Thin film and preparation method thereof, light-emitting device and display device

Abstract

The embodiment of the invention belongs to the technical field of display, and relates to a thin film which comprises an inorganic nano-material and a semiconductor material, the inorganic nano-material comprises an inorganic N-type semiconductor material or an inorganic P-type semiconductor material, and the semiconductor material comprises a perovskite material. The invention further relates to a preparation method of the thin film, a light-emitting device and a display device. According to the technical scheme provided by the invention, the carrier injection quantity can be increased.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and more particularly, to a thin film, a method for preparing the same, a light-emitting device, and a display device. Background Art

[0002] Quantum dot light-emitting diodes (QLEDs) have the advantages of saturated emission light color, adjustable wavelength, and high photoluminescence quantum yield and electroluminescence quantum yield. Currently, QLED devices are mainly divided into green quantum dot devices, red quantum dot devices, and blue quantum dot devices according to the emission color.

[0003] In QLED devices, an inorganic nanoparticle layer is often used to improve carrier transport. However, the carrier transport efficiency of inorganic nanoparticles still needs to be further improved. Summary of the Invention

[0004] Based on this, embodiments of the present application provide a thin film, a method for preparing the same, a light-emitting device, and a display device.

[0005] Embodiments of the present application provide a thin film, adopting the following technical solution:

[0006] A thin film includes an inorganic nanomaterial and a semiconductor material, wherein the inorganic nanomaterial includes an inorganic N-type semiconductor material or an inorganic P-type semiconductor material, and the semiconductor material includes a perovskite material.

[0007] Embodiments of the present application further provide a method for preparing a thin film, adopting the following technical solution:

[0008] A method for preparing a thin film includes the following steps:

[0009] Providing a first solution including an inorganic nanomaterial, a semiconductor material, and a solvent;

[0010] Depositing the first solution to obtain the thin film;

[0011] wherein the inorganic nanomaterial includes an inorganic N-type semiconductor material or an inorganic P-type semiconductor material, and the semiconductor material includes a perovskite material.

[0012] Embodiments of the present application provide a light-emitting device, adopting the following technical solution:

[0013] A light-emitting device includes an anodic layer, a light-emitting layer, and a cathodic layer which are stacked;

[0014] It also includes a first carrier transport layer and / or a second carrier transport layer. The first carrier transport layer is disposed between the light-emitting layer and the cathode layer; the second carrier transport layer is disposed between the anode layer and the light-emitting layer. The first carrier transport layer includes an inorganic N-type semiconductor material, and the second carrier transport layer includes an inorganic P-type semiconductor material;

[0015] Wherein, the first carrier transport layer further includes a first semiconductor material, and / or, the second carrier transport layer further includes a second semiconductor material. The first semiconductor material and the second semiconductor material each independently include a perovskite material.

[0016] An embodiment of the present application provides a display device, which adopts the following technical solutions:

[0017] A display device, the display device includes the light-emitting device as described above.

[0018] Compared with the prior art, the embodiments of the present application mainly have the following beneficial effects:

[0019] In the thin film provided by the present application, an inorganic nanomaterial is mixed with a semiconductor material having a low exciton binding energy. Due to the property of the low exciton binding energy of the semiconductor material, excitons inside it are easily split to form carriers, so as to increase the number of carrier injections, thereby improving the luminous efficiency and service life of the light-emitting device including the above thin film. Description of the Drawings

[0020] In order to more clearly illustrate the solutions of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 It is a schematic structural diagram of the light-emitting device of this embodiment;

[0022] Figure 2 It is a current density-voltage (J-V) characteristic curve graph of thin film Examples 1-3 and thin film Comparative Example 1 of the present application;

[0023] Figure 3 It is a current density-voltage (J-V) characteristic curve graph of thin film Examples 4-6 and thin film Comparative Example 2 of the present application.

[0024] Reference Signs:

[0025] 1. Anode layer; 2. Hole injection layer; 3. Hole transport layer; 4. Light-emitting layer; 5. Electron function layer; 6. Cathode layer; 7. Light extraction layer. Detailed Embodiments

[0026] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "comprising" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order.

[0027] Reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0028] An embodiment of this application provides a thin film, comprising an inorganic nanomaterial and a semiconductor material, wherein the inorganic nanomaterial comprises an inorganic N-type semiconductor material or an inorganic P-type semiconductor material, and the semiconductor material comprises a perovskite material.

[0029] The thin film provided by the embodiment of this application is formed by mixing an inorganic nanomaterial and a semiconductor material with a low exciton binding energy. By utilizing this property, excitons inside are easily decomposed into carriers under light illumination conditions, thereby increasing the number of carrier injections and further improving the carrier transport efficiency.

[0030] In some embodiments, the thin film is composed of the inorganic nanomaterial and the semiconductor material.

[0031] In some embodiments, the mass ratio of the inorganic nanomaterial to the semiconductor material is (95 - 99.5):(0.5 - 5). For example, the mass ratio of the inorganic nanomaterial to the semiconductor material is 95:5, the mass ratio of the inorganic nanomaterial to the semiconductor material is 96:4, the mass ratio of the inorganic nanomaterial to the semiconductor material is 97:3, the mass ratio of the inorganic nanomaterial to the semiconductor material is 98:2, the mass ratio of the inorganic nanomaterial to the semiconductor material is 99:1, and the mass ratio of the inorganic nanomaterial to the semiconductor material is 99.5:0.5.

[0032] In the embodiments of the present application, by controlling the mass ratio between the inorganic nanomaterial and the semiconductor material, while maintaining the original carrier transport efficiency, the number of carrier injections is increased, thereby achieving the effect of increasing the overall number of carrier injections.

[0033] In some embodiments, when the thin film serves as an electron functional layer, the inorganic nanomaterial includes an inorganic N-type semiconductor material, and the inorganic N-type semiconductor material is selected from at least one of doped or undoped first metal oxides, metal sulfides, and metal phosphides; wherein, the first metal oxide is selected from at least one of zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, and nickel oxide, the metal sulfide is selected from at least one of cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, copper sulfide, copper indium sulfide, and copper gallium sulfide, and the metal phosphide is selected from at least one of indium phosphide and gallium phosphide; the doped elements include at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium.

[0034] In some embodiments, when the thin film serves as a hole functional layer, the inorganic nanomaterial includes an inorganic P-type semiconductor material, and the inorganic P-type semiconductor material is selected from doped or undoped second metal oxides, wherein the second metal oxide is selected from at least one of molybdenum oxide, tungsten oxide, nickel oxide, copper oxide, vanadium pentoxide, and chromium oxide, the metal sulfide is selected from copper sulfide, and the doped elements include at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium.

[0035] In some embodiments, the molybdenum oxide is molybdenum trioxide (MoO3); the chemical formula of the tungsten oxide is WO m , where m is 1, 2, or 3; the chemical formula of the nickel oxide is NiO n , where n is 1 or 2; the chemical formula of the copper oxide is CuO q , where q is 1 or 2. It can be understood that the tungsten oxide can be any one tungsten oxide or a mixture of multiple tungsten oxides, the nickel oxide can be any one nickel oxide or a mixture of multiple nickel oxides, and the copper oxide can be any one copper oxide or a mixture of multiple copper oxides.

[0036] In some embodiments, the exciton binding energy of the perovskite material is less than 100 meV.

[0037] In some embodiments, the perovskite material is at least one of an inorganic perovskite material, an organic perovskite material, and an organic-inorganic hybrid perovskite material, wherein the structural general formula of the inorganic perovskite material is AMX3, where A is a Cs + ion, M is a divalent metal cation, and M is selected from Pb 2+, Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ and Eu 2+ One or more of the following, X is a halogen anion, and X is selected from Cl - , Br - , I - At least one of the following; the structural general formula of the organic perovskite material is CMX3, where C is formamidinium, M is a divalent metal cation, and M is selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ and Eu 2+ One or more of the following, X is a halogen anion, and X is selected from Cl - , Br - , I - At least one of the following; the structural general formula of the organic-inorganic hybrid perovskite material is BMX3, where B is selected from organic amine cations, M is a divalent metal cation, and M is selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ and Eu 2+ One or more of the following, X is a halogen anion, and X is selected from Cl - , Br - , I - At least one of the following.

[0038] In some embodiments, the perovskite material is selected from at least one of CsPbI3, CsPbBr3, formamidinium lead iodide (FAPbI3), formamidinium lead bromide (FAPbBr3), methylammonium lead iodide (CH3NH3PbI3), and methylammonium lead bromide (CH3NH3PbBr3). In this embodiment, the perovskite material is CH3NH3PbI3.

[0039] Based on the above thin film, an embodiment of the present application further provides a method for preparing a thin film, including the following steps:

[0040] Providing a first solution including inorganic nanomaterials, semiconductor materials, and a solvent;

[0041] Depositing the first solution to obtain the thin film;

[0042] Wherein, the inorganic nanomaterials include inorganic N-type semiconductor materials or inorganic P-type semiconductor materials, and the semiconductor materials include perovskite materials.

[0043] The method for preparing a thin film provided by the embodiment of the present application disperses inorganic nanomaterials and semiconductor materials in a solvent to form a first solution, and uses the first solution to prepare a thin film. By mixing a semiconductor material with a low exciton binding energy in the thin film, excitons in the thin film are easily decomposed to form carriers, thereby increasing the number of carrier injections in the carrier transport layer and improving the carrier transport efficiency.

[0044] In some embodiments, the first solution further includes a solvent. In some embodiments, the solvent is an alcohol solvent, and the alcohol solvent includes at least one of ethanol, isopropanol, n-butanol, 2-butanol, cyclohexanol, ethylene glycol, glycerol, butanediol, pentanediol, n-hexanol, heptanol, and thiol compounds; wherein, the thiol compounds can be selected from at least one of ethylene glycol bis(3-mercaptopropionate), ethylene glycol dimercaptoacetate, trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), 1,6-hexanedithiol, 1,3-propanedithiol, 1,2-ethanedithiol, and polyethylene glycol dithiol containing 1-10 ethylene glycol repeating units.

[0045] In some embodiments, the concentration range of the first solution is 20 mg / ml to 40 mg / ml. Specifically, the concentration of the first solution can be set to any value of 20 mg / ml, 30 mg / ml, 40 mg / ml, or a range formed between any two values.

[0046] In some embodiments, the mass ratio of the inorganic nanomaterial to the semiconductor material is (95 to 99.5):(0.5 to 5). For example, the mass ratio of the inorganic nanomaterial to the semiconductor material is 95:5, the mass ratio of the inorganic nanomaterial to the semiconductor material is 96:4, the mass ratio of the inorganic nanomaterial to the semiconductor material is 97:3, the mass ratio of the inorganic nanomaterial to the semiconductor material is 98:2, the mass ratio of the inorganic nanomaterial to the semiconductor material is 99:1, and the mass ratio of the inorganic nanomaterial to the semiconductor material is 99.5:0.5.

[0047] In some embodiments, the inorganic N-type semiconductor material is selected from at least one of doped or undoped first metal oxides, metal sulfides, and metal phosphides; the inorganic P-type semiconductor material is selected from doped or undoped second metal oxides. Specific inorganic N-type semiconductor materials and inorganic P-type semiconductor materials are as described above and will not be elaborated here.

[0048] In this embodiment, when the inorganic N-type semiconductor material is ZnMgO, the semiconductor material is CH3NH3PbI3, and the solvent is an ethanol solvent.

[0049] In other embodiments, when the inorganic P-type semiconductor material is NiO, the semiconductor material is CH3NH3PbI3, and the solvent is an ethanol solvent.

[0050] After mixing the inorganic nanomaterial and the semiconductor material, disperse them in the solvent to form a first solution.

[0051] In this embodiment, ZnMgO and CH3NH3PbI3 are mixed in a mass ratio of 97%:3% and then dispersed in an ethanol solvent to form a first solution as an electron transport ink.

[0052] In other embodiments, NiO and CH3NH3PbI3 are mixed in a mass ratio of 97%:3% and then dispersed in an ethanol solvent to form a first solution as a hole transport ink.

[0053] The first solution prepared in the embodiments of the present application is obtained by mixing an inorganic nanomaterial with a semiconductor material having a low exciton binding energy. By utilizing the property of the low exciton binding energy of the semiconductor material, excitons inside are easily decomposed into carriers under light illumination conditions, thereby achieving the effect of increasing the number of carrier injections; by controlling the mass ratio between the inorganic nanomaterial and the semiconductor material, on the premise of maintaining the original carrier transport efficiency, the number of carrier injections is increased, thereby increasing the overall number of carrier injections.

[0054] In some embodiments, the deposition of the first solution specifically includes the following steps:

[0055] Under room temperature conditions, the first solution is subjected to vacuum drying treatment and then annealing treatment.

[0056] In some embodiments, the room temperature conditions refer to the temperature range of 25°C to 30°C.

[0057] The range of the vacuum degree of the vacuum drying treatment is 0.1 Pa to 0.001 Pa.

[0058] The time of the vacuum drying treatment is 5 min to 15 min.

[0059] The time of the annealing treatment is 10 min to 15 min.

[0060] The temperature of the annealing treatment is 85°C to 95°C.

[0061] Please refer to Figure 1 As shown, the embodiment of the present application further provides a light-emitting device, and the light-emitting device contains the above-mentioned thin film.

[0062] In some embodiments, the light-emitting device includes a stacked anode layer 1, a light-emitting layer 4, and a cathode layer 6; it further includes a first carrier transport layer and / or a second carrier transport layer. The first carrier transport layer is disposed between the light-emitting layer 4 and the cathode layer 6 and serves as an electron transport layer; or, the second carrier transport layer is disposed between the anode layer and the light-emitting layer and serves as a hole transport layer.

[0063] Wherein, the first carrier transport layer includes an inorganic N-type semiconductor material, and the second carrier transport layer includes an inorganic P-type semiconductor material. Wherein, the first carrier transport layer further includes a first semiconductor material, and / or, the second carrier transport layer further includes a second semiconductor material, and the first semiconductor material and the second semiconductor material each independently include a perovskite material.

[0064] By using the above-mentioned thin film to prepare the carrier transport layer of the light-emitting device in the embodiment of the present application, the carrier migration efficiency of the light-emitting device is improved, so that the charge balance in the light-emitting layer 4 is achieved, and the effect of improving the device performance of the light-emitting device is realized.

[0065] In some embodiments, the mass ratio of the inorganic N-type semiconductor material to the first semiconductor material is (95 to 99.5):(0.5 to 5), where the inorganic N-type semiconductor material is selected from at least one of doped or undoped first metal oxides, metal sulfides, and metal phosphides, the first metal oxide is selected from at least one of zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide; and / or, the metal sulfide is selected from at least one of cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, and copper sulfide; and / or, the metal phosphide is selected from at least one of indium phosphide and gallium phosphide; and / or, the doped element includes at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium.

[0066] In some embodiments, the mass ratio of the inorganic P-type semiconductor material to the second semiconductor material is (95 to 99.5):(0.5 to 5), where the inorganic P-type semiconductor material is selected from doped or undoped second metal oxides, and the second metal oxide is selected from at least one of molybdenum oxide, tungsten oxide, nickel oxide, copper oxide, vanadium pentoxide, and chromium oxide; and / or, the doped element includes at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium.

[0067] In some embodiments, when the thin film serves as the electron transport layer, the light-emitting device further includes a hole injection layer 2 and a hole transport layer 3 disposed between the anode layer 1 and the light-emitting layer 4. The hole injection layer 2 is disposed close to the anode layer 1, and the hole transport layer 3 is disposed close to the light-emitting layer 4. In other embodiments, when the thin film serves as the hole transport layer 3, the light-emitting device further includes a hole injection layer 2 disposed between the anode layer 1 and the hole transport layer 3, and an electron functional layer 5 disposed between the light-emitting layer 4 and the cathode layer 6.

[0068] Please refer to Figure 1 As shown, in this embodiment, the light-emitting device is a normal light-emitting device, and the structure of the light-emitting device is anode layer 1 / hole injection layer 2 / hole transport layer 3 / light-emitting layer 4 / electron functional layer 5 / cathode layer 6. In other embodiments, the light-emitting device may also be an inverted light-emitting device, and the structure of the light-emitting device is cathode layer 6 / electron functional layer 5 / light-emitting layer 4 / hole transport layer 3 / hole injection layer 2 / anode layer 1.

[0069] In some embodiments, the material of the anode layer 1 and / or the cathode layer 6 includes at least one of a metal, a carbon material, and a metal oxide. The metal includes at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon material includes at least one of graphite, carbon nanotubes, graphene, and carbon fibers; the metal oxide includes a doped or undoped metal oxide, including at least one of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO, or a composite electrode including a metal sandwiched between doped or undoped transparent metal oxides. The composite electrode includes at least one 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. In this embodiment, the anode layer 1 is formed on a substrate to form an ITO / Ag / ITO substrate, and the material of the cathode layer 5 is Ag.

[0070] In some embodiments, the material of the hole injection layer 2 includes at least one of TFB, CuPc, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal stannides, doped graphene, undoped graphene, and C60. In this embodiment, the material of the hole injection layer 2 is PEDOT:PSS.

[0071] The material of the light-emitting layer 4 includes quantum dots; wherein, the quantum dots include at least one of single-structure quantum dots and core-shell structure quantum dots. The materials of the single-structure quantum dots, the core materials of the core-shell structure quantum dots, and the shell materials of the core-shell structure quantum dots are respectively 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 shell layer of the core-shell structure quantum dots includes one or more layers; wherein, the II-VI group compounds are selected from at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds are 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; the III-V group compounds are selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; and the I-III-VI group compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2.

[0072] The quantum dots further include ligands connected to their surfaces, and the ligands are selected from at least one of acid ligands, thiol ligands, amine ligands, (oxy)phosphine ligands, phospholipids, lecithins, polyvinylpyridines, etc.; the acid ligands include at least one of decanoic acid, undecylenic acid, myristic acid, oleic acid, and stearic acid; the thiol ligands include at least one of octyl mercaptan, dodecyl mercaptan, and octadecyl mercaptan; the amine ligands include one or more of oleylamine, octadecylamine, and octylamine; the (oxy)phosphine ligands include at least one of trioctylphosphine and trioctyloxidephosphine.

[0073] The light-emitting device provided by the embodiment of the present application uses the above-mentioned thin film as a carrier transport layer. By mixing a semiconductor material with a low exciton binding energy in the thin film, excitons in the thin film are easily decomposed to form carriers, thereby increasing the number of carrier injections in the electron functional layer 5, improving the carrier transport efficiency, thereby increasing the number of electrons in the light-emitting layer 4, balancing the number of carriers in the light-emitting layer 4, achieving a charge balance state, and improving the device performance and service life of the light-emitting device.

[0074] In other embodiments, the thin film can also be used as a hole transport layer 3 for red QLED devices and green QLED devices to increase the number of hole injections in the hole transport layer 3. Among them, the inorganic nanomaterial in the thin film is selected as MoO3, the semiconductor material is selected as CH3NH3PbI3, and the solvent is selected as an ethanol solvent.

[0075] Please refer back to Figure 1 As shown, in some embodiments, the light-emitting device further includes a light extraction layer 7, and the light extraction layer 7 is formed on the cathode layer 6.

[0076] In some embodiments, the material of the light extraction layer 7 includes N,N'-bis(1-naphthyl)-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (i.e., NPB) and its derivatives.

[0077] The embodiment of the present application also provides a display device, and the display device includes the above-mentioned light-emitting device.

[0078] The display device can be any electronic product with a display function. The electronic product includes but is not limited to a smart phone, a tablet computer, a notebook computer, a digital camera, a digital video camera, a smart wearable device, a smart weighing electronic scale, a vehicle-mounted display, a television, or an e-book reader. Among them, the smart wearable device can be, for example, a smart bracelet, a smart watch, a virtual reality (VR) helmet, etc.

[0079] The present application will be specifically described below through specific embodiments. The following embodiments are only partial embodiments of the present application and do not limit the present application.

[0080] Thin Film Example 1

[0081] Step ⑴: Mix ZnMgO powder and CH3NH3PbI3 in a mass ratio of 95%:5%, dissolve them in an ethanol solution to form a composite solution with a concentration of 20 mg / ml.

[0082] Step ⑵: Spin-coat the composite solution onto a substrate, vacuum dry to form a film, and then anneal at 80 °C for 15 min to form a thin film, where the thickness of the thin film is 30 nm.

[0083] Thin Film Example 2

[0084] Step ⑴: Mix ZnMgO powder and CH3NH3PbI3 in a mass ratio of 97%:3%, dissolve them in an ethanol solution to form a composite solution with a concentration of 20 mg / ml.

[0085] Step ⑵: Spin-coat the composite solution onto a substrate, vacuum dry to form a film, and then anneal at 80 °C for 15 min to form a thin film, where the thickness of the thin film is 30 nm.

[0086] Thin Film Example 3

[0087] Step ⑴: Mix ZnMgO powder and CH3NH3PbI3 in a mass ratio of 99%:1%, dissolve them in an ethanol solution to form a composite solution with a concentration of 20 mg / ml.

[0088] Step ⑵: Spin-coat the composite solution onto a substrate, vacuum dry to form a film, and then anneal at 80 °C for 15 min to form a thin film, where the thickness of the thin film is 30 nm.

[0089] Thin Film Example 4

[0090] Step ⑴: Mix NiO powder and CH3NH3PbI3 in a mass ratio of 95%:5%, dissolve them in an ethanol solution to form a composite solution with a concentration of 20 mg / ml.

[0091] Step ⑵: Spin-coat the composite solution onto a substrate, vacuum dry to form a film, and then anneal at 230 °C for 30 min to form a thin film, where the thickness of the thin film is 20 nm.

[0092] Thin Film Example 5

[0093] Step ⑴: Mix NiO powder and CH3NH3PbI3 in a mass ratio of 97%:3%, dissolve them in an ethanol solution to form a composite solution with a concentration of 20 mg / ml.

[0094] Step ⑵: Spin-coat the composite solution onto a substrate. After vacuum drying to form a film, perform an annealing treatment at 230 °C for 30 min to form a film, where the thickness of the film is 20 nm.

[0095] Thin film Example 6

[0096] Step ⑴: Mix NiO powder and CH3NH3PbI3 in a mass ratio of 99%:1%, and dissolve them in an ethanol solution to form a composite solution with a concentration of 20 mg / ml.

[0097] Step ⑵: Spin-coat the composite solution onto a substrate. After vacuum drying to form a film, perform an annealing treatment at 230 °C for 30 min to form a film, where the thickness of the film is 20 nm.

[0098] Thin film Comparative Example 1

[0099] Step ⑴: Dissolve ZnMgO powder in an ethanol solution to form ZnMgO ink.

[0100] Step ⑵: Spin-coat the ZnMgO ink onto a substrate. After vacuum drying to form a film, perform an annealing at 80 °C for 15 min to form a film, where the thickness of the film is 30 nm.

[0101] Thin film Comparative Example 2

[0102] Step ⑴: Dissolve NiO powder in an ethanol solution to form NiO ink with a concentration of 20 mg / ml.

[0103] Step ⑵: Spin-coat the NiO ink onto a substrate. After vacuum drying to form a film, perform an annealing treatment at 230 °C for 30 min to form a film, where the thickness of the film is 20 nm.

[0104] Take the films respectively prepared from Thin film Example 1 to Thin film Example 3 and Thin film Comparative Example 1 as the electron functional layer to prepare an EOD device (single electron device), and perform two electron injection efficiency tests on the prepared EOD devices respectively. The test results are as Figure 2 shown. (The structure of the EOD device is: ITO / film / light-emitting layer / film / cathode)

[0105] Take the films respectively prepared from Thin film Example 4 to Thin film Example 6 and Thin film Comparative Example 2 as the hole transport layer to prepare an HOD device (single hole device), and perform a hole injection efficiency test on the prepared HOD devices. The test results are as Figure 3 shown. (The structure of the HOD device is ITO / film / light-emitting layer / cathode).

[0106] Please refer to Figure 2As shown, it can be seen from the J-V curves of Thin Film Example 1 to Thin Film Example 3 and Thin Film Comparative Example 1 that as the voltage increases, the current density gradually increases; when at the same output voltage (i.e., the output voltage is 8V), the current density of the EOD device including Thin Film Example 1 is about 50 mA / cm 2 , the current density of the EOD device including Thin Film Example 2 is about 150 mA / cm 2 , the current density of the EOD device including Thin Film Example 3 is about 30 mA / cm 2 , the current density of the EOD device including Thin Film Comparative Example 1 is about 10 - 20 mA / cm 2 .

[0107] Please refer to Figure 3 As shown, it can be seen from the J-V curves of Thin Film Example 4 to Thin Film Example 6 and Thin Film Comparative Example 2 that as the voltage increases, the current density gradually increases; when at the same output voltage (i.e., the output voltage is 10V), the current density of the HOD device including Thin Film Example 4 is about 250 mA / cm 2 , the current density of the HOD device including Thin Film Example 5 is about 400 mA / cm 2 , the current density of the HOD device including Thin Film Example 6 is about 180 mA / cm 2 , the current density of the HOD device including Thin Film Comparative Example 2 is about 100 mA / cm 2 .

[0108] By comparing the J-V curves of Thin Film Examples 1 - 3 and Thin Film Comparative Example 1 and the J-V curves of Thin Film Examples 4 - 6 and Thin Film Comparative Example 2, it can be seen that when at the same output voltage, the current density of the EOD device including Thin Film Example 1, the current density of the EOD device including Thin Film Example 2, and the current density of the EOD device of Thin Film Example 3 are all greater than the current density of the EOD device including Thin Film Comparative Example 1, and the current density of the HOD device including Thin Film Example 4, the current density of the HOD device including Thin Film Example 5, and the current density of the HOD device of Thin Film Example 6 are all greater than the current density of the HOD device including Thin Film Comparative Example 2. Therefore, mixing semiconductor materials into inorganic nanomaterials can effectively increase the carrier transport efficiency.

[0109] By comparing the J-V curves of thin film Examples 1 to 3, it can be known that when at the same output voltage, the current density of the EOD device including thin film Example 2 is greater than that of the EOD device including composite thin film Example 1, and the current density of the EOD device including thin film Example 1 is greater than that of the EOD device including thin film Example 3; by comparing the J-V curves of thin film Examples 4 to 6, it can be known that when at the same output voltage, the current density of the EOD device including thin film Example 5 is greater than that of the EOD device including thin film Example 4, and the current density of the EOD device including thin film Example 4 is greater than that of the EOD device including thin film Example 6.

[0110] Therefore, it can be known that mixing semiconductor materials into inorganic nanomaterials can effectively improve the carrier transport efficiency, and mixing appropriate semiconductor materials into inorganic nanomaterials can effectively increase the carrier transport efficiency.

[0111] Light-emitting device Example 1

[0112] Step (1), provide a glass substrate, and prepare an IZO / Ag / IZO anode layer on the glass substrate;

[0113] Step (2), inkjet print a PEDOT:PSS solution on the anode layer, and after drying into a film, perform an annealing treatment at 150 °C for 15 min to form a 45-nm-thick hole injection layer;

[0114] Step (3), inkjet print a TFB solution on the hole injection layer, and after drying into a film, perform an annealing treatment at 230 °C for 30 min to form a 20-nm-thick hole transport layer;

[0115] Step (4), inkjet print a CdZnSe / ZnSe / ZnS (organic ligand is OA) blue quantum dot ink on the hole transport layer, and after drying into a film, perform an annealing treatment at 100 °C for 10 min to form a 15-nm-thick light-emitting layer;

[0116] Step (5), use the preparation method of the above thin film Example 1 to form a 30-nm electron transport layer on the light-emitting layer;

[0117] Step (6), by evaporation, deposit Ag on the electron transport layer to form a 30-nm-thick cathode layer;

[0118] Step (7), by evaporation, deposit NPB on the cathode layer to form a 65-nm-thick light extraction layer.

[0119] Light-emitting device Example 2

[0120] The difference between this embodiment and Embodiment 1 of the light-emitting device is that in step (5), the electron functional layer is formed on the light-emitting layer by using the preparation method of the above-mentioned thin film Embodiment 2.

[0121] Light-emitting device Embodiment 3

[0122] The difference between this embodiment and Embodiment 1 of the light-emitting device is that in step (5), the electron functional layer is formed on the light-emitting layer by using the preparation method of the above-mentioned thin film Embodiment 3.

[0123] Light-emitting device Embodiment 4

[0124] Step (1): Provide a glass substrate, and prepare an IZO / Ag / IZO anode layer on the glass substrate;

[0125] Step (2): Inkjet print PEDOT:PSS solution on the anode layer. After drying to form a film, perform annealing treatment at 150 °C for 15 min to form a 45-nm-thick hole injection layer;

[0126] Step (3): Use the preparation method of the above-mentioned thin film Embodiment 4 to form a 20-nm-thick hole transport layer on the hole injection layer;

[0127] Step (4): Inkjet print CdSe / ZnS (with OA as the organic ligand) red quantum dot ink on the hole transport layer. After drying to form a film, perform annealing treatment at 100 °C for 10 min to form a 15-nm-thick light-emitting layer;

[0128] Step (5): Spin-coat the ZnMgO ink on the substrate. After vacuum drying to form a film, perform annealing at 80 °C for 15 min to form a 30-nm electron transport layer;

[0129] Step (6): Deposit Ag by evaporation on the electron transport layer to form a 30-nm-thick cathode layer;

[0130] Step (7): Deposit NPB by evaporation on the cathode layer to form a 65-nm-thick light extraction layer.

[0131] Light-emitting device Embodiment 5

[0132] The difference between this embodiment and Embodiment 4 of the light-emitting device is that in step (3), the preparation method of the above-mentioned thin film Embodiment 5 is used to form a 20-nm-thick hole transport layer on the hole injection layer.

[0133] Light-emitting device Embodiment 6

[0134] The difference between this embodiment and Embodiment 4 of the light-emitting device is that in step (3), the preparation method of the above-mentioned thin film Embodiment 6 is used to form a 20-nm-thick hole transport layer on the hole injection layer.

[0135] Comparative Example 1 of Light-emitting Device

[0136] The difference between this example and Example 1 of the light-emitting device is that in step (4), the electron functional layer is formed on the light-emitting layer by using the preparation method of the above-mentioned thin film Comparative Example 1.

[0137] Comparative Example 2 of Light-emitting Device

[0138] The difference between this example and Example 4 of the light-emitting device is that in step (3), a 20-nm-thick hole transport layer is formed on the hole injection layer by using the preparation method of the above-mentioned thin film Comparative Example 2.

[0139] The light-emitting devices respectively prepared from Example 1 to Example 6 of the light-emitting device and Comparative Example 1 of the light-emitting device and Comparative Example 2 of the light-emitting device were tested for external quantum efficiency, current efficiency and operating life, and the test results are shown in Table 1.

[0140] Among them, the external quantum efficiency was tested by an external quantum efficiency optical test instrument; the current efficiency was tested by an FSTAR-FPD optical property measurement device with a 24V power supply; the operating life was tested by driving the device with a constant current of 2 mA by an FSTAR-FPD optical property measurement device with a 24V power supply and monitoring the brightness attenuation rate of the light-emitting device.

[0141] External quantum efficiency (%) Current efficiency (cd / A) Device lifetime (h) Light-emitting device Example 1 15.8 11.6 51 Light-emitting device Example 2 18.7 13.4 87 Light-emitting device Example 3 15.4 11.2 45 Light-emitting device Example 4 14.4 10.3 38 Light-emitting device Example 5 16.2 11.6 53 Light-emitting device Example 6 13.5 9.6 30 Light-emitting device Comparative Example 1 12.5 8.9 24 Light-emitting device Comparative Example 2 11.3 8.2 19

[0142] Table 1

[0143] According to the comparison of the test results between Example 1 to Example 3 of the light-emitting device and Comparative Example 1 of the light-emitting device, and the comparison of the test results between Example 4 to Example 6 of the light-emitting device and Comparative Example 2 of the light-emitting device, it can be known that when a semiconductor material with a low exciton binding energy is added to the electron transport layer and the hole transport layer, the external quantum efficiency, current efficiency and device life of the light-emitting device can be improved.

[0144] In summary, in the embodiments of the present application, a thin film is formed by mixing an inorganic nanomaterial and a semiconductor material with a low exciton binding energy, and the thin film is used for the electron transport layer of a blue QLED device or the hole transport layer of a red QLED device (and / or a green QLED device), which can increase the number of carrier injections in the electron transport layer / hole transport layer, thereby improving the carrier injection ability in the QLED device, so that the number of holes and electrons in the light-emitting layer is balanced, and the purpose of improving the device performance and device life of the QLED device is achieved.

[0145] Obviously, the embodiments described above are only a part of the embodiments of the present application, rather than all the embodiments. The preferred embodiments of the present application are shown in the drawings, but do not limit the patent scope of the present application. The present application can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosed content of the present application more thorough and comprehensive. Although the present application has been described in detail with reference to the foregoing embodiments, for those skilled in the art, they can still modify the technical solutions described in the foregoing specific embodiments, or perform equivalent replacements on some of the technical features. Any equivalent structure directly or indirectly using the content of the specification and drawings of the present application in other related technical fields shall be within the scope of the patent protection of the present application by the same token.

Claims

1. A film, characterized in that, It includes inorganic nanomaterials and semiconductor materials. Among them, the inorganic nanomaterials include inorganic N-type semiconductor materials or inorganic P-type semiconductor materials, and the semiconductor materials include perovskite materials.

2. The thin film according to claim 1, wherein The thin film is composed of the inorganic nanomaterials and the semiconductor materials; and / or The mass ratio of the inorganic nanomaterials to the semiconductor materials is (95-99.5):(0.5-5).

3. The thin film according to claim 1, wherein The inorganic N-type semiconductor material is selected from at least one of doped or undoped first metal oxides, metal sulfides and metal phosphides. The first metal oxide is selected from at least one of zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, nickel oxide; and / or, the metal sulfide is selected from at least one of cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide and copper sulfide; and / or, the metal phosphide is selected from at least one of indium phosphide and gallium phosphide; and / or, the doped element includes at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium and gadolinium; The inorganic P-type semiconductor material is selected from doped or undoped second metal oxides. The second metal oxide is selected from at least one of molybdenum oxide, tungsten oxide, nickel oxide, copper oxide, vanadium pentoxide, chromium oxide; and / or, the doped element includes at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium and gadolinium.

4. The thin film according to claim 1, wherein The exciton binding energy of the perovskite material is less than 100 meV; and / or The perovskite material is at least one of an inorganic perovskite material, an organic perovskite material, and an organic-inorganic hybrid perovskite material. Among them, the structural general formula of the inorganic perovskite material is AMX3, where A is Cs + ion, M is a divalent metal cation, and M is selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , and Eu 2+ One or more of them, X is a halogen anion, and X is selected from Cl - , Br - , I - At least one of them; the structural general formula of the organic perovskite material is CMX3, where C is formamidinium, M is a divalent metal cation, and M is selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , and Eu 2+ One or more of them, X is a halogen anion, and X is selected from Cl - , Br - , I - At least one of them; the structural general formula of the organic-inorganic hybrid perovskite material is BMX3, where B is selected from organic amine cations, M is a divalent metal cation, and M is selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , and Eu 2+ One or more of them, X is a halogen anion, and X is selected from Cl - , Br - , I - At least one of them.

5. The thin film according to claim 4, wherein The perovskite material is selected from at least one of CsPbI3, CsPbBr3, FAPbI3, FAPbBr3, CH3NH3PbI3, CH3NH3PbBr3.

6. A method for preparing a thin film, characterized in that, It includes the following steps: Provide a first solution including inorganic nanomaterials, semiconductor materials and a solvent; Deposit the first solution to obtain the thin film; Among them, the inorganic nanomaterials include inorganic N-type semiconductor materials or inorganic P-type semiconductor materials, and the semiconductor materials include perovskite materials.

7. The method for preparing the thin film according to claim 6, wherein, The solvent is an alcohol solvent, and the alcohol solvent includes at least one of ethanol, isopropanol, n-butanol, 2-butanol, cyclohexanol, ethylene glycol, glycerol, butanediol, pentanediol, n-hexanol, heptanol, thiol compounds; among them, the thiol compound can be selected from at least one of ethylene glycol bis-3-mercaptopropionate, ethylene glycol dimercaptoacetate, trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), pentaerythritol tetrakis(2-mercaptoacetate), 1,6-hexanedithiol, 1,3-propanedithiol, 1,2-ethanedithiol and polyethylene glycol dithiol containing 1-10 ethylene glycol repeating units; and / or The concentration range of the first solution is 20 mg / ml to 40 mg / ml; and / or The mass ratio of the inorganic nanomaterials to the semiconductor materials is (95-99.5):(0.5-5); and / or The inorganic N-type semiconductor material is selected from at least one of doped or undoped first metal oxides, metal sulfides and metal phosphides; and / or The inorganic P-type semiconductor material is selected from doped or undoped second metal oxides.

8. The method for preparing the thin film according to claim 6, wherein, The depositing of the first solution includes the following steps: Under room temperature conditions, the first solution is subjected to vacuum drying treatment and then annealing treatment.

9. The method for preparing a thin film according to claim 8, characterized in that, The vacuum degree of the vacuum drying treatment ranges from 0.1 Pa to 0.001 Pa; and / or The time of the vacuum drying treatment is 5 min to 15 min; and / or The time of the annealing treatment is 10 min to 15 min; and / or The temperature of the annealing treatment is 85 °C to 95 °C.

10. A light-emitting device, characterized in that, It includes an anodic layer, a light-emitting layer, and a cathodic layer which are stacked; It further includes a first charge carrier transport layer and / or a second charge carrier transport layer. The first charge carrier transport layer is disposed between the light-emitting layer and the cathodic layer; the second charge carrier transport layer is disposed between the anodic layer and the light-emitting layer. The first charge carrier transport layer includes an inorganic N-type semiconductor material, and the second charge carrier transport layer includes an inorganic P-type semiconductor material; Wherein, the first charge carrier transport layer further includes a first semiconductor material, and / or, the second charge carrier transport layer further includes a second semiconductor material. The first semiconductor material and the second semiconductor material each independently include a perovskite material.

11. The light-emitting device according to claim 10, characterized in that, The mass ratio of the inorganic N-type semiconductor material to the first semiconductor material is (95 - 99.5):(0.5 - 5); and / or The mass ratio of the inorganic P-type semiconductor material to the second semiconductor material is (95 - 99.5):(0.5 - 5); and / or The inorganic N-type semiconductor material is selected from at least one of doped or undoped first metal oxides, metal sulfides, and metal phosphides. The first metal oxide is selected from at least one of zinc oxide, barium oxide, aluminum oxide, nickel oxide, titanium oxide, tin oxide, tantalum oxide, zirconium oxide, and nickel oxide; and / or, the metal sulfide is selected from at least one of cadmium sulfide, zinc sulfide, molybdenum sulfide, tungsten sulfide, and copper sulfide; and / or, the metal phosphide is selected from at least one of indium phosphide and gallium phosphide; and / or, the doping element includes at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium; and / or The inorganic P-type semiconductor material is selected from doped or undoped second metal oxides. The second metal oxide is selected from at least one of molybdenum oxide, tungsten oxide, nickel oxide, copper oxide, vanadium pentoxide, and chromium oxide; and / or, the doping element includes at least one of aluminum, magnesium, lithium, manganese, yttrium, lanthanum, copper, nickel, zirconium, cerium, and gadolinium.

12. The light-emitting device according to claim 10, characterized in that, The material of the anode layer and / or the cathode layer includes one or more of metals, carbon materials, and metal oxides. The metals include one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon materials include one or more of graphite, carbon nanotubes, graphene, and carbon fibers; the metal oxides include doped or undoped metal oxides, including one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO, or a composite electrode including a metal sandwiched between doped or undoped transparent metal oxides. 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 light-emitting device further includes a hole injection layer disposed between the anode layer and the light-emitting layer. The material of the hole injection layer includes at least one of TFB, CuPc, PVK, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, polyaniline, transition metal oxides, transition metal sulfides, transition metal stannides, doped graphene, undoped graphene, and C60; and / or The material of the light-emitting layer includes quantum dots; wherein, the quantum dots include at least one of single-structure quantum dots and core-shell structure quantum dots. The materials of the single-structure quantum dots, the core materials of the core-shell structure quantum dots, and the shell materials of the core-shell structure quantum dots are respectively 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 shell layer of the core-shell structure quantum dots includes one or more layers; wherein, the II-VI group compounds are selected from at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds are 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; the III-V group compounds are selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; the I-III-VI group compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2; The quantum dots further include ligands connected to their surfaces, and the ligands are selected from at least one of acid ligands, thiol ligands, amine ligands, (oxy)phosphine ligands, phospholipids, lecithins, polyvinylpyridines, etc.; the acid ligands include at least one of decanoic acid, undecylenic acid, myristic acid, oleic acid, and stearic acid; the thiol ligands include at least one of octyl mercaptan, dodecyl mercaptan, and octadecyl mercaptan; the amine ligands include one or more of oleylamine, octadecylamine, and octylamine; the (oxy)phosphine ligands include at least one of trioctylphosphine and trioctylphosphine oxide.

13. A display device, characterized in that, The display device includes the light-emitting device according to any one of claims 10 to 12.

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