Light-emitting device, preparation method thereof and display device

Abstract

The invention provides a light-emitting device, a preparation method thereof and a display device. The light-emitting device comprises a first electrode, an electron transport layer, a light-emitting layer, a hole transport layer and a second electrode which are sequentially stacked, the component of at least one of the electron transport layer and the hole transport layer includes a thermoelectric material. The light-emitting device is high in efficiency and long in service life.

Description

Technical Field

[0001] The present application relates to the field of functional devices, and in particular to a light-emitting device and a preparation method thereof, and a display device. Background Art

[0002] Electroluminescent devices such as organic light-emitting diodes (OLEDs), quantum dot light-emitting diodes (QLEDs), and perovskite light-emitting diodes (PeLEDs) have the characteristics of high contrast, low energy consumption, and bendability, and have received more and more attention in the field of display and lighting. Among them, quantum dot light-emitting diodes (QLEDs) with semiconductor quantum dot materials as the light-emitting layer have received widespread attention due to their good characteristics such as high color purity, high luminous efficiency, adjustable luminous color, and stable devices, especially in the fields of flat panel displays and solid-state lighting.

[0003] Quantum dot light-emitting diodes usually include a hole functional layer, an electron functional layer and a light-emitting layer arranged in sequence. However, the efficiency and life span of traditional quantum dot light-emitting diodes are difficult to meet people's increasingly high practical application needs.

[0004] Therefore, the traditional technology still needs to be improved. Summary of the invention

[0005] Based on this, the present application provides a light-emitting device and a method for preparing the same, and a display device, which can improve the efficiency and life of the light-emitting device.

[0006] This application is implemented through the following technical solutions.

[0007] In a first aspect of the present application, a light-emitting device is provided, comprising a first electrode, an electron transport layer, a light-emitting layer, a hole transport layer, and a second electrode stacked in sequence; a component of at least one of the electron transport layer and the hole transport layer comprises a thermoelectric material.

[0008] In the above-mentioned light-emitting device, the components of at least one of the electron transport layer and the hole transport layer include thermoelectric materials. On the one hand, when the hole transport layer contains thermoelectric materials, the electrical conductivity of the thermoelectric materials will increase with the temperature rise, thereby reducing the negative impact of the Joule heat generated during the use of the light-emitting device on the hole transport layer material, that is, reducing the probability of its decomposition due to heat and improving stability. On the other hand, when the electron transport layer contains thermoelectric materials, the probability of being oxidized by the metal contained in the electrode can be reduced; in this way, the stability of the electron transport layer or the hole transport layer can be improved, thereby improving the stability of the light-emitting device, and improving efficiency and service life.

[0009] In a second aspect of the present application, a method for preparing a light-emitting device is further provided, comprising the following steps:

[0010] Forming a first electrode, an electron transport layer, a light-emitting layer, a hole transport layer and a second electrode stacked in sequence to prepare a light-emitting device;

[0011] A component of at least one of the electron transport layer and the hole transport layer includes a thermoelectric material.

[0012] In a third aspect of the present application, a display device is further provided, wherein the display device comprises the light-emitting device of the first aspect or a light-emitting device manufactured by the method for manufacturing the light-emitting device of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A schematic diagram of the structure of a light-emitting device provided in one embodiment of the present application.

[0014] Description of reference numerals:

[0015] 100. QLED device; 101. second electrode; 102. electron transport layer; 103. light-emitting layer; 104. hole transport layer; 105. hole injection layer; 106. first electrode. DETAILED DESCRIPTION

[0016] For ease of understanding of the present application, the present application will be described more fully below with reference to relevant embodiments. The preferred embodiments of the present application are provided in the embodiments. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. 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.

[0017] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0018] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum value and the maximum value) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed herein should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows broadly including numerical interval types such as percentage intervals, ratio intervals, and ratio intervals.

[0019] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0020] In the present application, the term "room temperature" or "normal temperature" generally refers to 4°C to 35°C, such as 20°C±5°C or 10°C to 30°C, and further refers to 20°C to 30°C.

[0021] In summary, traditional quantum dot light-emitting diodes are unstable and prone to degradation and aging during use, which in turn affects the efficiency and life of the device.

[0022] The study found that the important factors that lead to the degradation and aging of quantum dot light-emitting diodes include: the functional materials in the device are decomposed or oxidized by the Joule heat generated during use. For example, commonly used organic hole materials such as poly [(9,9-dioctylfluorenyl-2,7-diyl)-CO-(4,4'-(N-(p-butylphenyl))diphenylamine)] TFB are more prone to degradation, which in turn affects the life of the device. For example, traditional electron transport materials such as zinc oxide are hygroscopic and easily decompose after absorbing water. The structure of zinc oxide is Zn-O-Zn-O. In the electron transport layer formed in this way, at least one oxygen atom located at the outermost end is not combined with zinc, forming an oxygen active site. The oxygen active site is easily oxidized by the metal oxide in the electrode, thereby having a negative impact on the injection performance of electrons from the electrode to the electron transport layer.

[0023] Based on this, the technicians of the present application creatively proposed the idea of ​​utilizing the Joule heat generated during the use of the light-emitting device to improve the stability of the device. After a large number of creative experiments, they obtained the technical solution of the present application.

[0024] In one embodiment of the present application, a light-emitting device is provided, which includes a first electrode, an electron transport layer, a light-emitting layer, a hole transport layer and a second electrode stacked in sequence; the component of at least one layer of the electron transport layer and the hole transport layer includes a thermoelectric material.

[0025] In the above-mentioned light-emitting device, the components of at least one of the electron transport layer and the hole transport layer include thermoelectric materials. On the one hand, when the hole transport layer contains thermoelectric materials, the electrical conductivity of the thermoelectric materials will increase with the temperature rise, thereby reducing the negative impact of the Joule heat generated during the use of the light-emitting device on the hole transport layer material, that is, reducing the probability of its decomposition due to heat and improving stability. On the other hand, when the electron transport layer contains thermoelectric materials, the probability of being oxidized by the metal contained in the electrode can be reduced; in this way, the stability of the electron transport layer or the hole transport layer can be improved, thereby improving the stability of the light-emitting device, and improving efficiency and service life.

[0026] In some of these embodiments, the thermoelectric material includes at least one of a Group IB element, a Group IVA element, a Group VA element, and a Group VIA element.

[0027] It can be understood that IB, IVA, VA and VIA all refer to the "group" numbers in the periodic table of chemical elements, including the main group and sub-group. "B" represents the sub-group elements and "A" represents the main group elements.

[0028] In one embodiment, the IB group element includes at least one of Cu (copper) and Ag (silver).

[0029] In some embodiments, the Group IB element includes Ag (silver).

[0030] Ag (silver) has high stability and can further increase the life of the device.

[0031] In some embodiments, the Group VA element includes at least one of Sb (antimony) and Bi (bismuth).

[0032] In one embodiment, the VIA group element includes at least one of Se (selenium) and Te (tellurium).

[0033] In one embodiment, the VIA group element includes Se (selenium).

[0034] In some of these embodiments, the Group IVA element includes at least one of Si, Ge, Sn, and Pb.

[0035] In some of the embodiments, the thermoelectric material includes a Group IB metal element, a Group VA metal element, and a Group VIA non-metal element.

[0036] In some embodiments, the thermoelectric material includes bismuth telluride, lead telluride, silicon germanium based thermoelectric material and AgBi (1-y0) M1 y0 Se (2+x0) At least one of .

[0037] Among them, -0.1≤x0≤0.2, 0≤y0≤0.08, and M1 includes at least one element of group IIB to group IVA elements.

[0038] Optionally, M1 includes at least one of Zn, Ge, Cd, In and Pd.

[0039] In some embodiments, the thermoelectric material includes an IB-VA-VIA2 family of thermoelectric materials.

[0040] It should be noted that the molecular weight of each element in the "IB-VA-VIA2 group thermoelectric materials" is not exactly 1-1-2, but includes IB-VA-VIA2 group compounds and thermoelectric compounds derived therefrom.

[0041] In some embodiments, the thermoelectric material includes AgBi (1-y0) M1 y0 Se (2+x0) .

[0042] The components of at least one of the electron transport layer and the hole transport layer include IB-VA-VIA group thermoelectric materials. On the one hand, when the hole transport layer contains IB-VA-VIA group thermoelectric materials, the electrical conductivity of the thermoelectric materials will increase with the temperature rise, thereby reducing the negative impact of the Joule heat generated during the use of the light-emitting device on the hole transport layer material, that is, reducing the probability of its decomposition due to heat and improving stability. At the same time, specific thermoelectric materials can reduce the barrier between hole carriers from the hole transport layer to the light-emitting layer. On the other hand, when the electron transport layer contains IB-VA-VIA group thermoelectric materials, the probability of being oxidized by the metal contained in the electrode can be reduced. At the same time, specific thermoelectric materials can reduce the electronic barrier between the electrode and the electron transport layer; in this way, the stability of the electron transport layer or the hole transport layer can be improved, thereby improving the stability of the light-emitting device, and improving the efficiency and service life.

[0043] In one embodiment, the composition of at least one of the electron transport layer and the hole transport layer includes a thermoelectric material;

[0044] Optionally, the thermoelectric material of at least one of the electron transport layer and the hole transport layer comprises AgBi (1-y0) M1 y0 Se (2+x0) .

[0045] In one embodiment, the electron transport layer and the hole transport layer contain thermoelectric materials.

[0046] In some embodiments, the thermoelectric materials in the electron transport layer and the hole transport layer are independently selected from AgBi (1-y0) M1 y0 Se (2+x0) .

[0047] When the thermoelectric materials in the electron transport layer and the hole transport layer are of the same type, the balance of carrier transport in the light-emitting device can be further improved, and specific thermoelectric materials can further improve the carrier balance of the device.

[0048] It can be understood that: "Group IIB~Group IVA" refers to Group IIB, Group IVA and elements ranked between the two in the periodic table of chemical elements, including at least one of Group IIB elements, Group IIIA elements and Group IVA elements.

[0049] In the above “-0.1≤x0≤0.2”, the value of x0 includes the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiments and: -0.1, -0.09, -0.08, -0.07, -0.06, -0.05, -0.04, -0.03, -0.02, -0.01, 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2; or a range consisting of any two point values.

[0050] In the above “0≤y0≤0.08”, the value of y0 includes the minimum value and the maximum value of the range, and every value between the minimum value and the maximum value. Specific examples include but are not limited to the point values ​​in the embodiments and: 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08; or a range consisting of any two point values.

[0051] In some embodiments, M2 includes at least one metal element selected from the group consisting of Group IIB elements, Group IIIA elements, and Group IVA elements.

[0052] In some of the embodiments, M1 includes at least one of Zn (zinc), Ge (germanium), Cd (cadmium), In (indium), and Pd (palladium).

[0053] In some of these embodiments, the composition of the electron transport layer includes a thermoelectric material having n-type semiconductor properties.

[0054] In some of the embodiments, the component of the hole transport layer includes the thermoelectric material having p-type semiconductor properties.

[0055] The types of thermoelectric materials in the electron transport layer and the hole transport layer are regulated separately. Compared with thermoelectric materials with n-type semiconductor properties, thermoelectric materials with p-type semiconductor properties contain more Group VI elements, which can further reduce the potential barrier between the hole transport layer and the light-emitting layer and is more conducive to hole injection. The electron transport performance of thermoelectric materials with n-type semiconductor properties is better, which is more conducive to reducing the potential barrier between the electron transport layer and the electrode and improving the carrier balance of the device.

[0056] In some embodiments, the hole transport layer comprises a compound having a molecular formula of AgBi (1-y1) M2 y1 Se (2+x1) of thermoelectric materials.

[0057] Among them, 0≤x1≤0.2, 0≤y1≤0.08, and M2 includes at least one element of group IIB to group IVA elements.

[0058] It can be understood that: "Group IIB~Group IVA" refers to Group IIB, Group IVA and elements ranked between the two in the periodic table of chemical elements, including at least one element of Group IIB elements, Group IIIA elements and Group IVA elements.

[0059] Specific thermoelectric materials can further reduce the potential barrier between the hole transport layer and the light-emitting layer, and by doping with a specific element M2 and controlling its doping amount, the hole concentration in the hole transport layer can be further increased to improve the carrier balance of the device.

[0060] In the above “0≤x1≤0.2”, the value of x1 includes the minimum value and the maximum value of the range, and every value between the minimum value and the maximum value. Specific examples include but are not limited to the point values ​​in the embodiments and: 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2; or a range consisting of any two point values.

[0061] In the above “0≤y1≤0.08”, the value of y1 includes the minimum value and the maximum value of the range, and every value between the minimum value and the maximum value. Specific examples include but are not limited to the point values ​​in the embodiments and: 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08; or a range consisting of any two point values.

[0062] In some embodiments, M2 includes at least one metal element selected from the group consisting of Group IIB elements, Group IIIA elements, and Group IVA elements.

[0063] In some of these embodiments, M2 includes at least one of Zn, Ge, Cd, In, and Pd.

[0064] In some embodiments, the composition of the electron transport layer includes a molecular formula of AgBiSe (2+x2) Thermoelectric materials;

[0065] Among them, -0.1≤x2<0.

[0066] In the above “-0.1≤x2<0”, the value of x2 includes the minimum value and the maximum value of the range, and every value between the minimum value and the maximum value. Specific examples include but are not limited to the point values ​​in the embodiments and: -0.01, -0.02, -0.03, -0.04, -0.05, -0.06, -0.07, -0.08, -0.09, -0.1; or a range consisting of any two point values.

[0067] In some of the embodiments, the components of the electron transport layer also include inorganic electron transport materials; the inorganic electron transport materials are selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese 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.

[0068] In some of the embodiments, in the electron transport layer, the inorganic electron transport material accounts for 10% to 30% by weight.

[0069] In the above "10%~30%", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiments and: 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%; or a range consisting of any two point values.

[0070] In some embodiments, the component of the electron transport layer further includes doped or undoped zinc oxide.

[0071] In some embodiments, the thickness of the electron transport layer is 30 nm to 150 nm.

[0072] In the above "30nm~150nm", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiments and: 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm; or a range consisting of any two point values.

[0073] In some embodiments, the thickness of the hole transport layer is 30 nm to 50 nm.

[0074] In the above "30nm~50nm", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiments and: 30nm, 35nm, 40nm, 45nm, 50nm; or a range consisting of any two point values.

[0075] In some embodiments, the light-emitting layer 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, C At least one of dSeTe, 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.

[0076] The IV-VI group compound is selected from at least one of 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 at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, Ga At least one of NAs, 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 or InAlPSb. The I-III-VI group compound is at least one of CuInS2, CuInSe2 and AgInS2.

[0077] The core of the core-shell structured quantum dots includes any one of the above-mentioned single structure quantum dots, and the shell material of the core-shell structured quantum dots includes CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS and at least one of the above-mentioned single structure quantum dots.

[0078] In some of the embodiments, 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''-tri(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.

[0079] In some embodiments, the thickness of the light-emitting layer is 30 nm to 60 nm.

[0080] In the above "30nm~60nm", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiments and: 30nm, 35nm, 40nm, 45nm, 50nm, 55nm, 60nm; or a range consisting of any two point values.

[0081] In some embodiments, the light emitting device further includes a hole injection layer, and the hole injection layer is disposed between the hole transport layer and the first electrode.

[0082] In some of the embodiments, the material of the hole injection layer and / or the hole transport layer includes at least one of TFB, CuPc, PVK, Poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-Nphenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal tinides, doped graphene, undoped graphene and C60.

[0083] In some embodiments, the thickness of the hole injection layer is 30 nm to 40 nm.

[0084] In the above "30nm~40nm", the values ​​include the minimum and maximum values ​​of the range, and every value between the minimum and maximum values. Specific examples include but are not limited to the point values ​​in the embodiments and: 30nm, 31nm, 32nm, 33nm, 34nm, 35nm, 36nm, 37nm, 38nm, 39nm, 40nm; or a range consisting of any two point values.

[0085] In some of the embodiments, the light emitting device may further include an electron injection layer, wherein the electron injection layer is disposed between the electron transport layer and the second electrode.

[0086] In a specific example, the material of the electron injection layer or the electron transport layer includes an organic material and an inorganic material.

[0087] In some of the embodiments, the inorganic material is selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese 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.

[0088] In some embodiments, the organic material is selected from one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene compounds, and hydroxyquinoline compounds.

[0089] In some embodiments, the material of the electron injection layer includes tris(8-hydroxyquinolinate)aluminum, 8-hydroxyquinolinate lithium, 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, 3-(4-biphenyl)-4-phenyl-5-tert-butylphenyl-1,2,4-triazole, spiro-PBD, bis(2-methyl-8-quinolinate)-4-(phenylphenol)aluminum, One or more of (2,2',2-(1,3,5-benzenetriyl)-tri(1-phenyl-1-H-benzimidazole, oxadiazole, triazole, phenanthroline, benzoxazole, benzothiazole, 2-[4-(9,10-di-2-naphthalene-2-yl-2-anthracen-2-yl)phenyl]-1-phenyl-1H-benzimidazole, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline, 4,7-diphenyl-1,10-phenanthroline.

[0090] In some embodiments, the first electrode and the second electrode are independently selected from metal electrodes, carbon silicon material electrodes, inorganic semiconductor particle electrodes or composite electrodes, and the metal electrode includes at least one of metal single substance electrodes, metal alloy electrodes and metal oxide electrodes.

[0091] In some embodiments, the metal element in the metal electrode is selected from at least one of Ag, Al, Mg, Au, Cu, Mo, Pt, Ca and Ba.

[0092] In some embodiments, the material of the carbon silicon material electrode is selected from at least one of silicon, graphite, carbon nanotubes, graphene and carbon fiber.

[0093] In some embodiments, the material of the inorganic semiconductor particle electrode is selected from at least one of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide and aluminum-doped magnesium oxide.

[0094] In some of these embodiments, the composite electrode is selected from AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS or ZnS / Al / ZnS.

[0095] In some embodiments, the second electrode is a metal electrode.

[0096] In one embodiment of the present application, a method for preparing a light-emitting device is further provided, comprising the following step S10.

[0097] Step S10, forming a first electrode, an electron transport layer, a light-emitting layer, a hole transport layer and a second electrode which are stacked in sequence to prepare a light-emitting device.

[0098] Wherein, a component of at least one of the electron transport layer and the hole transport layer includes a thermoelectric material.

[0099] The selection of the type of thermoelectric material is the same as described above and will not be repeated here.

[0100] In some of the embodiments, in at least one of the steps of forming the electron transport layer and forming the hole transport layer, a target material corresponding to the thermoelectric material is used to perform magnetron sputtering to prepare the thermoelectric material.

[0101] In some embodiments, before the magnetron sputtering step, a step of preparing a target material corresponding to the thermoelectric material is also included, and the thermoelectric material includes a simple substance of an IB group element, a simple substance of a VA group element, and a VIA group element as an example, which is as follows:

[0102] The IB group element single substance, the VA group element single substance and the VIA group element single substance are pressed to form a target material corresponding to the thermoelectric material.

[0103] In some of the embodiments, the magnetron sputtering step is performed in a protective gas; further, the protective gas includes at least one of nitrogen and argon.

[0104] In some embodiments, the temperature of magnetron sputtering is 200° C. to 500° C.

[0105] In some of the embodiments, the pressure of magnetron sputtering is 0.6Pa~1.5Pa.

[0106] In some of the embodiments, the power of magnetron sputtering is 60W~180W.

[0107] In some of the embodiments, the rate of magnetron sputtering is 1 nm / min to 5 nm / min.

[0108] The first electrode or the second electrode can be prepared by a commonly used preparation method in the art, such as an evaporation method.

[0109] The hole injection layer or electron injection layer or light-emitting layer can be prepared by a common preparation method in the art, such as an evaporation method or a solution method.

[0110] Further, the solution method includes but is not limited to one or more of spin coating, printing, blade coating, dip coating, immersion coating, spray coating, roll coating, casting, slit coating, and strip coating. Further, the printing method includes but is not limited to: inkjet printing to form a film.

[0111] In one embodiment of the present application, a display device is further provided. The display device includes the above-mentioned light-emitting device or a light-emitting device manufactured by the above-mentioned method for manufacturing the light-emitting device.

[0112] The embodiments of the present application will be described in detail below in conjunction with examples. It should be understood that these examples are only used to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are preferably referred to the guidance provided in the present application, and can also be based on the experimental manual or normal conditions in this area, can also be based on the conditions recommended by the manufacturer, or refer to experimental methods known in the art.

[0113] In the following specific embodiments, the measured parameters of raw material components may have slight deviations within the range of weighing accuracy unless otherwise specified. For temperature and time parameters, acceptable deviations caused by instrument test accuracy or operation accuracy are allowed.

[0114] The following are specific embodiments.

[0115] Example 1

[0116] Preparation of quantum dot light emitting diodes (QLED devices); 100. QLED device structure such as Figure 1 As shown, it includes: 101, a second electrode (silver / 70 nm); 102, an electron transport layer (AgBiSe 1.98 / 50nm); 103, light-emitting layer (red quantum dots / 20nm); 104, hole transport layer (AgBi 0.97 Pb 0.03 Se 2.12 / 30 nm); 105, hole injection layer (PEDOT:PSS / 50 nm); 106, first electrode (ITO substrate). The structure of PEDOT:PSS is as follows:

[0117]

[0118] The specific preparation steps are as follows:

[0119] 1. Spin coating and drying of hole injection material PEDOT:PSS on the surface of the first electrode (ITO substrate) to obtain a hole injection layer;

[0120] 2. Prepare a hole transport layer by magnetron sputtering on the surface of the hole injection layer, as follows:

[0121] 40gAg particles, 76gBi powder, 0.33gPb and 63gSe powder were blended and ball-milled for 120h, and then hot-pressed into a target with a diameter of 60mm. The target was then placed in a muffle furnace and heated to 1000°C at a rate of 2°C / min and kept warm for 6h to obtain the corresponding target. The target was then placed in a magnetron sputtering device, 30sccm of argon was introduced, the sputtering pressure was 1Pa, the sputtering power was 80W, the sputtering rate was 2nm / min, and the sputtering was performed for 15min to obtain a hole transport layer with a thickness of 30nm.

[0122] 3. On the surface of the hole transport layer, red quantum dots (CdSe / CdS core-shell material) are used to prepare a light-emitting layer by printing and forming a film, and the thickness of the film is 20 nm.

[0123] 4. Form an electron transport layer (AgBiSe 1.98 ), and its preparation method is:

[0124] 41gAg particles, 79gBi powder and 59gSe powder were blended and ball-milled for 120h, and then hot-pressed into a target with a diameter of 60mm. The target was then placed in a muffle furnace and heated to 1000°C at a rate of 2°C / min and kept warm for 6h to obtain the corresponding target. The target was then placed in a magnetron sputtering device, 30sccm of argon was introduced, the sputtering pressure was 1Pa, the sputtering power was 80W, the sputtering rate was 2 nm / min, and the sputtering was performed for 25min to obtain an electron transport layer.

[0125] 5. Prepare the second electrode on the electron transport layer by evaporating silver, and then use a cover plate to encapsulate it to obtain a QLED device.

[0126] 6. Performance test:

[0127] (1) EQE (quantum efficiency) test: Prepare a complete QLED device, place the device in a Keithley 2400 tester, input current, obtain the total number of photons by the light energy rate released by the device, and then collect the total number of electrons released by the device through an integrating sphere, where the ratio of photons to electrons is the EQE. EQE is expressed as the ratio of excitons converted to photons in a light-emitting device. The higher the EQE, the higher the efficiency of the light-emitting device.

[0128] (2) Life test: The device is driven with a constant current so that the initial brightness of the device is 1000 nit, and then decays to 950 nit. The time required is recorded, which is LT95@1000Ni: It represents the time required for the device to decay from an initial brightness of 1000 nit to a brightness of 950 nit. The longer the time, the higher the stability of the device and the longer the life.

[0129] See Table 1 for specific test results.

[0130] Example 2

[0131] Example 2 is basically the same as Example 1, except that the material of the hole transport layer is replaced by AgBi 0.93 Pb 0.07 Se 2.12 , the preparation method is as follows:

[0132] 41gAg particles, 74gBi powder, 0.82gPb and 63.8gSe powder were blended and ball-milled for 120h, and then hot-pressed into a target with a diameter of 60mm. The target was then placed in a muffle furnace and heated to 1000°C at a rate of 2°C / min and kept warm for 6h to obtain the corresponding target. The target was then placed in a magnetron sputtering device, 30sccm of argon was introduced, the sputtering pressure was 1Pa, the sputtering power was 80W, the sputtering rate was 2nm / min, and the hole transport layer was obtained by sputtering for 15min.

[0133] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0134] Example 3

[0135] Example 3 is basically the same as Example 1, except that the material of the hole transport layer is replaced by AgBi 0.97 Pb 0.03 Se 2.2 , the preparation method is as follows:

[0136] 40g Ag particles, 75g Bi powder, 0.34g Pb and 65g Se powder were blended and ball-milled for 120h, and then hot-pressed into a target with a diameter of 60mm. The target was then placed in a muffle furnace and heated to 1000°C at a rate of 2°C / min and kept warm for 6h to obtain the corresponding target. The target was then placed in a magnetron sputtering device, 30sccm of argon was introduced, the sputtering pressure was 1Pa, the sputtering power was 80W, the sputtering rate was 2 nm / min, and the hole transport layer was obtained by sputtering for 15min.

[0137] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0138] Example 4

[0139] Example 4 is basically the same as Example 1, except that the material of the electron transport layer is replaced by AgBiSe 1.9 , the preparation method is as follows:

[0140] 41.6g Ag particles, 80.5g Bi powder and 57g Se powder were blended and ball-milled for 120h, and then hot-pressed into a target with a diameter of 60mm. The target was then placed in a muffle furnace and heated to 1000°C at a rate of 2°C / min and kept warm for 6h to obtain the corresponding target. The target was then placed in a magnetron sputtering device, 30sccm of argon was introduced, the sputtering pressure was 1Pa, the sputtering power was 80W, the sputtering rate was 2 nm / min, and the electron transport layer was obtained by sputtering for 25min.

[0141] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0142] Example 5

[0143] Example 5 is basically the same as Example 1, except that the material of the hole transport layer is replaced by CuSb 0.97 Pb 0.03 Te 2.12 , the preparation method is as follows:

[0144] 25gCu particles, 46gSb powder, 2.4gPb and 106gSe powder were blended and ball-milled for 120h, and then hot-pressed into a target with a diameter of 60mm. The target was then placed in a muffle furnace and heated to 1000°C at a rate of 2°C / min and kept warm for 6h to obtain the corresponding target. The target was then placed in a magnetron sputtering device, 30sccm of argon was introduced, the sputtering pressure was 0.8Pa, the sputtering power was 70W, the sputtering rate was 1nm / min, and the sputtering was performed for 30min to obtain a hole transport layer with a thickness of 30nm.

[0145] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0146] Example 6

[0147] Example 5 is basically the same as Example 1, except that the material of the hole transport layer is replaced by AgBi 0.97 Cd 0.03 Se 2.12 , the preparation method is as follows:

[0148] 40gAg particles, 75gBi powder, 1.25gCd and 62.6gSe powder were blended and ball-milled for 120h, and then hot-pressed into a target with a diameter of 60mm. The target was then placed in a muffle furnace and heated to 1000°C at a rate of 2°C / min and kept warm for 6h to obtain the corresponding target. The target was then placed in a magnetron sputtering device, 30sccm of argon was introduced, the sputtering pressure was 1Pa, the sputtering power was 80W, the sputtering rate was 2nm / min, and the sputtering was performed for 30min to obtain a hole transport layer with a thickness of 30nm.

[0149] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0150] Example 7

[0151] Example 7 is basically the same as Example 1, except that the material of the hole transport layer is replaced with AgBi 0.91 Pb 0.09 Se 2.12 ,

[0152] 40gAg particles, 70.6gBi powder, 6.9gPb and 62.24gSe powder were blended and ball-milled for 120h, and then hot-pressed into a target with a diameter of 60mm. The target was then placed in a muffle furnace and heated to 1000°C at a rate of 2°C / min and kept warm for 6h to obtain the corresponding target. The target was then placed in a magnetron sputtering device, 30sccm of argon was introduced, the sputtering pressure was 1Pa, the sputtering power was 80W, the sputtering rate was 2nm / min, and the sputtering was performed for 30min to obtain a hole transport layer with a thickness of 30nm.

[0153] The preparation method refers to the preparation steps of the hole transport layer in the examples.

[0154] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0155] Example 8

[0156] Example 8 is basically the same as Example 1, except that the material of the electron transport layer is replaced with ZnO.

[0157] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0158] Example 9

[0159] Example 9 is substantially the same as Example 1, except that the material of the hole transport layer is replaced with poly-TPD (poly[bis(4-phenyl)(4-butylphenyl)amine]).

[0160] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0161] Example 10

[0162] Example 10 is basically the same as Example 9, except that the material of the electron transport layer is replaced by ZnO and AgBiSe 1.98 The mixture is prepared as follows:

[0163] 41g Ag particles, 79g Bi powder and 59.5g Se powder were blended and ball-milled for 120h, and then hot-pressed into a target with a diameter of 60mm. The target was then placed in a muffle furnace and heated to 1000℃ at a rate of 2℃ / min and kept for 6h to obtain the corresponding AgBiSe 1.98 The target material is then placed in a magnetron sputtering device, the zinc oxide target is turned on at the same time, and 30 sccm of argon is introduced to simultaneously sputter AgBiSe using a co-sputtering method. 1.98 target and zinc oxide target, where the sputtering pressure is 1Pa, AgBiSe 1.98 The target material sputtering power is 70W, the sputtering rate is 1.8 nm / min, the zinc oxide target sputtering power is 30W, the sputtering rate is 0.2nm / min, and the electron transport layer is obtained. Based on the total mass of the electron transport layer, the mass proportion of ZnO is 10%, and the mass proportion of AgBiSe1.98 is 90%.

[0164] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0165] Embodiment 11

[0166] Example 11 is basically the same as Example 10, except that: during the preparation of the electron transport layer, AgBiSe 1.98 The target material sputtering power is 65W, the sputtering rate is 1.6 nm / min, the zinc oxide target sputtering power is 60W, the sputtering rate is 0.4nm / min, and the electron transport layer is obtained. Based on the total mass of the electron transport layer, the mass proportion of ZnO is 20%, and the mass proportion of AgBiSe1.98 is 80%.

[0167] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0168] Example 12

[0169] Example 12 is substantially the same as Example 10, except that: during the preparation of the electron transport layer, AgBiSe 1.98 The target material sputtering power is 60W, the sputtering rate is 1.4nm / min, the zinc oxide target sputtering power is 80W, the sputtering rate is 0.6nm / min, and the electron transport layer is obtained. Based on the total mass of the electron transport layer, the mass proportion of ZnO is 30%, and the mass proportion of AgBiSe1.98 is 70%.

[0170] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0171] Comparative Example 1

[0172] Comparative Example 1 is substantially the same as Example 1, except that the material of the hole transport layer is replaced by poly-TPD (poly[bis(4-phenyl)(4-butylphenyl)amine]), and the material of the electron transport layer is replaced by ZnO.

[0173] The other steps and process conditions are the same as those in Example 1, see Table 1 for details.

[0174] The parameters and test results of each embodiment and comparative example are shown in Table 1.

[0175] Table 1

[0176]

[0177] Note: “ / ” represents the existence of the substance or parameter.

[0178] As shown in Table 1, the light emitting device of the present application has excellent stability, high efficiency and high service life.

[0179] Furthermore, by regulating the types of thermoelectric materials in the electron transport layer and the hole transport layer, the efficiency and service life of the light-emitting device can be further improved.

[0180] Any combination can be made. In order to make the description concise, not all possible combinations of the various technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0181] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the protection scope of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the protection scope of the claims attached to the present application.

Claims

1. A light emitting device, characterized in that: The light-emitting device comprises a first electrode, an electron transport layer, a light-emitting layer, a hole transport layer and a second electrode which are sequentially stacked; and a component of at least one of the electron transport layer and the hole transport layer comprises a thermoelectric material.

2. The light emitting device according to claim 1, characterized in that: The thermoelectric material includes at least one of group IB elements, group IVA elements, group VA elements, and group VIA elements.

3. The light emitting device according to claim 2, characterized in that: The IB group element includes at least one of Cu and Ag; and / or The VA group element includes at least one of Sb and Bi; and / or The VIA group element includes at least one of Se and Te; and / or The IVA group element includes at least one of Si, Ge, Sn and Pb.

4. The light emitting device according to claim 1, characterized in that: The thermoelectric material includes bismuth telluride, lead telluride, silicon germanium based thermoelectric material and AgBi (1-y0) M1 y0 Se (2+x0) At least one of; Wherein, -0.1≤x0≤0.2, 0≤y0≤0.08, M1 includes at least one element of Group IIB~IVA elements; Optionally, M1 includes at least one of Zn, Ge, Cd, In and Pd.

5. The light emitting device according to claim 3, characterized in that: A component of at least one of the electron transport layer and the hole transport layer includes the thermoelectric material; Optionally, the thermoelectric material of at least one of the electron transport layer and the hole transport layer is independently selected from AgBi (1-y0) M1 y0 Se (2+x0) .

6. The light emitting device according to any one of claims 1 to 5, characterized in that: The components of the electron transport layer include the thermoelectric material having n-type semiconductor properties; and / or The component of the hole transport layer includes the thermoelectric material having a p-type semiconductor property.

7. The light emitting device according to claim 6, characterized in that: The components of the electron transport layer also include inorganic electron transport materials; the inorganic electron transport materials are selected from one or more of doped or undoped zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese 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.

8. The light emitting device according to claim 7, characterized in that: In the electron transport layer, the inorganic electron transport material accounts for 10% to 30% by mass; and / or The components of the electron transport layer further include doped or undoped zinc oxide.

9. The light-emitting device according to any one of claims 1 to 5, wherein the hole transport layer comprises a compound having a molecular formula of AgBi (1-y1) M2 y1 Se (2+x1) Thermoelectric materials; in, 0≤x1≤0.2, 0<y1≤0.08, M2 includes at least one element of group IIB~IVA elements; Optionally, M2 includes at least one of Zn, Ge, Cd, In and Pd; and / or the components of the electron transport layer include AgBiSe (2+x2) Thermoelectric materials; Among them, -0.1≤x2<0.

10. The light emitting device according to any one of claims 1 to 5, characterized in that: The light emitting device further comprises a hole injection layer, wherein the hole injection layer is arranged between the hole transport layer and the first electrode; and / or The light emitting device further includes an electron injection layer disposed between the hole transport layer and the second electrode.

11. The light emitting device according to claim 10, characterized in that: The thickness of the electron transport layer is 30nm to 150nm; and / or The thickness of the hole transport layer is 30 nm to 50 nm; and / or The thickness of the light-emitting layer is 30nm to 60nm; and / or The thickness of the hole injection layer is 30nm to 40nm; and / or The thickness of the electron injection layer is 30nm-60nm.

12. The light emitting device according to claim 10, characterized in that: The material of the first electrode and / or the second electrode includes one or more of metal, carbon material and 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 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, 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; and / or The material of the electron injection layer 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, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide, lithium titanium oxide, zinc aluminum oxide, zinc manganese 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; the organic material is selected from one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene compounds, and hydroxyquinoline compounds; and / or The light-emitting layer 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, ZnSeS, ZnS At least one of CdS, SnSe, SnTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, wherein the Group IV-VI compound is selected from SnS, SnSe, SnTe, PbS, PbSe ... At least one of SnPbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe and SnPbSTe, wherein the III-V 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; The core of the core-shell structured quantum dots includes any one of the single structured quantum dots, and the shell material of the core-shell structured quantum dots includes at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS, ZnS and the above single structured quantum dots; 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''-tri(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; and / or The material of the hole injection layer and / or the hole transport layer includes at least one of TFB, CuPc, PVK, Poly-TPD, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-Nphenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal tinides, doped graphene, undoped graphene and C60.

13. A method for preparing a light emitting device, characterized in that: The steps include: Forming a first electrode, an electron transport layer, a light-emitting layer, a hole transport layer and a second electrode stacked in sequence to prepare a light-emitting device; A component of at least one of the electron transport layer and the hole transport layer includes a thermoelectric material.

14. The method for preparing a light emitting device according to claim 13, characterized in that: In at least one of the steps of forming the electron transport layer and forming the hole transport layer, a target material corresponding to the thermoelectric material is used to perform magnetron sputtering to prepare the thermoelectric material.

15. A display device, characterized in that: The display device comprises the light-emitting device according to any one of claims 1 to 12 or a light-emitting device manufactured by the method for manufacturing a light-emitting device according to any one of claims 13 to 14.

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