with s-MoO3, poly(N-vinyl carbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-di(naphthalene-1-yl)-N,N'-diphenyl benzidine, spiro NPB, nano-polycrystalline diamond, microcrystalline cellulose and tetracyanoquinodimethane, doped graphene, undoped graphene, second doped metal oxide particles, one or more of the second non-doped metal oxide particles, metal sulfides, metal selenides and metal nitrides, the metal oxide in the second doped metal oxide particles and the metal oxide in the second non-doped metal oxide particles independently include one or more of MoO3, WO3, NiO, CrO3, CuO, V2O5, the doping element in the second doped metal oxide particles includes one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfide includes one or more of CuS, MoS3, WS3, the metal selenide includes one or more of MoSe3, WSe3, and the metal nitride includes P-type gallium nitride. ; 11. The optoelectronic device according to claim 9, characterized in that The optoelectronic device further includes a packaging unit, and the packaging unit is located at a side of the light extraction unit away from the light emitting unit.

12. The optoelectronic device according to claim 11, characterized in that The encapsulation unit comprises a first encapsulation film layer, a second encapsulation film layer and a third encapsulation film layer which are stacked in sequence, wherein the first encapsulation film layer is located between the light extraction unit and the second encapsulation film layer; The material of the first packaging film layer includes a first packaging material, the material of the second packaging film layer includes a second packaging material, and the material of the third packaging film layer includes a third packaging material; The third refractive layer includes a plurality of island-shaped units, and the first packaging material further fills gaps between adjacent island-shaped units.

13. The optoelectronic device according to claim 12, characterized in that The first packaging material includes a first inorganic packaging material, and the first inorganic packaging material includes SiNO x4 、SiN x5 、AlO x6 One or more of; and / or The second packaging material includes an organic packaging material, and the organic packaging material includes one or more of acrylic, epoxy resin, and polyimide; and / or The third packaging material includes a third inorganic packaging material, and the first inorganic packaging material includes SiNO x4 、SiN x5 、AlO x6 One or more of; and / or The first packaging material and the third packaging material are the same or different.

14. A display device, characterized in that: The invention comprises a photoelectric device as claimed in any one of claims 9 to 13.

Images