Light-emitting device, preparation method thereof and display device

Abstract

The invention discloses a light-emitting device and a preparation method thereof, and a display device, the light-emitting device comprises an anode and a cathode which are oppositely arranged, and N light-emitting units and N-1 charge generation units which are arranged between the anode and the cathode, and the N light-emitting units and the N-1 charge generation units are stacked, one charge generation unit is arranged between any two light-emitting units, and N is an integer greater than or equal to 2; wherein the charge generation unit comprises an auxiliary functional layer, the material of the auxiliary functional layer comprises a first material, and the first material comprises one or more of polymers with the structure shown in the formula (1). According to the invention, the charge transmission performance of the charge generation unit is improved, and the driving voltage of the device is reduced.

Description

Technical Field

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

[0002] Light-emitting devices emit light by releasing energy through the recombination of electrons and holes, and are widely used in the field of lighting. In recent years, in order to meet the demand for higher brightness and longer life of light-emitting devices, stacked device structures with two or more light-emitting layers have emerged. The stacked device structure connects multiple light-emitting units in series through a charge generation layer (CGL), which has doubled current efficiency, luminous brightness and service life. Summary of the invention

[0003] In view of this, the present application provides a light emitting device, a method for manufacturing the same, and a display device.

[0004] In a first aspect, the present application provides a light-emitting device, comprising an anode and a cathode arranged opposite to each other, and N light-emitting units and N-1 charge generating units arranged between the anode and the cathode, wherein the N light-emitting units and the N-1 charge generating units are stacked, and one charge generating unit is provided between any two of the light-emitting units, and N is an integer greater than or equal to 2; wherein the charge generating unit comprises an auxiliary functional layer, and the material of the auxiliary functional layer comprises a first material, wherein the first material comprises one or more of a polymer having a structure as shown in formula (1-1) or formula (1-2):

[0005]

[0006] Wherein, m is 10 to 100;

[0007] R1, R2, R3, R4, R5 and R6 are each independently selected from any one of hydrogen, deuterium, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C3-C20 cycloalkoxy, and the substituent when substituted includes one or more of C1-C5 alkoxy, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano and phosphonic acid groups.

[0008] In a second aspect, the present application also proposes a method for preparing a light-emitting device, comprising the following steps:

[0009] providing a first electrode;

[0010] A functional film layer is prepared on the first electrode, wherein the functional film layer includes N light-emitting units and N-1 charge generating units, the N light-emitting units and the N-1 charge generating units are stacked, and one charge generating unit is provided between any two of the light-emitting units, the charge generating unit includes an auxiliary functional layer, and N is an integer greater than or equal to 2;

[0011] Prepare a second electrode on a side of the functional film layer away from the first electrode;

[0012] When the first electrode is selected from an anode, the second electrode is selected from a cathode, and the preparation of the charge generating unit includes:

[0013] Providing an auxiliary functional layer material, wherein the auxiliary functional layer material includes a first material, depositing the auxiliary functional layer material, and annealing to obtain an auxiliary functional layer;

[0014] Wherein, the first material includes one or more polymers having a structure as shown in formula (1-1) or formula (1-2):

[0015]

[0016] Wherein, m is 10 to 100; R1, R2, R3, R4, R5 and R6 are each independently selected from any one of hydrogen, deuterium, substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C1 to C20 alkoxy, substituted or unsubstituted C3 to C20 cycloalkyl, and substituted or unsubstituted C3 to C20 cycloalkoxy.

[0017] In a third aspect, the present application further proposes a display device, which includes the light-emitting device described above.

[0018] The stacked light-emitting device provided by the technical solution of the present application comprises a charge generating unit including an auxiliary functional layer, the material of the auxiliary functional layer comprises a first material, the first material has pH neutrality and high conductivity, can improve the charge transfer performance of the charge generating unit, and help reduce the driving voltage of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 It is a schematic diagram of a process of preparing a light-emitting device proposed in one embodiment of the present application;

[0021] Figure 2is a schematic flow chart of a method for preparing a light-emitting device according to another embodiment of the present application;

[0022] Figure 3 is a schematic structural diagram of a light-emitting device proposed in one embodiment of the present application;

[0023] Figure 4 is a schematic structural diagram of a light emitting device proposed in another embodiment of the present application;

[0024] Reference numerals:

[0025] 100 - light-emitting device; 10 - anode; 21 - first light-emitting layer; 22 - first hole transport layer; 23 - first electron transport layer; 31 - second light-emitting layer; 32 - second hole transport layer; 33 - third electron transport layer; 40 - cathode; 51 - N-type layer; 52 - auxiliary functional layer; 53 - hole injection functional layer. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative work belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation methods described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0027] In this application, unless otherwise specified, the directional words used, such as "upper" and "lower", refer specifically to the directions of the drawings in the accompanying drawings. In addition, in the description of the specification of this application, the term "including" means "including but not limited to".

[0028] Various embodiments of the present application may be presented 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 understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0029] In this application, "and / or" describes the association relationship of associated objects, indicating that there may be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. A and B can be singular or plural.

[0030] In the present application, "at least one" means one or more, and "plurality" means two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can all mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, c can be single or multiple, respectively.

[0031] Explanation of terms

[0032] In the present application, "alkyl" may represent a straight chain alkyl or a branched chain alkyl. C1-10 alkyl refers to an alkyl group containing 1 to 10 carbon atoms, and each occurrence may be independently C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl or C10 alkyl. Non-limiting examples of alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, isobutyl, 2-ethylbutyl, 3,3-dimethylbutyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, 1-methylpentyl, 3-methylpentyl, n-hexyl, etc.

[0033] In the present application, an alkoxy group has a structural feature of the formula -OR; R refers to an alkyl group.

[0034] The technical solution of this application is implemented as follows:

[0035] In a first aspect, the present application provides a light-emitting device 100, which includes an anode 10 and a cathode 40 that are relatively arranged, and N light-emitting units and N-1 charge generating units that are arranged between the anode 10 and the cathode 40. The N light-emitting units and the N-1 charge generating units are stacked, and one charge generating unit is provided between any two of the light-emitting units, N is an integer greater than or equal to 2, and the charge generating unit includes an auxiliary functional layer 52.

[0036] For example, in a specific embodiment, N is 2, see Figure 3, the light-emitting device 100 has two light-emitting units and one charge generating unit, the two light-emitting units are named as the first light-emitting unit and the second light-emitting unit, specifically, the light-emitting device 100 includes an anode 10, a first light-emitting unit, a charge generating unit, a second light-emitting unit and a cathode 40 which are sequentially stacked. In another specific embodiment, N is 3, the light-emitting device 100 has three light-emitting units and two charge generating units, the three light-emitting units are named as the first light-emitting unit, the second light-emitting unit and the third light-emitting unit, the two charge generating units are named as the first charge generating unit and the second charge generating unit, specifically, the light-emitting device 100 includes an anode 10, a first light-emitting unit, a first charge generating unit, a second light-emitting unit, a second charge generating unit, a third light-emitting unit and a cathode 40 which are sequentially stacked.

[0037] It is understood that the N light-emitting units of the light-emitting device 100 may be completely the same or different in terms of film material, film thickness, etc. In some embodiments, the thickness of the N light-emitting units is equal; in other embodiments, the thickness of at least two of the N light-emitting units is unequal.

[0038] It can be understood that when the light emitting device 100 includes more than two charge generating units (N is greater than or equal to 3), the two or more charge generating units can be completely the same or different in terms of the material of each sub-film layer, the thickness of the sub-film layer, etc. In some embodiments, the thickness of N-1 charge generating units is equal; in other embodiments, the thickness of at least two of the N-1 charge generating units is not equal.

[0039] In some embodiments, the light emitting unit includes a light emitting layer.

[0040] In some embodiments, the light-emitting unit is a light-emitting layer. Accordingly, the light-emitting device 100 includes an anode 10 and a cathode 40 arranged opposite to each other, N light-emitting layers and N-1 charge generating units arranged between the anode 10 and the cathode 40, the N light-emitting layers and the N-1 charge generating units are stacked, and one charge generating unit is arranged between any two light-emitting layers, N is an integer greater than or equal to 2, and the charge generating unit includes an auxiliary functional layer 52.

[0041] For example, in a specific embodiment, N is 2, see Figure 3, the light-emitting device 100 has two light-emitting layers and a charge generating unit, the two light-emitting layers are named as the first light-emitting layer 21 and the second light-emitting layer 31, respectively, and specifically, the light-emitting device 100 includes an anode 10, a first light-emitting layer 21, a charge generating unit, a second light-emitting layer 31 and a cathode 40 stacked in sequence. In another specific embodiment, N is 3, the light-emitting device 100 has three light-emitting layers and two charge generating units, the three light-emitting layers are named as the first light-emitting layer 21, the second light-emitting layer 31 and the third light-emitting layer, and the two charge generating units are named as the first charge generating unit and the second charge generating unit, specifically, the light-emitting device 100 includes an anode 10, a first light-emitting layer 21, a first charge generating unit, a second light-emitting layer 31, a second charge generating unit, a third light-emitting layer and a cathode 40 stacked in sequence.

[0042] The light-emitting layer may be an organic light-emitting layer or a quantum dot light-emitting layer. When the light-emitting layer is an organic light-emitting layer, the light-emitting device 100 may be an organic light-emitting device 100; when the light-emitting layer is a quantum dot light-emitting layer, the light-emitting device 100 may be a quantum dot light-emitting device 100.

[0043] The material of the organic light-emitting layer is a material known in the art for the organic light-emitting layer of the light-emitting device 100, for example, it can be selected from but not limited to 4,4'-bis(N-carbazole)-1,1'-biphenyl:tri[2-(p-tolyl)pyridine iridium(III), 4,4',4"-tri(carbazole-9-yl)triphenylamine:tri[2-(p-tolyl)pyridine iridium, diaromatic anthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, TTA materials, thermally activated delayed materials, polymers containing BN covalent bonds, hybrid localized charge transfer excited state materials, and exciplex light-emitting materials. One or more.

[0044] The material of the quantum dot light-emitting layer is a quantum dot material known in the art for the quantum dot light-emitting layer of the light-emitting device 100, for example, it can be selected from but not limited to at least one of a single structure quantum dot, a core-shell structure quantum dot and a perovskite semiconductor material; the material of the single structure quantum dot, the core material of the core-shell structure quantum dot and the shell material of the core-shell structure quantum dot are respectively selected from at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds and I-III-VI group compounds; the II-VI group compound is selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, Hg At least one of S, 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 The compound is selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V compound is selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, and AlNP , AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs and InAlPSb; the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2 and AgInS2.

[0045] As an example, the core-shell structured quantum dots may be selected from but not limited to at least one of CdZnSe / CdZnSe / ZnSe / CdZnS / ZnS, CdZnSe / CdZnSe / CdZnS / ZnS 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.

[0046] It should be noted that, for the material of the aforementioned single structure quantum dot, or the material of the core of the core-shell structure quantum dot, or the material of the shell of the core-shell structure quantum dot, the chemical formula provided only indicates the elemental composition, but does not indicate the content of each element. For example, CdZnSe only indicates that it is composed of three elements, Cd, Zn and Se. If the content of each element is indicated, it corresponds to Cd x Zn 1-x Se,0 <x<1。

[0047] The perovskite semiconductor material may be selected from but not limited to doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors; the inorganic perovskite semiconductor has a general structural formula of AMX3, wherein A is Cs + ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ At least one of, X is a halogen anion selected from Cl - Br - ,I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, wherein B is an organic amine cation selected from CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ At least one of, X is a halogen anion selected from Cl - Br - ,I - At least one of .

[0048] In some embodiments, the material of the auxiliary function layer 52 includes a first material, wherein the first material includes one or more polymers having a structure as shown in formula (1):

[0049]

[0050] Wherein, m is 10 to 100, n is 0 or 1, and L is CR5R6;

[0051] R1, R2, R3, R4, R5 and R6 are each independently selected from any one of hydrogen, deuterium, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C3-C20 cycloalkyl, and substituted or unsubstituted C3-C20 cycloalkoxy.

[0052] The stacked light-emitting device provided by the technical solution of the present application comprises a charge generating unit including an auxiliary functional layer, the material of the auxiliary functional layer comprises a first material, the first material has pH neutrality and high conductivity, can improve the charge transfer performance of the charge generating unit, and help reduce the driving voltage of the device.

[0053] The polymer may be a homopolymer or a copolymer.

[0054] In some embodiments, the polymer is a polymer of a first monomer. Based on the polymer shown in formula (1), the first monomer includes one or more compounds having a structure shown in formula (6):

[0055]

[0056] Wherein, n is 0 or 1, and L is CR5R6;

[0057] In the charge generating unit of this embodiment, the material of the auxiliary functional layer 52 includes a first material, the first material includes one or more polymers of a first monomer, and the first monomer includes one or more compounds having a structure as shown in formula (6).

[0058] In some embodiments, R1, R2, R3, R4, R5 and R6 are each independently selected from any one of hydrogen, C1-C4 alkyl, and C1-C4 alkoxy.

[0059] In some embodiments, R1, R2, R3, R4, R5 and R6 are each independently selected from any one of hydrogen, methyl, ethyl, methoxy and ethoxy.

[0060] n can be 0 or 1. In some embodiments, n is 0, and the repeating unit of the polymer is a fused ring structure of thiophene and a six-membered ring, and the structural formula of the polymer is shown in the following formula (1-1). Further, based on the embodiment in which n is 0, in some embodiments, at least two of R1, R2, R3, and R4 are selected from hydrogen.

[0061] In other embodiments, n is 1, the repeating unit of the polymer is a fused ring structure of thiophene and a seven-membered ring, and the structural formula of the polymer is shown in formula (1-2). Further, based on the embodiment in which n is 1, in some embodiments, R1, R2, R3, and R4 are all selected from hydrogen.

[0062]

[0063] In some specific embodiments, the first monomer includes one or more compounds having structures shown in the following formulas (2) to (5): the compound shown in formula (2) is 3,4-ethylenedioxythiophene (EDOT), CAS: 126213-50-1; the compound shown in formula (3) is 3,4-propylenedioxythiophene, CAS: 155861-77-1; the compound shown in formula (4) is 3,4-(2,2-dimethylpropylenedioxy)thiophene, CAS: 255901-50-9; the compound shown in formula (5) is 3,4-(2,2-diethylpropylene)dioxythiophene, CAS: 259139-19-0.

[0064]

[0065] In some embodiments, the average particle size of the polymer is 10-50 nm; for example, it can be 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, and any value between the above two values. By controlling the particle size within this range, the thickness of the membrane layer and the degree of pore distribution in the membrane layer can be adjusted.

[0066] In some embodiments, the thickness of the auxiliary function layer 52 is 5-100 nm; for example, it can be 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, and any value between the above two values. By controlling the thickness of the auxiliary function layer 52 to be within this range, both the barrier effect and the electrical performance of the charge generating unit can be taken into account.

[0067] In some embodiments, the charge generating unit further includes an N-type layer 51 and a hole injection functional layer 53, and the auxiliary functional layer 52 is disposed between the N-type layer 51 and the hole injection functional layer 52. The charge generating unit includes an N-type layer 51, an auxiliary functional layer 52 and a hole injection functional layer 53 which are stacked in sequence. It can be understood that in the charge generating unit, the stacking order of the film layers can be the N-type layer 51, the auxiliary functional layer 52 and the hole injection functional layer 53 which are stacked in sequence from top to bottom, or the N-type layer 51, the auxiliary functional layer 52 and the hole injection functional layer 53 which are stacked in sequence from bottom to top. In the light-emitting device 100, it is necessary to ensure that in each charge generating unit, the N-type layer 51 is disposed close to the anode 10, and the hole injection functional layer 53 is disposed close to the cathode 40. In a specific embodiment, N is 2, see Figure 3 The light emitting device 100 includes an anode 10, a first light emitting unit, an N-type layer 51, an auxiliary functional layer 52, a hole injection functional layer 53, a second light emitting unit and a cathode 40 which are stacked in sequence.

[0068] It is understandable that the N light-emitting units of the light-emitting device 100 may have the same or different film materials. Accordingly, when selecting the light-emitting layers of the N light-emitting units, the materials of the N light-emitting layers are independently selected from the above-mentioned light-emitting materials.

[0069] Among them, the material of the N-type layer 51 can be selected from N-type semiconductor materials commonly used in the art, such as one or more of N-type metal oxides or doped N-type metal oxides; in other embodiments, the material of the N-type layer 51 can be selected from materials with an absolute value of the LUMO energy level less than or equal to 4eV, which helps to improve the energy level matching between film layers, thereby improving the electrical performance of the charge generation unit.

[0070] Specifically, the N-type metal oxide may include but is not limited to one or more of ZnO, TiO2, SnO2, and ZrO; the N-type metal oxide in the doped N-type metal oxide may include but is not limited to one or more of ZnO, TiO2, SnO2, and ZrO, and the doping element may include but is not limited to one or more of Al, Mg, Li, In, and Ga.

[0071] In some embodiments, the average particle size of the N-type metal oxide is 3 to 10 nm; for example, it can be 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, and a value between any two of the above values. In other embodiments, the average particle size of the doped N-type metal oxide is 3 to 10 nm; for example, it can be 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, and a value between any two of the above values.

[0072] In some embodiments, the thickness of the N-type layer 51 is 5 to 100 nm; for example, it can be 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, or a value between any two of the above values.

[0073] In some embodiments, the material of the N-type layer 51 may further include additives, the additives including one or more of aliphatic amine polymers and organic electron transport materials, the aliphatic amine polymers may be polymers with a mass average molecular weight greater than 5000, including but not limited to polyethyleneimine, polyethoxyethyleneimine, PFN-DOF (poly [(9,9-bis (3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)]), PFN-FP (poly [(9,9-bis (3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-1,4-phenylene]), the organic electron transport material includes one or more of phenanthroline compounds, phosphorus oxide compounds, and pyridine compounds. By adding additives, it helps to promote electron injection.

[0074] In some specific embodiments, the phenanthroline compound is selected from one or more of Bphen (4,7-diphenyl-1,10-phenanthroline), BCP (2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline), p-MeO-Phen (4,7-dimethoxy-1,10-o-phenanthroline), p-bPPhenB (1,4-di(2-phenyl-1,10-phenanthroline-4-yl)benzene), HNBphen (2-(naphthalene-2-yl)-4,7-diphenyl-1,10-phenanthroline); the phosphorus oxygen compound is selected from SPPO13 (2,7-bis(diphenylphosphino)-9,9'-spirofluoroether), SPPO01 (9,9-spirofluoroether-2-yl diphenylphosphine oxide), TP3PO (1,3,5-tris(diphenylphosphinophenyl)benzene), TSPO1 (diphenyl-4-triphenylsilane) One or more of the following: 1,2-diphenylphosphine oxide), 2,2'-(4,4'-(phenylphosphine)bis(4,1-phenyl)bis(1-phenyl-1H-benzo[d]imidazole)), and 4,6-diphenylphosphine oxide; the pyridine compound is selected from TPyQB (1,3,5-tris(4-(pyridin-4-yl)quinolin-2-yl)benzene), TmPyPB (1, One or more of 3,5-tris[(3-pyridinyl)-phenyl-3-yl]benzene)BP4mPy(3,3',5,5'-tetrakis[(m-pyridinyl)-phenyl-3-yl]biphenyl)3TPYMB(tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane), TmPPPyTz(2,4,6-tris(3'-(pyridin-3-yl)biphenyl-3-yl)-1,3,5-triazine).

[0075] In the N-type layer 51, the mass percentage of the additive is less than or equal to 50%. For example, the mass percentage of the additive can be 0%, 0.01%, 0.1%, 0.5%, 1%, 2%, 5%, 10%, 20%, 30%, 40%, 50% and a value between any two of the above values.

[0076] In some embodiments, the material of the hole injection functional layer 53 may include but is not limited to one or more of phosphomolybdic acid, phosphotungstic acid, ammonium molybdate, metavanadic acid, metatungstic acid, vanadium acetonate, ethoxide tungsten, ethoxide molybdenum, PEDOT:PSS (AI 4083), HATCN (12-hexaazatriphenylene), CN6-CP (hexacyano-trimethylcyclopropane), and NDP-9.

[0077] In some embodiments, the thickness of the hole injection functional layer 53 is 5 to 100 nm; for example, it can be 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, and a value between any two of the above values.

[0078] In some embodiments, the thickness of the N-type layer 51 in the N-1 charge generation units may be equal or different; their materials may be the same or different. The thickness of the auxiliary functional layer 52 in the N-1 charge generation units may be equal or different; their materials may be the same or different. The thickness of the hole injection functional layer 53 in the N-1 charge generation units may be equal or different; their materials may be the same or different.

[0079] In some embodiments, the light-emitting device 100 is an upright device, and the hole injection functional layer 53 is located above the auxiliary functional layer 52; thus, when the hole injection functional layer 53 is prepared using the above-mentioned material, the material of the hole injection functional layer 53 can dope the auxiliary functional layer 52 to further improve the conductivity.

[0080] At present, the mainstream preparation method of the film layer is the solution method. When the film layer is prepared by the solution process, since the material or ink of the hole injection functional layer is usually acidic, it is easy to affect the N-type layer material and damage the N-type layer, making the performance of the light-emitting device generally low. In view of this, in some embodiments, the material of the auxiliary functional layer 52 also includes a P-type semiconductor organic material. That is, the material of the auxiliary functional layer 52 includes the first material and the P-type semiconductor organic material.

[0081] The technical solution provided in the present application is to insert an auxiliary functional layer 52 between the N-type layer 51 and the hole injection functional layer 53. In the auxiliary functional layer 52, the first material has pH neutrality and high conductivity, which can improve the charge transfer performance of the charge generating unit. The P-type semiconductor organic material can effectively fill the gap between the first material. The film layer composed of the two has good barrier effect and charge transfer performance. While maintaining the conductivity of the charge generating unit, the hole injection functional layer 53 is effectively inhibited from damaging the N-type layer 51, and the ability of the charge generating unit to generate or separate charges under the action of an external electric field is effectively improved.

[0082] In some embodiments, the mass ratio of the first material to the P-type semiconductor organic material is (2-50):1; for example, it can be 2:1, 3:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1 and values ​​between any two of the above values. By controlling the ratio of the first material to the P-type semiconductor organic material within this range, the filling of the gap between the first material by the P-type semiconductor organic material can be regulated, so that the charge generation unit has high barrier effect, high charge transfer capability and high charge generation capability.

[0083] In some embodiments, the P-type semiconductor organic material may be an organic material having hole transport properties, for example, it may include but is not limited to one or more of polyvinylcarbazole (PVK), poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)] (TFB), poly[bis(4-phenyl)(4-butylphenyl)amine] (poly-TPD), and poly(9,9-dimethyl-10-(9-(4-vinylbenzyl)-9H-carbazole-3-yl)-9,10-dihydroacridine) (P-CzAc).

[0084] The anode 10 may be an anode 10 for a light-emitting device 100 known in the art, for example, may be selected from but not limited to a doped metal oxide particle electrode, a composite electrode of a metal and a metal oxide, a graphene electrode, a carbon nanotube electrode, a metal electrode or an alloy electrode, the material of the doped metal oxide particle electrode is selected from 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 and aluminum-doped magnesium oxide, the composite electrode of a metal and a metal oxide is selected from AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, and the material of the metal electrode is selected from one or more of Ag, Al, Cu, Mo, Au, Pt, Si, Ca, Mg and Ba.

[0085] The cathode 40 can be a cathode 40 for the light-emitting device 100 known in the art, for example, can be selected from but not limited to a doped metal oxide particle electrode, a composite electrode of metal and metal oxide, a graphene electrode, a carbon nanotube electrode, a metal electrode or an alloy electrode, the material of the doped metal oxide particle electrode is selected from 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 and aluminum-doped magnesium oxide, the composite electrode of metal and metal oxide is selected from AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, and the material of the metal electrode is selected from one or more of Ag, Al, Cu, Mo, Au, Pt, Si, Ca, Mg and Ba.

[0086] See also Figure 4In some embodiments, the light-emitting unit further comprises a hole functional layer disposed on the side of the light-emitting layer facing the anode 10, and the hole functional layer comprises one or two layers of a hole transport layer and a hole injection layer. It should be noted that when the hole functional layer comprises two layers of a hole transport layer and a hole injection layer, the hole transport layer is located between the hole injection layer and the light-emitting layer. The material of the hole functional layer can be a material commonly used in the art and having hole injection or transport properties. For example, in some embodiments, the material of the hole transport layer is selected from 4,4'-N,N'-dicarbazolyl-biphenyl (CBP), 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(spiro-TPD), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tri(N-carbazolyl)-triphenylamine, 4,4',4'-tri(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-TPD), polyaniline, polypyrrole , poly(p-phenylene vinylene), poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene] and poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], copper phthalocyanine, aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraaryl benzidine, PEDOT:PSS and its derivatives, poly(N-vinyl carbazole) (PVK ) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-di(naphthalene-1-yl)-N,N'-diphenylbenzidine, spiro NPB, 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.The material of the hole injection layer may include, but is not limited to, poly(ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS), poly(9,9-dioctyl-fluorene-co-N-(4-butylphenyl)-diphenylamine) (TFB), polyarylamine, poly(N-vinylcarbazole), polyaniline, polypyrrole, N,N,N',N'-tetrakis(4-methoxyphenyl)-benzidine (TPD), 4-bis[N-(1-naphthyl)-N-phenyl-amino]biphenyl (α-NPD), 4,4',4"-tris[phenyl(m-tolyl)amino]triphenylamine (m-MTDATA), 4,4',4" -tris(N-carbazolyl)-triphenylamine (TCTA), 1,1-bis[(di-4-tolylamino)phenylcyclohexane (TAPC), 4,4',4"-tris(diphenylamino)triphenylamine (TDATA) doped with tetrafluoro-tetracyano-quinodimethane (F4-TCNQ), p-doped phthalocyanine (e.g., F4-TCNQ-doped zinc phthalocyanine (ZnPc)), F4-TCNQ-doped N,N'-diphenyl-N,N'-di(1-naphthyl)-1,1'-biphenyl-4,4"-diamine (α-NPD), hexaazatriphenylene-capronitrile (HAT-CN) or one or more thereof.

[0087] In some embodiments, the light-emitting unit further includes an electron transport layer disposed on the side of the light-emitting layer facing the cathode 40. The material of the electron transport layer can be selected from materials known in the art for electron transport layers, such as but not limited to one or more of metal oxides and doped metal oxides; the metal oxides include one or more of ZnO, TiO2, SnO2, and ZrO; the metal oxides in the doped metal oxides include multiple of ZnO, TiO2, SnO2, and ZrO, and the doping elements include one or more of Al, Mg, Li, In, and Ga.

[0088] For example, Figure 4 As shown, in a specific embodiment, the light-emitting device 100 includes an anode 10, a first light-emitting unit (a first hole injection layer 24, a first hole transport layer 22, a first light-emitting layer 21, a first electron transport layer 23), an N-type layer 51, an auxiliary functional layer 52, a hole injection functional layer 53, a second light-emitting unit (a second hole transport layer 32, a second light-emitting layer 31, a second electron transport layer 33) and a cathode 40 stacked in sequence from bottom to top.

[0089] It can be understood that the materials of each layer of the light-emitting device 100 can be adjusted according to the light-emitting requirements of the light-emitting device 100 .

[0090] It can be understood that the light emitting device 100 can be an upright light emitting device 100 or an inverted light emitting device 100 .

[0091] Based on the above-mentioned light-emitting device 100 embodiment, the present application embodiment further provides a method for preparing the light-emitting device 100, comprising the following steps:

[0092] Step S100, providing a first electrode;

[0093] Step S200, preparing a functional film layer on the first electrode, the functional film layer comprising N light-emitting units and N-1 charge generating units, the N light-emitting units and the N-1 charge generating units are stacked, and one charge generating unit is provided between any two of the light-emitting units, and N is an integer greater than or equal to 2;

[0094] Step S300 , preparing a second electrode on a side of the functional film layer away from the first electrode.

[0095] In some embodiments, step S200 specifically includes: according to a preset film layer sequence, a functional film layer is arranged on the first electrode, the functional film layer includes N light-emitting units and N-1 charge generating units, the N light-emitting units and the N-1 charge generating units are stacked, and one charge generating unit is arranged between any two of the light-emitting units, and N is an integer greater than or equal to 2; wherein the charge generating unit includes the charge generating unit described above, and when the charge generating unit further includes an N-type layer 51 and a hole injection functional layer 53, the N-type layer 51 is arranged close to the anode 10. The preset film layer sequence refers to the stacking sequence of the N light-emitting units and the N-1 charge generating units in the functional film layer.

[0096] The first electrode is one of the cathode 40 and the anode 10, and the second electrode is the other of the cathode 40 and the anode 10. In some embodiments, the light emitting device 100 is a positive light emitting device 100, and accordingly, the first electrode is the anode 10, and the second electrode is the cathode 40; in other embodiments, the light emitting device 100 is an inverted light emitting device 100, and accordingly, the first electrode is the cathode 40, and the second electrode is the anode 10.

[0097] In some embodiments, the charge generation unit includes an auxiliary functional layer 52 , and the preparation of the charge generation unit includes: providing an auxiliary functional layer material, the auxiliary functional layer material includes a first material, depositing the auxiliary functional layer material, and annealing to obtain the auxiliary functional layer 52 .

[0098] In some embodiments, the charge generation unit includes a stacked N-type layer 51, an auxiliary functional layer 52, and a hole injection functional layer 53. The charge generation unit can be prepared as follows.

[0099] When the first electrode is selected from the anode and the second electrode is selected from the cathode, the preparation of the charge generating unit includes: preparing an N-type layer; providing a mixture comprising a first material and a P-type semiconductor organic material, depositing the mixture on the N-type layer, and annealing to obtain an auxiliary functional layer 52; and setting a hole injection functional layer on the auxiliary functional layer 52.

[0100] When the first electrode is selected from the cathode and the second electrode is selected from the anode, the preparation of the charge generating unit includes: preparing a hole injection functional layer; providing a mixture comprising a first material and a P-type semiconductor organic material, depositing the mixture on the hole injection functional layer, and annealing to obtain an auxiliary functional layer 52; and setting an N-type layer on the auxiliary functional layer 52.

[0101] The following is a detailed explanation of the method for preparing the charge generating unit.

[0102] See also Figure 1 In some embodiments, in the charge generating unit, the stacking order of the film layers is N-type layer 51, auxiliary functional layer 52 and hole injection functional layer 53 stacked in sequence from bottom to top. Accordingly, the preparation method includes the following steps:

[0103] S10a, providing an N-type layer 51;

[0104] S20a, providing a mixture comprising a first material and a P-type semiconductor organic material, depositing the mixture on the N-type layer 51, and annealing to obtain an auxiliary functional layer 52;

[0105] S30a, disposing a hole injection functional layer 53 on the auxiliary functional layer 52 .

[0106] See also Figure 2 In some other embodiments, in the charge generating unit, the stacking order of the film layers is the hole injection function layer 53, the auxiliary function layer 52 and the N-type layer 51 are stacked in sequence from bottom to top. Accordingly, the preparation method includes the following steps:

[0107] S10b, providing a hole injection functional layer 53;

[0108] S20b, providing a mixture comprising a first material and a P-type semiconductor organic material, depositing the mixture on the hole injection functional layer 53, and annealing to obtain an auxiliary functional layer 52;

[0109] S30b, disposing an N-type layer 51 on the auxiliary functional layer 52 .

[0110] Wherein, the first material includes one or more polymers having a structure as shown in formula (1), or includes one or more homopolymers of the first monomer, and the first monomer includes one or more compounds having a structure as shown in formula (6). In some specific embodiments, the first monomer includes one or more compounds having structures as shown in formulas (2) to (5). The structures of the polymer and the first monomer can be referred to above and are not described in detail here.

[0111] In actual preparation, the material of the first monomer can be purchased on the market. The polymer corresponding to the first monomer can be purchased on the market, or it can be prepared by referring to the conventional emulsion polymerization method or oxidative polymerization method. Taking the polymer corresponding to the compound of the structure shown in formula (2) as an example, the compound of the structure shown in formula (2), that is, the first monomer is EDOT, and its corresponding polymer is PEDOT, CAS: 126213-51-2. PEDOT can be purchased on the market, or it can be prepared by itself according to the following method:

[0112] In some specific embodiments, it is prepared by emulsion polymerization, and the preparation method can be: weigh 0.53g PI-b-PMMA copolymer (polyisoprene / methyl methacrylate block copolymer, poly(isoprene-b-methylmethacrylate)diblock copolymers) and add it to 30mL cyclohexane and stir it magnetically at room temperature to obtain a cyclohexane / copolymer solution; dissolve 1.3g anhydrous FeCl3 in 3.8mL acetonitrile and add it dropwise to the cyclohexane / copolymer solution, and stir it for 2h under argon to form an emulsion. Then, 0.5g 3,4-ethylenedioxythiophene (first monomer) is added dropwise to the emulsion under Ar atmosphere, and stirred for 8h for polymerization reaction. Then, the reaction product is transferred to a separation funnel, and a large amount of methanol:acetonitrile mixed solution with a volume ratio of 8:2 is added for washing to remove the emulsifier and residual iron salts. The precipitate was then centrifuged, washed with tetrahydrofuran, and redispersed in cyclohexane to obtain a PEDOT (ie, polymer of 3,4-ethylenedioxythiophene) dispersion.

[0113] In other embodiments, it is prepared by an oxidative polymerization method, and the preparation method can be: mixing 1.3 g of 3,4-ethylenedioxythiophene (first monomer) and 60 mL of CH2Cl2 in a conical flask at 0°C, adding 12 g of anhydrous FeCl3 dissolved in 30 mL of CH3CN to the above solution under vigorous stirring, and polymerizing at 0°C for 24 hours to obtain a mixed solution containing PEDOT nanoparticles; filtering the mixed solution and washing it with 1 mol / L hydrochloric acid several times to remove excess FeCl3, then freeze-drying, and dispersing it in cyclohexane to obtain a PEDOT dispersion.

[0114] Through the above method, PEDOT can be obtained and its acidity and dispersibility in organic solvents can be improved, so that low-polarity solvents such as n-hexane and toluene can be used as solvents to disperse the first material, and then prepare auxiliary functional layer ink with low-polarity solvent as solvent. When the N-type layer 51 is prepared first and then the auxiliary functional layer 52 is prepared, the ink can be used to avoid damaging the N-type layer 51.

[0115] Correspondingly, the preparation methods of other compounds are basically the same as the above methods, with the only difference being that the first monomer is replaced by the corresponding first monomer. For example, when preparing a polymer corresponding to the compound represented by formula (3), 3,4-ethylenedioxythiophene can be replaced by the compound represented by formula (3); when preparing a polymer corresponding to the compound represented by formula (4), 3,4-ethylenedioxythiophene can be replaced by the compound represented by formula (4); when preparing a polymer corresponding to the compound represented by formula (5), 3,4-ethylenedioxythiophene can be replaced by the compound represented by formula (5).

[0116] It is understandable that, during actual preparation, the polymerization reaction time can also be adjusted according to actual conditions. Specifically, the average size of the prepared polymer nanoparticles can be used as a reference. When the size reaches 10 to 50 nm, the polymerization is stopped.

[0117] In some embodiments, the mixture also includes a solvent, and the solvent includes one or more of n-hexane, cyclohexane, n-octane, n-decane, dodecane, tetralin, decalin, cyclohexylbenzene, xylene, toluene, chlorobenzene, and anisole; these low-polarity solvents can disperse the first material and the P-type semiconductor organic material well without damaging the N-type layer 51 and the hole injection functional layer 53.

[0118] In some embodiments, in the mixture, the mass ratio of the first material to the P-type semiconductor organic material is (2 to 50):1; for example, it can be 2:1, 3:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1 and values ​​between any two of the above values.

[0119] In some embodiments, in steps S20a and S20b, the mixture may be deposited by a solution method, for example, by spin coating, inkjet printing or printing the mixture on the previous film layer to form a liquid film, and then heating and annealing to form the auxiliary functional layer 52.

[0120] Further, in some embodiments, the annealing temperature is 100-200°C; for example, it can be 100°C, 110°C, 120°C, 130°C, 140°C, 150°C, 160°C, 170°C, 180°C, 190°C, 200°C, and values ​​between any two of the above values. In other embodiments, the annealing time is 10-120min; for example, it can be 10min, 20min, 30min, 40min, 50min, 60min, 70min, 80min, 90min, 100min, 110min, 120min, and values ​​between any two of the above values.

[0121] Among them, the material of the N-type layer 51 includes one or more of N-type metal oxides or doped N-type metal oxides; the N-type metal oxide may include but is not limited to one or more of ZnO, TiO2, SnO2, and ZrO; the N-type metal oxide in the doped N-type metal oxide may include but is not limited to one or more of ZnO, TiO2, SnO2, and ZrO, and the doping elements may include but are not limited to one or more of Al, Mg, Li, In, and Ga.

[0122] In some embodiments, the material of the N-type layer 51 may further include additives, the additives including one or more of aliphatic amine polymers and organic electron transport materials, the aliphatic amine polymers including polyethyleneimine, polyethoxyethyleneimine, PFN-DOF (poly [(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-2,7-(9,9-dioctylfluorene)]), PFN-FP (poly [(9,9-bis(3'-(N,N-dimethylamino)propyl)-2,7-fluorene)-1,4-phenylene]), and the organic electron transport material includes one or more of phenanthroline compounds, phosphorus oxide compounds, and pyridine compounds.

[0123] In some embodiments, the material of the hole injection functional layer 53 may include but is not limited to one or more of phosphomolybdic acid, phosphotungstic acid, ammonium molybdate, metavanadic acid, metatungstic acid, vanadium acetonate, ethoxide tungsten, ethoxide molybdenum, PEDOT:PSS (AI 4083), HATCN (12-hexaazatriphenylene), CN6-CP (hexacyano-trimethylcyclopropane), and NDP-9.

[0124] The preparation method of the N-type layer 51 and the hole injection functional layer 53 can be realized by conventional techniques in the art, such as chemical methods or physical methods. Specifically, the corresponding film material or the corresponding precursor of the film material can be deposited on the previous film layer by physical methods or chemical methods to form the N-type layer 51 or the hole injection functional layer 53. Among them, the chemical method includes chemical vapor deposition, continuous ion layer adsorption and reaction, anodization, electrolytic deposition, and coprecipitation. The physical method includes physical plating and solution method, among which the physical plating method includes: thermal evaporation coating, electron beam evaporation coating, magnetron sputtering, multi-arc ion plating, physical vapor deposition, atomic layer deposition, pulsed laser deposition, etc.; the solution method can be spin coating, printing, inkjet printing, doctor blade coating, printing, dip-coating, immersion, spraying, roll coating, casting, slit coating, strip coating, etc.

[0125] In addition, in the preparation method of the light-emitting device 100, the preparation method of the anode 10, the hole transport layer, the light-emitting layer, the electron transport layer, the N-type layer 51, the hole injection functional layer 53 and the cathode 40 can be achieved by conventional techniques in the field, such as chemical methods or physical methods.

[0126] In some embodiments, after the light emitting device 100 is prepared, the step of packaging the light emitting device 100 is further included. The packaging process can be performed by a common machine packaging or by manual packaging. Preferably, in the environment of the packaging process, the oxygen content and the water content are both less than 0.1 ppm to ensure the stability of the light emitting device 100.

[0127] In addition, the present application also relates to a display device, which includes the light-emitting device 100 described above. The display device can be any electronic product with a display function, including but not limited to smart phones, tablet computers, laptops, digital cameras, digital video cameras, smart wearable devices, smart weighing electronic scales, car displays, televisions or e-book readers, wherein the smart wearable device can be, for example, a smart bracelet, a smart watch, a virtual reality (VR) helmet, etc.

[0128] The technical scheme and technical effects of the present application are described in detail below through specific embodiments and comparative examples. The following embodiments are only some embodiments of the present application and do not specifically limit the present application.

[0129] Film Example 1

[0130] (1) Preparation of auxiliary functional layer ink: 0.53 g of PI-b-PMMA copolymer was weighed and added to 30 mL of cyclohexane and magnetically stirred at room temperature to obtain a cyclohexane / copolymer solution; 1.3 g of anhydrous FeCl3 was dissolved in 3.8 mL of acetonitrile and added dropwise to the cyclohexane / copolymer solution, and stirred for 2 h under argon to form an emulsion. Subsequently, 0.5 g of 3,4-ethylenedioxythiophene (the first monomer, a compound having a structure shown in formula (2)) was added dropwise to the emulsion under an Ar atmosphere and stirred for 8 h for polymerization reaction. The reaction product was then transferred to a separation funnel and washed with a large amount of a methanol:acetonitrile mixed solution with a volume ratio of 8:2 to remove the emulsifier and residual iron salts. The precipitate was then centrifuged and washed with tetrahydrofuran to obtain polymer nanoparticles with an average particle size of 30 nm.

[0131] Then, the polymer nanoparticles are redispersed in cyclohexane to obtain a dispersion of the first material (i.e., a polymer of 3,4-ethylenedioxythiophene with a degree of polymerization m of 20). According to a weight ratio of the first material to PVK of 10:1, PVK is taken and dissolved in toluene, and then mixed with the dispersion of the first material to obtain an auxiliary functional layer ink.

[0132] (2) Dispersing ZnO nanoparticles with an average particle size of about 8 nm and PEIE in ethanol to obtain a mixed solution, in which the mass ratio of ZnO to PEIE is 1:0.5, and the mass percentage of PEIE is 5%.

[0133] (3) providing a glass substrate, spin coating the mixed solution obtained in step (2) on the glass substrate to a total thickness of 20 nm, and annealing at 120° C. for 20 min to obtain an N-type layer; spin coating an auxiliary functional layer ink on the N-type layer to a total thickness of 30 nm, and annealing at 120° C. for 20 min to obtain an auxiliary functional layer; spin coating phosphomolybdic acid on the auxiliary functional layer to a total thickness of 20 nm, and annealing at 120° C. for 20 min to obtain a hole injection functional layer.

[0134] The N-type layer, the auxiliary functional layer and the hole injection functional layer together constitute a charge generation unit.

[0135] Film Example 2

[0136] This film embodiment is basically the same as film embodiment 1, with the only difference being that, in this film embodiment, the first material in the auxiliary functional layer ink is changed to a polymer corresponding to the compound shown in formula (3); correspondingly, in step (1): the first monomer is changed to the compound shown in formula (3).

[0137] Film Example 3

[0138] This film embodiment is basically the same as film embodiment 1, with the only difference being that, in this film embodiment, the first material in the auxiliary functional layer ink is changed to a polymer corresponding to the compound shown in formula (4); correspondingly, in step (1): the first monomer is changed to the compound shown in formula (4).

[0139] Film Example 4

[0140] This film embodiment is basically the same as film embodiment 1, with the only difference being that, in this film embodiment, the first material in the auxiliary functional layer ink is changed to a polymer corresponding to the compound shown in formula (5); correspondingly, in step (1): the first monomer is changed to the compound shown in formula (5).

[0141] Film Example 5

[0142] This film embodiment is substantially the same as film embodiment 1, except that, in this film embodiment, the weight ratio of PEDOT to PVK is 2:1.

[0143] Film Example 6

[0144] This film embodiment is substantially the same as film embodiment 1, except that, in this film embodiment, the weight ratio of PEDOT to PVK is 50:1.

[0145] Film Example 7

[0146] This film embodiment is substantially the same as film embodiment 1, except that, in this film embodiment, the weight ratio of PEDOT to PVK is 1:1.

[0147] Film Example 8

[0148] This film embodiment is substantially the same as film embodiment 1, except that, in this film embodiment, the weight ratio of PEDOT to PVK is 100:1.

[0149] Film Example 9

[0150] This thin film embodiment is substantially the same as thin film embodiment 1, with the only difference being that, in this thin film embodiment, the P-type semiconductor organic material is changed from PVK to TFB.

[0151] Film Example 10

[0152] This film embodiment is basically the same as film embodiment 1, except that, in this film embodiment, no additive is added to the N-type layer material, and accordingly:

[0153] Step (2) is changed to: dispersing ZnO nanoparticles with an average particle size of about 8 nm in ethanol to obtain a mixed solution;

[0154] In step (3), the annealing temperature and time for preparing the N-type layer are changed to annealing at 80° C. for 10 min.

[0155] Film Example 11

[0156] This film embodiment is substantially the same as film embodiment 1, except that in this film embodiment, the material of the auxiliary functional layer is the first material. Accordingly, in step (1), when preparing the auxiliary functional layer ink, PVK is not added.

[0157] Film Example 12

[0158] This film embodiment is basically the same as film embodiment 1, except that in this film embodiment, the N-type layer material is changed to ZnMgO, and accordingly:

[0159] Step (2) is changed to: dispersing ZnMgO nanoparticles (Mg doping concentration of 5 wt%) with an average particle size of about 8 nm in ethanol to obtain a mixed solution;

[0160] In step (3), the annealing temperature and time for preparing the N-type layer are changed to annealing at 80° C. for 10 min.

[0161] Film Comparative Example 1

[0162] This film comparative example is basically the same as film embodiment 1, except that in this film comparative example, the charge generating unit does not include an auxiliary functional layer. Accordingly, in the preparation steps:

[0163] Omit step (1);

[0164] In step (3), the step of "spin coating the auxiliary functional layer ink on the N-type layer to a total thickness of 30 nm, and annealing at 120° C. for 20 min to obtain the auxiliary functional layer" is omitted, and the hole injection functional layer is directly prepared on the N-type layer.

[0165] Film Comparative Example 2

[0166] This film comparative example is substantially the same as film embodiment 10, except that in this film comparative example, the charge generating unit does not include an auxiliary functional layer. Accordingly, in the preparation steps:

[0167] Omit step (1);

[0168] In step (3), the step of "spin coating the auxiliary functional layer ink on the N-type layer to a total thickness of 30 nm, and annealing at 120° C. for 20 min to obtain the auxiliary functional layer" is omitted, and the hole injection functional layer is directly prepared on the N-type layer.

[0169] Film Comparative Example 3

[0170] The film comparative example is substantially the same as the film embodiment 1, except that in the film comparative example, the material of the auxiliary functional layer is PVK. Accordingly, in step (1), when preparing the auxiliary functional layer ink, the first material is not added.

[0171] Device Example 1

[0172] (1) The ITO anode substrate was cleaned and then treated under UV conditions for 15 min;

[0173] (2) Spin coating a 30 nm thick PEDOT:PSS on the treated ITO substrate and baking it at 150°C for 20 min in air to obtain a hole injection layer;

[0174] (3) Spin coating a chlorobenzene solution of TFB on the hole transport layer, and then baking at 180° C. for 60 min in a nitrogen environment to obtain a hole transport layer with a thickness of 30 nm;

[0175] (4) A 60 nm thick F8BT polymer was spin-coated on the hole transport layer and baked at 150° C. for 10 min to obtain the first light-emitting layer.

[0176] (5) Referring to Thin Film Example 1, a charge generating unit of Thin Film Example 1 is prepared on the first light-emitting layer, wherein the N-type layer is formed on the first light-emitting layer, and the upper surface of the hole injection functional layer is used to prepare the second light-emitting layer in step (6).

[0177] (6) A 60 nm thick F8BT polymer was spin-coated on the charge generation unit and baked at 150° C. for 10 min to obtain a second light-emitting layer.

[0178] (7) vacuum evaporating 1 nm of LiF on the second light-emitting layer to obtain an electron transport layer;

[0179] (8) A 100 nm thick Al layer was vacuum evaporated on the electron transport layer to obtain a cathode, which was then packaged and annealed at 80° C. for 30 min to obtain a light-emitting device.

[0180] Device Examples 2 to 11

[0181] The scheme of device embodiment n is basically the same as device embodiment 1, with the only difference being that in device embodiment n, step (5) is changed to, with reference to thin film embodiment n, preparing the charge generating unit of thin film embodiment n on the first light-emitting layer, where n is any integer from 2 to 11.

[0182] Device Example 12

[0183] (1) The ITO anode substrate was cleaned and then treated under UV conditions for 15 min;

[0184] (2) Spin coating a 50 nm thick PEDOT:PSS on the treated ITO substrate and baking it at 150° C. for 20 min in an air atmosphere to obtain a first hole injection layer;

[0185] (3) spin coating a chlorobenzene solution of TFB on the hole transport layer, and then baking at 160° C. for 60 min in a nitrogen environment to obtain a first hole transport layer with a thickness of 30 nm;

[0186] (4) Spin-coat a 30 nm thick layer of green light quantum dots CdSe@ZnS on the first hole transport layer and bake at 100° C. for 10 min to obtain a first light-emitting layer.

[0187] (5) A charge generation unit is prepared on the first light-emitting layer. The preparation steps of the charge generation unit are as follows: ZnMgO nanoparticles (Mg doping concentration of 5wt%) with an average particle size of about 8nm are dispersed in ethanol to obtain a mixed solution. The mixed solution is spin-coated on the first light-emitting layer to a total thickness of 20nm, and annealed at 120°C for 20min to obtain an N-type layer; the auxiliary functional layer ink prepared in thin film Example 1 is spin-coated on the N-type layer to a total thickness of 30nm, and annealed at 120°C for 20min to obtain an auxiliary functional layer; phosphomolybdic acid is spin-coated on the auxiliary functional layer to a total thickness of 20nm, and annealed at 120°C for 20min to obtain a hole injection functional layer. The N-type layer, the auxiliary functional layer and the hole injection functional layer together constitute the charge generation unit.

[0188] (6) Spin coating a chlorobenzene solution of TFB on the charge generation unit, followed by baking at 120° C. for 20 min in a nitrogen environment to obtain a second hole transport layer with a thickness of 40 nm;

[0189] (7) Spin-coat a 20 nm thick layer of green light quantum dots CdSe@ZnS on the second hole transport layer and bake at 100° C. for 15 min to obtain a second light-emitting layer.

[0190] (8) Spin-coating a 30 nm thick ZnO layer on the second light-emitting layer and annealing at 100° C. for 10 min to obtain an electron transport layer;

[0191] (9) A 100 nm thick Al layer was vacuum evaporated on the electron transport layer to obtain a cathode, which was then packaged and annealed at 80° C. for 30 min to obtain a light-emitting device.

[0192] Device Comparison Example 1

[0193] The device comparison scheme is basically the same as device embodiment 1, with the only difference being that, in the device comparison scheme, the charge generating unit between the first light-emitting layer and the second light-emitting layer is composed of an N-type layer and a hole injection functional layer, and does not include an auxiliary functional layer; accordingly, step (5) is changed to, with reference to thin film comparison example 1, preparing the charge generating unit of thin film comparison example 1 on the first light-emitting layer.

[0194] Device Comparison Example 2

[0195] The device comparison scheme is basically the same as device embodiment 10, with the only difference being that, in the device comparison scheme, the charge generating unit between the first light-emitting layer and the second light-emitting layer is composed of an N-type layer and a hole injection functional layer, and does not include an auxiliary functional layer; accordingly, step (5) is changed to, with reference to thin film comparison example 2, preparing the charge generating unit of thin film comparison example 2 on the first light-emitting layer.

[0196] Device Comparison Example 3

[0197] The device comparative example scheme is basically the same as device embodiment 1, except that in the device comparative example, the material of the auxiliary functional layer is PVK, and does not include the first material. Step (5) is changed to, with reference to thin film comparative example 4, preparing the charge generating unit of thin film comparative example 4 on the first light-emitting layer.

[0198] Device Comparison Example 4

[0199] The device comparative example scheme is basically the same as device embodiment 11, with the only difference being that, in the device comparative example, there is no interface modification layer. Accordingly, in step (5), the step of "spin coating the auxiliary functional layer ink prepared in thin film embodiment 1 with a total thickness of 30 nm, and annealing at 120° C. for 20 min to obtain the auxiliary functional layer" is omitted, and phosphomolybdic acid is directly spin coated on the N-type layer.

[0200] Experimental example

[0201] (I) The performance of the charge generating units prepared from the above-mentioned film examples 1-11 and film comparison examples 1-4 was examined.

[0202] The test method is as follows: prepare the test device, test the I (current)-V (voltage) curve of the device, take the middle of the curve, and the current density is 10mA / cm 2 The voltage at 100 Hz was used as a parameter to evaluate the CGU performance, and the results are recorded in Table 1.

[0203] The structure of the test device is ITO (50nm) / F8BT (20nm) / charge generation unit (and the N-type layer is set close to ITO) / cathode (80nm). The N-type layer (20nm) / auxiliary functional layer (30nm) / hole injection functional layer (20nm) in the device structure corresponds to the charge generation unit prepared in thin film embodiments 1-12 and thin film comparison examples 1-3.

[0204] The preparation method of the test device corresponding to the film to be tested is as follows:

[0205] (1) The ITO anode substrate (thickness 50 nm) was cleaned and then treated under UV conditions for 15 min;

[0206] (2) On the treated ITO substrate, a 20 nm thick F8BT polymer was spin-coated and baked at 150° C. for 10 min to obtain the first light-emitting layer.

[0207] (3) Referring to the preparation method corresponding to the film to be tested, a film to be tested is prepared on the first light-emitting layer, and an N-type layer is formed on the upper surface of the first light-emitting layer. The film to be tested refers to the charge generation unit prepared in film examples 1-11 and film comparison examples 1 to 4.

[0208] (4) Vacuum-evaporating 80 nm thick Al on the charge generating unit to obtain a cathode, thereby obtaining a test device corresponding to the thin film to be tested.

[0209] Table 1

[0210] Voltage (V) Film Example 1 1.3 Film Example 2 1.4 Film Example 3 1.4 Film Example 4 1.4 Film Example 5 3.1 Film Example 6 1.9 Film Example 7 6.8 Film Example 8 5.8 Film Example 9 1.4 Film Example 10 3.2 Film Example 11 4.8 Film Comparative Example 1 7.0 Film Comparative Example 2 7.1 Film Comparative Example 3 7.0

[0211] As can be seen from the table above, compared with the film comparative examples 1 to 3, the test devices corresponding to the film embodiments 1 to 11 have a current density of 10 mA / cm 2 The voltage is lower when , indicating that setting up the auxiliary functional layer helps to improve the conductivity;

[0212] Furthermore, by comparing the film examples 1, 9, 10 and 11, it can be seen that the test devices corresponding to the film examples 1, 9 and 10 have a current density of 10 mA / cm 2 The voltage during the test is relatively low, which may be due to the fact that after the auxiliary functional layer also includes a P-type semiconductor organic material, the auxiliary functional layer can also play a barrier role, thereby avoiding damage to the N-type layer when preparing the hole injection functional layer, thereby making the charge generating unit prepared in each thin film embodiment have lower resistance, higher charge generation / separation ability, and lower heat generation during operation.

[0213] Furthermore, by comparing film embodiments 1 and 11 with film comparison example 3, film embodiment 1 has a lower voltage, indicating that when the auxiliary functional layer material is a single component, it cannot take into account both the barrier and efficient conductivity functions. This may be because, when the two components exist at the same time, the first material has pH neutrality and high conductivity, which can improve the charge transfer performance of the charge generating unit, and the P-type semiconductor organic material can effectively fill the gaps between the first material, thereby improving the barrier effect of the film, and while maintaining the conductivity of the charge generating unit, effectively inhibiting the damage of the hole injection functional layer to the N-type layer, thereby effectively improving the ability of the charge generating unit to generate or separate charges under the action of an external electric field.

[0214] (II) The devices prepared in the above device examples 1-12 and device comparative examples 1-4 were tested for driving voltage, current efficiency and T95@1000nit. The detection method was based on the conventional method in the art, and the results were recorded in Table 2. Wherein:

[0215] The lifespan T95@1000nit indicates the time required for the brightness of the device to decrease to a certain percentage of the maximum brightness when driven by a constant current or voltage. The time when the brightness drops to 95% of the maximum brightness is defined as T95, and this lifespan is the measured lifespan. In order to shorten the test cycle, the device lifespan test is usually carried out at high brightness by accelerating device aging, and the lifespan at high brightness is obtained by fitting the extended exponential decay brightness attenuation fitting formula. For example, the lifespan at 1000nit is calculated as T95@1000nit. The specific calculation formula is as follows:

[0216]

[0217] Among them, T95 L For lifespan at low brightness, T95 H is the measured lifetime under high brightness, L H To accelerate the device to the highest brightness, L L is 1000nit, A is the acceleration factor, and this experiment measured the lifespan of several groups of light-emitting devices at rated brightness and found that the A value was 1.7.

[0218] The detection method of driving voltage @J10 is as follows: the current variation trend of the device with voltage is tested by voltammetry, and the current density is 10mA / cm 2 The voltage below.

[0219] Table 2

[0220]

[0221]

[0222] Refer to Table 2, we can see that:

[0223] Compared with device comparative examples 1 to 2, device embodiments 1 to 11 have lower driving voltages, indicating that providing an auxiliary functional layer helps to reduce the driving voltage;

[0224] Compared with device comparative examples 1 to 2, device embodiments 1-10 have lower driving voltage, higher CE and T95@1000nit. Meanwhile, compared with device comparative example 4, device embodiment 12 has lower driving voltage, higher CE and T95@1000nit, indicating that the light-emitting device proposed in the present application has higher luminous performance and lifespan. The reason may be that after adopting the charge generation unit composed of the N-type layer, the auxiliary functional layer and the hole injection functional layer as the charge generation unit, the charge generation unit has higher charge injection / separation ability, and can efficiently generate and inject charges, thereby greatly improving the luminous performance of the device; at the same time, the charge generation unit has low resistance, which helps to reduce the heat generation of the device, and the auxiliary functional layer in the film effectively plays a barrier role, avoiding damage to the N-type layer when preparing the hole injection functional layer, thereby effectively extending the service life of the device;

[0225] Further comparing device embodiments 1, 5 to 8 and device comparison example 3, it can be seen that the device embodiments have lower driving voltage, higher CE and T95@1000nit, and among the embodiments, device embodiments 1, 5 to 6 have better effects, indicating that when the content of the first material in the two components of the auxiliary functional layer is too low or too high, it is not conducive to improving the luminous performance and life of the device. This may be because, when the content of the first material is too low, it will affect the conductivity of the film layer, and thus affect the device performance. When the content of the first material is too high, the P-type semiconductor organic material cannot achieve the expected effect of filling the gap of the first material, resulting in insufficient barrier properties of the auxiliary functional layer, which will also affect the performance and life of the device.

[0226] The light-emitting device, preparation method thereof and display device provided in the embodiments of the present application are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for technical personnel in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A light emitting device, characterized in that: The invention comprises an anode and a cathode arranged opposite to each other, N light-emitting units and N-1 charge generating units arranged between the anode and the cathode, wherein the N light-emitting units and the N-1 charge generating units are stacked, and one charge generating unit is arranged between any two of the light-emitting units, and N is an integer greater than or equal to 2; wherein the charge generating unit comprises an auxiliary functional layer, and the material of the auxiliary functional layer comprises a first material, and the first material comprises one or more of the polymers having the structure shown in formula (1-1) or formula (1-2): Wherein, m is 10 to 100; R1, R2, R3, R4, R5 and R6 are each independently selected from any one of hydrogen, deuterium, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C3-C20 cycloalkyl, substituted or unsubstituted C3-C20 cycloalkoxy, and the substituent when substituted includes one or more of C1-C5 alkoxy, amino, halogen, hydroxyl, carboxyl, nitro, sulfonic acid, aldehyde, mercapto, cyano and phosphonic acid groups.

2. The light emitting device according to claim 1, characterized in that: R1, R2, R3, R4, R5 and R6 are each independently selected from any one of hydrogen, C1-C4 alkyl, C1-C4 alkoxy; and / or, The polymer is a homopolymer.

3. The light emitting device according to claim 2, characterized in that: R1, R2, R3, R4, R5 and R6 are each independently selected from any one of hydrogen, methyl, ethyl, methoxy and ethoxy; and / or, At least two of R1, R2, R3, and R4 are selected from hydrogen.

4. The light emitting device according to claim 3, characterized in that: The average particle size of the polymer is 10 to 50 nm; and / or, The polymer is a homopolymer of a first monomer, and the first monomer includes one or more compounds having structures represented by the following formulae (2) to (5):

5. The light emitting device according to any one of claims 1 to 4, characterized in that: The charge generation unit further comprises an N-type layer and a hole injection functional layer, the auxiliary functional layer is arranged between the N-type layer and the hole injection functional layer, and the N-type layer is arranged close to the anode.

6. The light emitting device according to claim 5, characterized in that: The material of the auxiliary functional layer also includes a P-type semiconductor organic material; and / or, The material of the N-type layer includes one or more of N-type metal oxide or doped N-type metal oxide, wherein the N-type metal oxide includes one or more of ZnO, TiO2, SnO2, and ZrO; the N-type metal oxide in the doped N-type metal oxide includes one or more of ZnO, TiO2, SnO2, and ZrO, and the doping element includes one or more of Al, Mg, Li, In, and Ga; and / or, The material of the hole injection functional layer includes one or more of phosphomolybdic acid, phosphotungstic acid, ammonium molybdate, metavanadic acid, metatungstic acid, vanadyl acetate acetonate, tungsten ethoxide, molybdenum ethoxide, PEDOT:PSS, HATCN, CN6-CP, and NDP-9; and / or, The thickness of the N-type layer is 5 to 100 nm; and / or, The thickness of the hole injection functional layer is 5 to 100 nm; and / or, The thickness of the auxiliary functional layer is 5-100 nm.

7. The light emitting device according to claim 6, characterized in that: The P-type semiconductor organic material includes one or more of polyvinylcarbazole, poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)], poly[bis(4-phenyl)(4-butylphenyl)amine], poly(9,9-dimethyl-10-(9-(4-vinylbenzyl)-9H-carbazole-3-yl)-9,10-dihydroacridine); and / or, The mass ratio of the first material to the P-type semiconductor organic material is (2-50):1; and / or, The average particle size of the N-type metal oxide is 3 to 10 nm; and / or, The average particle size of the doped N-type metal oxide is 3 to 10 nm; and / or, The material of the N-type layer also includes additives, which include one or more of aliphatic amine polymers and organic electron transport materials. The aliphatic amine polymer includes one or more of polyethylene imine, polyethoxyethylene imine, poly [(9,9-bis (3'- (N, N-dimethylamino) propyl) -2,7-fluorene) -2,7- (9,9-dioctylfluorene)], and poly [(9,9-bis (3'- (N, N-dimethylamino) propyl) -2,7-fluorene) -1,4-phenylene]; the organic electron transport material includes one or more of phenanthroline compounds, phosphorus oxide compounds, and pyridine compounds.

8. The light emitting device according to claim 7, characterized in that: In the N-type layer, the mass percentage of the additive is less than or equal to 50%.

9. The light emitting device according to claim 1, characterized in that: When N is greater than or equal to 3, the thicknesses of N-1 charge generating units are equal; or, Among the N-1 charge generating units, at least two of the charge generating units have unequal thicknesses.

10. The light emitting device according to claim 1, characterized in that: The thicknesses of the N light-emitting units are equal; or, Among the N light-emitting units, at least two of the light-emitting units have unequal thicknesses.

11. The light emitting device according to claim 1, characterized in that: The light-emitting unit includes a light-emitting layer; the material of the light-emitting layers of the N light-emitting units independently includes an organic light-emitting material or a quantum dot light-emitting material, and the organic light-emitting material is selected from 4,4'-bis(N-carbazole)-1,1'-biphenyl:tris[2-(p-tolyl)pyridine iridium(III), 4,4',4"-tri(carbazole-9-yl)triphenylamine:tris[2-(p-tolyl)pyridine iridium, poly[(9,9-dioctylfluorene-2,7-diyl)-alternate-(2,1,3-benzothiadiazole-4,7-diyl)], diaromatic anthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, One or more of fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials, DBP fluorescent materials, delayed fluorescent materials, TTA materials, thermally activated delayed materials, polymers containing BN covalent bonds, hybrid localized charge transfer excited state materials, and exciplex luminescent materials, wherein the quantum dot luminescent material is selected from at least one of single-structure quantum dots, core-shell quantum dots, and perovskite semiconductor materials; the material of the single-structure quantum dots, the core material of the core-shell quantum dots, and the shell material of the core-shell quantum dots are selected from II-VI group compounds, IV-VI group compounds, respectively. , at least one of a III-V compound and a I-III-VI compound; the II-VI compound is selected from 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, Cd At least one of ZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe and HgZnSTe; the IV-VI group compound is at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe and SnPbSTe;The III-V compound is selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, and AlN P, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInN P, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs and InAlPSb; the I-III-VI group compound is selected from at least one of CuInS2, CuInSe2 and AgInS2; the perovskite semiconductor material is selected from doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors; the inorganic perovskite semiconductor has a general structural formula of AMX3, wherein A is Cs; + ion, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2+ 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ At least one of, X is a halogen anion selected from Cl - Br - ,I - At least one of the following; the general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, wherein B is an organic amine cation selected from CH3(CH2) n-2 NH 3+ or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation selected from Pb 2+ Sn 2+ , Cu 2+ 、Ni 2 + 、Cd 2+ Cr 2+ , Mn 2+ 、Co 2+ , Fe 2+ ,Ge 2+ , Yb 2+ 、Eu 2+ At least one of, X is a halogen anion selected from Cl - Br - ,I - At least one of; and / or, The anode and the cathode are each independently selected from a doped metal oxide particle electrode, a composite electrode of metal and metal oxide, a graphene electrode, a carbon nanotube electrode, a metal electrode or an alloy electrode. The material of the doped metal oxide particle electrode is selected from 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 and aluminum-doped magnesium oxide. The composite electrode of metal and metal oxide is selected from AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS. The material of the metal electrode is selected from one or more of Ag, Al, Cu, Mo, Au, Pt, Si, Ca, Mg and Ba.

12. The light emitting device according to claim 1, characterized in that: N is 2; The N light emitting units include a first light emitting unit, a charge generating unit and a second light emitting unit which are stacked.

13. A method for preparing a light emitting device, characterized in that: The following steps are involved: providing a first electrode; A functional film layer is prepared on the first electrode, wherein the functional film layer includes N light-emitting units and N-1 charge generating units, the N light-emitting units and the N-1 charge generating units are stacked, and one charge generating unit is provided between any two of the light-emitting units, the charge generating unit includes an auxiliary functional layer, and N is an integer greater than or equal to 2; Prepare a second electrode on a side of the functional film layer away from the first electrode; When the first electrode is selected from an anode, the second electrode is selected from a cathode, and the preparation of the charge generating unit includes: Providing an auxiliary functional layer material, wherein the auxiliary functional layer material includes a first material, depositing the auxiliary functional layer material, and annealing to obtain an auxiliary functional layer; Wherein, the first material includes one or more polymers having a structure as shown in formula (1-1) or formula (1-2): Wherein, m is 10 to 100; R1, R2, R3, R4, R5 and R6 are each independently selected from any one of hydrogen, deuterium, substituted or unsubstituted C1-C20 alkyl, substituted or unsubstituted C1-C20 alkoxy, substituted or unsubstituted C3-C20 cycloalkyl, and substituted or unsubstituted C3-C20 cycloalkoxy.

14. The preparation method according to claim 13, characterized in that: The auxiliary functional layer material further includes a P-type semiconductor organic material, and the P-type semiconductor organic material includes one or more of polyvinylcarbazole, poly[(9,9-dioctylfluorene-2,7-diyl)-co-(4,4′-(N-(4-sec-butylphenyl)diphenylamine)], poly[bis(4-phenyl)(4-butylphenyl)amine], and poly(9,9-dimethyl-10-(9-(4-vinylbenzyl)-9H-carbazole-3-yl)-9,10-dihydroacridine); and / or, The auxiliary function layer material further includes a solvent, and the solvent includes one or more of n-hexane, cyclohexane, n-octane, n-decane, dodecane, tetralin, decalin, cyclohexylbenzene, xylene, toluene, chlorobenzene, and anisole; and / or, In the step of depositing the auxiliary functional layer material and annealing to obtain the auxiliary functional layer, the annealing temperature is 100-200° C.; and / or, In the step of depositing the auxiliary functional layer material and annealing to obtain the auxiliary functional layer, the annealing time is 10 to 120 minutes; and / or, The average particle size of the polymer is 10 to 50 nm; and / or, The polymer is a homopolymer of a first monomer, and the first monomer includes one or more compounds having structures represented by the following formulae (2) to (5):

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

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