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, and relates to the technical field of display. The light-emitting device comprises a first electrode, a modification layer, a light-emitting layer and a second electrode which are arranged in a stacked mode. Wherein the material of the modification layer comprises a compound A, and the compound A has a structural formula as shown in a formula (I): # imgabs0 #. According to the light-emitting device disclosed by the invention, the light-emitting efficiency of the light-emitting device can be 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 light-emitting device, and a display device including the light-emitting device. Background Art

[0002] Currently, the widely used light-emitting devices are organic light-emitting diodes (OLEDs) and quantum dot light-emitting diodes (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 and adjustable wavelength, and high photoluminescence and electroluminescence quantum yields, and has become a strong competitor of OLED in recent years.

[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 of the light-emitting diode and the electrons generated by the cathode move, and 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, thereby exciting the light-emitting molecules to finally generate visible light.

[0004] Currently, the luminous efficiency of the light-emitting device is relatively low 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 relatively low luminous efficiency of the existing light-emitting devices.

[0006] An embodiment of the present application is implemented as follows. A light-emitting device includes a first electrode, a modification layer, a light-emitting layer, and a second electrode which are stacked; wherein, the material of the modification layer includes compound A, and compound A has a structural formula shown in formula (I):

[0007]

[0008] Wherein, L and R1 are each independently selected from a single bond, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=N-, -N=CH-, -N=N-, -NH-, -NH-CO-, -CH2-, an alkylene group of C1-C10 or an alkenyl group of C2-C10, at least one hydrogen atom in the alkylene group of C1-C10 or the alkenyl group of C2-C10 being substituted by F, Cl or CN; at least one -CH2- or at least two non-adjacent -CH2- in the alkylene group of C1-C10 or the alkenyl group of C2-C10 being substituted by -O-, -S-, -NH-, -CO-, -COO-, -OCO-, -OCOO-, -SCO- or -COS- in a non-directly connected manner to each other;

[0009] R2, R3 and R4 are each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid group, aldehyde group, mercapto group, cyano group; a C1-C20 hydrocarbon group, a C1-C20 hydrocarbon oxy group, a cyclo hydrocarbon group with 3 to 60 ring atoms, a heterocyclic hydrocarbon group with 3 to 60 ring atoms, an aryl group with 5 to 60 ring atoms, a heteroaryl group with 5 to 60 ring atoms, an aryloxy group with 5 to 60 ring atoms, a heteroaryloxy group with 5 to 60 ring atoms, which are unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid group, aldehyde group, mercapto group, cyano group, and one or more combinations thereof, wherein the hetero atoms in the heteroaryl group or heteroaryloxy group are N, S, O, P, Si, and the number of hetero atoms is 1 to 20;

[0010] Ar is selected from a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a combination thereof.

[0011] Correspondingly, an embodiment of the present application further provides a method for preparing a light-emitting device, including:

[0012] Providing a light-emitting device preform, the light-emitting device preform including a first electrode;

[0013] Providing compound A in the above light-emitting device, and disposing the compound A on the light-emitting device preform to form a modification layer;

[0014] Forming a light-emitting layer and a second electrode on the modification layer to obtain a light-emitting device;

[0015] Or,

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

[0017] Providing compound A, and disposing the compound A on the light-emitting device prefabricate to form a modification layer;

[0018] A first electrode is formed on the modification layer to obtain a light-emitting device.

[0019] Correspondingly, an embodiment of the present application further provides a display device, which includes the above-mentioned light-emitting device, or a light-emitting device prepared by the above-mentioned preparation method.

[0020] For the light-emitting device provided by the present application, the light-emitting efficiency of the light-emitting device can be improved by adding a modification layer. Description of the Drawings

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0022] Figure 1 is a schematic structural diagram of the light-emitting device provided by the embodiment of the present application;

[0023] Figure 2 is a schematic structural diagram of another light-emitting device provided by the embodiment of the present application;

[0024] Figure 3 is a flowchart of the preparation method of the forward-type light-emitting device provided by the embodiment of the present application;

[0025] Figure 4 is a flowchart of the preparation method of the inverted-type light-emitting device provided by the embodiment of the present application.

[0026] Reference Numerals:

[0027] First electrode 10; Hole injection layer 20; Modification layer 30; Hole transport layer 40; Light-emitting layer 50; Electron functional layer 60; Second electrode 70. Detailed Embodiments

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the 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 embodiments described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0029] In this application, unless otherwise specified, the orientation terms such as "upper" and "lower" generally refer to the upper and lower in the actual use or working state of the device, specifically the drawing direction in the attached drawings; while "inner" and "outer" refer to the outline of the device. In addition, 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 and do not impose numerical requirements or establish an order.

[0030] 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, and B exists alone. Where A and B can be singular or plural.

[0031] In this application, "at least one" means one or more, and "a plurality" means two or more. "One or several", "at least one (item)" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one (item) of a, b, or c", or, "at least one (item) 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.

[0032] The various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub - ranges and single 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 single numbers within that range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. In addition, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0033] Currently, through continuous improvement and optimization of the structure of light - emitting devices, the efficiency and lifespan of existing light - emitting devices have been greatly improved. However, the electron mobility in the electron functional layer of light - emitting devices is much higher than the hole mobility, resulting in excessive electron injection and causing the phenomenon of electron accumulation in the light - emitting layer. Especially when the hole mobility in the organic hole - transporting layer is low, the insufficient hole injection further exacerbates this carrier imbalance.

[0034] In the prior art, organic semiconductor materials are often used as hole injection layers or transport layers, such as poly(3,4-ethylenedioxythiophene)-polystyrenesulfonic acid (PEDOT:PSS), poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine) (TFB), polyvinylcarbazole (PVK), 4,4'-bis(9-carbazolyl)biphenyl (CBP), and N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD), etc. Among them, PEDOT:PSS has excellent hole mobility and film-forming properties and is usually used as a hole injection layer material. However, this substance is weakly acidic, and the PSS unit that is prone to water absorption is easily affected by moisture, which will affect the hole transport layer of the same organic semiconductor and ultimately affect the luminous efficiency, luminous uniformity, lifespan, and stability of the light-emitting device.

[0035] The technical solution of this application is as follows:

[0036] In a first aspect, please refer to Figure 1 and Figure 2 , an embodiment of this application provides a light-emitting device, including a first electrode 10, a modification layer 30, a light-emitting layer 50, and a second electrode 70 that are stacked; wherein, the material of the modification layer 30 includes compound A, and compound A has a structural formula shown in formula (Ⅰ):

[0037]

[0038] Wherein, L and R1 each independently selected from a single bond, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=N-, -N=CH-, -N=N-, -NH-, -NH-CO-, -CH2-, C,-C,, an alkylene group or a C,-C, alkenyl group, at least one hydrogen atom in the C,-C,, alkylene group or C,-C, alkenyl group is substituted by F, Cl or CN; at least one -CH,- or at least two non-adjacent -CH,- in the C,-C,, alkylene group or C,-C, alkenyl group are substituted by -O-, -S-, -NH-, -CO-, -COO-, -OCO-, -OCOO-, -SCO- or -COS- in a non-directly connected manner;

[0039] Each of the R2, R3, and R4 is independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid group, aldehyde group, mercapto group, and cyano group; a C1-C20 hydrocarbon group, a C1-C20 hydrocarbon oxy group, a cycloalkyl group having 3 to 60 ring atoms, a heterocycloalkyl group having 3 to 60 ring atoms, an aryl group having 5 to 60 ring atoms, a heteroaryl group having 5 to 60 ring atoms, an aryloxy group having 5 to 60 ring atoms, and a heteroaryloxy group having 5 to 60 ring atoms, which are unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid group, aldehyde group, mercapto group, and cyano group, and one or more combinations thereof, wherein the heteroatoms in the heteroaryl group or heteroaryloxy group are N, S, O, P, Si, and the number of heteroatoms is 1 to 20;

[0040] The Ar is selected from a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a combination thereof.

[0041] In the light-emitting device described in the present application, a modification layer 30 prepared from a compound A is added between the first electrode 10 and the light-emitting layer 50. The aromatic ring of Ar in the compound A and the oxygen connected thereto can form a P-π conjugation, enhancing the electron cloud density and the electrophilic substitution activity on the benzene ring, having a stable free radical signal and a high conductivity, thereby increasing the migration rate of carriers. The migration rate of carriers passing through the modification layer 30 increases and is quickly and effectively transmitted to the light-emitting layer 50, which can effectively improve the light-emitting efficiency of the light-emitting device and extend the service life of the light-emitting device.

[0042] In some embodiments, the material of the modification layer includes a paracetamol ketone derivative, and the structural formula of the paracetamol ketone derivative is shown in formula (Ⅱ):

[0043]

[0044] Among them, L1 includes a single bond, -NH-, or -NH-CO-, and Ar1 includes a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a combination thereof.

[0045] When L is a single bond, the structural formula of the paracetamol ketone derivative is shown in formula (Ⅲ):

[0046]

[0047] In some embodiments, the Ar1 includes: benzene, biphenyl, terphenyl, naphthalene, anthracene, phenanthrene, carbazole, benzocarbazole, triphenylamine, thiophene, furan, pyrrole, benzofuran, benzothiophene, benzopyrrole, pyridine, or spirobifluorene.

[0048] In some embodiments, the substituents in the substituted aryl group of Ar1 and the substituents in the substituted heteroaryl group each independently include one or more of F, Cl, Br, CH3, OCH3, NO2, ONHNH2, NHNH2, and NH2.

[0049] In some embodiments, the number of substituents in the substituted aryl group of Ar1 and the number of substituents in the substituted heteroaryl group each independently are 1 to 2.

[0050] In some embodiments, the heteroatoms in the heteroaryl group of Ar1 include one or more of P, N, and S.

[0051] As an example, in some embodiments, compound A may be selected from at least one of the compounds represented by the following structural formulas, but not limited thereto:

[0052]

[0053] In some embodiments, the thickness of the modification layer 30 is 15 nm to 40 nm, and for example, it may be 16 nm to 38 nm, 18 nm to 35 nm, 20 nm to 32 nm, 22 nm to 30 nm, 25 nm to 26 nm, etc. Within the thickness range, the modification layer 30 is beneficial to improving the hole transport rate.

[0054] In some embodiments, the light-emitting device further includes one or more of a hole functional layer and an electron functional layer 60.

[0055] In some embodiments, the electron functional layer 60 is disposed between the light-emitting layer 50 and the second electrode 70.

[0056] The electron functional layer 60 includes one or more of an electron injection layer and an electron transport layer;

[0057] In some embodiments, the hole functional layer is disposed between the first electrode 10 and the light-emitting layer 50.

[0058] The hole functional layer includes one or more of a hole injection layer 20 and a hole transport layer 40.

[0059] More specifically, the hole injection layer 20 is disposed between the first electrode 10 and the modification layer 30, and the hole transport layer 40 is disposed between the modification layer 30 and the light-emitting layer 50.

[0060] A modification layer 30 prepared from compound A is added between the hole injection layer 20 and the hole transport layer 40. The hole injection layer 20 can effectively inject holes from the anode 10 into the modification layer 30. In compound A, the aromatic ring of Ar and the oxygen connected thereto can form a P-π conjugation, enhancing the electron cloud density and the electrophilic substitution activity on the benzene ring, having a stable free radical signal and a relatively high conductivity, so that the migration rate of holes can be increased. The migration rate of holes passing through the modification layer 30 increases and is quickly and effectively transmitted to the light-emitting layer 50 through the hole transport layer 40, thereby effectively balancing the electron transport rate and the hole transport rate in the light-emitting device, improving the recombination efficiency of holes and electrons in the light-emitting layer 50, and further improving the light-emitting efficiency of the light-emitting device and extending the service life of the light-emitting device.

[0061] It can be understood that some hole injection materials and hole transport materials such as PEDOT:PSS are prone to absorbing water and getting damp, thus causing damage to other functional layers. The aryl or heteroaryl ring system contains aromatic rings and has strong hydrophobic properties. Using it as the material of the modification layer 30 can reduce the water absorption of the hole injection layer 20 and the hole transport layer 40, keep the light-emitting device dry, and thus ensure the normal operation of the light-emitting device.

[0062] In some embodiments, the materials of the first electrode 10 and the second electrode 70 respectively include 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 a metal oxide electrode or a composite electrode with a metal sandwiched between doped or undoped transparent metal oxides. The materials of the metal oxide electrode include one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, MoO3, and AMO, and the composite electrodes include 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. Herein, " / " represents a laminated structure. For example, AZO / Ag / AZO represents a composite electrode including an AZO layer, an Ag layer, and an AZO layer laminated in sequence.

[0063] In some embodiments, the thickness of the first electrode 10 is 35 nm to 60 nm, and can be, for example, 38 nm to 58 nm, 40 nm to 55 nm, 42 nm to 52 nm, 45 nm to 50 nm, 46 nm to 48 nm, etc.

[0064] In some embodiments, the thickness of the second electrode 70 is 60 nm to 100 nm, and for example, it may be 62 nm to 98 nm, 65 nm to 95 nm, 68 nm to 90 nm, 70 nm to 85 nm, 75 nm to 80 nm, etc.

[0065] In some embodiments, the materials of the hole injection layer 20 and the hole transport layer 40 respectively include but are not limited to 4,4'-N,N'-dicarbazolyl-biphenyl, N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(carbazol-9-yl)triphenylamine, trichloroisocyanuric acid, terbium-doped phosphate-based green luminescent material, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 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(4-butylphenyl-diphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], polyaniline, polypyrrole, poly(p-phenylene vinylene), poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], copper phthalocyanine, aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraarylbenzidine, PEDOT, PEDOT:PSS and its derivatives, PEDOT:PSS derivatives doped with s-MoO3, poly(N-vinylcarbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-bis(naphthalen-1-yl)-N,N'-diphenylbenzidine, spiro-NPB, nanocrystalline diamond, microcrystalline cellulose and tetracyanoquinodimethane, doped graphene, undoped graphene, second doped metal oxide particles, second undoped metal oxide particles, metal sulfides, metal selenides and metal nitrides, wherein the metal oxides in the second doped metal oxide particles and the metal oxides in the second undoped metal oxide particles independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5, the doping elements in the second doped metal oxide particles include one or more of Mo, W, Ni, Cr, Cu, V, the metal sulfides include one or more of CuS, MoS3, WS3, the metal selenides include one or more of MoSe3, WSe3, and the metal nitrides include p-type gallium nitride.

[0066] In some embodiments, the thickness of the hole injection layer 20 is 20 nm to 50 nm, and can be, for example, 22 nm to 48 nm, 25 nm to 45 nm, 28 nm to 42 nm, 30 nm to 40 nm, 32 nm to 36 nm, etc.

[0067] In some embodiments, the thickness of the hole transport layer 40 is 20 nm to 50 nm, and can be, for example, 22 nm to 48 nm, 25 nm to 45 nm, 28 nm to 42 nm, 30 nm to 40 nm, 32 nm to 36 nm, etc.

[0068] In some embodiments, the material of the light-emitting layer 50 includes one or more of an organic light-emitting material and a quantum dot light-emitting material.

[0069] The organic light-emitting material includes one or more of CBP:Ir(mppy)3 (4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridine iridium(III)]), TCTX:Ir(mmpy) (4,4',4”-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridine iridium]), diaryl anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent material, TTPX fluorescent material, TBRb fluorescent material, DBP fluorescent material, delayed fluorescence material, TTA material, TADF (thermally activated delayed) material, a polymer containing a B-N covalent bond, an HLCT (hybrid local charge transfer excited state) material, and an Exciplex (excimer complex) light-emitting material.

[0070] The quantum dot light-emitting material includes one or more of a single-structure quantum dot, a core-shell structure quantum dot, and a perovskite-type semiconductor material.

[0071] 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 can be respectively selected from, but not limited to, one or several of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The shell of the core-shell structure quantum dots is one or more layers; the II-VI group compounds include one or several of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, 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 several 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 several 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 several of CuInS2, CuInSe2, and AgInS2.

[0072] As an example, the quantum dots with core-shell structure include 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.

[0073] The perovskite semiconductor material includes doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors. The general structural formula of the inorganic perovskite semiconductor is AMX3, where A is a Cs + ion, M is a divalent metal cation selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ and one or more of the like, and X is a halogen anion selected from Cl - , Br - , I - and one or more of the like. The general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, where B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or

[0074] [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation selected from Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ and one or more of the like, and X is a halogen anion selected from Cl - , Br - , I - and one or more of the like.

[0075] In some embodiments, the thickness of the light-emitting layer 50 is 30 nm to 70 nm, and for example, it can be 32 nm to 68 nm, 35 nm to 65 nm, 40 nm to 70 nm, 45 nm to 65 nm, 50 nm to 60 nm, etc.

[0076] In some embodiments, the materials of the electron injection layer and the electron transport layer respectively include one or more of first doped metal oxide particles, first undoped metal oxide particles, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials, and IB-IIIA-VIA group semiconductor materials. The materials of the first undoped metal oxide particles include one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxides in the first doped metal oxide particles include one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping elements in the first doped metal oxide particles include one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. 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.

[0077] In some embodiments, the thickness of the electron functional layer 60 is 50 nm to 80 nm, and for example, it can be 52 nm to 78 nm, 55 nm to 75 nm, 58 nm to 72 nm, 60 nm to 70 nm, 62 nm to 68 nm, etc.

[0078] In a second aspect, please refer to Figure 3 , embodiments of the present application further provide a method for manufacturing a light-emitting device, including:

[0079] S11: Provide a light-emitting device preform, and the light-emitting device preform includes a first electrode 10;

[0080] S12: Provide compound A in the above-mentioned light-emitting device, and dispose the compound A on the light-emitting device preform to form a modification layer 30;

[0081] S13: Form a light-emitting layer 50 and a second electrode 70 on the modification layer 30 to obtain a light-emitting device.

[0082] It can be understood that the above-mentioned light-emitting device is a normal-type light-emitting device, and the light-emitting device can also be an inverted-type light-emitting device. Please refer to Figure 4 , and the manufacturing method of the inverted-type light-emitting device includes:

[0083] S21. Provide a light-emitting device preform, the light-emitting device preform including a stacked second electrode 70 and a light-emitting layer 50;

[0084] S22. Provide compound A in the above-mentioned light-emitting device, and dispose the compound A on the light-emitting device preform to form a modification layer 30;

[0085] S23. Form a first electrode 10 on the modification layer 30 to obtain a light-emitting device.

[0086] In some embodiments, the material of the modification layer 30 includes paracetamol ketone derivatives.

[0087] In some embodiments, the preparation method of the paracetamol ketone derivative includes:

[0088] S121. Provide paracetamol and haloacetone, mix the paracetamol, the haloacetone and a first solvent to obtain a precursor;

[0089] S122. Provide a substituted amine, the substituted amine including one or more of aromatic amines and heteroaromatic amines, mix the substituted amine with the precursor and a second solvent to obtain a paracetamol ketone derivative.

[0090] In S121:

[0091] In some embodiments, the haloacetone includes one or more of chloroacetone, bromoacetone, fluoroacetone, and iodoacetone.

[0092] In some embodiments, the first solvent includes one or more of acetone, toluene, dimethylformamide, dimethyl sulfoxide, sulfolane, ethylene nitrate, xylene, anisole, decalin, cyclohexane, cyclohexene, methylcyclohexane, ethylcyclohexane, limonene, hexane, octane, nonane, decane, dimethylacetamide, acetyl carbonate, N-methylpyrrolidone, tetrahydrofuran, ethyl acetate, and dichloromethane.

[0093] In some embodiments, the molar ratio of the paracetamol to the haloacetone is 1:(1-2), for example, it can be 1:(1.1-1.9), 1:(1.2-1.8), 1:(1.3-1.7), 1:(1.4-1.6), etc. Within the range of the molar ratio, it is beneficial for the paracetamol and the haloacetone to react fully.

[0094] In some embodiments, the preparation method of the paracetamol ketone derivative further includes providing a basic substance and mixing it with the paracetamol and the first solvent.

[0095] In some embodiments, the basic substance includes one or more of potassium carbonate, sodium carbonate, sodium bicarbonate, lithium carbonate, and ammonium bicarbonate.

[0096] In some embodiments, the molar ratio of the acetaminophen to the potassium carbonate is 1:(1 - 2), for example, it can be 1:(1.1 - 1.9), 1:(1.2 - 1.8), 1:(1.3 - 1.7), 1:(1.4 - 1.6), etc. Within the range of the molar ratio, it is beneficial for the basic substance to neutralize the acid in the acetaminophen and can also dry and remove moisture.

[0097] In some embodiments, the method for preparing the acetaminophen ketone derivative further includes providing a catalyst and mixing it with the acetaminophen and the first solvent.

[0098] In some embodiments, the catalyst includes one or more of potassium iodide, sodium iodide, rubidium iodide, and potassium iodate.

[0099] In some embodiments, the molar ratio of the acetaminophen to the potassium iodide is 1:(1 - 2), for example, it can be 1:(1.1 - 1.9), 1:(1.2 - 1.8), 1:(1.3 - 1.7), 1:(1.4 - 1.6), etc. Within the range of the molar ratio, it is beneficial to increase the reaction rate of the acetaminophen and the haloacetone.

[0100] In some embodiments, after the acetaminophen, the haloacetone, and the first solvent are mixed, the molar concentration of the acetaminophen is 6 mmol / L to 20 mmol / L, for example, it can be 7 mmol / L to 18 mmol / L, 8 mmol / L to 16 mmol / L, 9 mmol / L to 15 mmol / L, 10 mmol / L to 14 mmol / L, 11 mmol / L to 12 mmol / L, etc.

[0101] In some embodiments, the mixing time of the acetaminophen, the haloacetone, and the first solvent is 4 h to 8 h, for example, it can be 4.2 h to 7.8 h, 4.5 h to 7.5 h, 4.8 h to 7.2 h, 5 h to 7 h, 5.5 h to 6 h, etc. The mixing temperature is 80 °C to 100 °C, for example, it can be 81 °C to 99 °C, 82 °C to 98 °C, 85 °C to 97 °C, 86 °C to 95 °C, 90 °C to 92 °C, etc. It can be understood that within the range of the mixing time and temperature, it is beneficial for the reflux reaction to occur, promoting the complete participation of the acetaminophen in the reaction and improving the reaction efficiency.

[0102] In some embodiments, after the acetaminophen, the haloacetone, and the first solvent are mixed, it further includes removing the first solvent.

[0103] In some embodiments, after removing the first solvent, extraction with an extractant is further included. Further, the extractant includes one or more of water and ethyl acetate.

[0104] In some embodiments, after extraction with the extractant, taking the organic layer and drying it to obtain a precursor is further included. Further, the drying can be carried out using a desiccant, and the desiccant can be one or more of anhydrous sodium sulfate, anhydrous magnesium sulfate, anhydrous calcium sulfate, and anhydrous copper sulfate.

[0105] In S122:

[0106] In some embodiments, the substituted amine includes one or more of aniline, meta-substituted aniline, ortho-substituted aniline, para-substituted aniline, phenylhydrazine, meta-substituted phenylhydrazine, ortho-substituted phenylhydrazine, para-substituted phenylhydrazine, benzoylhydrazine, meta-substituted benzoylhydrazine, ortho-substituted benzoylhydrazine, and para-substituted benzoylhydrazine.

[0107] In some embodiments, the second solvent includes one or more of acetone, toluene, dimethylformamide, dimethyl sulfoxide, sulfolane, ethylene glycol dinitrate, xylene, anisole, decalin, cyclohexane, cyclohexene, methylcyclohexane, ethylcyclohexane, limonene, hexane, octane, nonane, decane, dimethylacetamide, acetyl carbonate, N-methylpyrrolidone, tetrahydrofuran, ethyl acetate, and dichloromethane.

[0108] In some embodiments, the molar ratio of the precursor to the substituted amine is 1:1.

[0109] In some embodiments, after the substituted amine is mixed with the precursor and the second solvent, the molar concentration of the precursor is 5 mmol / L to 20 mmol / L, for example, it can be 7 mmol / L to 18 mmol / L, 8 mmol / L to 16 mmol / L, 9 mmol / L to 15 mmol / L, 10 mmol / L to 14 mmol / L, 11 mmol / L to 12 mmol / L, etc.

[0110] In some embodiments, the mixing time of the substituted amine with the precursor and the second solvent is 2 h to 4 h, for example, it can be 2.1 h to 3.8 h, 2.2 h to 3.6 h, 2.5 h to 3.5 h, 2.6 h to 3.2 h, 2.8 h to 3 h, etc. The mixing temperature is 65 °C to 80 °C, for example, it can be 66 °C to 79 °C, 68 °C to 78 °C, 70 °C to 76 °C, 71 °C to 75 °C, 72 °C to 74 °C, etc. It can be understood that within the mixing time and temperature range, it is beneficial to carry out a reflux reaction and improve the reaction efficiency.

[0111] In some embodiments, after the substituted amine, the precursor, and the second solvent are mixed, the second solvent is further removed.

[0112] In some embodiments, after removing the second solvent, recrystallization is further performed using a recrystallization reagent. Further, the recrystallization reagent includes one or more of methanol, ethanol, acetone, and acetonitrile.

[0113] It can be understood that the formation of the modification layer 30 can adopt conventional techniques in the art, such as chemical methods or physical methods. Among them, chemical methods include chemical vapor deposition, continuous ion layer adsorption and reaction, anodic 10 oxidation, electrolytic deposition, and coprecipitation. Physical methods include physical coating methods and solution methods. Among them, physical coating methods include: thermal evaporation coating method, electron beam evaporation coating method, magnetron sputtering method, multi-arc ion coating method, physical vapor deposition method, atomic layer deposition method, pulsed laser deposition method, etc.; solution methods can be spin coating method, printing method, inkjet printing method, doctor blade coating method, printing method, dip coating method, immersion method, spraying method, roll coating method, casting method, slot die coating method, and bar coating method, etc.

[0114] In at least one embodiment, the method for forming the modification layer 30 is a solution method.

[0115] Specifically, when the light-emitting device is a normal structure, Compound A is provided, dissolved in a third solvent to obtain a Compound A solution, and the Compound A solution is disposed on the light-emitting device preform to form the modification layer 30.

[0116] When the light-emitting device is an inverted structure, Compound A is provided, dissolved in a third solvent to obtain a Compound A solution, and the Compound A is disposed on the light-emitting device preform to form the modification layer 30.

[0117] In some embodiments, the third solvent includes one or more of acetone, toluene, dimethylformamide, dimethyl sulfoxide, sulfolane, ethylene nitrate, xylene, anisole, decalin, cyclohexane, cyclohexene, methylcyclohexane, ethylcyclohexane, limonene, hexane, octane, nonane, decane, dimethylacetamide, acetyl carbonate, N-methylpyrrolidone, tetrahydrofuran, ethyl acetate, and dichloromethane.

[0118] In some embodiments, in the Compound A solution, the concentration of Compound A is 15 mg / mL to 30 mg / mL, for example, it can be 16 mg / mL to 28 mg / mL, 18 mg / mL to 27 mg / mL, 20 mg / mL to 26 mg / mL, 21 mg / mL to 25 mg / mL, 22 mg / mL to 24 mg / mL, etc.

[0119] When fabricating a top-emitting light-emitting device, in some embodiments, the light-emitting device preform includes a first electrode 10 and a hole injection layer 20 which are stacked in sequence.

[0120] In some embodiments, forming a light-emitting layer 50 and a second electrode 70 on the modification layer 30 includes sequentially forming a hole transport layer 40, a light-emitting layer 50, an electron-functional layer 60, and a second electrode 70 on the modification layer 30.

[0121] Correspondingly, when fabricating an inverted light-emitting device, in some embodiments, the light-emitting device preform includes a second electrode 70, an electron-functional layer 60, a light-emitting layer 50, and a hole transport layer 40 which are stacked in sequence.

[0122] In some embodiments, forming a first electrode 10 on the modification layer 30 includes sequentially forming a hole injection layer 20 and a first electrode 10 on the modification layer 30.

[0123] The materials of the first electrode 10, the hole injection layer 20, the hole transport layer 40, the light-emitting layer 50, the electron-functional layer 60, the second electrode 70, and the substituted amine are as described above and will not be elaborated here.

[0124] In a third aspect, the present application also relates to a display device, and the display device includes the light-emitting device.

[0125] The display device can be any electronic product with a display function. The electronic products include but are not limited to smartphones, tablet computers, laptop computers, digital cameras, digital video cameras, smart wearable devices, smart weighing electronic scales, in-vehicle displays, televisions, or e-book readers. Among them, the smart wearable devices can be, for example, smart bracelets, smart watches, virtual reality (VR) helmets, etc.

[0126] 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.

[0127] Embodiment 1

[0128] This device embodiment provides a light-emitting device, and the preparation method is as follows:

[0129] Provide ITO glass, clean the ITO glass with a cleaning agent to remove surface stains, and then ultrasonically clean the ITO glass with deionized water, isopropyl acetone, acetone, and deionized water for 20 minutes in sequence, and then dry it with nitrogen to obtain an ITO anode with a thickness of 30 nm;

[0130] Deposit PEDOT:PSS on the ITO anode, heat it at 150 °C for 30 minutes to remove moisture, and form a hole injection layer with a thickness of 30 nm.

[0131] Dissolve 0.5 mmol of paracetamol, monochloroacetone, potassium carbonate, and potassium iodide in 50 mL of acetone, reflux at 85 °C for 6 h, evaporate the solvent, extract with water and ethyl acetate, and dry the organic solvent layer with anhydrous sodium sulfate to obtain the precursor; take 1 mol of the precursor and 1 mol of aniline and dissolve them in 100 ml of toluene, reflux at 65 °C for 2 h, evaporate the solvent, and recrystallize with methanol to obtain paracetamol ketone aniline shown in the following formula:

[0132]

[0133] Dissolve the prepared paracetamol ketone aniline in an acetone solvent and disperse it evenly by ultrasonic treatment to obtain a paracetamol ketone aniline solution with a concentration of 15 mg / mL. Deposit the paracetamol ketone aniline solution on the hole injection layer, heat at 150 °C for 30 min to remove the solvent, and form a modified layer with a thickness of 20 nm;

[0134] Use a pipette to aspirate 40 μL of the TFB solution, slowly drop it on the modified layer, and perform spin coating at a rotation speed of 4000 rpm for 30 s. Then perform annealing at an annealing temperature of 150 °C for 30 min to obtain a 30-nm hole transport layer;

[0135] Dissolve quantum dots with CdZnSeS as the core and ZnS as the shell in n-octane to prepare a quantum dot solution with a concentration of 15 mg / mL; use a pipette to aspirate 45 μL, drop it on the hole transport layer, and perform spin coating at a rotation speed of 3500 rpm for 45 s. Then perform annealing at an annealing temperature of 80 °C for 30 min to obtain a 40-nm light-emitting layer;

[0136] Set a 20 mg / mL ethanol dispersion of ZnO on the light-emitting layer, perform spin coating at a rotation speed of 3000 rpm for 30 s. Then perform annealing at an annealing temperature of 80 °C for 30 min to obtain an 80-nm electron functional layer;

[0137] Place the device in an evaporation chamber and thermally evaporate a layer of silver metal through a mask plate to obtain an 80-nm cathode;

[0138] Heat-treat the above device at 120 °C for 15 min and encapsulate it to obtain a light-emitting device.

[0139] Example 2

[0140] This example is basically the same as Example 1, except that in this example, aniline is replaced by phenylhydrazine, and the paracetamol ketone derivative is paracetamol ketone phenylhydrazine. The structural formula of paracetamol ketone phenylhydrazine is shown in the following formula:

[0141]

[0142] Example 3

[0143] This example is basically the same as Example 1, except that in this example, aniline is replaced by benzohydrazide, and the p-acetaminophenone derivative is p-acetaminophenone benzohydrazide. The structural formula of p-acetaminophenone benzohydrazide is shown as follows:

[0144]

[0145] Example 4

[0146] This example is basically the same as Example 1, except that in this example, aniline is replaced by o-bromoaniline, and the p-acetaminophenone derivative is p-acetaminophenone o-bromoaniline. The structural formula of p-acetaminophenone o-bromoaniline is shown as follows:

[0147]

[0148] Example 5

[0149] This example is basically the same as Example 1, except that in this example, aniline is replaced by p-chlorophenylhydrazine, and the p-acetaminophenone derivative is p-acetaminophenone p-chlorophenylhydrazine. The structural formula of p-acetaminophenone p-chlorophenylhydrazine is shown as follows:

[0150]

[0151] Example 6

[0152] This example is basically the same as Example 1, except that in this example, aniline is replaced by m-fluorobenzohydrazide, and the p-acetaminophenone derivative is p-acetaminophenone m-fluorobenzohydrazide. The structural formula of p-acetaminophenone m-fluorobenzohydrazide is shown as follows:

[0153]

[0154] Example 7

[0155] This example is basically the same as Example 1, except that in this example, the thickness of the modification layer is 15 nm.

[0156] Example 8

[0157] This example is basically the same as Example 1, except that in this example, the thickness of the modification layer is 40 nm.

[0158] Example 9

[0159] This embodiment is basically the same as Embodiment 1, except that the TFB hole transport layer is not prepared in this embodiment.

[0160] Comparative Example 1

[0161] This comparative example is basically the same as Embodiment 1, except that the modification layer is not provided in this comparative example.

[0162] Comparative Example 2

[0163] This comparative example is basically the same as Embodiment 9, except that the modification layer is not provided in this comparative example.

[0164] The external quantum efficiency EQE and hole mobility of the quantum dot light-emitting diodes in Embodiments 1 to 9 and Comparative Examples 1 to 2 were tested, and the test results are shown in Table 1.

[0165] Among them, the test method for the external quantum efficiency EQE is:

[0166] The ratio of the number of electron-hole pairs injected into the quantum dots to the number of emitted photons, with the unit of %, is an important parameter for measuring the quality of electroluminescent devices and can be obtained by measuring with an EQE optical test instrument. The specific calculation formula is as follows:

[0167]

[0168] Among them, ηe is the optical output coupling efficiency, ηr is the ratio of the number of recombined carriers to the number of injected carriers, χ is the ratio of the number of excitons generating photons to the total number of excitons, KR is the radiation process rate, and KNR is the non-radiation process rate.

[0169] Test conditions: Conducted at room temperature, with the air humidity of 30 - 60%.

[0170] The test method for hole mobility is: Control QE PRO and Keithley 2400 through LabView to build a set of QLED efficiency test system. The current density-voltage curve of the single-carrier transport thin film device (HOD) is tested by this system. Through the current density-voltage curve, the space charge limited current (SCLC) region in the curve is obtained, and then according to the formula J = (9 / 8)ε r ε0μ e V 2 / d 3 calculate the hole mobility, where J represents the current density, with the unit mAcm -2 ; ε r represents the relative dielectric constant, ε0 represents the vacuum dielectric constant; μ e represents the hole mobility, with the unit cm 2 V -1 s -1; V represents the driving voltage, with the unit V; d represents the film thickness, with the unit m.

[0171] Table 1

[0172]

[0173]

[0174] As can be seen from Table 1:

[0175] From Examples 1 to 3 and Comparative Example 1, it can be known that whether it is p-acetaminophenone aniline, p-acetaminophenone phenylhydrazine or p-acetaminophenone benzoylhydrazine, compared with the light-emitting device of Comparative Example 1, the external quantum efficiency of the light-emitting devices of Examples 1 to 3 has been significantly improved, and the hole mobility has also been significantly enhanced. There is no significant difference among different R groups on the p-acetaminophenone derivative, indicating that the setting of the modification layer can effectively improve the migration rate of holes, promote their recombination with electrons, and thus improve the luminous efficiency of the light-emitting device;

[0176] From Example 1, Examples 4 to 6 and Comparative Example 1, it can be known that the substituent of R3 in Compound A has no obvious effect on the performance of the light-emitting device, and the luminous efficiency and hole mobility of the light-emitting devices of Examples 4 to 6 are higher than those of the light-emitting device of the comparative example;

[0177] From Example 1, Examples 7 to 8 and Comparative Example 1, it can be known that when the thickness of the modification layer is relatively low, the performance of its light-emitting device is slightly worse than that of the light-emitting devices of Example 1 and Example 8. This is because when the thickness of the modification layer is small, the function of the modification layer cannot be fully and effectively exerted, but its effect is still better than that of the light-emitting device of the comparative example;

[0178] From Example 1, Example 9 and Comparative Example 2, it can be known that when the hole functional layer in the light-emitting device only contains a hole injection layer, the performance of the light-emitting device is slightly worse than that of the light-emitting device whose hole functional layer contains both a hole injection layer and a hole transport layer at the same time; from Example 9, it can be obtained that for the light-emitting device only containing a hole injection layer, the addition of the modification layer can significantly improve the hole mobility and the luminous efficiency of the light-emitting device.

[0179] In summary, using Compound A as the material of the modification layer and setting the modification layer in the light-emitting device is beneficial to improving the migration rate of holes, promoting the recombination of holes and electrons, and thus improving the luminous efficiency of the light-emitting device.

[0180] The above has introduced in detail the light-emitting device, its manufacturing method, and the display device provided by the embodiments of the present application. Specific examples are used herein to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is 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 manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A light-emitting device, characterized in that, It includes a first electrode, a modification layer, a light-emitting layer, and a second electrode which are stacked; wherein, the material of the modification layer includes compound A, and compound A has a structural formula shown in formula (Ⅰ): Wherein, L and R1 each independently selected from a single bond, -O-, -S-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -CH=N-, -N=CH-, -N=N-, -NH-, -NH-CO-, -CH2-, C,-C,, alkylene or C,-C, alkenyl, and at least one hydrogen atom in the C,-C,, alkylene or C,-C, alkenyl is substituted by F, Cl or CN; at least one -CH,- or at least two non-adjacent -CH,- in the C,-C,, alkylene or C,-C, alkenyl are substituted by -O-, -S-, -NH-, -CO-, -COO-, -OCO-, -OCOO-, -SCO- or -COS- in a non-directly connected manner to each other; R2, R3 and R4 each independently selected from hydrogen, deuterium, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid group, aldehyde group, mercapto group, cyano group; C1-C20 hydrocarbon group, C1-C20 hydrocarbon oxy group, cycloalkyl group with 3 to 60 ring atoms, heterocycloalkyl group with 3 to 60 ring atoms, aryl group with 5 to 60 ring atoms, heteroaryl group with 5 to 60 ring atoms, aryloxy group with 5 to 60 ring atoms, heteroaryloxy group with 5 to 60 ring atoms which are unsubstituted or substituted by amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid group, aldehyde group, mercapto group, cyano group, and one or more combinations thereof, wherein the heteroatoms in the heteroaryl group or heteroaryloxy group are N, S, O, P, Si, and the number of heteroatoms is 1 to 20; Ar is selected from substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, or a combination thereof.

2. The light-emitting device according to claim 1, characterized in that, The material of the modification layer includes paracetamol ketone derivative, and the structural formula of the paracetamol ketone derivative is shown in formula (Ⅱ): Wherein, L1 includes a single bond, -NH- or -NH-CO-, and Ar1 includes substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, or a combination thereof.

3. The light-emitting device according to claim 2, wherein Ar includes benzene, biphenyl, terphenyl, naphthalene, anthracene, phenanthrene, carbazole, benzocarbazole, triphenylamine, thiophene, furan, pyrrole, benzofuran, benzothiophene, benzopyrrole, pyridine or spirobifluorene; and / or The substituents in the substituted aryl group of Ar and the substituents in the substituted heteroaryl group of Ar each independently include one or several of F, Cl, Br, CH3, OCH3, NO2, ONHNH2, NHNH2, NH2; and / or The number of substituents in the substituted aryl group of Ar and the number of substituents in the substituted heteroaryl group of Ar each independently is 1 to 2; and / or The heteroatoms in the heteroaryl group include one or several of P, N, S.

4. The light-emitting device according to any one of claims 1 to 3, characterized in that, Compound A includes at least one of the compounds shown in the following structural formula:

5. The light-emitting device according to claim 1, wherein The light-emitting device further includes one or more of a hole functional layer and an electron functional layer; The electron functional layer is disposed between the light-emitting layer and the second electrode, and the electron functional layer includes one or more of an electron injection layer and an electron transport layer; The hole functional layer includes one or more of a hole injection layer and a hole transport layer. The hole injection layer is disposed between the first electrode and the modification layer, and the hole transport layer is disposed between the modification layer and the light-emitting layer.

6. The light-emitting device according to claim 5, wherein the materials of the first electrode and the second electrode respectively include one or more of a metal, a carbon material, and a metal oxide; the metal includes one or more of Al, Ag, Cu, Mo, Au, Ba, Ca, Yb, and Mg; the carbon material includes one or more of graphite, carbon nanotubes, graphene, and carbon fiber; the metal oxide includes a metal oxide electrode or a composite electrode with a metal sandwiched between doped or undoped transparent metal oxides. The material of the metal oxide electrode includes one or more of ITO, FTO, ATO, AZO, GZO, IZO, MZO, and AMO, and the composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, ZnS / Ag / ZnS, ZnS / Al / ZnS, TiO2 / Ag / TiO2, and TiO2 / Al / TiO2; and / or The materials of the hole injection layer and the hole transport layer respectively include one or more of 4,4'-N,N'-dicarbazolyl-biphenyl, N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(carbazol-9-yl)triphenylamine, trichloroisocyanuric acid, terbium-doped phosphate-based green luminescent material, 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, 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(4-butylphenyl-diphenylamine), poly[bis(4-phenyl)(4-butylphenyl)amine], polyaniline, polypyrrole, poly(p-phenylene vinylene), poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], copper phthalocyanine, aromatic tertiary amine, polynuclear aromatic tertiary amine, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compound, N,N,N',N'-tetraarylbenzidine, PEDOT, PEDOT:PSS and its derivatives, PEDOT:PSS derivatives doped with s-MoO3, poly(N-vinylcarbazole) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-bis(naphthalen-1-yl)-N,N'-diphenylbenzidine, spiro-NPB, nanocrystalline diamond, microcrystalline cellulose and tetracyanoquinodimethane, doped graphene, undoped graphene, second doped metal oxide particles, second undoped metal oxide particles, metal sulfides, metal selenides and metal nitrides. The metal oxides in the second doped metal oxide particles and the metal oxides in the second undoped metal oxide particles independently include one or more of MoO3, WO3, NiO, CrO3, CuO, Cu2O, V2O5. The doping elements in the second doped metal oxide particles include one or more of Mo, W, Ni, Cr, Cu, V. The metal sulfides include one or more of CuS, MoS3, WS3. The metal selenides include one or more of MoSe3, WSe3. The metal nitrides include p-type gallium nitride; and / or The material of the light-emitting layer includes one or more of organic light-emitting materials and quantum dots; the organic light-emitting materials include one or more of 4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridineiridium(III)], 4,4',4”-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridineiridium], diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescence materials, TTA materials, TADF materials, polymers containing B-N covalent bonds, HLCT materials, and Exciplex light-emitting materials; the quantum dots are selected from one or more of single-structure quantum dots, core-shell structure quantum dots, and perovskite-type 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 one or more 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 is one or more layers; the II-VI group compounds are selected from 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 are selected from one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe;The III-V group compounds are selected from 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 are selected from one or more of CuInS2, CuInSe2 and AgInS2; the core-shell structure quantum dots are selected from one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS and InP / ZnSe / ZnS; the perovskite quantum dots are selected from doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors; the structural general formula of the inorganic perovskite semiconductor is AMX3, where A is Cs; + ion, M is a divalent metal cation selected from 2+ Pb 2+ Sn 2+ Cu 2+ Ni 2+ Cd 2+ Cr 2+ Mn 2+ Co 2+ Fe 2+ Ge 2+ Yb 2+ Eu - Cl - Br - I n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ 、 Cu 2+ 、 Ni 2+ 、 Cd 2+ 、 Cr 2+ 、 Mn 2+ 、 Co 2+ 、 Fe 2+ 、 Ge 2+ 、 Yb 2+ 、 Eu 2+ one or more of, X is a halogen anion selected from Cl - 、 Br - 、 I - one or more of; and / or The materials of the electron injection layer and the electron transport layer respectively include one or more of first doped metal oxide particles, first undoped metal oxide particles, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials, and IB-IIIA-VIA group semiconductor materials. The materials of the first undoped metal oxide particles include one or more of ZnO, TiO2, SnO2, ZrO2, and Ta2O5. The metal oxides in the first doped metal oxide particles include one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, and Al2O3. The doping elements in the first doped metal oxide particles include one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, and Ga. 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.

7. The light-emitting device according to claim 5, wherein the thickness of the first electrode is 35 nm to 60 nm; and / or the thickness of the hole injection layer is 20 nm to 50 nm; and / or the thickness of the modification layer is 15 nm to 40 nm; and / or the thickness of the hole transport layer is 20 nm to 50 nm; and / or the thickness of the second electrode is 60 nm to 100 nm; and / or the thickness of the electron functional layer is 50 nm to 80 nm.

8. A method for preparing a light-emitting device, characterized in that, Comprising: Providing a light-emitting device preform, the light-emitting device preform including a first electrode; Providing compound A in the light-emitting device according to any one of claims 1 to 7, and disposing the compound A on the light-emitting device preform to form a modification layer; Forming a light-emitting layer and a second electrode on the modification layer to obtain a light-emitting device; Or, Providing a light-emitting device prefabricate, the light-emitting device prefabricate including a second electrode and a light-emitting layer stacked; Providing compound A, and disposing the compound A on the light-emitting device prefabricate to form a modification layer; Forming a first electrode on the modification layer to obtain a light-emitting device.

9. The preparation method according to claim 8, characterized in that, The method for forming the modification layer includes: Providing compound A, dissolving the compound A in a third solvent to obtain a compound A solution, and disposing the compound A solution on the light-emitting device preform or the light-emitting device prefabricate to form a modification layer.

10. The preparation method according to claim 9, wherein the third solvent includes one or more of acetone, toluene, dimethylformamide, dimethyl sulfoxide, sulfolane, ethylene nitrate, xylene, anisole, decalin, cyclohexane, cyclohexene, methylcyclohexane, ethylcyclohexane, limonene, hexane, octane, nonane, decane, dimethylacetamide, acetyl carbonate, N-methylpyrrolidone, tetrahydrofuran, ethyl acetate, and dichloromethane; and / or In the solution of compound A, the concentration of compound A is 15 mg / mL to 30 mg / mL.

11. The preparation method according to claim 8, wherein The light-emitting device preform includes a first electrode and a hole injection layer stacked in sequence; forming a light-emitting layer and a second electrode on the modification layer includes sequentially forming a hole transport layer, a light-emitting layer, an electron functional layer, and a second electrode on the modification layer; or The light-emitting device preform includes a second electrode, an electron functional layer, a light-emitting layer, and a hole transport layer stacked in sequence; forming a first electrode on the modification layer includes sequentially forming a hole injection layer and a first electrode on the modification layer.

12. A display device, characterized in that, It includes the light-emitting device according to any one of claims 1 to 7, or includes the light-emitting device prepared by the preparation method according to any one of claims 8 to 11.

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