Light-emitting device, preparation method thereof and display device

Abstract

The invention discloses a light-emitting device, a preparation method thereof and a display device. According to the light-emitting device, the surface of the first inorganic material in the first electron transport layer close to the light-emitting layer is connected with the halogen ligand, on one hand, the halogen ligand can improve the position of the conduction band energy level of the first inorganic material, and therefore the potential barrier of an interface between the light-emitting layer and the electron function layer is increased; the organic light-emitting device can limit the region of excitons in the light-emitting layer, can improve the recombination efficiency of the light-emitting layer and can avoid damage to the electronic function layer, and the surface of a second inorganic material in the second electron transport layer close to the second electrode is connected with a long carbon chain ligand with the carbon atom number of 4-12, so that the electron mobility of the second electron transport layer can be reduced, and the light-emitting efficiency of the organic light-emitting device is improved. Electron injection is reduced, carrier balance is improved, and the service life of the light-emitting device is prolonged.

Description

Technical Field

[0001] The present application relates to the field of optoelectronic technology, and in particular to a light-emitting device and a method for preparing the same, and a display device. Background Art

[0002] Currently, widely used light-emitting devices include organic light-emitting diodes (OLEDs) and quantum dot light-emitting diodes (QLEDs). The structure of traditional OLED and QLED devices mainly includes an anode, a hole functional layer, a light-emitting layer, an electron functional layer and a cathode. Under the action of the electric field, the holes generated by the anode of the light-emitting device and the electrons generated by the cathode move and are injected into the hole transport layer and the electron transport layer respectively, and finally migrate to the light-emitting layer. When the two meet in the light-emitting layer, energy excitons are generated, and visible light is finally generated.

[0003] Since the electron transport layer is in contact with both the light-emitting layer and the cathode, there are interface problems between the electron transport layer and the light-emitting layer, and between the electron transport layer and the cathode, which affect the life of the light-emitting device. When solving the interface problem between the electron transport layer and the light-emitting layer, it often brings about the interface problem between the electron transport layer and the cathode, or when solving the interface problem between the electron transport layer and the cathode, it brings about the interface problem between the electron transport layer and the light-emitting layer.

[0004] Therefore, how to solve the problem of the two interfaces between the electron transport layer and the adjacent film layer in the light-emitting device is an important strategy to improve the life of the light-emitting device. Summary of the invention

[0005] In view of this, the present application provides a light-emitting device and a method for preparing the same, and a display device.

[0006] The embodiment of the present application is implemented as follows:

[0007] In a first aspect, the present application provides a light-emitting device, comprising: a first electrode and a second electrode arranged opposite to each other; a light-emitting layer arranged between the first electrode and the second electrode; an electronic functional layer arranged between the second electrode and the light-emitting layer; wherein the electronic functional layer comprises a first electron transport layer and a second electron transport layer, the first electron transport layer is arranged close to the light-emitting layer, and the second electron transport layer is arranged close to the second electrode, the material of the first electron transport layer comprises a first inorganic material, and the material of the second electron transport layer comprises a second inorganic material, wherein a first ligand is connected to the first inorganic material, and a second ligand is connected to the second inorganic material, the first ligand comprises a halogen ligand, and the second ligand comprises a long carbon chain ligand with a carbon number of 4 to 12.

[0008] In a second aspect, the present application provides a method for preparing a light-emitting device, comprising: providing a preset device, the preset device comprising a second electrode; arranging an electronic functional layer on the preset device; arranging a light-emitting layer on the electronic functional layer; arranging a stacked light-emitting layer and a first electrode on the light-emitting layer; or, the preparation method comprises: providing a preset device, the preset device comprising a stacked first electrode and a light-emitting layer; arranging an electronic functional layer on the preset device; arranging a second electrode on the electronic functional layer; wherein the electronic functional layer comprises a first electron transport layer and a second electron transport layer, the first electron transport layer is arranged close to the light-emitting layer, and the second electron transport layer is arranged close to the second electrode; the material of the first electron transport layer comprises a first inorganic material, a first ligand is connected to the first inorganic material, the first ligand comprises a halogen ligand, the material of the second electron transport layer comprises a second inorganic material, a second ligand is connected to the second inorganic material, and the second ligand comprises a long carbon chain ligand with a carbon number of 4 to 12.

[0009] In a third aspect, the present application provides a display device, comprising the above-mentioned light-emitting device, or a light-emitting device manufactured by the above-mentioned method for manufacturing the light-emitting device.

[0010] The light-emitting device of the present application has a halogen ligand connected to the surface of the first inorganic material in the first electron transport layer close to the light-emitting layer. On the one hand, the halogen ligand can increase the position of the conduction band energy level of the first inorganic material, thereby increasing the potential barrier at the interface between the light-emitting layer and the electronic functional layer, which can limit the area of ​​the excitons in the light-emitting layer, improve the recombination efficiency of the light-emitting layer, and avoid damage to the electronic functional layer. In the second electron transport layer close to the second electrode, the surface of the second inorganic material is connected to a long carbon chain ligand with 4 to 12 carbon atoms, which can reduce the electron mobility of the second electron transport layer and play a role in reducing electron injection, thereby improving the carrier balance and increasing the life of the light-emitting device. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] 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 creative work.

[0012] Figure 1 A structural schematic diagram of an embodiment of a light emitting device is provided for the present application;

[0013] Figure 2 A schematic diagram of a process of an embodiment of a method for preparing a light-emitting device provided in the present application;

[0014] Figure 3 A schematic diagram of another embodiment of a method for preparing a light-emitting device provided in the present application;

[0015] Figure 4 is a dissolution state diagram of aluminum-doped zinc oxide corresponding to device comparative example 3;

[0016] Figure numerals: 100 - light-emitting device; 10 - first electrode; 20 - second electrode; 30 - light-emitting layer; 40 - electron functional layer; 41 - first electron transport layer; 42 - second electron transport layer; 50 - hole functional layer, hole injection layer 51, hole transport layer 52. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without 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. In the present application, unless otherwise specified, the directional words such as "upper" and "lower" used are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the present application, the term "including" means "including but not limited to". Various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and simplicity, and should not be understood as a rigid limitation on the scope of the present invention; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single values ​​within the range. For example, description of a range 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 stated range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integral) within the stated range.

[0018] 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.

[0019] In the present application, "at least one" means one or more, and "plurality" means two or more. "At least one", "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.

[0020] The present application provides a light emitting device, referring to Figure 1 , Figure 1 The present application provides a structural schematic diagram of an embodiment of a light-emitting device, wherein the light-emitting device 100 includes a first electrode 10 and a second electrode 20 that are relatively arranged, and a light-emitting layer 30 that is arranged between the first electrode 10 and the second electrode 20, and an electronic functional layer 40 that is arranged between the second electrode 20 and the light-emitting layer 30.

[0021] Among them, the electronic functional layer 40 includes a first electron transport layer 41 and a second electron transport layer 42, the first electron transport layer 41 is arranged close to the light-emitting layer 30, and the second electron transport layer 42 is arranged close to the second electrode 20, wherein the material of the first electron transport layer 41 includes a first inorganic material, a first ligand is connected to the first inorganic material, and the first ligand includes a halogen ligand, and the material of the second electron transport layer includes a second inorganic material, a second ligand is connected to the second inorganic material, and the second ligand includes a long carbon chain ligand with a carbon atom number of 4 to 12.

[0022] In this embodiment, in the first electron transport layer 41 close to the light-emitting layer 30, the surface of the first inorganic material is connected with a halogen ligand. On the one hand, the halogen ligand can improve the position of the conduction band energy level of the first inorganic material, thereby increasing the potential barrier at the interface between the light-emitting layer 30 and the electronic functional layer 40, which can limit the area of ​​the excitons in the light-emitting layer 30, thereby improving the recombination efficiency of the light-emitting layer 30 and avoiding damage to the electronic functional layer 40. In the second electron transport layer 42 close to the second electrode 20, the surface of the second inorganic material is connected with a long carbon chain ligand with a carbon number of 4 to 12, which can reduce the electron mobility of the second electron transport layer 42 and play a role in reducing electron injection, thereby improving the carrier balance and improving the efficiency and life of the light-emitting device 100.

[0023] In a specific embodiment, the light-emitting device 100 is a blue quantum dot light-emitting device. Through the configuration of a double-layer electron transport layer in the present application, electron injection is appropriately reduced, which is beneficial to the balance of carriers in the light-emitting device 100.

[0024] In addition, the arrangement of the ligands in the first electron transport layer 41 and the second electron transport layer 42 can avoid dissolution and penetration damage to a previously prepared film layer, thereby improving the film quality of the electronic functional layer 40 and reducing the possibility of leakage in the light-emitting device 100, thereby improving the efficiency and life of the light-emitting device 100.

[0025] Specifically, in the first electron transport layer 41 , the surface of the first inorganic material is connected with a halogen ligand to enhance the surface polarity of the first inorganic material, so that the material of the first electron transport layer 41 has better solubility and dispersibility in polar solvents. In the second electron transport layer 42, the surface of the second inorganic material is connected with a long carbon chain ligand with 4 to 12 carbon atoms, which can weaken the surface polarity of the second inorganic material and increase its solubility and dispersibility in non-polar solvents. When preparing the two-layer stacked film of the first electron transport layer 41 and the second electron transport layer 42 by a solution method, after one of the first electron transport layer 41 and the second electron transport layer 42 is prepared, during the preparation process of the later film layer, polar solvents and non-polar solvents are used respectively due to the different surface polarities of the first inorganic material and the second inorganic material, thereby avoiding dissolution and penetration damage to the earlier prepared film layer, improving the film quality of the electronic functional layer 40, reducing the possibility of leakage of the light-emitting device 100, and improving the efficiency and life of the light-emitting device 100.

[0026] For example, after preparing the first electron transport layer 41, when preparing the second electron transport layer 42 on the first electron transport layer 41 by a solution method, the solvent used can be a non-polar solvent, which will not dissolve the material in the film layer of the first electron transport layer 41 that has been formed, nor will it cause dissolution damage to the first electron transport layer 41. After preparing the second electron transport layer 42, when preparing the first electron transport layer 41 on the second electron transport layer 42 by a solution method, the solvent used can be a polar solvent. Similarly, the polar solvent will not dissolve the material of the second electron transport layer 42, nor will it cause dissolution damage to the second electron transport layer 42.

[0027] It can be understood that the polar solvent and the non-polar solvent can be polar or non-polar solvents known in the art. For example, the polar solvent can include one or more of ethanol, isopropanol, n-butanol, n-pentanol, etc., and the non-polar solvent can include one or more of n-hexane, n-octane, n-nonane, etc.

[0028] In the first electron transport layer 41:

[0029] In one embodiment, the halogen ligand includes one or more of a fluoride ion ligand, a chloride ion ligand, a bromide ion ligand, and an iodide ion ligand.

[0030] In one embodiment, the molar percentage of the halogen ligand in the first ligand is greater than or equal to 20%, specifically 20% to 100%, such as 20% to 30%, 30% to 50%, 50% to 80%, 80% to 100%, etc. The molar percentage of the halogen ligand can increase the surface polarity of the first inorganic material.

[0031] In one embodiment, the first ligand comprises only the halogen ligand.

[0032] In one embodiment, the first ligand may also include one or more of oleic acid, stearic acid, acetic acid, lauric acid, etc. It is understandable that the first ligand may be introduced through a reaction precursor, or may be introduced through an additionally added ligand reagent or ligand solvent.

[0033] In one embodiment, the first inorganic material includes at least one of a metal oxide, a doped metal oxide, a IIB-VIA semiconductor material, a IIIB-VA semiconductor material and an IB-IIIB-VIA semiconductor material, the metal oxide being selected from at least one of ZnO, TiO2, SnO2, BaO, Ga2O3 and ZrO2; the metal oxide in the doped metal oxide being selected from at least one of ZnO and TiO2, the doping element being selected from at least one of Mg, Ca, Li, Ga, Al, Co, Mn, Zr, W, Ti, Y and In, the IIB-VIA semiconductor material being selected from at least one of ZnS, ZnSe and CdS; the IIIB-VA semiconductor material being selected from at least one of InP and GaP; the IB-IIIB-VIA semiconductor material being selected from at least one of CuInS and CuGaS.

[0034] In one embodiment, the first inorganic material is selected from the doped metal oxide, in which the molar ratio of the metal oxide to the doping element can be (100-3):1, such as (100-5):1, (80-10):1, (80-10):1, (60-10):1, (60-30):1, (40-30):1, (30-20):1, (20-10):1, (10-5):1, etc.

[0035] In a specific embodiment, the first inorganic material is selected from doped or undoped ZnO.

[0036] In the second electron transport layer 42:

[0037] In one embodiment, the long carbon chain ligand with 4 to 12 carbon atoms includes one or more of a carboxylic acid ligand with 4 to 12 carbon atoms, a phosphate ligand with 4 to 12 carbon atoms, a thiol ligand with 4 to 12 carbon atoms, or an amine ligand with 4 to 12 carbon atoms.

[0038] Furthermore, the carboxylic acid ligand having 4 to 12 carbon atoms includes one or more of butyric acid, valeric acid, hexanoic acid, heptanoic acid, n-octanoic acid, n-decanoic acid, undecanoic acid, lauric acid and the like.

[0039] The phosphate ligand having 4 to 21 carbon atoms includes one or more of n-hexyl phosphate, 1-octyl phosphate, 1-decyl phosphate, n-dodecyl phosphate and the like.

[0040] The thiol ligand having 4 to 12 carbon atoms includes one or more of butyl mercaptan, 1-pentyl mercaptan, 1-hexyl mercaptan, 1-heptyl mercaptan, n-octyl mercaptan, isooctyl mercaptan, 1-decyl mercaptan, 1-undecanethiol, 1-dodecanethiol and the like.

[0041] The amine ligand having 4 to 12 carbon atoms includes one or more of n-butylamine, pentylamine, hexylamine, heptylamine, n-octylamine, decylamine, 1-aminoundecane, dodecylamine and the like.

[0042] In this embodiment, the long-chain ligand with 4 to 12 carbon atoms has relatively good charge conductivity, which prevents poor charge conductivity from hindering electron transmission, thereby preventing the operating voltage of the light-emitting device 100 from being too high.

[0043] In one embodiment, the molar percentage of the long carbon chain ligand with carbon atoms of 4 to 12 in the second ligand is greater than or equal to 10%. Specifically, it can be 10% to 20%, 20% to 50%, 20% to 30%, 30% to 40%, 40% to 50%, 20% to 70%, 20% to 80%, 20% to 90%, etc. It is understandable that the second ligand connected to the surface of the first inorganic material, in addition to the long carbon chain ligand with carbon atoms of 4 to 12, also includes other ligands, such as acetate ligands, hydroxyl ligands, etc., and other ligands are not limited here. It is understandable that the second ligand can be a ligand introduced by a reaction precursor, or a ligand introduced by an additionally added ligand reagent or ligand solvent, etc.

[0044] The molar percentage of the long carbon chain ligand to the second ligand is greater than or equal to 10%, that is, the percentage of the long carbon chain ligand to the total ligand is greater than or equal to 10%, which can block electron injection and reduce the surface polarity of the second inorganic material.

[0045] In one embodiment, the second inorganic material in the second electron transport layer 42 includes at least one of a metal oxide, a doped metal oxide, a IIB-VIA semiconductor material, a IIIB-VA semiconductor material and an IB-IIIB-VIA semiconductor material, the metal oxide is selected from at least one of ZnO, TiO2, SnO2, BaO, Ga2O3, and ZrO2; the metal oxide in the doped metal oxide is selected from at least one of ZnO, TiO2, and SnO2, the doping element is selected from at least one of Mg, Ca, Li, Ga, Al, Co, Mn, Zr, W, Ti, Y, and In, the IIB-VIA semiconductor material is selected from at least one of ZnS, ZnSe, and CdS; the IIIB-VA semiconductor material is selected from at least one of InP and GaP; the IB-IIIB-VIA semiconductor material is selected from at least one of CuInS and CuGaS.

[0046] In a specific embodiment, the second inorganic material is selected from doped or undoped ZnO.

[0047] It is understandable that the second inorganic material may be the same as the first inorganic material or different from the first inorganic material. In a specific embodiment, the first inorganic material is selected from doped or undoped ZnO, and the second inorganic material is selected from doped or undoped ZnO.

[0048] In one embodiment, the electronic functional layer 40 is composed of the first electron transport layer 41 and the second electron transport layer 42. The electronic functional layer 40 includes a double-layer structure, which can improve the interface problem between the electronic functional layer 40 and the second electrode 20, and the interface problem between the electronic functional layer 40 and the light-emitting layer 30 on the basis of improving electron injection and transport, and can also avoid the problem of dissolution damage during stacking preparation, thereby improving the efficiency and life of the light-emitting device 100.

[0049] In one embodiment, the thickness of the first electron transport layer 41 is 5-40 nm, specifically 5-35 nm, 10-35 nm, 10-30 nm, 15-30 nm, 15-25 nm, 20-25 nm, etc.

[0050] In one embodiment, the thickness of the second electron transport layer 42 is 5-40 nm, specifically 5-35 nm, 10-35 nm, 10-30 nm, 15-30 nm, 15-25 nm, 20-25 nm, etc.

[0051] In one embodiment, the material of the light-emitting layer 30 is selected from one or more of organic light-emitting materials and quantum dot light-emitting materials.

[0052] The organic light-emitting material is selected from at least one of diaromatic anthracene derivatives, distyrene aromatic derivatives, pyrene derivatives or fluorene derivatives, TBPe fluorescent materials emitting blue light, TTPA fluorescent materials emitting green light, TBRb fluorescent materials emitting orange light, and DBP fluorescent materials emitting red light.

[0053] The quantum dot luminescent material can be selected from at least one of a single structure quantum dot, a core-shell structure quantum dot and a perovskite semiconductor material. 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. 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, CdS At least one of dZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe, and the IV-VI group compound is selected from SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, Sn At least one of PbTe, SnPbSSe, SnPbSeTe, and SnPbSTe, and 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, 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 is selected from at least one of CuInS, CuInSe and AgInS; the core of the quantum dots of the core-shell structure is selected from any one of the above-mentioned single-structure quantum dots, and the shell material of the quantum dots of the core-shell structure is selected from at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS and ZnS;

[0054] The perovskite semiconductor material is selected from 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+ At least one of, X is a halogen anion selected from Cl - Br - ,I - At least one 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+ At least one of, X is a halogen anion selected from Cl - Br - ,I - When n=2, the inorganic metal halide octahedron MX6 4- The metal cation M is located at the center of the halogen octahedron, and the organic amine cation B fills the gap between the octahedrons to form an infinitely extended three-dimensional structure. When n>2, the inorganic metal halide octahedron MX6 connected by the top-sharing method 4- It extends in two dimensions to form a layered structure, with an organic amine cation bilayer (protonated monoamine) or an organic amine cation monolayer (protonated diamine) inserted between the layers, and the organic layer and the inorganic layer overlap to form a stable two-dimensional layered structure.

[0055] In a specific embodiment, the material of the light-emitting layer 30 is selected from the quantum dot light-emitting material.

[0056] The thickness of the light emitting layer 30 may be 15 to 40 nm, specifically 15 to 35 nm, 25 to 35 nm, 25 to 30 nm, 30 to 40 nm, etc.

[0057] In one embodiment, the light emitting device 100 may further include a hole functional layer 50, and the hole functional layer 50 is disposed between the first electrode 10 and the light emitting layer 30. The hole functional layer 50 may include a hole injection layer 51 and / or a hole transport layer 52. When the hole functional layer 50 includes two layers, the hole injection layer 51 and the hole transport layer 52, the hole injection layer 51 is disposed close to the first electrode 10, and the hole transport layer 52 is disposed close to the light emitting layer 30.

[0058] In one embodiment, the thickness of the hole injection layer 51 may be 20-200 nm, specifically 20-150 nm, 80-150 nm, 80-120 nm, etc. The thickness of the hole transport layer 52 may be 30-180 nm, specifically 30-150 nm, 50-150 nm, 50-120 nm, 80-120 nm, 80-100 nm, etc.

[0059] The material of the hole transport layer 52 is selected from arylamine, polyaniline, polypyrrole, poly(p-)phenylene vinylene and its derivatives, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, poly(N-vinylcarbazole) (PVK) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, doped or undoped NiO, MoO3, WO3, V2O5, CrO3, CuO, MoS2, MoSe2, WS3, WSe3 , CuS, CuSCN; wherein the aromatic amine is selected from 4,4'-bis(9-carbazole)biphenyl (CBP), poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine) (TFB), poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine) (poly-TPD), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine (DNTPD), poly(9,9-dioctylfluorene-co-bis-N,N-phenyl-1,4-phenylenediamine) (PFB), 4 ,4',4"-tri(carbazol-9-yl)triphenylamine (TCATA), 4,4',4"-tri(N-carbazol-9-yl)triphenylamine (TCTA), 4,4',4"-tri(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4"-diamine (α-NPD), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), N,N'-diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl- One or more of 4,4'-diamine (NPB), Spiro-NPB, Spiro-TPD, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro(spiro-TPD), and spiro-NPB; the poly(p-)phenylene vinylene and its derivatives are selected from one or more of poly(phenylene vinylene) (PPV), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV) and poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene] (MOMO-PPV).

[0060] The material of the hole injection layer 51 is a material having hole injection capability, selected from poly(ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinone-dimethane (F4-TCNQ), 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene (HATCN), copper phthalocyanine (CuPc ), poly(9,9-dioctyl-fluorene-co-N-(4-butylphenyl)-diphenylamine) (TFB), polyarylamine, poly(N-vinylcarbazole), polyaniline, polypyrrole, N,N,N',N'-tetrakis(4-methoxyphenyl)-benzidine (TPD), 4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (α-NPD), 4,4',4"-tris[phenyl(m-tolyl)amino]triphenylamine (m-MTDATA), 4,4',4"-tri(N-carbazolyl)-triphenylamine (TCTA), 1,1-bis[(di-4-tolylamino)phenylcyclohexane (TAPC), 4,4',4"-tri(diphenylamino)triphenylamine (TDATA) doped with F4-TCNQ, p-doped phthalocyanine (e.g., F4-TCNQ-doped zinc phthalocyanine (ZnPc)), F4-TCNQ-doped N,N'-diphenyl-N,N'-di(1-naphthyl)-1,1'-biphenyl-4,4"-diamine (α-NPD), transition metal oxides, transition metal sulfur compounds; wherein the transition metal oxides include one or more of NiO, MoO2, WO3, CuO; the metal sulfur compounds include one or more of MoS2, MoSe2, WS3, WSe3, CuS.

[0061] In one embodiment, the first electrode 10 and the second electrode 20 are independently selected from metal electrodes, carbon electrodes, doped or undoped metal oxide electrodes and composite electrodes; wherein the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, Ni, Ir and Mg; the material of the carbon electrode is selected from at least one of graphite, carbon nanotubes, graphene and carbon fiber; the material of the doped or undoped metal oxide electrode is selected from ITO, FTO, ATO, AZO, GZO, IZO, MZO, I At least one of TZO, ICO, AMO, SnO2, In2O3, Cd:ZnO, F:SnO2, In:SnO2, and Ga:SnO2; the material of the composite electrode is selected from at least one of 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, and ZnS / Al / ZnS. Wherein, " / " represents a stacked structure, for example, the composite electrode AZO / Ag / AZO represents an electrode of a composite structure of three stacked layers consisting of an AZO layer, an Ag layer, and an AZO layer.

[0062] In one embodiment, the first electrode 10 is composed of a conductive material with a relatively high work function, and may be composed of a doped or undoped metal oxide, such as ITO, IZO, ITZO, ICO, SnO2, In2O3, Cd:ZnO, F:SnO2, In:SnO2, Ga:SnO2 or AZO, etc.; or in addition to the above-mentioned metal oxides, it may be composed of a metal material including nickel (Ni), platinum (Pt), gold (Au), silver (Ag), iridium (Ir) or CNT.

[0063] In one embodiment, the second electrode 20 is composed of a conductive material with a relatively low work function, which may be one or more of Ca, Ba, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, Al, Mg, Au:Mg or Ag:Mg.

[0064] It is understandable that, in addition to the above-mentioned functional layers, the light-emitting device 100 may also be provided with some functional layers conventionally used in light-emitting devices to help improve the performance of the light-emitting device, such as an electron blocking layer, an electron injection layer, a hole blocking layer and / or an interface modification layer.

[0065] It can be understood that the material and thickness of each layer of the light-emitting device 100 can be set and adjusted accordingly according to the light-emitting requirements of the light-emitting device 100 .

[0066] The light emitting device 100 further includes a substrate (not shown), which may also be referred to as a substrate. The substrate may be a rigid substrate or a flexible substrate. The rigid substrate may be a ceramic material or various glass materials. The flexible substrate may be a substrate formed of materials such as polyimide film (PI) and its derivatives, polyethylene naphthalate (PEN), phosphoenolpyruvic acid (PEP) or diphenylene ether resin. In one embodiment, the material of the substrate includes glass, silicon wafer, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, polyether sulfone, or a combination thereof.

[0067] It can be understood that when the first electrode 10 or the second electrode 20 is connected to the substrate, it can be called a bottom electrode, and the one away from the substrate is a top electrode, wherein the thickness of the bottom electrode can be 20 to 200 nm, and the thickness of the top electrode can be 40 to 190 nm.

[0068] It can be understood that the light emitting device 100 can be an upright light emitting device or an inverted light emitting device. When the light emitting device 100 is an upright light emitting device, the substrate is combined with a side of the first electrode 10 away from the light emitting layer 30. When the light emitting device 100 is an inverted light emitting device, the substrate is combined with a side of the second electrode 20 away from the light emitting layer 30.

[0069] The present application also provides a method for preparing a light-emitting device to prepare a light-emitting device with good luminous efficiency.

[0070] See also Figure 2 , Figure 2 The present invention provides a flow chart of a method for preparing a light-emitting device according to an embodiment of the present invention, which specifically includes the following steps:

[0071] Step S11: providing a preset device, wherein the preset device includes a second electrode;

[0072] Step S12: providing an electronic functional layer on the preset device;

[0073] Step S13: sequentially disposing a light-emitting layer and a first electrode on a side of the electronic functional layer away from the second electrode.

[0074] The light-emitting device prepared in this embodiment is an inverted device.

[0075] See also Figure 3 , Figure 3 A schematic flow chart of another embodiment of a method for preparing a light-emitting device provided in the present application specifically includes the following steps:

[0076] Step S21: providing a preset device, wherein the preset device includes a stacked first electrode and a light-emitting layer;

[0077] Step S22: providing an electronic functional layer on the preset device;

[0078] Step S23: disposing a second electrode on the electronic functional layer at a side away from the light-emitting layer.

[0079] The light-emitting device prepared in this embodiment is an upright device.

[0080] In the above two embodiments, the electronic functional layer includes a first electron transport layer and a second electron transport layer, the first electron transport layer is arranged close to the light emitting layer, and the second electron transport layer is arranged close to the second electrode;

[0081] Among them, the material of the first electron transport layer includes a first inorganic material, wherein a first ligand is connected to the first inorganic material, and the first ligand includes a halogen ligand; the material of the second electron transport layer includes a second inorganic material, wherein a second ligand is connected to the second inorganic material, and the second ligand includes a long carbon chain ligand with a carbon atom number of 4 to 12.

[0082] In the above two embodiments, in the first electron transport layer close to the light-emitting layer, the surface of the first inorganic material is connected with a halogen ligand. On the one hand, the halogen ligand can improve the position of the conduction band energy level of the first inorganic material, thereby increasing the potential barrier at the interface between the light-emitting layer and the electronic functional layer, which can limit the area of ​​the excitons in the light-emitting layer, improve the recombination efficiency of the light-emitting layer, and avoid damage to the electronic functional layer. In the second electron transport layer close to the second electrode, the surface of the second inorganic material is connected with a long carbon chain ligand with a carbon number of 4 to 12, which can reduce the electron mobility of the second electron transport layer and play a role in reducing electron injection, thereby improving the carrier balance and improving the efficiency and life of the light-emitting device.

[0083] In step S12 and step S22, the step of providing an electronic functional layer on the preset device includes:

[0084] A first electron transport layer is formed, and a second electron transport layer is formed, wherein the first electron transport layer is formed on a side close to the light-emitting layer, and the second electron transport layer is formed on a side away from the light-emitting layer.

[0085] It is understandable that the first electron transport layer may be formed first, and then the second electron transport layer may be formed on the first electron transport layer; or the second electron transport layer may be formed first, and then the first electron transport layer may be formed on the second electron transport layer.

[0086] Wherein, the forming of the first electron transport layer specifically includes:

[0087] Step S31: providing a first solution, wherein the first solution includes a first inorganic material and a first solvent;

[0088] Wherein, a first ligand is connected to the first inorganic material, and the first ligand comprises a halogen ligand;

[0089] Step S32: placing the first solution on the light-emitting layer or the second electron transport layer to form a wet film, and drying to obtain the first electron transport layer.

[0090] In one embodiment, in the first solution, the concentration of the first inorganic material is 10-50 mg / mL, specifically 10-45 mg / mL, 15-45 mg / mL, 15-40 mg / mL, 20-40 mg / mL, 20-35 mg / mL, 25-35 mg / mL, etc.

[0091] The first solvent may be selected from polar solvents, and specifically may include one or more of ethanol, isopropanol, n-butanol, n-pentanol, etc. It is understandable that the first solvent may be a single solvent or a mixed solvent.

[0092] The first inorganic material may refer to the related description of the light emitting device 100 mentioned above, which will not be described in detail here.

[0093] In one embodiment, before forming the first electron transport layer, the method further includes preparing a first electron transport material, specifically including:

[0094] Step S51: providing a third solution, wherein the third solution includes a first metal source and a third solvent;

[0095] Step S52: adding a first base to the third solution, mixing and reacting to obtain a first inorganic material connected with the first ligand.

[0096] In step S51:

[0097] In one embodiment, the first metal source includes a first metal halide and a first main metal source, the first main metal source includes one or more of a first zinc source and a first titanium source; wherein the first zinc source may include at least one of diethyl zinc, zinc oleate, zinc stearate, zinc acetate, zinc laurate and zinc oxide, and the first titanium source may include one or more of tetrabutyl titanate, isopropyl titanate, titanyl sulfate, etc. The first metal halide includes one or more of zinc fluoride, zinc chloride, zinc bromide, zinc iodide, titanium tetrachloride, etc.

[0098] The molar ratio of the metal element in the first main metal source to the metal element in the first metal halide is 10 to 1:1, specifically 8 to 1:1, 8 to 3:1, 5 to 3:1, 8 to 5:1, etc. The molar ratio is within a range such that the molar percentage of the halogen ligands connected to the first inorganic material is greater than or equal to 20%.

[0099] Furthermore, the first metal source also includes a first doping metal source, which may include one or more of a Mg source, a Ca source, a Li source, a Ga source, an Al source, a Co source, a Mn source, a Zr source, a W source, a Ti source, a Y source, an In source, etc. Specifically, the first doping metal source may be selected from corresponding metal salts and hydrates thereof, etc., which are not limited here.

[0100] In one embodiment, the first doping metal source includes an aluminum (Al) source, and the aluminum source includes one or more of aluminum acetate and its hydrate, aluminum nitrate and its hydrate, aluminum sulfate and its hydrate, and aluminum chloride and its hydrate.

[0101] In a specific embodiment, the first doping metal source includes a magnesium (Mg) source, and the magnesium source includes one or more of magnesium acetate and its hydrate, magnesium nitrate and its hydrate, magnesium sulfate and its hydrate, and magnesium chloride and its hydrate.

[0102] The third solvent may include one or more of dimethyl sulfoxide, N,N-dimethylformamide, methanol, ethanol, and tetrahydrofuran.

[0103] In one embodiment, the first metal source, the first ligand solvent and the third solvent are stirred at room temperature for 1 to 8 hours to obtain the third solution.

[0104] In step S52:

[0105] In one embodiment, the molar ratio of the metal element in the first metal source to the first base is 1:(0.5-2), specifically 1:(0.5-1.5), 1:(1.0-1.5), 1:(1.1-1.5), 1:(1.1-1.3), etc.

[0106] The first base may include one or more of lithium hydroxide, sodium hydroxide, potassium hydroxide, aqueous ammonia, tetramethylammonium hydroxide and hydrates thereof.

[0107] It is understandable that the first base can be added in the form of an alkaline solution. Specifically, the solvent in the alkaline solution can include one or more of dimethyl sulfoxide, N,N-dimethylformamide, methanol, ethanol, and tetrahydrofuran. It is understandable that the solvent in the alkaline solution can be the same as or different from the third solvent. In a specific embodiment, the first base is added to the corresponding solution and stirred at room temperature for 1 to 8 hours to obtain the alkaline solution. Among them, the alkaline solution can also be called an oxygen precursor.

[0108] In one embodiment, the mixing reaction time can be 1 to 20 hours, specifically 1 to 15 hours, 1 to 13 hours, 3 to 13 hours, 5 to 11 hours, 8 to 10 hours, etc. The mixing reaction temperature can be 20 to 80° C., specifically 20 to 30° C., 20 to 40° C., 40 to 60° C., 60 to 80° C., etc. In a specific embodiment, the mixing reaction is carried out at room temperature of 20 to 30° C.

[0109] It is understandable that after the mixing reaction, purification may be performed to obtain the first inorganic material. Specifically, the purification may be performed by repeated centrifugation and dispersion using ethanol and n-octane.

[0110] The forming of the second electron transport layer specifically includes:

[0111] Step S41: providing a second solution, wherein the second solution includes a second inorganic material and a second solvent; wherein a second ligand is connected to the second inorganic material, and the second ligand includes a long carbon chain ligand having 4 to 12 carbon atoms;

[0112] Step S42: setting the second solution to form a wet film, and drying to obtain the second electron transport layer.

[0113] In this embodiment, the description of the first inorganic material, the second inorganic material, the first ligand, the second ligand, the halogen ligand, the long carbon chain ligand with 4 to 12 carbon atoms, etc. can refer to the corresponding content in the light-emitting device 100 described above, and will not be repeated here.

[0114] In one embodiment, in the second solution, the concentration of the second inorganic material is 10-50 mg / mL, specifically 10-45 mg / mL, 15-45 mg / mL, 15-40 mg / mL, 20-40 mg / mL, 20-35 mg / mL, 25-35 mg / mL, etc.

[0115] The second solvent may be selected from non-polar solvents, and specifically may include one or more of n-hexane, cyclohexane, n-pentane, isopentane, n-octane, n-nonane, etc. It is understandable that the second solvent may be a single solvent or a mixed solvent.

[0116] The second inorganic material may refer to the related description of the light emitting device 100 mentioned above, which will not be described in detail here.

[0117] In the above-mentioned forming of the first electron transport layer and forming of the second electron transport layer, a drying step is included. The drying can be heating drying, the heating drying temperature is 60 to 150° C., and the time is 1 min to 30 min. The drying can be vacuum drying, and the vacuum drying pressure is 10 -1 ~10 -2 Pa, the temperature is 0-30°C, for example, it can be at room temperature of about 25°C.

[0118] In one embodiment, before forming the second electron transport layer, the method further includes preparing a second electron transport material, specifically including:

[0119] Step S61: providing a fourth solution, wherein the fourth solution includes a second metal source, a second ligand solvent and a fourth solvent;

[0120] Step S62: adding a second base to the fourth solution, mixing and reacting to obtain a second inorganic material.

[0121] Wherein, in step S61:

[0122] The second metal source includes a second main metal source, and the second main metal source includes one or more of a second zinc source and a second titanium source; wherein the second zinc source may include at least one of zinc acetate, zinc chloride and zinc oxide, and the second titanium source may include one or more of isopropyl titanate, titanyl sulfate, titanium tetrachloride, etc.

[0123] Furthermore, the second metal source also includes a second doping metal source, and the second doping metal source may include one or more of a Mg source, a Ca source, a Li source, a Ga source, an Al source, a Co source, a Mn source, a Zr source, a W source, a Ti source, a Y source, an In source, etc. Specifically, the second doping metal source may be selected from corresponding metal salts and hydrates thereof, etc., which are not limited here.

[0124] The fourth solvent may include one or more of dimethyl sulfoxide, N,N-dimethylformamide, methanol, ethanol, and tetrahydrofuran.

[0125] The second ligand solvent includes one or more of a carboxylic acid solvent having 4 to 12 carbon atoms, a thiol solvent having 4 to 12 carbon atoms, an amine solvent having 4 to 12 carbon atoms, and a phosphoric acid solvent having 4 to 12 carbon atoms.

[0126] Specifically, the carboxylic acid solvent with 4 to 12 carbon atoms includes one or more of butyric acid, pentanoic acid, hexanoic acid, heptanoic acid, n-octanoic acid, n-decanoic acid, undecanoic acid, dodecanoic acid (lauric acid), etc. The thiol solvent with 4 to 12 carbon atoms includes one or more of butyl mercaptan, hexyl mercaptan, 1-heptyl mercaptan, n-octyl mercaptan, isooctyl mercaptan, 1-decyl mercaptan, 1-undecyl mercaptan, 1-dodecanethiol, 1-pentyl mercaptan, etc. The amine solvent with 4 to 12 carbon atoms includes one or more of n-butylamine, pentylamine, hexylamine, heptylamine, n-octylamine, decylamine, 1-aminoundecane, dodecylamine, etc. The phosphoric acid solvent with 4 to 12 carbon atoms includes one or more of n-hexyl phosphoric acid, 1-octyl phosphoric acid, 1-decyl phosphoric acid, n-dodecyl phosphoric acid, etc.

[0127] In one embodiment, the second metal source includes a second metal cation and a second anion, wherein the second metal cation may include a second main metal and a second doping metal. The molar ratio of the second ligand solvent to the second anion is greater than or equal to 1:5, specifically 1:5 to 1.1, 1:5 to 1:2, 1:4 to 1:2, 1:4 to 1:3, 1:5 to 3:10, 3:10 to 1:1, etc. The molar ratio of the second ligand solvent to the second anion can make the molar percentage of the long-chain ligands connected to the surface of the second inorganic material finally formed greater than or equal to 10% of all ligands.

[0128] In one embodiment, the second metal source, the second ligand solvent and the fourth solvent are stirred at 20-80° C. and condensed under reflux for 1-8 hours to obtain the fourth solution.

[0129] In step S62:

[0130] The molar ratio of the metal element in the second metal source to the second base is 1:(0.5-2), specifically 1:(0.5-1.5), 1:(1.0-1.5), 1:(1.1-1.5), 1:(1.1-1.3), etc.

[0131] The second base may include one or more of lithium hydroxide, sodium hydroxide, potassium hydroxide, aqueous ammonia, tetramethylammonium hydroxide, and one or more of hydrates thereof.

[0132] It is understandable that the second base can be added in the form of an alkaline solution. Specifically, the solvent in the alkaline solution can include one or more of dimethyl sulfoxide, N,N-dimethylformamide, methanol, ethanol, and tetrahydrofuran. It is understandable that the solvent in the alkaline solution can be the same as or different from the fourth solvent. In a specific embodiment, the second base is added to the corresponding solution and stirred at room temperature for 1 to 8 hours to obtain the alkaline solution.

[0133] In one embodiment, the mixing reaction time can be 0.1 to 10 hours, specifically 0.1 to 1 hour, 1 to 3 hours, 3 to 5 hours, 5 to 8 hours, 8 to 10 hours, etc. The mixing reaction temperature can be 20 to 80°C, specifically 20 to 40°C, 40 to 60°C, 60 to 80°C, etc. In a specific embodiment, the mixing reaction is specifically: mixing at 20 to 80°C, stirring and condensing and refluxing for 0.1 to 10 hours.

[0134] It is understandable that after the mixing reaction, purification may be performed to obtain the second inorganic material. Specifically, the purification may be performed by repeated centrifugation and dispersion using ethanol and n-octane.

[0135] In one embodiment, the method for preparing the light-emitting device further includes: forming a hole functional layer between the light-emitting layer and the first electrode.

[0136] Among them, the first electrode, the second electrode, the light-emitting layer, the hole functional layer, etc. can all refer to the relevant contents in the light-emitting device 100 described above, and will not be repeated here.

[0137] In the light-emitting device provided in the present application, the preparation of the first electrode, the second electrode, the light-emitting layer, the hole functional layer and other film layers can be achieved by conventional techniques in the art, such as chemical methods or physical methods. 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 plating method and solution method, among which the physical plating method includes: thermal evaporation coating method, electron beam evaporation coating method, magnetron sputtering method, multi-arc ion plating method, physical vapor deposition method, atomic layer deposition method, pulsed laser deposition method, etc.; the solution method can be spin coating, printing method, inkjet printing method, blade coating method, printing method, dip pulling method, immersion method, spraying method, roll coating method, casting method, slit coating method and strip coating method, etc.

[0138] It is understandable that the method for preparing the light-emitting device may further include a packaging step, and the packaging step may refer to packaging methods known in the art. For example, the packaging material used for packaging may be selected from at least one of UV glue, metal film, and glass glue. In a specific embodiment, the packaging material may be acrylic resin or epoxy resin. The packaging may be machine packaging or manual packaging, and may be sealed with ultraviolet curing glue. The concentration of oxygen and water in the environment of the packaging step is less than 0.1ppm to ensure the stability of the light-emitting device.

[0139] The present application also relates to a display device, which includes the light-emitting device provided in the present application. The display device can be any electronic product with a display function, including but not limited to smart phones, tablet computers, laptop computers, digital cameras, digital video cameras, smart wearable devices, smart weighing electronic scales, car displays, televisions or e-book readers, wherein the smart wearable device can be, for example, a smart bracelet, a smart watch, a virtual reality (VR) helmet, etc.

[0140] 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.

[0141] The device embodiment provides a quantum dot light emitting diode and a method for preparing the same, which specifically includes the following steps.

[0142] Step 1: providing a substrate with a bottom electrode, wherein the bottom electrode is ITO;

[0143] Step 2: Spin-coat PEDOT:PSS on the bottom electrode at a speed of 4000 rpm for 30 seconds, and dry to remove the solvent to obtain a hole injection layer with a thickness of 90 nm;

[0144] Step 3: In an inert atmosphere, spin-coat TFB (concentration of 8 mg / mL) on the hole injection layer at a speed of 3000 rpm for 30 s, and dry to remove the solvent to obtain a hole transport layer with a thickness of 80 nm;

[0145] Step 4: Blue quantum dots (CdZnS / ZnS) are arranged on the hole transport layer to obtain a light-emitting layer with a thickness of 15 nm.

[0146] Step 5: Prepare the first electron transport layer on the light-emitting layer: add 10mmol zinc acetate dihydrate and 2mmol zinc chloride to 30ml dimethyl sulfoxide, stir at room temperature for 2 hours to obtain a zinc precursor; add 15mmol lithium hydroxide to 30ml ethanol and stir at room temperature for 2 hours to obtain an oxygen precursor; mix the zinc precursor and the oxygen precursor at room temperature and stir for 15 hours, repeatedly centrifuge and disperse with ethanol and heptane to obtain a purified zinc oxide ethanol solution. Deposit the above zinc oxide ethanol solution on the light-emitting layer, and after removing the solvent, form a first electron transport layer with a thickness of 15nm;

[0147] Step 6: Prepare the second electron transport layer on the first electron transport layer: add 10mmol zinc acetate dihydrate to 30ml dimethyl sulfoxide, add 6mmol dodecanoic acid, then stir and condense reflux at 50°C for 2 hours to obtain a metal precursor; add 13mmol lithium hydroxide to 30ml ethanol and stir at room temperature for 2 hours to obtain an oxygen precursor; mix the metal precursor and the oxygen precursor at 70°C, stir and condense reflux for 10 hours, and repeatedly centrifuge and disperse with ethanol and n-octane to obtain a purified n-octane solution of zinc oxide. Deposit the n-octane solution of zinc oxide on the first electron transport layer, remove the solvent to form a second electron transport layer with a thickness of 15nm.

[0148] Step 7: By thermal evaporation, the vacuum degree is not higher than 3×10 -4 Pa, Ag was evaporated on the electron transport layer to obtain a top electrode with a thickness of 60 nm, and then encapsulated.

[0149] Device Example 2

[0150] This device embodiment is substantially the same as device embodiment 1, except that the molar ratio of zinc acetate dihydrate to zinc chloride used in step 5 is changed from 5:1 to 10:1, and the sum of the molar amounts of the two remains unchanged.

[0151] Device Example 3

[0152] This device embodiment is substantially the same as device embodiment 1, except that the molar ratio of zinc acetate dihydrate to zinc chloride used in step 5 is changed from 5:1 to 1:1, and the sum of the molar amounts of the two remains unchanged.

[0153] Device Example 4

[0154] This device example is substantially the same as device example 1, except that in step 6, the amount of dodecanoic acid is reduced from 6 mmol to 4 mmol.

[0155] Device Example 5

[0156] This device example is substantially the same as device example 1, except that in step 6, the amount of dodecanoic acid used is 20 mmol.

[0157] Device Example 6

[0158] This device example is substantially the same as device example 1, except that in step 6, 1-undecanethiol is used instead of dodecanoic acid.

[0159] Device Example 7

[0160] This device embodiment is substantially the same as device embodiment 1, except that in step 6, n-dodecyl phosphoric acid is used instead of dodecanoic acid.

[0161] Device Example 8

[0162] This device embodiment is substantially the same as device embodiment 1, except that in step 6, dodecylamine is used instead of dodecanoic acid.

[0163] Device Comparison Example 1

[0164] The device comparative example is basically the same as device embodiment 1, with the only difference being that the first electron transport layer is prepared only according to step 5 with a thickness of 30 nm, and step 6 is not performed. The finally formed light-emitting device only includes the first electron transport layer and does not include the second electron transport layer.

[0165] Device Comparison Example 2

[0166] This device embodiment is basically the same as device embodiment 1, with the only difference being that: step 5 is not performed, and only the preparation of the second electron transport layer in step 6 is performed, and a second electron transport layer with a thickness of 30 nm is formed. The light-emitting device finally formed only includes the second electron transport layer, and does not include the first electron transport layer.

[0167] Test 1

[0168] Zinc oxide was prepared according to the method for preparing zinc oxide in step 6 of Example 1, except that the amount of dodecanoic acid was reduced from 6 mmol to 1 mmol. The prepared zinc oxide (B) and the zinc oxide (A) prepared in step 6 of Example 1 were dissolved, and the mixture was stirred for 2 hours. Figure 4 , Figure 4 Schematic diagram of zinc oxide dissolution corresponding to Test 1.

[0169] Depend on Figure 4 It can be seen that the zinc oxide in A is turbid in the non-polar solvent-n-octane, that is, the dispersibility is poor, while the zinc oxide in B is clear in the non-polar solvent-n-octane, that is, the solubility is good. This shows that the addition of dodecanoic acid can make zinc oxide have better solubility in non-polar solvents, so that the different settings of zinc oxide surface ligands in the two electron transport layers can be used to avoid dissolution and penetration damage to the materials between the two electron transport layers, thereby improving the film quality and the life of the device. When the amount of dodecanoic acid added is small, the dispersibility and solubility of zinc oxide in non-polar solvents are poor, so agglomeration may occur, affecting the film forming property.

[0170] Test 2

[0171] The quantum dot light-emitting diodes of device embodiments 1-8 and device comparison examples 1-2 were tested, specifically including the turn-on voltage V@1nit, the maximum device efficiency CE@max at a current of 2mA, and the device life T95-1000 nit. The test data are shown in Table 1.

[0172] Among them, device life: the time required for the brightness of the device to decrease to a certain proportion of the maximum brightness when driven by a constant current or voltage. The time when the brightness drops to 95% of the maximum brightness is defined as T95, and this life is the measured life. In order to shorten the test cycle, the device life test is usually carried out by accelerating device aging at high brightness with reference to the OLED device test, and the life under high brightness is obtained by fitting the extended exponential decay brightness attenuation fitting formula, for example: the life under 1000nit is calculated as T95-1000 nit. The specific calculation formula is as follows:

[0173]

[0174] Where T95 L For lifespan at low brightness, T95 H is the measured lifetime under high brightness, L H To accelerate the device to the highest brightness, L L is 1000nit, A is the acceleration factor, and this experiment measured the lifespan of several groups of QLED devices at rated brightness and found that the A value was 1.7.

[0175] The life test system is used to carry out life test on the corresponding devices. The test conditions are: at room temperature and the air humidity is 30-60%.

[0176] Table 1

[0177] V@1nit(V) CE@max(cd / A) T95@1knit(h) Device Example 1 3.5 17 77 Device Example 2 3.7 12 45 Device Example 3 3.2 18 85 Device Example 4 3.4 12 60 Device Example 5 4.7 15 72 Device Example 6 3.7 14 82 Device Example 7 3.8 16 71 Device Example 8 4.0 16 68 Device Comparison Example 1 3.1 10 45 Device Comparison Example 2 4.8 11.7 51

[0178] It can be seen from Table 1 that compared with the single-layer electron transport layer in device comparison examples 1 and 2, the light-emitting devices of device embodiments 1-8 can have a smaller turn-on voltage (V@1nit) while also having better current efficiency CE@max and life T95-1000 nit, indicating that the use of a double-layer electron transport layer in the present application can improve the operating voltage of the light-emitting device and has a significant effect on improving the luminous efficiency and life.

[0179] It can be seen from Examples 1-3 that when the amount of halogen ligand used is small, the conduction band energy level of zinc oxide may not be significantly improved, and the exciton recombination area is not limited, so the improvement of the luminous efficiency of the device is not obvious.

[0180] The light-emitting device and its preparation method, and the 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 light emitting device, characterized in that: include: A first electrode and a second electrode arranged opposite to each other; A light-emitting layer is disposed between the first electrode and the second electrode; An electronic functional layer, disposed between the second electrode and the light-emitting layer; Among them, the electronic functional layer includes a first electron transport layer and a second electron transport layer, the first electron transport layer is arranged close to the light-emitting layer, and the second electron transport layer is arranged close to the second electrode, the material of the first electron transport layer includes a first inorganic material, and the material of the second electron transport layer includes a second inorganic material, wherein a first ligand is connected to the first inorganic material, and a second ligand is connected to the second inorganic material, the first ligand includes a halogen ligand, and the second ligand includes a long carbon chain ligand with a carbon atom number of 4 to 12.

2. The light emitting device according to claim 1, characterized in that: The molar percentage of the halogen ligand in the first ligand is greater than or equal to 20%; and / or, The halogen ligand includes one or more of a fluoride ion ligand, a chloride ion ligand, a bromide ion ligand, and an iodide ion ligand; and / or, The molar percentage of the long carbon chain ligand having 4 to 12 carbon atoms in the second ligand is greater than or equal to 10%; and / or, The long carbon chain ligand with 4 to 12 carbon atoms includes one or more of a carboxylic acid ligand with 4 to 12 carbon atoms, a phosphate ligand with 4 to 12 carbon atoms, a thiol ligand with 4 to 12 carbon atoms or an amine ligand with 4 to 12 carbon atoms.

3. The light emitting device according to claim 2, characterized in that: The carboxylic acid ligand having 4 to 12 carbon atoms includes one or more of butyric acid, valeric acid, caproic acid, heptanoic acid, n-octanoic acid, n-decanoic acid, undecanoic acid, and lauric acid; and / or, The phosphate ligand having 4 to 21 carbon atoms includes one or more of n-hexyl phosphate, 1-octyl phosphate, 1-decyl phosphate, and n-dodecyl phosphate; and / or, The thiol ligand having 4 to 12 carbon atoms includes one or more of butyl mercaptan, 1-pentyl mercaptan, 1-hexyl mercaptan, 1-heptyl mercaptan, n-octyl mercaptan, isooctyl mercaptan, 1-decyl mercaptan, 1-undecanethiol, and 1-dodecanethiol; and / or, The amine ligand having 4 to 12 carbon atoms includes one or more of n-butylamine, pentylamine, hexylamine, heptylamine, n-octylamine, decylamine, 1-aminoundecane, and dodecylamine.

4. The light emitting device according to claim 1, characterized in that: The electronic functional layer consists of the first electron transport layer and the second electron transport layer; and / or, The first inorganic material comprises at least one of a metal oxide, a doped metal oxide, a IIB-VIA semiconductor material, a IIIB-VA semiconductor material and an IB-IIIB-VIA semiconductor material, the metal oxide being selected from at least one of ZnO, TiO2, SnO2, BaO, Ga2O3 and ZrO2; the metal oxide in the doped metal oxide being selected from at least one of ZnO, TiO2 and SnO2, the doping element being selected from at least one of Mg, Ca, Li, Ga, Al, Co, Mn, Zr, W, Ti, Y and In, the IIB-VIA semiconductor material being selected from at least one of ZnS, ZnSe and CdS; the IIIB-VA semiconductor material being selected from at least one of InP and GaP; the IB-IIIB-VIA semiconductor material being selected from at least one of CuInS and CuGaS; and / or, The second inorganic material comprises at least one of a metal oxide, a doped metal oxide, a IIB-VIA semiconductor material, a IIIB-VA semiconductor material and an IB-IIIB-VIA semiconductor material, the metal oxide being selected from at least one of ZnO, TiO2, SnO2, BaO, Ga2O3 and ZrO2; the metal oxide in the doped metal oxide being selected from at least one of ZnO, TiO2 and SnO2, the doping element being selected from at least one of Mg, Ca, Li, Ga, Al, Co, Mn, Zr, W, Ti, Y and In, the IIB-VIA semiconductor material being selected from at least one of ZnS, ZnSe and CdS; the IIIB-VA semiconductor material being selected from at least one of InP and GaP; the IB-IIIB-VIA semiconductor material being selected from at least one of CuInS and CuGaS; and / or, The thickness of the first electron transport layer is 5 to 40 nm; and / or, The thickness of the second electron transport layer is 5 to 40 nm; and / or, The material of the light-emitting layer is an organic light-emitting material or a quantum dot light-emitting material, and the organic light-emitting material is selected from at least one of diaromatic anthracene derivatives, distilbene aromatic derivatives, pyrene derivatives or fluorene derivatives, TBPe fluorescent materials emitting blue light, TTPA fluorescent materials emitting green light, TBRb fluorescent materials emitting orange light, and DBP fluorescent materials emitting red light; the quantum dot light-emitting material can be selected from at least one of single-structure quantum dots, core-shell structure quantum dots and perovskite semiconductor materials, the single-structure quantum dots are selected from at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds and I-III-VI group compounds, the I Group I-VI compounds are selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZn S, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZ 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, 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, GaNAs, GaNSb, at least one of GaPAs, GaPSb, AlNPs, AlNAs, AlNSb, AlPAs, AlPSb, InNPs, InNAs, InNSb, InPAs, InPSb, GaAlNPs, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNPs, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNPs, InAlNAs, InAlNSb, InAlPAs and InAlPSb, and the Group I-III-VI compound is at least one of CuInS, CuInSe and AgInS;The core of the quantum dots of the core-shell structure is selected from any one of the above-mentioned single-structure quantum dots, and the shell material of the quantum dots of the core-shell structure is selected from at least one of CdS, CdTe, CdSeTe, CdZnSe, CdZnS, CdSeS, ZnSe, ZnSeS and ZnS; the perovskite semiconductor material is selected from 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+ At least one of, X is a halogen anion selected from Cl - Br - ,I - At least one 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+ At least one of, X is a halogen anion selected from Cl - Br - ,I - At least one of; and / or, The first electrode and the second electrode are independently selected from metal electrodes, carbon electrodes, doped or undoped metal oxide electrodes and composite electrodes; wherein the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, Ni, Ir and Mg; the material of the carbon electrode is selected from at least one of graphite, carbon nanotubes, graphene and carbon fiber; the material of the doped or undoped metal oxide electrode is selected from ITO, FTO, ATO, AZO, GZO, IZO, MZO, ITZO, ICO, At least one of AMO, SnO2, In2O3, Cd:ZnO, F:SnO2, In:SnO2, and Ga:SnO2; the material of the composite electrode is selected from at least one of 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, and ZnS / Al / ZnS; and / or, The light-emitting device further comprises a hole functional layer, which is arranged between the first electrode and the light-emitting layer. The hole functional layer comprises at least one layer of a hole injection layer and a hole transport layer. The material of the hole transport layer is selected from arylamine, polyaniline, polypyrrole, poly(p-phenylene vinylene) and its derivatives, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, poly(N-vinyl carbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octyl)-1,1'-biphenyl compound, poly(p-carbazolyl ... Fluorene) and its derivatives, poly (spirofluorene) and its derivatives, doped or undoped NiO, MoO3, WO3, V2O5, CrO3, CuO, MoS2, MoSe2, WS3, WSe3, CuS, CuSCN one or more; wherein the aromatic amine is selected from 4,4'-bis (9-carbazole) biphenyl, poly (9,9-dioctylfluorene-CO-N- (4-butylphenyl) diphenylamine), poly (N,N'-bis (4-butylphenyl) -N,N'-bis (phenyl) benzidine), N,N'-bis (4- (N,N'-diphenyl-amino) phenyl )-N,N'-diphenylbenzidine, poly(9,9-dioctylfluorene-co-bis-N,N-phenyl-1,4-phenylenediamine), 4,4',4"-tri(carbazol-9-yl)triphenylamine, 4,4',4"-tri(N-carbazolyl)-triphenylamine, 4,4',4"-tri(N-3-methylphenyl-N-phenylamino)triphenylamine, 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'- One or more of diphenyl-N,N'-(1-naphthyl)-1,1'-biphenyl-4,4'-diamine, Spiro-NPB, Spiro-TPD, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, Spiro-NPB; the poly(p-)phenylene vinylene and its derivatives are selected from one or more of poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene] and poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene];The material of the hole injection layer is selected from poly(ethylenedioxythiophene): polystyrene sulfonate, 2,3,5,6-tetrafluoro-7,7',8,8'-tetracyanoquinone-dimethane, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, copper phthalocyanine, poly(9,9-dioctyl-fluorene-co-N-(4-butylphenyl)-diphenylamine), polyarylamine, poly(N-vinylcarbazole), polyaniline, polypyrrole, N,N,N',N'-tetrakis(4-methoxyphenyl)-benzidine, 4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl, 4,4',4"-tris[phenyl(m-tolyl)amino]triphenylamine, 4,4' ,4"-tri(N-carbazolyl)-triphenylamine (TCTA), 1,1-bis[(di-4-tolylamino)phenylcyclohexane, 4,4',4"-tri(diphenylamino)triphenylamine doped with F4-TCNQ, p-doped phthalocyanine, F4-TCNQ doped N,N'-diphenyl-N,N'-di(1-naphthyl)-1,1'-biphenyl-4,4"-diamine, transition metal oxides, transition metal sulfur compounds; wherein the transition metal oxides include one or more of NiO, MoO2, WO3, and CuO; the metal sulfur compounds include one or more of MoS2, MoSe2, WS3, WSe3, and CuS.; 5. A method for preparing a light-emitting device, characterized in that: include: Providing a preset device, the preset device comprising a second electrode; Arranging an electronic functional layer on the preset device; sequentially disposing a light-emitting layer and a first electrode on a side of the electronic functional layer away from the second electrode; or, The preparation method comprises: Providing a preset device, the preset device comprising a stacked first electrode and a light-emitting layer; Providing an electronic functional layer on the preset device; Disposing a second electrode on the electronic functional layer at a side away from the light-emitting layer; Among them, the electronic functional layer includes a first electron transport layer and a second electron transport layer, the first electron transport layer is arranged close to the light-emitting layer, and the second electron transport layer is arranged close to the second electrode; the material of the first electron transport layer includes a first inorganic material, a first ligand is connected to the first inorganic material, and the first ligand includes a halogen ligand; the material of the second electron transport layer includes a second inorganic material, a second ligand is connected to the second inorganic material, and the second ligand includes a long carbon chain ligand with a carbon atom number of 4 to 12.

6. The preparation method according to claim 5, characterized in that: The step of providing an electronic functional layer on the preset device includes forming a first electron transport layer and forming a second electron transport layer; Wherein, the forming of the first electron transport layer comprises: Providing a first solution, wherein the first solution includes a first inorganic material and a first solvent; wherein a first ligand is connected to the first inorganic material, and the first ligand includes a halogen ligand; and, disposing the first solution in the light-emitting layer or the second electron transport layer to obtain the first electron transport layer; The forming of the second electron transport layer comprises: providing a second solution, wherein the second solution comprises a second inorganic material and a second solvent; and arranging the second solution on the first electron transport layer or the second electrode to obtain the second electron transport layer.

7. The preparation method according to claim 6, characterized in that: Before forming the first electron transport layer, the method further includes preparing a first electron transport material, including: Providing a third solution, wherein the third solution includes a first metal source, wherein the first metal source includes a first metal halide and a first main metal source; A first base is added to the third solution, and mixed to react to obtain a first inorganic material connected with the first ligand.

8. The preparation method according to claim 7, characterized in that: The molar ratio of the metal element in the first main metal source to the metal element in the first metal halide is 10 to 1:1; and / or, The first metal halide includes one or more of zinc fluoride, zinc chloride, zinc bromide, zinc iodide, and titanium tetrachloride; and / or, The first main metal source includes one or more of diethyl zinc, zinc oleate, zinc stearate, zinc acetate, zinc laurate, zinc oxide, tetrabutyl titanate, isopropyl titanate, and titanyl sulfate; and / or, The molar ratio of the metal element in the first metal source to the first base is 1:(0.5-2); and / or, The first base includes one or more of lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonia water, tetramethylammonium hydroxide and hydrates thereof.

9. The preparation method according to claim 6, characterized in that: Before forming the second electron transport layer, the second electron transport material is prepared, which specifically includes: Providing a fourth solution, wherein the fourth solution includes a second metal source and a second ligand solvent; A second base is added to the fourth solution, and mixed to react to obtain a second inorganic material connected with the second ligand.

10. The preparation method according to claim 9, characterized in that: The second metal source includes a second metal cation and a second anion, and the molar ratio of the second ligand solvent to the second anion is greater than or equal to 1:5; and / or, The second ligand solvent includes one or more of a carboxylic acid solvent having 4 to 12 carbon atoms, a thiol solvent having 4 to 12 carbon atoms, an amine solvent having 4 to 12 carbon atoms, and a phosphoric acid solvent having 4 to 12 carbon atoms; and / or, The molar ratio of the metal element in the second metal source to the second base is 1:(0.5-2); and / or, The second base includes one or more of lithium hydroxide, sodium hydroxide, potassium hydroxide, ammonia water, tetramethylammonium hydroxide and hydrates thereof.

11. The preparation method according to claim 6, characterized in that: In the first solution, the concentration of the first inorganic material is 10 to 50 mg / mL; and / or, The first solvent may be selected from polar solvents; and / or, The first inorganic material comprises at least one of a metal oxide, a doped metal oxide, a IIB-VIA semiconductor material, a IIIB-VA semiconductor material and an IB-IIIB-VIA semiconductor material, the metal oxide being selected from at least one of ZnO, TiO2, SnO2, BaO, Ga2O3 and ZrO2; the metal oxide in the doped metal oxide being selected from at least one of ZnO, TiO2 and SnO2, the doping element being selected from at least one of Mg, Ca, Li, Ga, Al, Co, Mn, Zr, W, Ti, Y and In, the IIB-VIA semiconductor material being selected from at least one of ZnS, ZnSe and CdS; the IIIB-VA semiconductor material being selected from at least one of InP and GaP; the IB-IIIB-VIA semiconductor material being selected from at least one of CuInS and CuGaS; and / or, In the second solution, the concentration of the second inorganic material is 10 to 50 mg / mL; and / or, The second solvent may be selected from a non-polar solvent; and / or, The second inorganic material includes at least one of metal oxide, doped metal oxide, IIB-VIA semiconductor material, IIIB-VA semiconductor material and IB-IIIB-VIA semiconductor material, the metal oxide is selected from at least one of ZnO, TiO2, SnO2, BaO, Ga2O3, and ZrO2; the metal oxide in the doped metal oxide is selected from at least one of ZnO, TiO2, and SnO2, the doping element is selected from at least one of Mg, Ca, Li, Ga, Al, Co, Mn, Zr, W, Ti, Y, and In, the IIB-VIA semiconductor material is selected from at least one of ZnS, ZnSe, and CdS; the IIIB-VA semiconductor material is selected from at least one of InP and GaP; the IB-IIIB-VIA semiconductor material is selected from at least one of CuInS and CuGaS.

12. A display device, characterized in that: A light-emitting device comprising the light-emitting device as claimed in any one of claims 1 to 4, or a light-emitting device manufactured by the method for manufacturing the light-emitting device as claimed in any one of claims 5 to 11.

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