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

Abstract

The invention discloses a composite film and a preparation method thereof, a light-emitting device and a display device.In the technical scheme, the composite film comprises an auxiliary material, and the auxiliary material can absorb ultraviolet rays, play a role of an antioxidant and interact with inorganic semiconductor particles, so that the performance stability of the composite film is improved.

Description

Technical Field

[0001] This application relates to the field of semiconductor materials, and particularly to a composite film, a preparation method thereof, a light-emitting device, and a display device. Background Art

[0002] Inorganic semiconductor particles have semiconductor properties and can be solution-processed, thus attracting wide attention. However, inorganic semiconductor particles have the defect of poor photo-stability, which limits the application and development of the materials. Summary of the Invention

[0003] In view of this, this application provides a composite film, a preparation method thereof, a light-emitting device, and a display device.

[0004] The embodiments of this application are implemented as follows:

[0005] In a first aspect, the embodiments of this application provide a composite film. The material of the composite film includes an auxiliary material and inorganic semiconductor particles. The auxiliary material includes one or more of the compounds having the structure shown in formula (I):

[0006]

[0007] wherein, n1 is selected from any integer from 0 to 5, and n2 is selected from any integer from 0 to 5;

[0008] M is selected from any one of the Group VIIB metal atoms and the Group VIII metal atoms;

[0009] Each occurrence of X and Y is independently selected from one or more combinations of D, C1-C30 alkyl, C1-C30 alkoxy, C2-C30 alkoxycarbonyl, C2-C30 alkylcarbonyl, C6-C30 aryl, cyano, nitro, mercapto, hydroxyl, carboxyl, amino, and halogen groups.

[0010] In a second aspect, this application provides a method for preparing a composite film, including the following steps:

[0011] Provide a film material, where the film material includes an auxiliary material and inorganic semiconductor particles;

[0012] Deposit the film material to obtain a composite film;

[0013] wherein, the auxiliary material includes one or more of the compounds having the structure shown in formula (I):

[0014]

[0015] wherein, n1 is selected from any integer from 0 to 5, and n2 is selected from any integer from 0 to 5;

[0016] M is selected from any one of Group VIIB metal atoms and Group VIII metal atoms;

[0017] Each occurrence of X and Y is independently selected from one or more combinations of D, C1-C30 alkyl, C1-C30 alkoxy, C2-C30 alkoxycarbonyl, C2-C30 alkylcarbonyl, C6-C30 aryl, cyano, nitro, mercapto, hydroxy, carboxy, amino, and halogen groups.

[0018] In a third aspect, the present application provides a light-emitting device, including an anode, a functional layer, and a cathode, wherein the functional layer includes the composite film described above, or includes the composite film prepared by the preparation method described above.

[0019] In a fourth aspect, the present application provides a display device, including the light-emitting device described above.

[0020] In the technical solution of the present application, the composite film includes an auxiliary material, which can absorb ultraviolet light, act as an antioxidant, and interact with the inorganic semiconductor particles to further stabilize the inorganic semiconductor particles, thereby contributing to improving the performance stability of the composite film. 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 following drawings are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

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

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

[0024] Figure 3 is a schematic structural diagram of yet another embodiment of a light-emitting device provided by the present application;

[0025] Reference numerals: light-emitting device 100; anode 10; cathode 20; electron transport layer 30; light-emitting functional layer 40; first film layer 41; second film layer 42; hole injection layer 50; hole transport layer 60. Detailed Embodiments

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present application with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present application. In addition, it should be understood that the specific implementation manners described herein are only used to illustrate and explain the present application, and are not used to limit the present application. In the present application, unless otherwise stated, the orientation terms such as "upper" and "lower" specifically refer to the drawing directions in the accompanying drawings. In addition, in the description of the present application, the term "including" means "including but not limited to". The various embodiments of the present 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 the present application; therefore, it should be considered that the described 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, 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.

[0027] In the present application, "and / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, or B exists alone. Where A and B may be singular or plural.

[0028] In the present application, "at least one" means one or more, and "a plurality" means two or more. "At least one kind", "at least one of the following items (pieces)" or similar expressions refer to any combination of these items, including any combination of single items (pieces) or plural items (pieces). For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0029] Term Explanation

[0030] In the present application, "substituted or unsubstituted" means that the defined group may be substituted or may not be substituted. When the defined group is substituted, it should be understood as being optionally substituted by groups acceptable in the art, including but not limited to: hydroxyl, amino, halogen, carboxyl, nitro, sulfonic acid group, mercapto, cyano, C1-C5 alkoxy, C1-C5 alkylcarbonyl, heteroaryl with 5-20 ring atoms, aryl with 6-20 ring atoms, heteroaryloxy with 5-20 ring atoms, aryloxy with 6-20 ring atoms, or a combination of one or more of them. In the present application, "a combination of multiple" means a situation where at least one hydrogen in a group is substituted by other groups (it can be substituted by one other group or by multiple other groups). For example, a combination of hydroxyl, halogen, and amino may mean that at least two hydrogens in the amino group are respectively substituted by hydroxyl and halogen.

[0031] In the present application, when the same substituent appears multiple times, it can be independently selected from different groups. If the general formula contains multiple R1s, then R1s can be independently selected from different groups. For example 6 Rs on the benzene ring 1 may be the same as or different from each other.

[0032] In the present application, "alkyl" may represent a straight-chain alkyl, a branched-chain alkyl, and / or a cyclic alkyl. The number of carbon atoms in the alkyl may be 1-50, 1-30, 1-20, 1-10, or 1-6. Phrases containing this term, for example, "C 1-9"Alkyl" refers to an alkyl group containing 1 to 9 carbon atoms, and each occurrence can independently be a C1 alkyl group, C2 alkyl group, C3 alkyl group, C4 alkyl group, C5 alkyl group, C6 alkyl group, C7 alkyl group, C8 alkyl group or C9 alkyl group. 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, cyclopentyl, 1-methylpentyl, 3-methylpentyl, 2-ethylpentyl, 4-methyl-2-pentyl, n-hexyl, 1-methylhexyl, 2-ethylhexyl, 2-butylhexyl, cyclohexyl, 4-methylcyclohexyl, 4-tert-butylcyclohexyl, n-heptyl, 1-methylheptyl, 2,2-dimethylheptyl, 2-ethylheptyl, 2-butylheptyl, n-octyl, tert-octyl, 2-ethyloctyl, 2-butyl octyl, 2-hexyloctyl, 3,7-dimethyloctyl, cyclooctyl, n-nonyl, n-decyl, adamantyl, 2-ethyldecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n-undecyl, n-dodecyl, 2-ethyldodecyl, 2-butyldodecyl, 2-hexyldodecyl, 2-octyldodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, 2-ethylhexadecyl, 2-butyldecyl, 2-hexyldecyl, 2-octyldecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl, 2-ethyleicosyl, 2-butyleicosyl, 2-hexyleicosyl, 2-octyleicosyl, n-heneicosyl, n-docosyl, n-tricosyl, n-tetracosyl, n-pentacosyl, n-hexacosyl, n-heptacosyl, n-octacosyl, n-nonacosyl, n-triacontyl, etc. Thioalkyl refers to a group in which at least one hydrogen in the alkyl group is replaced by a sulfur atom.

[0033] In this application, "-C n H 2n+1 ", without special indication or limitation, represents a straight-chain alkyl group. For example, -C6H 13 represents n-hexyl, -C 12 H 25 represents n-dodecyl.

[0034] In this application, "ring atom number" represents the number of atoms in the ring itself of a structural compound formed by bonding atoms in a ring (for example, a monocyclic compound or a polycyclic compound). It can be understood that the ring atoms are not limited to carbon atoms. When a heterocycle is contained in a cyclic compound, the heteroatom is also an atom constituting the heterocycle and belongs to the ring atoms. When the ring is substituted by a substituent, the atoms contained in the substituent are not included in the ring-forming atoms. The same applies to the "ring atom number" described below without special explanation. For example, the ring atom number of a benzene ring is 6, the ring atom number of a naphthalene ring is 10, and the ring atom number of a thiophenyl group is 5.

[0035] In the present application, "aryl, aryl group or aromatic group" refers to a hydrocarbon group containing at least one aromatic ring, such as monocyclic compounds, fused-ring compounds or polycyclic non-fused compounds, etc. "Heteroaryl or heteroaryl group" refers to an aromatic hydrocarbon group containing at least one heteroatom, such as a monocyclic compound containing at least one heteroatom, a fused-ring compound containing at least one heteroatom or a polycyclic non-fused compound containing at least one heteroatom, etc. The heteroatom is preferably selected from Si, N, P, O, S and / or Ge, and particularly preferably selected from Si, N, P, O and / or S. Among them, fused-ring compounds or fused compounds have the same meaning and can be interchanged. Specifically, it means that a compound can have two or more rings, and two ring atoms are shared by two adjacent rings, that is, a fused ring. For the purposes of the present application, aromatic groups or heteroaryl groups include not only aromatic ring systems but also non-aromatic ring systems. Therefore, for example, systems such as pyridine, thiophene, pyrrole, pyrazole, triazole, imidazole, oxazole, oxadiazole, thiazole, tetrazole, pyrazine, pyridazine, pyrimidine, triazine, carbene, etc. are also considered aromatic groups or heteroaromatic groups for the purposes of this invention. For the purposes of the present application, fused-ring aromatic or fused heteroaromatic ring systems include not only aromatic group or heteroaryl group systems, but also, in which multiple aromatic groups or heteroaromatic groups can also be interrupted by short non-aromatic units (<10% of non-H atoms, preferably less than 5% of non-H atoms, such as C, N or O atoms). Therefore, for example, systems such as 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ether, etc. are also considered fused-ring aromatic ring systems for the purposes of this invention.

[0036] In a preferred embodiment, the aromatic group is selected from: benzene, naphthalene, anthracene, fluoranthene, phenanthrene, benzo[a]phenanthrene, dibenzo[a,h]anthracene, tetracene, pyrene, benzo[a]pyrene, acenaphthene, fluorene, and their derivatives; the heteroaryl group is selected from triazine, pyridine, pyrimidine, imidazole, furan, thiophene, benzofuran, benzothiophene, indole, carbazole, pyrroloimidazole, pyrrolopyrrole, thiophenopyrrole, thiophenothiophene, furanopyrrole, furanofuran, thiophenofuran, benzoisoxazole, benzoisothiazole, benzimidazole, quinoline, isoquinoline, phthalazine, quinoxaline, phenanthridine, perimidine, quinazoline, quinazolinone, dibenzothiophene, dibenzofuran, carbazole and their derivatives.

[0037] In the present application, amino represents -NR 1 R 2 wherein R 1 and R 2 each independently represent H or an alkyl group, that is, amino can refer to -NH2, or -NH(alkyl), or -N(alkyl)(alkyl).

[0038] In the present application, "halogen group" represents -Cl, -Br, -F or -I; hydroxyl group represents -OH; carboxyl group represents -COOH; nitro group represents -NO2; mercapto group represents -SH; cyano group represents *-C≡N; alkoxy group represents -OR; carboxyalkyl refers to -R'COOH, hydroxyalkyl refers to -R'OH, aminoalkyl refers to -R'-NR 1 R 2 ; alkoxycarbonyl represents alkylcarbonyl represents wherein, R represents an alkyl group; R' represents an alkylene group; Ar represents an aromatic group; Ar' represents a heteroaromatic group.

[0039] In the present application, "its combination", "any combination thereof", "any combination mode thereof", etc. include all suitable combination modes of any two or more of the listed items.

[0040] In a first aspect, an embodiment of the present application provides a composite film, and the material of the composite film includes auxiliary materials and inorganic semiconductor particles. The auxiliary materials include one or more of the compounds having the structure shown in formula (I):

[0041]

[0042] wherein, M is selected from any one of the Group VIIB metal atoms and the Group VIII metal atoms.

[0043] wherein: n1 is selected from any integer from 0 to 5, such as 0, 1, 2, 3, 4 or 5; n2 is selected from any integer from 0 to 5, such as 0, 1, 2, 3, 4 or 5.

[0044] Specifically, the compound has the structure shown in the following formula. n1 hydrogens at 0 to 5 sites on one cyclopentadiene ring are each independently substituted by X. When the number of substituted X is two or more, two or more Xs may be the same or different; n2 hydrogens at 0 to 5 sites on the other cyclopentadiene ring are each independently substituted by Y. When the number of substituted Y is two or more, two or more Ys may be the same or different.

[0045]

[0046] Each occurrence of X and Y is independently selected from one or more combinations of D, C1-C30 alkyl, C1-C30 alkoxy, C2-C30 alkoxycarbonyl, C2-C30 alkylcarbonyl, C6-C30 aryl, cyano, nitro, mercapto, hydroxyl, carboxyl, amino, and halogen group.

[0047] In the technical solution of the present application, the composite film includes an auxiliary material, and the auxiliary material is a metallocene complex. The metallocene complex can absorb ultraviolet light, reduce the decomposition of materials caused by ultraviolet light, thereby improving the light stability of the composite film and reducing the damage of ultraviolet light to the film; the metallocene complex has a redox center, and its electronic structure is beneficial to the chemical stability and thermal stability of the molecule, and can play the role of an antioxidant, thereby improving the antioxidant performance of the composite film and avoiding the attenuation of the film performance due to material oxidation; in addition, the metallocene complex can also interact with inorganic semiconductor particles to further stabilize the inorganic semiconductor particles.

[0048] Among them, the inorganic semiconductor particles can be quantum dot light-emitting materials or N-type metal oxides. The composite film proposed in the present application has good performance stability, and the composite film can be used as the light-emitting functional layer 40 or the electronic functional layer of the light-emitting device 100, which helps to improve the light-emitting efficiency and service life of the device.

[0049] The inorganic semiconductor particles include nanoparticles and ligands connected to the surface of the nanoparticles. In some embodiments, active groups are connected to the metallocene complex, which helps to better form intermolecular interactions (such as hydrogen bonds, dipole interactions, van der Waals forces, etc.) with the ligands.

[0050] In some embodiments, the inorganic semiconductor particles include quantum dots, which can be selected from, but not limited to, at least one of single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials; the materials of the single-structure quantum dots, the core materials of the core-shell structure quantum dots, and the shell materials of the core-shell structure quantum dots are respectively selected from at least one of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds; the II-VI group compounds are selected from at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds are selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V group compounds are selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; the I-III-VI group compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2.

[0051] As an example, the quantum dots of the core-shell structure may be selected from, but not limited to, at least one of CdZnSe / CdZnSe / ZnSe / CdZnS / ZnS, CdZnSe / CdZnSe / CdZnS / ZnSCdSe / 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.

[0052] It should be noted that for the materials of the aforementioned single-structure quantum dots, or the core materials of the core-shell structure quantum dots, or the shell materials of the core-shell structure quantum dots, the chemical formulas provided only indicate the elemental composition and do 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 to be represented, it corresponds to Cd x Zn 1-x Se, where 0 < x < 1.

[0053] The perovskite semiconductor material is selected from doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors; the general structural formula of the inorganic perovskite semiconductor is AMX3, 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 at least one of them, X is a halogen anion selected from Cl - , Br-, I - and at least one of them; 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 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+ , Cr2+ 、 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.

[0054] In some embodiments, the raw materials of the ligand include at least one of substituted or unsubstituted C10-C24 chain organic carboxylic acids, substituted or unsubstituted C10-C24 chain organic amines, substituted or unsubstituted C1-C24 chain thiols, substituted or unsubstituted C10-C24 chain organic phosphines, substituted or unsubstituted C10-C24 chain organic phosphine oxides, and halides. Among them, "substituted or unsubstituted" means that the defined group can be substituted or not substituted. When the defined group is substituted, it should be understood that the defined group can be substituted by one or more substituents; the substituents are selected from at least one of C1-C8 alkyl groups, C1-C8 alkoxy groups, and halogens; optionally, the substituents are selected from at least one of C1-C5 alkyl groups, C1-C5 alkoxy groups, and halogens; or the substituents are selected from at least one of C1-C3 alkyl groups, C1-C3 alkoxy groups, and halogens. The halogen refers to -F, -Cl, -Br, or -I. Specifically, the organic carboxylic acids include one or more of decanoic acid (CAS: 334-48-5), undecylenic acid (CAS: 112-38-9), myristic acid (CAS: 544-63-8), oleic acid (CAS: 112-80-1), and stearic acid (CAS: 57-11-4); the organic amines include one or more of oleylamine (CAS: 112-90-3) and octadecylamine (CAS: 124-30-1); the organic (oxy)phosphines include one or more of trioctylphosphine (CAS: 4731-53-7) and trioctyloxophosphine (CAS: 78-50-2); the thiols include one or more of n-octanethiol (CAS: 111-88-6), dodecanethiol (CAS: 112-55-0), and octadecanethiol (CAS: 2885-00-9); the halides are selected from one or more of hydrofluoric acid, hydrochloric acid, hydroiodic acid, hydrobromic acid, metal fluorides, metal chlorides, metal iodides, and metal bromides.

[0055] In some other embodiments, the inorganic semiconductor particles include N-type metal oxides, and the N-type metal oxides include one or more of metal oxides and doped metal oxides; the metal oxides include one or more of ZnO, TiO2, and SnO2; the metal oxides in the doped metal oxides include one or more of ZnO, TiO2, and SnO2, and the doping elements include one or more of Al, Mg, Li, In, and Ga. Hydroxyl groups, carboxyl groups and other ligands may be connected to the surface of the N-type metal oxide, and the ligands may be introduced by additional addition or in the form of alkalis or metal salts during the preparation of the metal oxides.

[0056] In some embodiments, in formula (I), M is selected from Fe (iron), Co (cobalt), Ni (nickel) or Mn (manganese).

[0057] In some embodiments, in formula (I), n1 is 0 or 1. In some embodiments, in formula (I), n2 is 0 or 1.

[0058] In some embodiments, in formula (I), each occurrence of X and Y is independently selected from any one of D, C1-C24 carboxyalkyl, carboxyl, C1-C24 hydroxyalkyl, hydroxy, C1-C24 aminoalkyl, amino, C2-C24 alkylcarbonyl, cyano, nitro, and halogen groups. Among them, the carboxyalkyl refers to -C n H 2n COOH, where n is any integer from 1 to 24; the hydroxyalkyl refers to -C n H 2n OH, where n is any integer from 1 to 24; the aminoalkyl refers to -C n H 2n NH2, where n is any integer from 1 to 24; the alkylcarbonyl refers to -C(O)C m H 2m+1 , and m is selected from any integer from 1 to 24.

[0059] In some embodiments, in formula (I), each occurrence of X and Y is independently selected from any one of C1-C4 carboxyalkyl, carboxyl, C1-C3 hydroxyalkyl, hydroxy, C1-C3 aminoalkyl, amino, C2-C4 alkylcarbonyl, cyano, nitro, and halogen groups.

[0060] In some specific embodiments, the auxiliary material includes one or more of the compounds represented by the following formulas (1) to (10). Specifically, the CAS number of the compound represented by formula (1) is 102-54-5; the CAS number of the compound represented by formula (2) is 1277-43-6; the CAS number of the compound represented by formula (3) is 1271-28-9; the CAS number of the compound represented by formula (4) is 73138-26-8; the CAS number of the compound represented by formula (5) is 1273-76-3; the CAS number of the compound represented by formula (6) is 1273-84-3; the CAS number of the compound represented by formula (7) is 1271-55-2; the CAS number of the compound represented by formula (8) is 1273-82-1; the CAS number of the compound represented by formula (9) is 1287-16-7; the CAS number of the compound represented by formula (10) is 1277-49-2. In some other embodiments, the auxiliary material includes one or more of the compounds represented by the following formulas (5) to (10). These auxiliary materials can better form intermolecular forces with the quantum dots, and can further improve the stability of the composite film.

[0061]

[0062] The composite film has various implementation forms.

[0063] In the first embodiment, the composite film is a film layer with a single structure. Specifically, the material of the composite film is a mixture of the auxiliary material and the inorganic semiconductor particles. During preparation, depositing the mixture of the auxiliary material and the inorganic semiconductor particles can obtain the composite film. The auxiliary material is doped in the inorganic semiconductor particles, which can not only effectively absorb ultraviolet light and play the role of an antioxidant, but also make full contact with the inorganic semiconductor particles, effectively improving the stability.

[0064] Based on the above first embodiment, in some embodiments, in the mixture of the auxiliary material and the inorganic semiconductor particles, the mass percentage content of the auxiliary material is 1% to 50%; for example, the doping amount can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 20%, 25%, 30%, 35%, 40%, 45%, 50% and values between any two of the above values. Controlling the mass percentage content of the auxiliary material within the above range helps to evenly improve the gain effect of the auxiliary material on the thin film and the optoelectronic properties of the thin film. When the thin film is used as the light-emitting functional layer 40 or the electronic functional layer of the light-emitting device 100, it helps to evenly improve the EQE and lifetime of the device. In other embodiments, in the mixture of the auxiliary material and the inorganic semiconductor particles, the mass percentage content of the auxiliary material is 5% to 15%. Within this range, it helps to better improve the EQE and lifetime of the device.

[0065] The light-emitting device 100 realizes light emission by injecting holes and electrons to cause recombination of semiconductor materials to release energy; in some devices, such as some red-light devices or green-light devices, there is a situation where the hole injection level is lower than the electron injection level, which easily causes the un-recombined electrons in the light-emitting functional layer 40 to damage the hole functional layer material, thereby affecting the device stability. Based on this, in some embodiments, the composite thin film is a film layer with a laminated structure. Specifically, the composite thin film includes a light-emitting layer and an auxiliary film layer arranged in a laminated manner, wherein the material of the light-emitting layer includes quantum dot light-emitting materials, and the material of the auxiliary film layer includes auxiliary materials. When this composite thin film is used in the light-emitting device 100, the auxiliary film layer is located between the hole functional layer and the light-emitting layer, and can form a relatively large conduction band energy level barrier between the hole functional layer and the light-emitting layer, preventing electrons from tunneling from the light-emitting layer to the hole functional layer, playing a role in blocking electrons and regulating the carrier balance in the device, thereby effectively alleviating the damage of the hole transport layer 60 material caused by electron leakage, and macroscopically manifested as a significant improvement in the light-emitting efficiency and service life of the device.

[0066] In some devices, such as some blue-light devices, there is a situation where the hole injection level is higher than the electron injection level. Based on this, in some embodiments, the composite thin film is a film layer with a laminated structure. Specifically, the composite thin film includes an electron transport layer 30 and an auxiliary film layer arranged in a laminated manner, wherein the material of the electron transport layer 30 includes an N-type metal oxide, and the material of the auxiliary film layer includes auxiliary materials. When this composite thin film is used in the light-emitting device 100, the auxiliary film layer is located between the electron transport layer 30 and the cathode 20, and can further increase electron injection and improve the interface stability, and macroscopically manifested as a significant improvement in the light-emitting efficiency and service life of the device.

[0067] Based on this, a second embodiment and a third embodiment are proposed.

[0068] Please refer to Figure 2 , in the second embodiment, the composite film includes a first film layer 41 and a second film layer 42 which are stacked. The material of the first film layer 41 includes the inorganic semiconductor particles, and the material of the second film layer 42 includes the auxiliary material.

[0069] In some embodiments, the thickness of the first film layer 41 is 10 - 100 nm; for example, it can be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, and values between any two of the above.

[0070] In some embodiments, the thickness of the second film layer 42 is 1 - 10 nm; for example, it can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, and values between any two of the above. Controlling the thickness of the second film layer 42 within this range helps to improve its electron blocking effect and better regulate the carrier balance when the second film layer 42 is used as the light - emitting functional layer 40, and helps to better enhance electron injection when it is used as the electron functional layer.

[0071] In the third embodiment, the composite film includes a third film layer and a fourth film layer which are stacked. The material of the third film layer includes a mixture of the auxiliary material and the inorganic semiconductor particles, and the material of the fourth film layer includes the auxiliary material. The doping of the auxiliary material in the third film layer enables the composite film to further improve the film performance stability while playing the role of blocking electrons or enhancing electron injection, which helps to further improve the service life and luminous efficiency of the device.

[0072] In some embodiments, the thickness of the third film layer is 10 - 100 nm; for example, it can be 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, 100 nm, and values between any two of the above.

[0073] In some embodiments, in the third film layer, in the mixture of the auxiliary material and the inorganic semiconductor particles, the mass percentage content of the auxiliary material is 1% - 50%; for example, it can be 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, and values between any two of the above.

[0074] In some embodiments, the thickness of the fourth film layer is 1 to 10 nm; for example, it can be 1 nm, 2 nm, 3 nm, 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 9 nm, 10 nm, and values between any two of the above.

[0075] In a second aspect, the present application provides a method for preparing a composite film. The composite film prepared by the preparation method includes an auxiliary material. The auxiliary material can absorb ultraviolet light, act as an antioxidant, and can also interact with inorganic semiconductor particles to further stabilize the inorganic semiconductor particles. The composite film has good performance stability and can be used as the light-emitting functional layer 40 of the light-emitting device 100, which helps to improve the light-emitting efficiency and service life of the device.

[0076] The preparation method includes the following steps:

[0077] S10, providing a film material, the film material including an auxiliary material and inorganic semiconductor particles;

[0078] S20, depositing the film material to obtain a composite film;

[0079] Wherein, the auxiliary material includes one or more of the compounds having the structure shown in formula (I):

[0080]

[0081] Wherein, n1 is selected from any integer from 0 to 5, and n2 is selected from any integer from 0 to 5;

[0082] M is selected from any one of Group VIIB metal atoms and Group VIII metal atoms;

[0083] Each occurrence of X and Y is independently selected from one or more combinations of D, C1-C30 alkyl, C1-C30 alkoxy, C2-C30 alkoxycarbonyl, C2-C30 alkylcarbonyl, C6-C30 aryl, cyano, nitro, mercapto, hydroxyl, carboxyl, amino, and halogen groups.

[0084] In some specific embodiments, the auxiliary material includes one or more of the compounds shown in the above formulas (1) to (10).

[0085] When the composite film is a film layer with a single structure as shown in the first embodiment, step S20 can be implemented through the following steps:

[0086] S20a, mixing the auxiliary material and the inorganic semiconductor particles to form a first mixture, and depositing the first mixture to obtain a composite film.

[0087] Specifically, physical vapor deposition methods such as evaporation can be used to deposit the first mixture into a film, or film formation methods such as solution methods can be used. For example, step S20a may specifically include: providing a first solvent, mixing the auxiliary material, inorganic semiconductor particles and the first solvent to form a first solution; providing a substrate, coating the first solution on the substrate, and removing the solvent to obtain a composite film.

[0088] Among them, the substrate may be a conventional substrate for film formation, such as a rigid substrate or a flexible substrate. The rigid substrate may be a glass substrate, etc., and the flexible substrate may be a PI substrate, etc.; it may also be a semi-finished device that has been formed in the manufacturing process of the light-emitting device 100.

[0089] Among them, the first solvent may be one or more of C6-C20 alkane solvents, C6-C20 cycloalkane solvents, C6-C20 aromatic hydrocarbon solvents, acetonitrile, and acetone. The C6-C20 alkane solvents may be selected from n-hexane, n-octadecane, etc., the C6-C20 cycloalkane solvents may be cyclohexane, cycloheptane, etc., and the C6-C20 aromatic hydrocarbon solvents may be benzene, toluene, naphthalene, etc.

[0090] Among them, the method of removing the solvent may be a heating method or a vacuum evaporation drying method. When using the heating method, the heating temperature may be 80-150°C; for example, 80°C, 90°C, 95°C, 100°C, 105°C, 110°C, 120°C, and values between any two of the above. The heating time may be 5-30 min; for example, it may be 5 min, 10 min, 20 min, 30 min, and values between any two of the above.

[0091] When the composite film is a film layer of the stacked structure shown in the second embodiment, and the composite film includes a first film layer 41 and a second film layer 42 stacked in sequence from bottom to top, step S20 can be realized through the following steps:

[0092] S21b, depositing the inorganic semiconductor particles to obtain the first film layer 41; S22b, depositing the auxiliary material on one side of the first film layer 41 to obtain the second film layer 42, and the first film layer 41 and the second film layer 42 together form the composite film.

[0093] When the composite film is a film layer of the stacked structure shown in the second embodiment, and the composite film includes a second film layer 42 and a first film layer 41 stacked in sequence from bottom to top, step S20 can be realized through the following steps:

[0094] S23b, depositing the auxiliary material to obtain the second film layer 42; S24b, depositing the inorganic semiconductor particles on one side of the second film layer 42 to obtain the first film layer 41, and the first film layer 41 and the second film layer 42 together form the composite film.

[0095] When the composite film is the film layer of the laminated structure shown in the third embodiment, and the composite film includes a third film layer and a fourth film layer laminated in sequence from bottom to top, the auxiliary material is divided into a first auxiliary material and a second auxiliary material. Step S20 can be implemented through the following steps:

[0096] S21c, mixing the first auxiliary material and inorganic semiconductor particles to form a second mixture, depositing the second mixture to obtain a third film layer; S22c, depositing the second auxiliary material on one side of the third film layer to obtain a fourth film layer, and the third film layer and the fourth film layer together form a composite film.

[0097] When the composite film is the film layer of the laminated structure shown in the third embodiment, and the composite film includes a fourth film layer and a third film layer laminated in sequence from bottom to top, the auxiliary material is divided into a first auxiliary material and a second auxiliary material. Step S20 can be implemented through the following steps:

[0098] S23c, depositing the second auxiliary material to obtain a fourth film layer; S24c, mixing the first auxiliary material and inorganic semiconductor particles to form a second mixture, depositing the second mixture on one side of the fourth film layer to obtain a third film layer, and the third film layer and the fourth film layer together form a composite film.

[0099] Among them, when preparing the first film layer 41 or the third film layer, an evaporation method or a solution method can be used. When using the solution method, the preparation of the first film layer 41 or the third film layer includes: dispersing the film layer material in a second solvent to form a second solution, and the film layer material includes inorganic semiconductor particles, or a mixture of the first auxiliary material and inorganic semiconductor particles; providing a substrate, coating the second solution on the substrate, and removing the solvent to obtain the first film layer 41 or the third film layer. The second solvent can be one or more of C6-C20 alkane solvents, C6-C20 cycloalkane solvents, C6-C20 aromatic hydrocarbon solvents, acetonitrile, and acetone. The C6-C20 alkane solvent can be selected from n-hexane, n-octadecane, etc., the C6-C20 cycloalkane solvent can be cyclohexane, cycloheptane, etc., and the C6-C20 aromatic hydrocarbon solvent can be benzene, toluene, naphthalene, etc.

[0100] Among them, the method for removing the solvent can be a heating method or a vacuum evaporation drying method. When using the heating method, the heating temperature can be 80-150°C; for example, 80°C, 90°C, 95°C, 100°C, 105°C, 110°C, 120°C, and values between any two of the above. The heating time can be 5-30 min; for example, it can be 5 min, 10 min, 20 min, 30 min, and values between any two of the above.

[0101] Among them, when preparing the second film layer 42 or the fourth film layer, vapor deposition or solution method can be used. When the solution method is used, the preparation of the second film layer 42 or the fourth film layer includes: dispersing the film layer material in a third solvent to form a third solution, where the film layer material includes an auxiliary material or a second auxiliary material; providing a substrate, coating the third solution on the substrate, and removing the solvent to obtain the second film layer 42 or the fourth film layer. The third solvent can be one or more of acetonitrile, ethanol, butanol, and ethyl acetate.

[0102] Among them, the method of removing the solvent can be heating method or vacuum evaporation method. When using the heating method, the heating temperature can be 80 - 150 °C; for example, 80 °C, 90 °C, 95 °C, 100 °C, 105 °C, 110 °C, 120 °C, and values between any two of the above. The heating time can be 5 - 30 min; for example, it can be 5 min, 10 min, 20 min, 30 min, and values between any two of the above.

[0103] In a third aspect, the present application provides a light-emitting device 100, which can be, for example, a quantum dot light-emitting diode (QLED), an organic light-emitting diode (OLED), etc. Please refer to Figure 1 , the light-emitting device 100 includes an anode 10, a functional layer, and a cathode 20. Among them, the functional layer includes the composite film described above or the composite film prepared by the preparation method described above.

[0104] The functional layer can be a light-emitting functional layer 40 or an electron functional layer. When the light-emitting functional layer 40 or the electron functional layer of the light-emitting device 100 uses the composite film, the composite film has good performance stability, which helps to improve the light-emitting efficiency and service life of the device.

[0105] In some embodiments, the composite film is a film layer with a laminated structure. Specifically, the composite film may include a light-emitting layer and an auxiliary film layer arranged in a laminated manner. Among them, the material of the light-emitting layer includes a quantum dot light-emitting material, and the material of the auxiliary film layer includes an auxiliary material. When this composite film is used in the light-emitting device 100, the auxiliary film layer is located between the hole functional layer and the light-emitting layer, and can form a relatively large conduction band energy level barrier between the hole functional layer and the light-emitting layer, preventing electrons from tunneling from the light-emitting layer to the hole functional layer, playing a role in blocking electrons and regulating the carrier balance in the device, thereby effectively alleviating the damage of the material of the hole transport layer 60 caused by electron leakage, which is macroscopically manifested as a significant improvement in the light-emitting efficiency and service life of the device. The composite film may also include an electron transport layer 30 and an auxiliary film layer arranged in a laminated manner. Among them, the material of the electron transport layer 30 includes an N-type metal oxide, and the material of the auxiliary film layer includes an auxiliary material. When this composite film is used in the light-emitting device 100, the auxiliary film layer is located between the electron transport layer 30 and the cathode 20, and can further increase electron injection and improve the interface stability, which is macroscopically manifested as a significant improvement in the light-emitting efficiency and service life of the device.

[0106] Please refer to Figure 2 , in some embodiments, the light-emitting functional layer 40 includes the first film layer 41 and the second film layer 42 arranged in a laminated manner. When the material of the first film layer 41 includes the inorganic semiconductor particles and the material of the second film layer 42 includes the auxiliary material, the first film layer 41 is disposed between the second film layer 42 and the cathode 20. The second film layer 42 can play a role in blocking electrons.

[0107] In some embodiments, the light-emitting functional layer 40 includes a third film layer and a fourth film layer arranged in a laminated manner. When the material of the third film layer includes a mixture of the auxiliary material and the inorganic semiconductor particles and the material of the fourth film layer includes the auxiliary material, the third film layer is disposed between the fourth film layer and the cathode 20. The fourth film layer can play a role in blocking electrons.

[0108] Please refer to Figure 3 , in some embodiments, the electron functional layer includes the first film layer 41 and the second film layer 42 arranged in a laminated manner. The second film layer 42 is disposed between the first film layer 41 and the cathode 20, and the second film layer 42 can play a role in enhancing electron injection. In some other embodiments, when the electron functional layer includes a third film layer and a fourth film layer arranged in a laminated manner, the fourth film layer is disposed between the third film layer and the cathode 20, and the fourth film layer can play a role in enhancing electron injection.

[0109] In some embodiments, the light-emitting device 100 further includes a hole functional layer disposed between the light-emitting functional layer 40 and the anode 10. The hole functional layer includes one or both of a hole injection layer 50 and a hole transport layer 60. When the hole functional layer includes both the hole injection layer 50 and the hole transport layer 60, the hole injection layer 50 is disposed closer to the anode 10. Further, in some embodiments, the light-emitting functional layer 40 includes the first film layer 41 and the second film layer 42 stacked on each other. The light-emitting device 100 includes the anode 10, the hole functional layer, the second film layer 42, the first film layer 41, and the cathode 20 stacked on each other. In other embodiments, the light-emitting functional layer 40 includes the third film layer and the fourth film layer stacked on each other. The light-emitting device 100 includes the anode 10, the hole functional layer, the fourth film layer, the third film layer, and the cathode 20 stacked on each other.

[0110] The anode 10 can be an anode 10 known in the art for use in the light-emitting device 100. For example, it can be selected from, but not limited to, doped metal oxide particle electrodes, composite electrodes of metal and metal oxide, graphene electrodes, carbon nanotube electrodes, metal electrodes, or alloy electrodes. 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. Herein, " / " represents a stacked structure. For example, the composite electrode AZO / Ag / AZO represents an electrode with a three-layer stacked composite structure composed of an AZO layer, an Ag layer, and an AZO layer.

[0111] The cathode 20 can be a cathode 20 known in the art for use in the light-emitting device 100. For example, it can be selected from, but not limited to, doped metal oxide particle electrodes, composite electrodes of metals and metal oxides, graphene electrodes, carbon nanotube electrodes, metal electrodes or alloy electrodes. 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.

[0112] The material of the hole functional layer may be a material commonly used in the art and having hole injection or transport performance. For example, in some embodiments, the material of the hole transport layer 60 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'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(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'-tetraarylbenzidine, PEDOT:PSS and its derivatives, poly(N-vinylcarbazole) (PVK) and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, N,N'-bis(naphthalen-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, at least one of them.

[0113] The material of the hole injection layer 50 may include but is not limited to one or more of poly(ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS), poly(9,9-dioctylfluorene-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-phenylamino]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)phenyl]cyclohexane (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'-bis(1-naphthyl)-1,1'-biphenyl-4,4''-diamine (α-NPD), hexaazatriphenylenehexanitrile (HAT-CN).

[0114] It can be understood that the materials of the respective layers of the light-emitting device 100 can be adjusted according to the light-emitting requirements of the light-emitting device 100.

[0115] It can be understood that the light-emitting device 100 can be a normal device or an inverted device.

[0116] Based on the above embodiments of the light-emitting device 100, an embodiment of the present application further provides a method for manufacturing a light-emitting device 100, including the following steps:

[0117] The manufacturing method includes the following steps: preparing a plurality of film layers in sequence according to a preset film layer order to obtain the light-emitting device 100; wherein, the plurality of film layers include an anode 10, a cathode 20, and at least one functional layer disposed between the anode 10 and the cathode 20, and the at least one functional layer includes a light-emitting functional layer 40, or includes at least one of an electron transport layer 30, a hole transport layer 60, a hole injection layer 50, and a light-emitting functional layer 40. Wherein, the preset film layer order refers to the order in which the light-emitting device 100 is stacked layer by layer from bottom to top.

[0118] In the light-emitting device 100 provided by the present application, for the functional layer, the anode 10, and the cathode 20, conventional preparation methods can also be used for preparation. Specifically, the conventional preparation method can be a chemical method or a physical method. Among them, the chemical method includes chemical vapor deposition, sequential ionic layer adsorption and reaction, anodic oxidation, electrodeposition, and coprecipitation. The physical method includes physical coating and solution methods. Among them, the physical coating method includes: thermal evaporation coating, electron beam evaporation coating, magnetron sputtering, multi-arc ion coating, physical vapor deposition, atomic layer deposition, pulsed laser deposition, etc.; the solution method can be spin coating, printing, inkjet printing, blade coating, printing, dip coating, immersion, spraying, roll coating, casting, slot die coating, and bar coating, etc.

[0119] In some embodiments, after the light-emitting device 100 is prepared, it further includes the step of encapsulating the light-emitting device 100. The encapsulation process can be carried out by using a common machine encapsulation or manual encapsulation. Preferably, in the environment of the encapsulation process, the oxygen content and the water content are both lower than 0.1 ppm to ensure the stability of the light-emitting device 100.

[0120] In addition, the present application also relates to a display device, and the display device includes the above-mentioned light-emitting device 100. The display device can be any electronic product with a display function. The electronic product includes but is not limited to a smart phone, a tablet computer, a notebook computer, a digital camera, a digital video camera, a smart wearable device, a smart weighing electronic scale, a vehicle-mounted display, a television, or an e-book reader. Among them, the smart wearable device can be, for example, a smart bracelet, a smart watch, a virtual reality (VR) helmet, etc.

[0121] The present application will be specifically described below through specific embodiments. The following embodiments are only partial embodiments of the present application and do not limit the present application. The raw materials used in the following embodiments are all commercially available products unless otherwise specified.

[0122] Film Example 1

[0123] (1) Take auxiliary materials and quantum dot materials. Among them, the auxiliary material is ferrocene, a compound with the structure shown in formula (1), and the quantum dot material is a red-light quantum dot CdSe with oleic acid ligands connected to its surface.

[0124] (2) Disperse the quantum dot materials in cyclohexane, and then add the auxiliary materials in proportion. The addition amount satisfies that the mass of the auxiliary materials accounts for 10% of the total mass of the auxiliary materials and the quantum dot materials. Stir at room temperature (28 °C) for 1 h to obtain a mixed solution, and the concentration of the quantum dot materials in the mixed solution is 30 mg / ml.

[0125] (3) Spin-coat the mixed solution prepared in step (2) on the glass substrate at a rotation speed of 1500 rpm, and then heat it at 100 °C for 5 min to obtain a composite film with a thickness of 35 nm.

[0126] Film Example 2

[0127] This film example is basically the same as Film Example 1, except that in this film example, the auxiliary material is changed to the compound shown in formula (9) - ferrocene acetic acid.

[0128] Film Example 3

[0129] This film example is basically the same as Film Example 2, except that in this film example, the mass of the auxiliary material accounts for 1% of the total mass of the auxiliary material and the quantum dot material.

[0130] Film Example 4

[0131] This film example is basically the same as Film Example 2, except that in this film example, the mass of the auxiliary material accounts for 5% of the total mass of the auxiliary material and the quantum dot material.

[0132] Film Example 5

[0133] This film example is basically the same as Film Example 2, except that in this film example, the mass of the auxiliary material accounts for 20% of the total mass of the auxiliary material and the quantum dot material.

[0134] Film Example 6

[0135] This film example is basically the same as Film Example 2, except that in this film example, the mass of the auxiliary material accounts for 50% of the total mass of the auxiliary material and the quantum dot material.

[0136] Film Example 7

[0137] This film example is basically the same as Film Example 2, except that in this film example, the mass of the auxiliary material accounts for 51% of the total mass of the auxiliary material and the quantum dot material.

[0138] Film Example 8

[0139] This film example is basically the same as Film Example 1, except that in this film example, the auxiliary material is changed to the compound shown in formula (10) - ferrocene ethanol.

[0140] Film Example 9

[0141] This film example is basically the same as Film Example 1, except that in this film example, the auxiliary material is changed to the compound shown in formula (8) - aminoferrocene.

[0142] Thin Film Example 10

[0143] (1) Take auxiliary materials and quantum dot materials. Among them, the auxiliary material is Compound 1-iodoferrocene with the structure shown in Formula (5), and the quantum dot material is red-light quantum dot CdSe with oleic acid ligands connected to its surface. Disperse the quantum dot material in cyclohexane to make a quantum dot solution with a concentration of the quantum dot material of 30 mg / ml; disperse the auxiliary material in acetonitrile to make an auxiliary material solution with a concentration of the auxiliary material of 4 mg / ml.

[0144] (2) Spin-coat the auxiliary material solution on a glass substrate at a speed of 4000 rpm, and then heat it at 100 °C for 5 min to obtain an auxiliary film layer with a thickness of 5 nm; spin-coat the quantum dot solution on the auxiliary film layer at a speed of 1500 rpm, and then heat it at 100 °C for 5 min to obtain a light-emitting layer with a thickness of 30 nm. The auxiliary film layer and the light-emitting layer together form a composite thin film.

[0145] Thin Film Example 11

[0146] This thin film example is basically the same as Thin Film Example 10, except that in this thin film example, the thickness of the auxiliary film layer is changed to 1 nm, and the concentration of the corresponding auxiliary material solution is changed to 1 mg / ml.

[0147] Thin Film Example 12

[0148] This thin film example is basically the same as Thin Film Example 10, except that in this thin film example, the thickness of the auxiliary film layer is changed to 10 nm, and the concentration of the corresponding auxiliary material solution is changed to 10 mg / ml.

[0149] Thin Film Example 13

[0150] This thin film example is basically the same as Thin Film Example 10, except that in this thin film example, the thickness of the auxiliary film layer is changed to 11 nm, and the concentration of the corresponding auxiliary material solution is changed to 10 mg / ml.

[0151] Thin Film Example 14

[0152] This thin film example is basically the same as Thin Film Example 10, except that in this thin film example, the auxiliary material is changed to Compound - cyanoferrocene with the structure shown in Formula (6).

[0153] Thin Film Example 15

[0154] This thin film example is basically the same as Thin Film Example 10, except that in this thin film example, the auxiliary material is changed to Compound - acetylferrocene with the structure shown in Formula (7).

[0155] Thin Film Example 16

[0156] This thin film example is basically the same as Thin Film Example 10, except that in this thin film example, the auxiliary material is changed to ferrocenylamine with the compound shown in formula (8).

[0157] Thin Film Example 17

[0158] This thin film example is basically the same as Thin Film Example 10, except that in this thin film example, the auxiliary material is changed to cobaltocene with the compound shown in formula (2).

[0159] Thin Film Example 18

[0160] This thin film example is basically the same as Thin Film Example 10, except that in this thin film example, the auxiliary material is changed to nickelocene with the compound shown in formula (3).

[0161] Thin Film Example 19

[0162] This example is a composite thin film of an electron transport material ZnMgO and an auxiliary material. Among them, the mass of the auxiliary material accounts for 10% of the total mass of the auxiliary material and the electron transport material. Specifically, the preparation method is as follows:

[0163] (1) Take the auxiliary material and the electron transport material. Among them, the auxiliary material is ferrocene with the compound shown in formula (1); the electron transport material ZnO is ZnMgO with hydroxyl and carboxyl ligands connected to its surface. Its specific preparation steps are as follows: In a 100 mL solution bottle, mix 22 mmol of lithium hydroxide with 60 mL of absolute ethanol, stir at room temperature and normal pressure for 1 h, and then sonicate for 5 min to obtain a colorless and transparent alkaline solution. Subsequently, add a mixture of 17 mmol of zinc acetate and 3 mmol of magnesium acetate to 60 mL of ethanol (tetrahydrate). The mixture of magnesium acetate tetrahydrate is added to 60 mL of dimethyl sulfoxide (DMSO) solution, and the reaction is carried out for 20 h. The resulting mixture is purified with a large amount of ethyl acetate and n-heptane, and then centrifuged. Discard the supernatant, and the residue is redissolved in ethanol to finally obtain a solution of ZnMgO nanoparticles in ethanol.

[0164] (2) Disperse the electron transport material in ethanol, and then add the auxiliary material in proportion. The addition amount satisfies that the mass of the auxiliary material accounts for 10% of the total mass of the auxiliary material and the electron transport material. Stir at room temperature (28 °C) for 1 h to obtain a mixed solution, and the concentration of the electron transport material in the mixed solution is 40 mg / ml.

[0165] (3) Spin-coat the mixed solution prepared in step (2) on a glass substrate at a speed of 3000 rpm, and then heat at 100 °C for 15 min to obtain a composite thin film with a thickness of 25 nm.

[0166] Thin Film Example 20

[0167] (1) Take auxiliary material and electron transport material ZnMgO. Among them, the auxiliary material is nickelocene with the structure shown in formula (3), and the electron transport material ZnMgO is the ZnMgO with hydroxyl and carboxyl ligands connected to its surface prepared in Thin Film Example 19. Disperse the electron transport material in ethanol to make a ZnMgO solution with a concentration of 40 mg / ml; disperse the auxiliary material in acetonitrile to make an auxiliary material solution with a concentration of 4 mg / ml.

[0168] (2) Spin-coat the auxiliary material solution on a glass substrate at a speed of 4000 rpm, and then heat it at 100 °C for 5 min to obtain an auxiliary film layer with a thickness of 5 nm; spin-coat the ZnMgO solution on the auxiliary film layer at a speed of 3000 rpm, and then heat it at 100 °C for 15 min to obtain an electron transport layer with a thickness of 25 nm. The auxiliary film layer and the electron transport layer together form a composite thin film.

[0169] Thin Film Example 21

[0170] This thin film example is basically the same as Thin Film Example 20, except that in this thin film example, the auxiliary material is changed to manganeseocene with the compound shown in formula (4).

[0171] Thin Film Comparative Example 1

[0172] This thin film comparative example is basically the same as Thin Film Example 1, except that in this comparative example, the thin film is a quantum dot thin film. Correspondingly, no auxiliary material is added to the mixed solution in step (2), and the prepared solution is a quantum dot material solution with a concentration of 30 mg / ml.

[0173] Thin Film Comparative Example 2

[0174] This thin film comparative example is basically the same as Thin Film Example 19, except that in this comparative example, the thin film is a ZnMgO thin film. Correspondingly, no auxiliary material is added to the mixed solution in step (2), and the prepared solution is a ZnMgO ethanol solution with a concentration of 40 mg / ml.

[0175] Device Example 1

[0176] This device example provides a quantum dot light-emitting diode and its preparation method, which specifically includes the following steps.

[0177] Step 1: After cleaning and drying an ITO substrate (with a thickness of 100 nm), treat it in an ultraviolet ozone cleaner for 15 min. Then spin-coat a chlorobenzene solution of TFB (10 mg / mL) on the ITO substrate at a speed of 2500 rpm, and then heat it at 200 °C for 30 min to obtain a hole transport layer with a thickness of 40 nm.

[0178] Step 2: Prepare a composite film as the light-emitting layer on the hole transport layer according to the method of Film Example 1.

[0179] Step 3: Spin-coat an ethanol solution of ZnO (40 mg / ml) on the light-emitting layer at a rotational speed of 3000 rpm, and then heat it at 100 °C for 15 min to obtain an electron transport layer with a thickness of 25 nm.

[0180] Step 4: Vacuum-evaporate an Ag cathode with a thickness of 100 nm on the electron transport layer; then perform epoxy resin encapsulation to obtain a QLED device, and its device structure is: ITO / TFB / QD + auxiliary material / ZnO / Ag.

[0181] Device Examples 2 to 18

[0182] Device Example n is basically the same as Device Example 1, except that in Device Example n: in Step 2, prepare a composite film as the light-emitting layer on the hole transport layer according to the method of Film Example n, where n is any integer from 2 to 18. Other parameters and steps remain unchanged.

[0183] It can be understood that when n = 10 to 18, the corresponding device structure is: ITO / TFB / auxiliary material / QD / ZnO / Ag, that is, first prepare an auxiliary film layer on the hole transport layer, and then prepare the light-emitting layer.

[0184] Device Examples 19 to 21

[0185] Device Example m provides a quantum dot light-emitting diode and its preparation method, and the corresponding device structure is: ITO / TFB / QD / auxiliary material + ZnO / Ag.

[0186] Specifically, it includes the following steps.

[0187] Step 1: After cleaning and drying an ITO substrate (with a thickness of 100 nm), treat it in an ultraviolet ozone cleaning instrument for 15 min. Then spin-coat a chlorobenzene solution of TFB (10 mg / mL) on the ITO substrate at a rotational speed of 2500 rpm, and then heat it at 200 °C for 30 min to obtain a hole transport layer with a thickness of 40 nm.

[0188] Step 2: Disperse the blue light quantum dot CdSe with oleic acid ligands on its surface in cyclohexane to make a quantum dot solution with a concentration of 30 mg / ml, spin-coat the quantum dot solution on the hole transport layer at a rotational speed of 1500 rpm, and then heat it at 100 °C for 5 min to obtain a light-emitting layer with a thickness of 35 nm.

[0189] Step 3: Prepare a composite film as the electron transport layer (with a thickness of 25 nm) on the light-emitting layer according to the method of Film Embodiment m, where m is any integer from 19 to 21.

[0190] Step 4: Vacuum deposit an Ag cathode with a thickness of 100 nm on the electron transport layer; then perform epoxy resin encapsulation to obtain a QLED device, and its device structure is: ITO / TFB / QD + auxiliary material / ZnO / Ag.

[0191] It can be understood that when m = 20 to 21, the corresponding device structure is: ITO / TFB / QD / ZnO / auxiliary material / Ag, that is, first prepare the electron transport layer on the light-emitting layer, and then prepare the auxiliary film layer.

[0192] Device Comparative Example 1

[0193] This device comparative example is basically the same as Device Embodiment 1, except that in Step 2 of this device comparative example, a quantum dot film is prepared as the light-emitting layer on the hole transport layer according to the method of Film Comparative Example 1. Other parameters and steps remain unchanged.

[0194] Device Comparative Example 2

[0195] This device comparative example is basically the same as Device Embodiment 19, except that in Step 2 of this device comparative example, it is used as the electron transport layer on the light-emitting layer according to the method of Film Comparative Example 2. Other parameters and steps remain unchanged.

[0196] Experimental Example

[0197] Perform external quantum efficiency EQE and service life T95@1000nit tests on the quantum dot light-emitting diodes of the device embodiments and device comparative examples, and the test results are shown in Table 1.

[0198] (1) The test method for the external quantum efficiency EQE is:

[0199] The ratio of the number of electron-hole pairs injected into the quantum dots converted into the number of emitted photons, with the unit of %, is an important parameter to measure the quality of electroluminescent devices, and it can be obtained by measuring with an EQE optical test instrument. The specific calculation formula is as follows:

[0200]

[0201] Among them, ηe is the light 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, K R is the radiation process rate, K NR is the non-radiation process rate.

[0202] Test conditions: Conducted at room temperature, with air humidity of 30 - 60%.

[0203] (2) The test method for the lifetime T95@1000nit is as follows:

[0204] When the device is driven by a constant current or voltage, the time required for the brightness to decrease to a certain proportion of the maximum brightness. The time when the brightness drops to 95% of the maximum brightness is defined as T95, and this lifetime is the measured lifetime. To shorten the test cycle, the device lifetime test is usually carried out at high brightness by accelerating the device aging, and the lifetime at high brightness is obtained by fitting with the extended exponential decay brightness decay fitting formula. For example, the lifetime at 1000nit is denoted as T95@1000nit. The specific calculation formula is as follows:

[0205]

[0206] Among them, T95 L is the lifetime at low brightness, T95 H is the measured lifetime at high brightness, L H is the device accelerated to the maximum brightness, L L is 1000nit, A is the acceleration factor. In this experiment, the value of A is obtained as 1.7 by measuring the lifetimes of several groups of QLED devices at the rated brightness.

[0207] Table 1

[0208]

[0209]

[0210] As can be seen from the above table, compared with the device of Comparative Example 1, the devices prepared in Examples 1 - 18 of the device all have higher EQE and T95@1000nit. Compared with the device of Comparative Example 2, the devices prepared in Examples 19 - 21 of the device all have higher EQE and T95@1000nit, indicating that the composite film prepared by the method of the present application can effectively improve its performance stability, which helps to improve the luminous efficiency and lifetime of the device;

[0211] In addition, compared with Device Embodiment 9, Device Embodiment 16 has significantly higher luminous efficiency and lifespan. This may be because when an auxiliary film layer is provided between the light-emitting layer and the hole-transporting layer, it can also block electrons, preventing electrons from tunneling from the light-emitting layer to the hole-transporting layer, and effectively alleviating the damage to the hole-transporting layer material caused by electron leakage. Compared with Device Embodiment 19, Device Embodiment 20 has significantly higher luminous efficiency and lifespan, indicating that setting an auxiliary film layer between the cathode and the electron-transporting layer helps increase electron injection, improve the defect of few electrons existing in the blue light device, and enhance the interface stability, thus macroscopically manifested as an improvement in EQE and T95@1000nit.

[0212] The technical solutions provided by the embodiments of the present application have been introduced in detail above. Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The descriptions of the above embodiments are only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A composite film, characterized in that, The materials of the composite film include auxiliary materials and inorganic semiconductor particles, and the auxiliary materials include one or more of the compounds having the structure shown in formula (I): Wherein, n1 is selected from any integer from 0 to 5, and n2 is selected from any integer from 0 to 5; M is selected from any one of the Group VIIB metal atoms and Group VIII metal atoms; Each occurrence of X and Y is independently selected from one or more combinations of D, C1-C30 alkyl, C1-C30 alkoxy, C2-C30 alkoxycarbonyl, C2-C30 alkylcarbonyl, C6-C30 aryl, cyano, nitro, mercapto, hydroxyl, carboxyl, amino, halogen groups.

2. The composite film according to claim 1, characterized in that, n1 is 0 or 1; and / or, n2 is 0 or 1; and / or, M is selected from Fe, Co, Ni or Mn; and / or, Each occurrence of X and Y is independently selected from any one of D, C1-C24 carboxyalkyl, carboxyl, C1-C24 hydroxyalkyl, hydroxyl, C1-C24 aminoalkyl, amino, C2-C24 alkylcarbonyl, cyano, nitro, halogen groups.

3. The composite film according to claim 2, characterized in that, Each occurrence of X and Y is independently selected from any one of C1-C4 carboxyalkyl, carboxyl, C1-C3 hydroxyalkyl, hydroxyl, C1-C3 aminoalkyl, amino, C2-C4 alkylcarbonyl, cyano, nitro, halogen groups.

4. The composite film according to any one of claims 1 to 3, characterized in that, The auxiliary materials include one or more of the compounds having the following formula:

5. The composite film according to claim 1, characterized in that, The materials of the composite film are a mixture of the auxiliary materials and the inorganic semiconductor particles; or, The composite film includes a first film layer and a second film layer arranged in a stacked manner, the material of the first film layer includes the inorganic semiconductor particles, and the material of the second film layer includes the auxiliary materials; or, The composite film includes a third film layer and a fourth film layer arranged in a stacked manner, the material of the third film layer is a mixture of the auxiliary materials and the inorganic semiconductor particles, and the material of the fourth film layer includes the auxiliary materials.

6. The composite film according to claim 5, characterized in that, In the mixture of the auxiliary materials and the inorganic semiconductor particles, the mass percentage content of the auxiliary materials is 1% to 50%; and / or, The thickness of the first film layer is 10 to 100 nm; and / or, The thickness of the second film layer is 1 to 10 nm; and / or, The thickness of the third film layer is 10 to 100 nm; and / or, The thickness of the fourth film layer is 1 to 10 nm.

7. The composite film according to claim 1, characterized in that, The inorganic semiconductor particles include quantum dot luminescent materials, and the quantum dot luminescent materials include at least one 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 each 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 compounds are selected from at least one of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe; the IV-VI group compounds are selected from at least one of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe; the III-V group compounds are selected from at least one of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb; the I-III-VI group compounds are selected from at least one of CuInS2, CuInSe2, and AgInS2; the perovskite-type semiconductor material is selected from doped or undoped inorganic perovskite-type semiconductors, or organic-inorganic hybrid perovskite-type semiconductors; the structural general formula of the inorganic perovskite-type 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+ at least one of, X is a halogen anion, selected from Cl - , Br - , I - at least one of; the structural general 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 [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 inorganic semiconductor particles include N-type metal oxides, and the N-type metal oxides include one or more of metal oxides and doped metal oxides; the metal oxides include one or more of ZnO, TiO2, SnO2; the metal oxides in the doped metal oxides include one or more of ZnO, TiO2, SnO2, and the doping elements include one or more of Al, Mg, Li, In, Ga.

8. A method for preparing a composite film, characterized in that, Comprising the following steps: Providing a thin film material, the thin film material including auxiliary materials and inorganic semiconductor particles; Depositing the thin film material to obtain a composite film; Wherein, the auxiliary materials include one or more of the compounds having the structure shown in formula (I): Wherein, n1 is selected from any integer from 0 to 5, and n2 is selected from any integer from 0 to 5; M is selected from any one of metal atoms of Group VIIB and metal atoms of Group VIII; Each occurrence of X and Y is independently selected from one or more combinations of D, C1-C30 alkyl, C1-C30 alkoxy, C2-C30 alkoxycarbonyl, C2-C30 alkylcarbonyl, C6-C30 aryl, cyano, nitro, mercapto, hydroxyl, carboxyl, amino, and halogen groups.

9. The preparation method according to claim 8, characterized in that, The steps of depositing the thin film material to obtain a composite film include: Mixing an auxiliary material and inorganic semiconductor particles to form a first mixture, and depositing the first mixture to obtain a composite film.

10. The preparation method according to claim 8, characterized in that, The steps of depositing the thin film material to obtain a composite film include: Depositing the inorganic semiconductor particles to obtain a first film layer; depositing the auxiliary material on one side of the first film layer to obtain a second film layer, and the first film layer and the second film layer together form a composite film; or, Depositing the auxiliary material to obtain a second film layer; depositing the inorganic semiconductor particles on one side of the second film layer to obtain a first film layer, and the first film layer and the second film layer together form a composite film.

11. The preparation method according to claim 8, characterized in that, The auxiliary material includes a first auxiliary material and a second auxiliary material; The steps of depositing the thin film material to obtain a composite film include: Mixing the first auxiliary material and inorganic semiconductor particles to form a second mixture, depositing the second mixture to obtain a third film layer; depositing the second auxiliary material on one side of the third film layer to obtain a fourth film layer, and the third film layer and the fourth film layer together form a composite film; or, Depositing the second auxiliary material to obtain a fourth film layer; mixing the first auxiliary material and inorganic semiconductor particles to form a second mixture, and depositing the second mixture on one side of the fourth film layer to obtain a third film layer, and the third film layer and the fourth film layer together form a composite film.

12. The preparation method according to claim 8, characterized in that, The auxiliary material includes one or more of the compounds represented by the following formula:

13. A light-emitting device, characterized in that, Comprising an anode, a functional layer, and a cathode, wherein the functional layer includes the composite film according to any one of claims 1 to 7, or includes the composite film prepared by the preparation method according to any one of claims 8 to 12.

14. The light-emitting device according to claim 13, characterized in that, The functional layer includes the light-emitting functional layer. When the light-emitting functional layer includes the first film layer and the second film layer stacked, the first film layer is disposed between the second film layer and the cathode. When the light-emitting functional layer includes the third film layer and the fourth film layer stacked, the third film layer is disposed between the fourth film layer and the cathode; and / or, The functional layer includes an electron functional layer. When the electron functional layer includes the first film layer and the second film layer stacked, the second film layer is disposed between the first film layer and the cathode. When the light-emitting functional layer includes the third film layer and the fourth film layer stacked, the fourth film layer is disposed between the third film layer and the cathode.

15. The light-emitting device according to claim 13 or 14, characterized in that, The anode and the cathode are each independently selected from one of a metal electrode, a carbon electrode, a doped or undoped metal oxide electrode, and a composite electrode; wherein, the material of the metal electrode is selected from at least one of Al, Ag, Cu, Mo, Au, Ba, Ca, Ni, Ir, and Mg; the material of the carbon electrode is selected from at least one of graphite, carbon nanotubes, graphene, and carbon fiber; the material of the doped or undoped metal oxide electrode is selected from at least one of ITO, FTO, ATO, AZO, GZO, IZO, MZO, ITZO, ICO, AMO, SnO2, In2O3, Cd:ZnO, Ga:SnO2; the material of the composite electrode is selected from one of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, and ZnS / Al / ZnS.

16. A display device, characterized in that, Comprising the light-emitting device according to any one of claims 13 to 15.

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