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. The light-emitting device comprises a first electrode, a light-emitting layer, an interface modification layer and a second electrode which are stacked in sequence, and the interface modification layer is made of zinc ferrite. According to the light-emitting device, the interface modification layer is arranged between the light-emitting layer and the second electrode, so that the light-emitting device has relatively high electron transmission efficiency, and the properties such as the light-emitting efficiency and the service life of the light-emitting device are improved.

Description

Technical Field

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

[0002] Currently, the widely used light-emitting devices are organic light-emitting devices (OLEDs) and quantum dot light-emitting devices (QLEDs). Due to its excellent display performance such as self-luminescence, simple structure, ultra-thinness, fast response speed, wide viewing angle, low power consumption, and flexible display, OLED has become the mainstream technology in the field of display technologies. QLED has the advantages of saturated emission light color, adjustable wavelength, low turn-on voltage, good solution processability, easy fine control of quantum dots, etc., and has high photoluminescence and electroluminescence quantum yields. In recent years, it has become a strong competitor to OLED.

[0003] The structures of traditional OLED and QLED devices generally include an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode. Under the action of an electric field, the holes generated by the anode and the electrons generated by the cathode of the light-emitting device move, are respectively injected into the hole transport layer and the electron transport layer, and finally migrate to the light-emitting layer. When the two meet in the light-emitting layer, energy excitons are generated, which excite the light-emitting molecules to finally generate visible light.

[0004] The lifespan of existing light-emitting devices is relatively short and needs to be further improved. Summary of the Invention

[0005] In view of this, the present application provides a light-emitting device, aiming to improve the problem of the relatively short lifespan of existing light-emitting devices.

[0006] The embodiment of the present application is implemented as follows. A light-emitting device includes a first electrode, a light-emitting layer, an interface modification layer, and a second electrode that are sequentially stacked, and the material of the interface modification layer includes zinc ferrite.

[0007] Optionally, in some embodiments of the present application, the thickness of the interface modification layer is 1-10 nm.

[0008] Optionally, in some embodiments of the present application, the material of the light-emitting layer includes quantum dots, the quantum dots include one or more of single-structure quantum dots and core-shell structure quantum dots, and 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 each independently selected from one or more of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The II-VI group compounds include one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds include one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds include one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds include one or more of CuInS2, CuInSe2, and AgInS2.

[0009] Optionally, in some embodiments of the present application, ligands are connected to the surface of the quantum dots. The ligands include one or more of acid ligands, thiol ligands, amine ligands, (oxy)phosphine ligands, phospholipids, lecithins, polyvinylpyridines, etc. The acid ligands include one or more of decanoic acid, undecylenic acid, myristic acid, oleic acid, stearic acid. The thiol ligands include one or more of octyl mercaptan, dodecyl mercaptan, octadecyl mercaptan. The amine ligands include one or more of oleylamine, octadecylamine, octylamine. The (oxy)phosphine ligands include one or more of trioctylphosphine, trioctyloxidephosphine.

[0010] Optionally, in some embodiments of the present application, the light-emitting device further includes an electron functional layer. The electron functional layer is located between the interface modification layer and the second electrode. The material of the electron functional layer includes inorganic semiconductor particles. The inorganic semiconductor particles include one or more of doped metal oxide particles, undoped metal oxide particles, ceramic semiconductor materials, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials, and IB-IIIA-VIA group semiconductor materials. The metal oxides in the undoped metal oxide particles include one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5. The metal oxides in the doped metal oxide include one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, Al2O3. The doping elements in the doped metal oxide include one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, Sn. The IIB-VIA group semiconductor materials include one or more of ZnS, ZnSe, CdS. The IIIA-VA group semiconductor materials include one or more of InP, GaP. The IB-IIIA-VIA group semiconductor materials include one or more of CuInS, CuGaS.

[0011] Optionally, the average particle size of the inorganic semiconductor particles is 2 to 15 nm.

[0012] Optionally, in some embodiments of the present application, the first electrode and the second electrode each independently include a doped metal oxide electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal elemental electrode, or an alloy electrode. The material of the doped metal oxide electrode includes one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, aluminum-doped magnesium oxide, and cadmium-doped zinc oxide. The composite electrode includes 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, ZnS / Al / ZnS, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, or BaF2 / Ca / Al. The material of the metal elemental electrode includes one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba. The alloy electrode includes an Au:Mg alloy electrode or an Ag:Mg alloy electrode; and / or

[0013] The light-emitting device further includes a hole transport layer located between the first electrode and the light-emitting layer. The material of the hole transport layer includes one or more of 4,4'-N,N'-dicarbazolyl-biphenyl, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], 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, poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(N-vinylcarbazole) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine, spiro-NPB, poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline], 1,3-bis(carbazol-9-yl)benzene, polyaniline, polypyrrole, poly(p-phenylene vinylene), aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, doped graphene, undoped graphene, C60, doped or undoped NiO, doped or undoped MoO3, doped or undoped WO3, doped or undoped V2O5, doped or undoped p-type gallium nitride, doped or undoped CrO3, doped or undoped CuO; and / or

[0014] The light-emitting device further includes a hole injection layer located between the first electrode and the light-emitting layer. The material of the hole injection layer includes one or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, PEDOT, PEDOT:PSS, a derivative of PEDOT:PSS doped with s-MoO3, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, tetracyanoquinodimethane, copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide.

[0015] Correspondingly, an embodiment of the present application further provides a method for manufacturing a light-emitting device, including the following steps:

[0016] Providing a light-emitting device preform, the light-emitting device preform including a stacked first electrode and a light-emitting layer;

[0017] Setting a zinc ferrite solution on the light-emitting layer to obtain an interface modification layer;

[0018] Successively forming a stacked electron functional layer and a second electrode on the interface modification layer to obtain a light-emitting device.

[0019] Optionally, in some embodiments of the present application, the concentration of the zinc ferrite solution is 0.01% to 5% by mass;

[0020] The zinc ferrite solution includes a polar solvent, the polar solvent includes an alcohol solvent, and the alcohol solvent includes one or more of methanol, ethanol, isopropanol, n-butanol, n-pentanol, isopentanol, ethylene glycol, diethylene glycol, dipropylene glycol, and glycerol.

[0021] Optionally, in some embodiments of the present application, the method of setting the zinc ferrite solution on the light-emitting layer includes: soaking the light-emitting layer in the zinc ferrite solution for a period of time and then taking it out. Preferably, the temperature of the zinc ferrite solution is 50 to 80 °C, and the soaking time is 5 to 30 minutes.

[0022] Correspondingly, an embodiment of the present application further provides a display device including the above light-emitting device.

[0023] In the light-emitting device of the present application, an interface modification layer is provided between the light-emitting layer and the second electrode. The interface modification layer includes zinc ferrite, and the zinc ferrite contains Zn-O bonds and has good electron transport performance. Thus, after the electrons of the second electrode enter the interface modification layer, they can be better transported to the light-emitting layer, thereby improving the electron transport efficiency of the light-emitting device and further extending the lifespan of the light-emitting device. Description of the Drawings

[0024] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0025] Figure 1 It is a schematic structural diagram of a light-emitting device provided by an embodiment of the present application;

[0026] Figure 2 It is a schematic structural diagram of another light-emitting device provided by an embodiment of the present application;

[0027] Figure 3 It is a schematic structural diagram of yet another light-emitting device provided by an embodiment of the present application;

[0028] Figure 4 It is a flowchart of a preparation method of a light-emitting device provided by an embodiment of the present application.

[0029] Reference numerals:

[0030] Light-emitting device 100; first electrode 10; light-emitting layer 20; interface modification layer 30; second electrode 40; electron functional layer 50; hole transport layer 60; hole injection layer 70. Detailed implementation manners

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation manners described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention herein are only for the purpose of describing specific embodiments, and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0033] In this application, unless otherwise specified, the orientation terms such as "upper" and "lower" generally refer to the upper and lower directions in the actual use or working state of the device, specifically the drawing directions in the attached drawings; while "inner" and "outer" refer to the outline of the device. Additionally, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are only used as labels without imposing numerical requirements or establishing an order.

[0034] In this application, "and / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, or B exists alone. Here, A and B can be singular or plural.

[0035] In this application, "at least one" means one or more, and "a plurality" means two or more. "One or more kinds", "at least one of the following items (pieces)" or similar expressions refer to any combination of these items, including any combination of single items (pieces) or plural items (pieces). For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0036] In this application, when forming another layer "on" a certain layer, the so-called "on" is a broad concept, which can mean that the formed another layer is adjacent to a certain layer, or there are other spacer structure layers between the another layer and a certain layer. For example, when forming a second electrode "on" the first carrier functional layer, the so-called "on" can mean that the formed second electrode is adjacent to the first carrier functional layer, or there are other spacer structure layers between the second electrode and the first carrier functional layer, such as a light-emitting layer.

[0037] The various embodiments of this application can 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 brevity and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the described range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that the range description from 1 to 6 has 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., and individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0038] Since the quantum dot light-emitting layer is an oily material, in the preparation process of the light-emitting device, in order not to damage the light-emitting layer, the material of the electron transport layer disposed on the quantum dot light-emitting layer usually selects a material with a relatively high polarity to form a sandwich structure device. However, this inevitably causes problems such as poor film spreading effect between the electron transport layer and the light-emitting layer. In addition, both the quantum dot material and the electron transport layer material are inorganic nanoparticles, and the interface formed by their contact is prone to problems of poor exciton transport.

[0039] The technical solution of this application is as follows:

[0040] In a first aspect, please refer to Figure 1 , an embodiment of this application provides a light-emitting device 100, including a first electrode 10, a light-emitting layer 20, an interface modification layer 30, and a second electrode 40 stacked in sequence, wherein the material of the interface modification layer 30 includes zinc ferrite (ZnFe2O4), and the material of the light-emitting layer 20 includes quantum dots.

[0041] In the light-emitting device 100 of this application, an interface modification layer 30 is disposed between the light-emitting layer 20 and the second electrode 40, and the interface modification layer 30 includes zinc ferrite. On the one hand, zinc ferrite contains Zn-O bonds and has good electron transport performance. Thus, after the electrons of the second electrode 40 enter the interface modification layer 30, they can be more quickly and effectively transported into the light-emitting layer 20, thereby improving the electron transport efficiency of the light-emitting device 100, and further improving the performance such as the light-emitting efficiency and lifespan of the light-emitting device 100.

[0042] In addition, when the quantum dots contain non-metal elements such as S, Se, Te, N, P, As, and Sb, due to the strong attraction between the iron atoms in zinc ferrite and the above non-metal atoms, a strong coordination can be formed between zinc ferrite and the quantum dots, so that the interface modification layer 30 is firmly bonded to the surface of the light-emitting layer 20.

[0043] In some embodiments, the light-emitting device 100 further includes an electron functional layer 50, and the electron functional layer 50 is located between the interface modification layer 30 and the second electrode 40.

[0044] Zinc ferrite can be used as an interface protector. When excessive electrons accumulate at the interface between the light-emitting layer 20 and the electron functional layer 50, trivalent iron can actively protect the electron functional materials at the interface and be preferentially reduced, thereby improving the operating stability of the electron functional layer 50, and further improving the lifespan of the light-emitting device 100.

[0045] Furthermore, zinc ferrite has strong polarity, and the materials of the electron functional layer of the light-emitting device usually include polar materials. In this way, better interfacial contact can be achieved between the light-emitting layer 20 and the electron functional layer 50, which is beneficial to the electron transfer between the electron functional layer 50 and the light-emitting layer 20, improving the electron transfer efficiency of the light-emitting device 100, and further enhancing the performance such as the light-emitting efficiency and lifespan of the light-emitting device 100.

[0046] In some embodiments, the thickness of the interfacial modification layer 30 is 1 to 10 nm, for example, 1 nm, 1.5 nm, 2 nm, 2.5 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, etc. Within this thickness range, it is beneficial to improve the performance such as the efficiency and lifespan of the light-emitting device.

[0047] The quantum dots can be one or more of single-structure quantum dots and core-shell structure quantum dots.

[0048] 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 may respectively include, but are not limited to, one or more of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The II-VI group compounds may include, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds may include, but are not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds may include, but are not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds may include, but are not limited to, one or more of CuInS2, CuInSe2, and AgInS2.

[0049] As an example, the quantum dots of the core-shell structure may include, but are not limited to, one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, and InP / ZnSe / ZnS.

[0050] In some embodiments, ligands are connected to the surface of the quantum dots. In at least some embodiments, the ligands include, but are not limited to, one or more of acid ligands, thiol ligands, amine ligands, (oxy)phosphine ligands, phospholipids, lecithins, polyvinylpyridines, etc. As a specific embodiment, the acid ligands include, but are not limited to, one or more of decanoic acid, undecylenic acid, myristic acid, oleic acid, and stearic acid; the thiol ligands include, but are not limited to, one or more of octyl mercaptan, dodecyl mercaptan, and octadecyl mercaptan; the amine ligands include, but are not limited to, one or more of oleylamine, octadecylamine, and octylamine; the (oxy)phosphine ligands include, but are not limited to, one or more of trioctylphosphine and trioctylphosphine oxide.

[0051] It can be understood that the electronic functional layer 50 may be an electron transport layer or an electron injection layer.

[0052] The material of the electronic functional layer 50 is a direct bandgap semiconductor material with a bandgap of 1.5 to 3.5 eV known in the art for electronic functional layers, and can be selected from, but not limited to, inorganic semiconductor particles. The inorganic semiconductor particles include, but are not limited to, one or more of doped metal oxide particles, undoped metal oxide particles, ceramic semiconductor materials, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials, and IB-IIIA-VIA group semiconductor materials. The metal oxides in the undoped metal oxide particles include, but are not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5. The metal oxides in the doped metal oxide include, but are not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, Al2O3, and the doping elements in the doped metal oxide include, but are not limited to, one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, Sn. By way of example, the doped metal oxide can be aluminum-doped zinc oxide (AZO), lithium-doped zinc oxide (LZO), magnesium-doped zinc oxide (MZO), tin-doped zinc oxide (Sn-ZnO), etc. The ceramic semiconductor materials include, but are not limited to, barium titanate. The IIB-VIA group semiconductor materials include, but are not limited to, one or more of ZnS, ZnSe, CdS. The IIIA-VA group semiconductor materials include, but are not limited to, one or more of InP, GaP. The IB-IIIA-VIA group semiconductor materials include, but are not limited to, one or more of CuInS, CuGaS.

[0053] It can be understood that the morphology of the inorganic semiconductor particles can be nanospheres, nanosheets, nanorods, etc. In at least one embodiment, the average particle size of the inorganic semiconductor particles is 2 to 15 nm.

[0054] In at least one embodiment, the material of the electronic functional layer 50 is doped or undoped ZnO. Since zinc ferrite in the interface modification layer 30 has Zn-O bonds, thus, a strong bonding force and good electron transport performance can be achieved between the electronic functional layer 50 and the interface modification layer 30.

[0055] Please refer to Figure 2 , in some embodiments, the light-emitting device 100 further includes a hole transport layer 60 located between the first electrode 10 and the light-emitting layer 20. In other words, the light-emitting device 100 includes a first electrode 10, a hole transport layer 60, a light-emitting layer 20, an interface modification layer 30, an electronic functional layer 50, and a second electrode 40 stacked in sequence.

[0056] Please refer to Figure 3, in one embodiment, the light-emitting device 100 further includes a hole injection layer 70 located between the first electrode 10 and the hole transport layer 60. In other words, the light-emitting device 100 includes, in sequence, a first electrode 10, a hole injection layer 70, a hole transport layer 60, a light-emitting layer 20, an interface modification layer 30, an electron functional layer 50, and a second electrode 40.

[0057] The first electrode 10 and the second electrode 40 are electrodes known in the art for use in light-emitting devices. For example, they can each independently include, but are not limited to, doped metal oxide electrodes, composite electrodes, graphene electrodes, carbon nanotube electrodes, elemental metal electrodes, or alloy electrodes. The materials of the doped metal oxide electrodes can include, but are not limited to, one or more of indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), magnesium-doped zinc oxide (MZO), aluminum-doped magnesium oxide (AMO), and cadmium-doped zinc oxide. The composite electrode is an electrode formed by laminating two or more layers of conductive materials, such as 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, ZnS / Al / ZnS, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc. Here, " / " represents a laminated structure. For example, AZO / Ag / AZO represents a composite electrode including, in sequence, an AZO layer, an Ag layer, and an AZO layer. The materials of the elemental metal electrodes can include, but are not limited to, one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba. The alloy electrodes include, but are not limited to, Au:Mg alloy electrodes and Ag:Mg alloy electrodes.

[0058] In some embodiments, the first electrode 10 is an electrode with a relatively high work function. For example, it can include, but is not limited to, doped metal oxide electrodes with a relatively high work function, elemental metal electrodes with a relatively high work function, and carbon nanotube electrodes. The elemental metal electrodes with a relatively high work function can be selected from, but are not limited to, Ni, Pt, Au, Ag, Ir, etc.

[0059] In some embodiments, the second electrode 40 is an electrode with a relatively low work function, and may include, for example, but not limited to, a single metal electrode with a relatively low work function, a composite electrode with a relatively low work function, and an alloy electrode with a relatively low work function. The single metal electrode with a relatively low work function may be Ca, Ba, Al, Mg, etc. The composite electrode with a relatively low work function may be Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc. The alloy electrodes with a relatively low work function are Au:Mg and Ag:Mg, etc.

[0060] The material of the hole transport layer 60 can be a material known in the art for hole transport layers. For example, it can be selected from, but not limited to, 4,4'-N,N'-dicarbazolyl-biphenyl (CBP), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), 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), poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine) (Poly-TPD), N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro(spiro-TPD), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine (DNTPD), 4,4',4'-tris(N-carbazolyl)-triphenylamine (TCTA), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), poly(N-vinylcarbazole) (PVK) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine (NPB), spiro-NPB, poly(phenylene vinylene) (PPV), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene] (MEH-PPV), poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene] (MOMO-PPV), 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-omeTAD), 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (TAPC), 1,3-bis(carbazol-9-yl)benzene (MCP), polyaniline, polypyrrole, poly(p-phenylene vinylene), aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, doped graphene, undoped graphene, C60, doped or undoped NiO, doped or undoped MoO3, doped or undoped WO3, doped or undoped V2O5, doped or undoped p-type gallium nitride, doped or undoped CrO3, doped or undoped CuO, one or more of them.

[0061] The material of the hole injection layer 70 may be a material known in the art for hole injection layers, and may be selected from, but not limited to, 2,3,6,7,10,11 - hexacyano - 1,4,5,8,9,12 - hexaazatriphenylene (HAT - CN), PEDOT, PEDOT:PSS, a derivative of PEDOT:PSS doped with s - MoO3 (PEDOT:PSS:s - MoO3), 4,4',4' - tris(N - 3 - methylphenyl - N - phenylamino) triphenylamine (m - MTDATA), tetracyanoquinodimethane (F4 - TCQN), copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide, or one or more of them.

[0062] It can be understood that the light - emitting device 100 may further be provided with some functional layers that are commonly used in light - emitting devices and are helpful for improving the performance of the light - emitting device, such as an electron blocking layer, a hole blocking layer, an electron injection layer, an interface modification layer, etc.

[0063] It can be understood that the materials of the respective layers of the light - emitting device 100 can be adjusted according to the light - emitting requirements of the light - emitting device 100.

[0064] In some embodiments, the light - emitting device 100 further includes a substrate, and the substrate is disposed on a side of the first electrode 10 away from the light - emitting layer 20, or the substrate is disposed on a side of the second electrode 40 away from the light - emitting layer 20.

[0065] The substrate can be a rigid substrate or a flexible substrate. In some embodiments, the material of the substrate may include, but is not limited to, one or more of glass, silicon wafer, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyethersulfone.

[0066] It can be understood that the light - emitting device 100 can be a normal - type light - emitting device or an inverted - type light - emitting device. The light - emitting device 100 can be a quantum dot light - emitting device.

[0067] In a second aspect, please refer to Figure 4 , the embodiments of the present application further provide a method for manufacturing a light - emitting device, including the following steps:

[0068] Step S11: Provide a light - emitting device pre - form, where the light - emitting device pre - form includes a stacked first electrode 10 and a light - emitting layer 20;

[0069] Step S12: Set a zinc ferrite solution on the light - emitting layer 20 to obtain an interface modification layer 30;

[0070] Step S13: Form a second electrode 40 on the interface modification layer 30 to obtain the light - emitting device 100.

[0071] The mass concentration of the zinc ferrate solution is 0.01% to 5%, for example, 0.01%, 0.1%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, etc. Within this concentration range, the light-emitting layer 20 can be sufficiently and effectively modified, and it is also beneficial to prepare an interface modification layer 30 with better film-forming properties, for example, an interface modification layer 30 with a higher surface flatness can be obtained.

[0072] The zinc ferrate solution includes a polar solvent, the polar solvent includes an alcohol solvent, and the alcohol solvent includes one or more of methanol, ethanol, isopropanol, n-butanol, n-pentanol, isopentanol, ethylene glycol, diethylene glycol, dipropylene glycol, and glycerol.

[0073] It can be understood that the method of setting the zinc ferrate solution on the light-emitting layer 20 can be a known solution method for film formation, etc., and the solution method can be spin coating, printing, inkjet printing, doctor blading, printing, dip coating, immersion, spraying, roll coating, casting, slot die coating, and bar coating, etc.

[0074] In at least one embodiment, the method of setting the zinc ferrate solution on the light-emitting layer 20 includes: immersing the light-emitting layer 20 in the zinc ferrate solution for a period of time and then taking it out.

[0075] In some embodiments, the temperature of the zinc ferrate solution is 50 to 80 °C, such as 50 °C, 55 °C, 60 °C, 65 °C, 70 °C, 75 °C, 80 °C, and the immersion time is 5 to 30 min, such as 5 min, 8 min, 10 min, 12 min, 15 min, 20 min, 25 min, 28 min, 30 min, etc. In this way, it is beneficial for zinc ferrate to react with the light-emitting layer 20 to form the interface modification layer 30.

[0076] It can be understood that in some embodiments, after the taking out, it further includes: cleaning the interface modification layer 30 with a cleaning agent. In this way, it is beneficial for the subsequent film formation of the electron functional layer 50, and thus beneficial for preparing a light-emitting device 100 with higher luminous efficiency and lifespan.

[0077] In some embodiments, forming the second electrode on the interface modification layer includes: sequentially forming a stacked electron functional layer 50 and a second electrode 40 on the interface modification layer.

[0078] Please refer to Figure 2 , in some embodiments, the light-emitting device preform includes a hole transport layer located between the first electrode 10 and the light-emitting layer 20.

[0079] Please refer toFigure 3 , in one embodiment, the light-emitting device 100 further includes a hole injection layer 70 located between the first electrode 10 and the hole transport layer 60.

[0080] The first electrode 10, the light-emitting layer 20, the electron functional layer 50, the second electrode 40, the hole transport layer 60, and the hole injection layer 70 are as described above and will not be elaborated here.

[0081] The preparation methods of the first electrode 10, the light-emitting layer 20, the electron functional layer 50, the second electrode 40, the hole transport layer 60, and the hole injection layer 70 can be realized by conventional techniques in the art, such as chemical methods or physical methods. Among them, chemical methods include chemical vapor deposition, sequential ionic layer adsorption and reaction, anodic oxidation, electrodeposition, and coprecipitation. Physical methods include physical coating methods and solution methods. Among them, physical coating methods include: thermal evaporation coating, electron beam evaporation coating, magnetron sputtering, multi-arc ion coating, physical vapor deposition, atomic layer deposition, pulsed laser deposition, etc.; solution methods can be spin coating, printing, inkjet printing, blade coating, printing, dip coating, immersion, spraying, roll coating, casting, slot die coating, and bar coating, etc.

[0082] It can be understood that when the light-emitting device 100 further includes functional layers that are commonly used in light-emitting devices and help improve the performance of the light-emitting device, such as an electron blocking layer, a hole blocking layer, an electron injection layer, an interface modification layer, etc., the preparation method of the light-emitting device 100 may further include the step of preparing the above functional layers by conventional techniques in the art.

[0083] In a third aspect, the present application also relates to a display device, and the display device includes the light-emitting device 100.

[0084] 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 laptop computer, a digital camera, a digital video camera, a smart wearable device, a smart weighing electronic scale, an in-vehicle 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.

[0085] 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. The raw materials used in the following embodiments are all commercially available products unless otherwise specified.

[0086] Example 1

[0087] Provide an ITO first electrode 10 with a thickness of 120 nm;

[0088] Spin-coat PEDOT:PSS material on the first electrode 10, anneal at 100 °C for 15 min to obtain a hole injection layer 70 with a thickness of 80 nm;

[0089] Spin-coat TFB material on the hole injection layer 70, anneal at 100 °C for 15 min to obtain a hole transport layer 60 with a thickness of 80 nm;

[0090] Spin-coat CdSeS / ZnS green quantum dot material on the hole transport layer 60 to obtain a light-emitting layer 20 with a thickness of 70 nm;

[0091] Spin-coat an ethanol solution of zinc ferrite with a mass concentration of 5% on the light-emitting layer 20, soak at 60 °C for 10 min, then wash with ethanol to remove the surface solution to obtain an interface modification layer 30 with a thickness of 3 nm;

[0092] Spin-coat an ethanol solution of ZnO with a concentration of 30 mg / mL on the interface modification layer 30, dry at 80 °C for 10 min to obtain an electron transport layer with a thickness of 50 nm;

[0093] Evaporate Ag on the electron transport layer to obtain a second electrode 40 with a thickness of 60 nm;

[0094] Encapsulate in an environment where both the oxygen content and the water content are lower than 0.1 ppm to obtain a light-emitting device 100.

[0095] Example 2

[0096] Provide an ITO first electrode 10 with a thickness of 120 nm;

[0097] Spin-coat PEDOT:PSS material on the first electrode 10, where the molar ratio of PEDOT to PSS is 1:1, anneal at 100 °C for 15 min to obtain a hole injection layer 70 with a thickness of 80 nm;

[0098] Spin-coat TFB material on the hole injection layer 70, anneal at 100 °C for 15 min to obtain a hole transport layer 60 with a thickness of 80 nm;

[0099] Spin-coat a CdSeS / ZnS green quantum dot material with a concentration of 30 mg / mL on the hole transport layer 60, the surface of the quantum dots is connected with octanethiol ligands, and there are 0.2 mmol of ligands in every 1 mg of quantum dots to obtain a light-emitting layer 20 with a thickness of 70 nm;

[0100] Spin-coat an ethanol solution of zinc ferrite with a mass concentration of 5% on the light-emitting layer 20, soak at 60 °C for 10 min, then wash with ethanol to remove the surface solution to obtain an interface modification layer 30 with a thickness of 3 nm;

[0101] Spin-coat an ethanol solution of TiO2 with a concentration of 30 mg / mL on the interface modification layer 30, and dry it at 80 °C for 10 min to obtain an electron transport layer with a thickness of 50 nm;

[0102] Evaporate Ag on the electron transport layer to obtain a second electrode 40 with a thickness of 60 nm;

[0103] Package it in an environment where both the oxygen content and the water content are lower than 0.1 ppm to obtain the light-emitting device 100.

[0104] Example 3

[0105] This example is basically the same as Example 1, except that in this example, the mass concentration of the zinc ferrite ethanol solution is 3%.

[0106] Example 4

[0107] This example is basically the same as Example 1, except that in this example, the mass concentration of the zinc ferrite ethanol solution is 1%.

[0108] Example 5

[0109] This example is basically the same as Example 1, except that in this example, the thickness of the interface modification layer is 1 nm.

[0110] Example 6

[0111] This example is basically the same as Example 1, except that in this example, the thickness of the interface modification layer is 2 nm.

[0112] Example 7

[0113] This example is basically the same as Example 1, except that in this example, CdSeS / ZnS red quantum dots are used to replace the CdSeS / ZnS green quantum dots in Example 1.

[0114] Example 8

[0115] This example is basically the same as Example 1, except that in this example, CdSeS / ZnS blue quantum dots are used to replace the CdSeS / ZnS green quantum dots in Example 1.

[0116] Example 9

[0117] This example is basically the same as Example 1, except that in this example, Mg-doped ZnO is used to replace ZnO in Example 1.

[0118] Comparative Example 1

[0119] This comparative example is basically the same as Example 1, except that this comparative example does not include the step of disposing an interface modification layer on the light-emitting layer.

[0120] Comparative Example 2

[0121] This comparative example is basically the same as Example 2, except that this comparative example does not include the step of disposing an interface modification layer on the light-emitting layer.

[0122] Comparative Example 3

[0123] This comparative example is basically the same as Example 7, except that this comparative example does not include the step of disposing an interface modification layer on the light-emitting layer.

[0124] Comparative Example 4

[0125] This comparative example is basically the same as Example 8, except that this comparative example does not include the step of disposing an interface modification layer on the light-emitting layer.

[0126] Comparative Example 5

[0127] This comparative example is basically the same as Example 9, except that this comparative example does not include the step of disposing an interface modification layer on the light-emitting layer.

[0128] The life T95@1000nit, luminous efficiency C.E., and on-off efficiency fluctuation of the light-emitting devices of Examples 1 to 9 and Comparative Examples 1 to 5 were respectively tested, and the test results are shown in Table 1.

[0129] Among them, the test method for the life T95@1000nit is as follows: in CDA gas, under the drive of a constant current or voltage, the time taken for the brightness of the device to decay to a certain proportion of the maximum brightness is measured, and the time when the brightness decays to 95% of the maximum brightness is defined as T95, and this life is the measured life. To shorten the life test cycle, the device life test is usually carried out by accelerating the device aging at a high brightness and obtaining the life at a low brightness through fitting with a decay fitting formula. For example, the life at 1000 nits is denoted as T95@1000nits, and the calculation formula is:

[0130]

[0131] Among them, T95 L is the life at a low brightness, generally taking the life at 1000 nits, T95 H is the life at a high brightness, that is, the measured life, L H is the maximum brightness to which the device is accelerated, L L is generally 1000 nits, A is the acceleration factor, taking 1.7. Among them, the constant current is 1 mA;

[0132] The luminous efficiency is measured by an optical test instrument;

[0133] The efficiency fluctuation of device turn-on / turn-off refers to the efficiency change of the device when it operates at 1000 nits and restarts after being turned off for 1 minute.

[0134] Table 1:

[0135]

[0136] As can be seen from Table 1:

[0137] Compared with the light-emitting devices of Comparative Example 1, the light-emitting devices of Examples 1, 3 to 6 have a longer lifespan, a higher luminous efficiency, and a lower efficiency fluctuation of device turn-on / turn-off. The reason may be that the light-emitting devices of Examples 1, 3 to 6 include the interface modification layer of the present application. The zinc ferrite in the interface modification layer has a high binding force with the quantum dot light-emitting layer, can protect the electron functional layer material, can make the light-emitting layer and the electron functional layer have a good interface contact, and the zinc ferrite contains Zn-O bonds and has good electron transport performance;

[0138] Compared with the light-emitting devices of Comparative Example 2, the light-emitting devices of Example 2 have a longer lifespan, a higher luminous efficiency, and a lower efficiency fluctuation of device turn-on / turn-off. The reason may be that the light-emitting devices of Example 2 include the interface modification layer of the present application. The zinc ferrite in the interface modification layer has a high binding force with the quantum dot light-emitting layer, can protect the electron functional layer material, can make the light-emitting layer and the electron functional layer have a good interface contact, and the zinc ferrite contains Zn-O bonds and has good electron transport performance;

[0139] Compared with the light-emitting devices of Comparative Example 3, the light-emitting devices of Example 7 have a longer lifespan, a higher luminous efficiency, and a lower efficiency fluctuation of device turn-on / turn-off. The reason may be that the light-emitting devices of Example 7 include the interface modification layer of the present application. The zinc ferrite in the interface modification layer has a high binding force with the quantum dot light-emitting layer, can protect the electron functional layer material, can make the light-emitting layer and the electron functional layer have a good interface contact, and the zinc ferrite contains Zn-O bonds and has good electron transport performance;

[0140] Compared with the light-emitting devices of Comparative Example 4, the light-emitting devices of Example 8 have a longer lifespan, a higher luminous efficiency, and a lower efficiency fluctuation of device turn-on / turn-off. The reason may be that the light-emitting devices of Example 8 include the interface modification layer of the present application. The zinc ferrite in the interface modification layer has a high binding force with the quantum dot light-emitting layer, can protect the electron functional layer material, can make the light-emitting layer and the electron functional layer have a good interface contact, and the zinc ferrite contains Zn-O bonds and has good electron transport performance;

[0141] Compared with the light-emitting device of Comparative Example 5, the light-emitting device of Example 9 has a longer lifespan, higher luminous efficiency, and lower efficiency fluctuations in device turn-on / turn-off. The reason may be that the light-emitting device of Example 9 includes the interface modification layer of the present application. There is a high binding force between zinc ferrite in the interface modification layer and the quantum dot light-emitting layer, which can protect the electron functional layer material, enable better interface contact between the light-emitting layer and the electron functional layer, and zinc ferrite contains Zn-O bonds and has good electron transport performance.

[0142] The technical solutions provided by the embodiments of the present application have been introduced in detail above. Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A light-emitting device, comprising a first electrode, a light-emitting layer, an interface modification layer, and a second electrode stacked in sequence, characterized in that, The material of the interface modification layer includes zinc ferrite.

2. The light-emitting device according to claim 1, characterized in that, The thickness of the interface modification layer is 1 to 10 nm.

3. The light-emitting device according to claim 1, wherein The material of the light-emitting layer includes quantum dots. The quantum dots include one or more 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 each independently selected from one or more of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The II-VI group compounds include one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds include one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds include one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds include one or more of CuInS2, CuInSe2, and AgInS2.

4. The light-emitting device according to claim 3, wherein, The surface of the quantum dots is connected with ligands, and the ligands include one or more of acid ligands, thiol ligands, amine ligands, (oxy)phosphine ligands, phospholipids, lecithin, and polyvinylpyridine. The acid ligands include one or more of decanoic acid, undecylenic acid, myristic acid, oleic acid, and stearic acid. The thiol ligands include one or more 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 one or more of trioctylphosphine and trioctyloxidephosphine.

5. The light-emitting device according to claim 1, characterized in that, The light-emitting device further includes an electron functional layer, which is located between the interface modification layer and the second electrode. The material of the electron functional layer includes inorganic semiconductor particles, and the inorganic semiconductor particles include one or more of doped metal oxide particles, undoped metal oxide particles, ceramic semiconductor materials, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials, and IB-IIIA-VIA group semiconductor materials. The metal oxides in the undoped metal oxide particles include one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxides in the doped metal oxides include one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping elements in the doped metal oxides include one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, and Sn. The IIB-VIA group semiconductor materials include one or more of ZnS, ZnSe, and CdS. The IIIA-VA group semiconductor materials include one or more of InP and GaP. The IB-IIIA-VIA group semiconductor materials include one or more of CuInS and CuGaS. Optionally, the average particle size of the inorganic semiconductor particles is 2 to 15 nm.

6. The light-emitting device according to claim 1, wherein The first electrode and the second electrode each independently include a doped metal oxide electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal elemental electrode, or an alloy electrode. The material of the doped metal oxide electrode includes one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide, aluminum-doped magnesium oxide, and cadmium-doped zinc oxide. The composite electrode includes 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, ZnS / Al / ZnS, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, or BaF2 / Ca / Al. The material of the metal elemental electrode includes one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba. The alloy electrode includes an Au:Mg alloy electrode or an Ag:Mg alloy electrode; and / or The light-emitting device further includes a hole transport layer, which is located between the first electrode and the light-emitting layer. The material of the hole transport layer includes one or more of 4,4'-N,N'-dicarbazolyl-biphenyl, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], 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, poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(N-vinylcarbazole) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine, spiro-NPB, poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline], 1,3-bis(carbazol-9-yl)benzene, polyaniline, polypyrrole, poly(p-)phenylene vinylene, aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbiphenylamines, PEDOT:PSS and its derivatives, polymethacrylates and their derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, doped graphene, undoped graphene, C60, doped or undoped NiO, doped or undoped MoO3, doped or undoped WO3, doped or undoped V2O5, doped or undoped p-type gallium nitride, doped or undoped CrO3, doped or undoped CuO; and / or The light-emitting device further includes a hole injection layer, which is located between the first electrode and the light-emitting layer, and the material of the hole injection layer includes one or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, PEDOT, PEDOT:PSS, a derivative of PEDOT:PSS doped with s-MoO3, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, tetracyanoquinodimethane, copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide.

7. A method for preparing a light-emitting device, characterized in that, It includes the following steps: Providing a light-emitting device preform, which includes a stacked first electrode and a light-emitting layer; Setting a zinc ferrite solution on the light-emitting layer to obtain an interface modification layer; Forming a second electrode on the interface modification layer to obtain a light-emitting device.

8. The preparation method according to claim 7, wherein The concentration of the zinc ferrite solution is 0.01% to 5% by mass; The zinc ferrite solution includes a polar solvent, the polar solvent includes an alcohol solvent, and the alcohol solvent includes one or more of methanol, ethanol, isopropanol, n-butanol, n-pentanol, isopentanol, ethylene glycol, diethylene glycol, dipropylene glycol, and glycerol.

9. The preparation method according to claim 7, wherein The method of setting the zinc ferrite solution on the light-emitting layer includes: soaking the light-emitting layer in the zinc ferrite solution for a period of time and then taking it out, wherein the temperature of the zinc ferrite solution is 50 to 80 °C, and the soaking time is 5 to 30 min; and / or Forming the second electrode on the interface modification layer includes: sequentially forming a stacked electron functional layer and a second electrode on the interface modification layer.

10. A display device, characterized in that, It includes the light-emitting device according to any one of claims 1 to 6, or includes the light-emitting device prepared by the preparation method according to any one of claims 7 to 9.

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