CN118284251A - Film and preparation method thereof, light-emitting device and preparation method thereof, and display device - Google Patents

Abstract

The application discloses a film and a preparation method thereof, a light-emitting device and a preparation method thereof, and a display device. According to the preparation method of the film, the first film layer is prepared from the inorganic particles, the first ligands are connected to the inorganic particles, the first film layer is placed in a first atmosphere containing target ligands, and ultraviolet irradiation treatment is applied to the first film layer to perform ligand exchange, so that in-situ ligand exchange is realized, the condition that the target ligands fall off after connection is reduced, impurity solvents bonded and connected with the inorganic particles can be damaged, the connection between the first ligands and the inorganic particles is damaged, more sites on the surfaces of the inorganic particles are exposed, the exchange and connection of the target ligands are promoted, the specific surface area of ligand exchange is greatly improved, and the ligand exchange efficiency is greatly improved.

Description

Film and preparation method thereof, light-emitting device and preparation method thereof, and display device

Technical Field

The application relates to the technical field of display, in particular to a film and a preparation method thereof, a light-emitting device and a preparation method thereof, and a display device.

Background

At present, there are many methods for preparing inorganic particles with micro-size such as nanometer or micrometer, and the sol-gel method is widely used because of simple process and low cost, but the surface of the inorganic particles prepared by the method has more defects such as oxygen vacancy defects, etc., thereby influencing the performance of the inorganic particles. In order to reduce or even eliminate these defects, ligand exchange is usually performed on the surface of the prepared inorganic particles, so as to modify the surface of the inorganic particles through target ligands, thereby improving the performance of the inorganic particles.

However, how to improve the ligand exchange efficiency and how to promote the target ligand to be connected to the surface of the inorganic particles so as to reduce defects and improve the performance of the inorganic particles becomes a key problem for the application of the inorganic particles.

Disclosure of Invention

In view of the above, the present application provides a thin film and a preparation method thereof, a light emitting device and a preparation method thereof, and a display device, which aim to improve ligand exchange efficiency and improve performance of inorganic particles.

The embodiment of the application is realized in such a way that a preparation method of a film is provided, which comprises the following steps: providing a first film layer, wherein the first film layer comprises inorganic particles, and the inorganic particles are connected with first ligands; placing the first film layer in a first atmosphere for first treatment in a first preset time period, and applying ultraviolet irradiation to the first film layer for second treatment in a second preset time period to obtain a film; wherein the first atmosphere contains a target ligand.

Optionally, in some embodiments of the application, the first atmosphere consists of a gas of the target ligand; and/or the vapor pressure of the target ligand is 1 to 10atm in the first atmosphere; and/or the power of the ultraviolet irradiation treatment is 1-5000 mW; and/or the first preset time period is 5-3600 s; and/or the second preset time period is 5-3600 s; and/or the start time of the second preset time period is earlier than the end time of the first preset time period; and/or the average particle diameter of the inorganic particles is 2-10 nm; and/or the target ligand comprises one or more of halogen ligand, amino ligand, sulfhydryl ligand, carboxyl ligand, pyridine ligand and the like.

Optionally, in some embodiments of the present application, the time when the first preset time period coincides with the second preset time period is a third preset time, where the third preset time is greater than 0s and less than or equal to 3600s; and/or after the second processing is finished, starting the first processing at intervals of fourth time, wherein the fourth time is more than 0 and less than or equal to 60s.

Optionally, in some embodiments of the present application, the inorganic particles include at least one of a metal oxide, a doped metal oxide, a group II-VI semiconductor material, a group III-V semiconductor material, and a group I-III-VI semiconductor material, the metal oxide being selected from at least one of ZnO, baO, tiO ₂、SnO₂; the metal oxide in the doped metal oxide is at least one of ZnO and TiO ₂、SnO₂, the doping element is at least one of Al, mg, li, in, ga, co, mn, and the II-VI semiconductor material is at least one of ZnS, znSe, cdS; The III-V semiconductor material is at least one selected from InP and GaP; the I-III-VI semiconductor material is at least one of CuInS and CuGaS; and/or the inorganic particles comprise one of LiF,LiF/Yb、MgP,MgF₂,Al₂O₃、Ga₂O₃、ZnO、Cs₂CO₃、Rb₂CO₃、RbBr; And/or the inorganic particles comprise at least one of the quantum dots selected from single-structure quantum dots, core-shell structure quantum dots and perovskite-type semiconductor materials, the single-structure quantum dots are selected from at least one of II-VI compounds, IV-VI compounds, III-V compounds and I-III-VI compounds, the II-VI 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 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、SnPbSTe, The III-V compound is at least one selected from GaN、GaP、GaAs、GaSb、AlN、AlP、AlAs、AlSb、InN、InP、InAs、InSb、GaNP、GaNAs、GaNSb、GaPAs、GaPSb、AlNP、AlNAs、AlNSb、AlPAs、AlPSb、InNP、InNAs、InNSb、InPAs、InPSb、GaAlNP、GaAlNAs、GaAlNSb、GaAlPAs、GaAlPSb、GaInNP、GaInNAs、GaInNSb、GaInPAs、GaInPSb、InAlNP、InAlNAs、InAlNSb、InAlPAs and InAlPSb, and the I-III-VI compound is at least one selected from CuInS, cuInSe and AgInS; The core of the quantum dot with the core-shell structure is selected from any one of the quantum dots with the single structure, and the shell material of the quantum dot with the core-shell structure is selected from at least one of CdS, cdTe, cdSeTe, cdZnSe, cdZnS, cdSeS, znSe, znSeS and ZnS; the perovskite type semiconductor material is selected from doped or undoped inorganic perovskite type semiconductor or organic-inorganic hybrid perovskite type semiconductor; The structural general formula of the inorganic perovskite semiconductor is AMX ₃, wherein A is Cs ⁺ ion, M is divalent metal cation, at least one of Pb²⁺、Sn²⁺、Cu²⁺、Ni²⁺、Cd^{2 +}、Cr²⁺、Mn²⁺、Co²⁺、Fe²⁺、Ge²⁺、Yb²⁺、Eu²⁺ and X is halogen anion, at least one of Cl ^-、Br^-、I^-; The structural general formula of the organic-inorganic hybrid perovskite semiconductor is BMX ₃, wherein B is an organic amine cation selected from CH ₃(CH₂)_n-2NH₃ ⁺ or [ NH ₃(CH₂)_nNH₃]²⁺ ], wherein n is more than or equal to 2, M is a divalent metal cation selected from at least one of Pb²⁺、Sn²⁺、Cu²⁺、Ni²⁺、Cd²⁺、Cr²⁺、Mn²⁺、Co²⁺、Fe²⁺、Ge²⁺、Yb²⁺、Eu²⁺, X is halogen anion, which is selected from at least one of Cl ^-、Br^-、I^-; And/or the inorganic particles comprise one or more of doped or undoped NiO、V₂O₅、CrO₃、CuO、CuS、MoO₃、MoS₂、MoSe₂、WO₃、WS₂、WSe₂ and CuSCN; and/or the halogen ligand comprises one or more of fluorine, chlorine, bromine and iodine; and/or the amino ligand comprises one or more of ethylamine, 1-octylamine, 1, 2-propylene diamine, 1, 4-butylene diamine, 9-octadecylene amine, aniline, p-phenylenediamine and o-phenylenediamine; and/or the sulfhydryl ligand comprises one or more of ethanethiol, octanethiol, mercaptoethylamine and 3-mercapto-1-propylamine; and/or the carboxyl ligand comprises one or more of propionic acid, butyric acid, (Z) -9-octadecenoic acid and thioglycollic acid; and/or the pyridine ligand comprises one or more of pyridine and picoline.

Optionally, in some embodiments of the present application, the providing a first film layer includes: providing inorganic particles and a first solvent, and mixing to obtain an inorganic particle solution; providing a substrate, and arranging the inorganic particle solution on the substrate to form the first film layer.

Optionally, in some embodiments of the present application, after the disposing the inorganic particle solution on the substrate, the method further includes: drying to form a solid first film layer; wherein the pressure of the vacuum drying is 0.001-10 Pa; and/or the temperature of the heating and drying is 40-140 ℃.

Optionally, in some embodiments of the application, the first solvent comprises one or more of an alcohol solvent; and/or the concentration of the inorganic particle solution is 1-120 mg/mL.

Correspondingly, the embodiment of the application also provides a film, which is prepared by the preparation method of the film.

Correspondingly, the embodiment of the application also provides a light-emitting device, wherein the first electrode and the second electrode are oppositely arranged; a functional layer disposed between the first electrode and the second electrode; the functional layer is prepared by the preparation method of the film or comprises the film.

Optionally, in some embodiments of the present application, the functional layer includes a light-emitting layer, where the light-emitting layer is a film prepared by the method for preparing a film or is a film as described above; and/or the functional layer comprises an electronic functional layer, wherein the electronic functional layer comprises an electronic transmission layer and/or an electronic injection layer, and the electronic transmission layer and/or the electronic injection layer are films prepared by the preparation method of the films or the films; and/or the functional layer comprises a hole functional layer comprising a hole injection layer and/or a hole transport layer; wherein the hole injection layer and/or the hole transport layer is a film prepared by the preparation method of the film, or is the film; and/or the first electrode and the second electrode are independently selected from 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 at least one selected from Al, ag, cu, mo, au, ba, ca and Mg; the material of the carbon electrode is at least one selected from graphite, carbon nano tube, graphene and carbon fiber; the material of the doped or undoped metal oxide electrode is at least one selected from ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO; the material of the composite electrode is at least one 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 and ZnS/Al/ZnS.

Correspondingly, the embodiment of the application also provides a preparation method of the light-emitting device, which comprises the following steps:

Providing a prefabricated device, the prefabricated device comprising a first electrode;

forming a functional layer on the prefabricated device, wherein the functional layer is prepared by the preparation method of the film; and

And forming a second electrode on the functional layer to obtain the light-emitting device.

Optionally, in some embodiments of the present application, the functional layer includes an electronic functional layer, wherein the electronic functional layer includes an electron transport layer and/or an electron injection layer; and/or

The functional layer comprises a hole functional layer, and the hole functional layer comprises a hole injection layer and/or a hole transport layer; and/or

The functional layer includes a light emitting layer.

Correspondingly, the embodiment of the application also provides a display device which comprises the light-emitting device.

According to the preparation method of the film, the first film layer is prepared from the inorganic particles, the first ligands are connected to the inorganic particles, the first film layer is placed in a first atmosphere containing target ligands, and ultraviolet irradiation treatment is applied to the first film layer to perform ligand exchange, so that in-situ ligand exchange is realized, the condition that the target ligands fall off after connection is reduced, impurity solvents bonded and connected with the inorganic particles can be damaged, the connection between the first ligands and the inorganic particles is damaged, more sites on the surfaces of the inorganic particles are exposed, the exchange and connection of the target ligands are promoted, the specific surface area of ligand exchange is greatly improved, and the ligand exchange efficiency is greatly improved. And simultaneously, the residues of the impurity solvents in the film are reduced, and the negative influence of the impurity solvents and the like on the performance of the film is reduced, so that the performance of the film is improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic flow chart of an embodiment of a method for preparing a thin film according to the present application;

fig. 2 is a schematic structural diagram of a light emitting device according to an embodiment of the present application.

Reference numerals:

A light emitting device 100; a first electrode 10; a second electrode 20; a functional layer 30; a light emitting layer 31; an electronic functional layer 32; a hole function layer 33.

Detailed Description

The following description of the embodiments of the present application will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present application, but not all embodiments. All other embodiments, which can be made by a person skilled in the art without making any inventive effort, are intended to be within the scope of the present application based on the embodiments of the present application. Furthermore, it should be understood that the detailed description is presented herein for purposes of illustration and description only, and is not intended to limit the application. In the present application, unless otherwise specified, terms such as "upper" and "lower" are used specifically to refer to the orientation of the drawing in the figures. In addition, in the description of the present application, the term "comprising" means "including but not limited to". Various embodiments of the application may exist in a range of forms; it should be understood that the description in a range format is merely for convenience and brevity and should not be construed as a rigid limitation on the scope of the application; it is therefore to be understood that the range description has specifically disclosed all possible sub-ranges and individual values within that range. For example, it should be considered that a description of a range 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., as well as single numbers within the range, such as 1,2, 3, 4, 5, and 6, wherever applicable. In addition, whenever a numerical range is referred to herein, it is meant to include any reference number (fractional or integer) within the indicated range.

In the present application, "and/or" describing the association relationship of the association object means that there may be three relationships, for example, a and/or B may mean: a alone, a and B together, and B alone. Wherein A, B may be singular or plural.

In the present application, "at least one" means one or more, and "a plurality" means two or more. "at least one", "at least one" or the like refer to any combination of these items, including any combination of single item(s) or plural items(s). For example, "at least one (individual) of a, b, or c," or "at least one (individual) of a, b, and c," may each represent: a, b, c, a-b (i.e., a and b), a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple, respectively.

Referring to fig. 1, fig. 1 is a schematic flow chart of an embodiment of a method for preparing a thin film according to the present application, where the method includes the following steps:

Step S11: providing a first film layer, wherein the first film layer comprises inorganic particles, and the inorganic particles are connected with first ligands;

Step S12: placing the first film layer in a first atmosphere for first treatment in a first preset time period, and applying ultraviolet irradiation to the first film layer for second treatment in a second preset time period to obtain the film; wherein the first atmosphere contains a target ligand.

In this embodiment, the first film layer is made of inorganic particles, the inorganic particles are connected with first ligands, and the first film layer is placed in a first atmosphere containing target ligands and subjected to ultraviolet irradiation treatment to perform ligand exchange, so that in-situ ligand exchange is realized, the situation that the target ligands fall off after connection is reduced, impurity solvents bonded and connected with the inorganic particles can be damaged, the connection of the first ligands and the inorganic particles is damaged, more sites on the surfaces of the inorganic particles are exposed, the exchange and connection of the target ligands are promoted, the specific surface area of ligand exchange is greatly improved, and the ligand exchange efficiency is greatly improved. And simultaneously, the residues of the impurity solvents in the film are reduced, and the negative influence of the impurity solvents and the like on the performance of the film is reduced, so that the performance of the film is improved.

In addition, in the first atmosphere, the gas of the target ligand can infiltrate inwards from the surface of the first film layer through gaps among the inorganic particles, so that the contact area of the target ligand and the first film layer is increased, the contact area of ligand exchange is increased, and the ligand exchange effect is improved.

In the step S11:

In an embodiment, the first ligand is an initial ligand on the surface of the inorganic particle, and may be introduced during preparation of the inorganic particle, and the first ligand is attached to the surface of the prepared inorganic particle.

In an embodiment, the first ligand may be one or more of a hydroxyl ligand, a carboxylic acid ligand, a halogen ligand, and the like. Wherein the carboxylic acid ligand may be acetate or the like. The halogen ligand is selected from one or more of fluorine, chlorine, bromine and iodine.

It will be appreciated that the first ligand may be a single ligand or may be a mixed ligand comprising two or more ligands.

In one embodiment, the inorganic particles have an average particle size of 2 to 10nm. Specifically, the average particle diameter of the inorganic particles may be 2～7nm、2～6nm、2～5nm、2～4nm、2～3nm、3～8nm、3～7nm、3～6nm、3～5nm、3～4nm、4～8nm、4～7nm、4～6nm、4～5nm、5～8nm、5～7nm、5～6nm、6～8nm、6～7nm、7～8nm、8～9nm、9～10nm or the like.

In one embodiment, the thickness of the first film layer is 10-60 nm, specifically 10-50 nm, 20-40 nm, 30-40 nm, 10-20 nm, 50-60 nm, etc. In an embodiment, the thickness of the first film layer may be the same as the thickness of the film finally obtained. I.e. during the ligand exchange treatment by placing the first membrane layer in the first atmosphere, no increase or decrease in the thickness of the first membrane layer may result.

In an embodiment, the inorganic particles may include at least one of a metal oxide, a doped metal oxide, a group II-VI semiconductor material, a group III-V semiconductor material, and a group I-III-VI semiconductor material, the metal oxide being selected from at least one of ZnO, baO, tiO ₂、SnO₂; the metal oxide in the doped metal oxide is at least one of ZnO and TiO ₂、SnO₂, the doping element is at least one of Al, mg, li, in, ga, co, mn, and the II-VI semiconductor material is at least one of ZnS, znSe, cdS; the III-V semiconductor material is at least one selected from InP and GaP; the I-III-VI semiconductor material is at least one selected from CuInS and CuGaS. In this embodiment, the obtained thin film has good electron transport properties.

In one embodiment, the inorganic particles may include one of LiF,LiF/Yb、MgP,MgF₂,Al₂O₃、Ga₂O₃、ZnO、Cs₂CO₃、Rb₂CO₃、RbBr, and the thin film has superior electron injection properties.

In one embodiment, the inorganic particles may be quantum dots, including at least one of the quantum dots selected from the group consisting of single-structure quantum dots selected from at least one of group II-VI compounds, group IV-VI compounds, group III-V compounds, and group I-III-VI compounds, the group II-VI compounds 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 group IV-VI compounds selected from at least one of SnS、SnSe、SnTe、PbS、PbSe、PbTe、SnSeS、SnSeTe、SnSTe、PbSeS、PbSeTe、PbSTe、SnPbS、SnPbSe、SnPbTe、SnPbSSe、SnPbSeTe、SnPbSTe, The III-V compound is at least one selected from GaN、GaP、GaAs、GaSb、AlN、AlP、AlAs、AlSb、InN、InP、InAs、InSb、GaNP、GaNAs、GaNSb、GaPAs、GaPSb、AlNP、AlNAs、AlNSb、AlPAs、AlPSb、InNP、InNAs、InNSb、InPAs、InPSb、GaAlNP、GaAlNAs、GaAlNSb、GaAlPAs、GaAlPSb、GaInNP、GaInNAs、GaInNSb、GaInPAs、GaInPSb、InAlNP、InAlNAs、InAlNSb、InAlPAs and InAlPSb, and the I-III-VI compound is at least one selected from CuInS, cuInSe and AgInS; The core of the quantum dot with the core-shell structure is selected from any one of the quantum dots with the single structure, and the shell material of the quantum dot with the core-shell structure is selected from at least one of CdS, cdTe, cdSeTe, cdZnSe, cdZnS, cdSeS, znSe, znSeS and ZnS; the perovskite type semiconductor material is selected from doped or undoped inorganic perovskite type semiconductor or organic-inorganic hybrid perovskite type semiconductor; The structural general formula of the inorganic perovskite semiconductor is AMX ₃, wherein A is Cs ⁺ ion, M is divalent metal cation, at least one of Pb²⁺、Sn²⁺、Cu²⁺、Ni²⁺、Cd²⁺、Cr²⁺、Mn²⁺、Co²⁺、Fe²⁺、Ge²⁺、Yb²⁺、Eu²⁺ and X is halogen anion, at least one of Cl ^-、Br^-、I^-; The structural general formula of the organic-inorganic hybrid perovskite semiconductor is BMX ₃, wherein B is an organic amine cation selected from CH ₃(CH₂)_n-2NH₃ ⁺ or [ NH ₃(CH₂)_nNH₃]²⁺ ], wherein n is more than or equal to 2, M is a divalent metal cation selected from at least one of Pb²⁺、Sn²⁺、Cu²⁺、Ni²⁺、Cd²⁺、Cr²⁺、Mn²⁺、Co²⁺、Fe²⁺、Ge²⁺、Yb²⁺、Eu²⁺, x is halogen anion and is selected from at least one of Cl ^-、Br^-、I^-. In this embodiment, the film has good light-emitting performance.

In an embodiment, the inorganic particles may include one or more of doped or undoped NiO、V₂O₅、CrO₃、CuO、CuS、MoO₃、MoS₂、MoSe₂、WO₃、WS₂、WSe₂ and CuSCN. In this embodiment, the thin film has good hole injection and transport properties.

It can be understood that the types of the inorganic particles are different, the first ligands attached to the surfaces of the inorganic particles are also different, and the target ligands in step S12 may be set correspondingly according to the types of the inorganic particles and the performance requirements of the thin film.

In the step S12:

The ultraviolet light used in the ultraviolet light irradiation treatment, wherein the wavelength of the ultraviolet light is less than or equal to 400nm, and specifically, the wavelength can be 10-400 nm.

In an embodiment, the power of the ultraviolet irradiation treatment may be 1 to 5000mW, i.e. 1 to 5W, specifically 1 to 100mW, 100 to 500mW, 500 to 1000mW, 1000 to 2000mW, 2000 to 3000mW, 3000 to 4000mW, 4000 to 5000mW, etc. The ultraviolet irradiation treatment of the power can destroy the impurity solvent bonded and connected with the inorganic particles, and expose more sites on the surfaces of the inorganic particles, so that the exchange and connection of the target ligand are promoted, the specific surface area of ligand exchange is greatly improved, and the ligand exchange efficiency is greatly improved.

The first atmosphere comprises a target ligand, i.e. the first atmosphere comprises the target ligand in a gaseous state.

In an embodiment, the first atmosphere consists of the target ligand in a gaseous state. In other embodiments, the first atmosphere may include other gases such as nitrogen, helium, argon, and the like, in addition to the target ligand.

In one embodiment, the target ligand may be selected from one or more of halogen ligands, amine ligands, mercapto ligands, carboxyl ligands, pyridine ligands, and the like. The target ligand can be coordinately connected with the inorganic particles so as to modify the surfaces of the inorganic particles and reduce surface defects.

In particular, the halogen ligand may include one or more of fluorine, chlorine, bromine, iodine. The amine-based ligand may include one or more of ethylamine (1-aminoethane), 1-octylamine (1-aminooctane), 1, 2-propylenediamine, 1, 4-butylenediamine, 9-octadecylenamine, aniline, p-phenylenediamine (1, 4-phenylenediamine), and o-phenylenediamine (1, 2-phenylenediamine). The sulfhydryl ligand can comprise one or more of ethanethiol, octanethiol, mercaptoethylamine and 3-mercapto-1-propylamine. The carboxyl ligand can comprise one or more of propionic acid, butyric acid, (Z) -9-octadecenoic acid and thioglycollic acid. The pyridine ligand comprises one or more of pyridine, picoline and the like.

In one embodiment, the vapor pressure of the target ligand in the first atmosphere is 1 to 10atm, and may specifically be 2 to 10atm, 2 to 9atm, 3 to 8atm, 3 to 7atm, 4 to 6atm, 5 to 6atm, etc. The target ligand with vapor pressure carries out ligand exchange treatment on the first film layer, so that more molecules of the target ligand can enter a shallow surface layer of the first film layer, the specific surface area of the target ligand in contact with inorganic particles is improved, the exchange efficiency is improved, the first film layer is prevented from being damaged, the requirement on equipment for providing the first atmosphere is reduced, and the cost improvement caused by the improvement of the compressive capacity of the equipment is reduced.

In an embodiment, the first preset time period may be 5 to 3600s, that is, 5s to 60min. Specifically, the first preset time period may be 5～60s、1～5min、5～50min、10～50min、10～40min、20～40min、20～30min、5～10min、10～20min、20～30min、30～40min、40～50min、50～60min or the like.

In an embodiment, the second preset time period may be 5 to 3600s, that is, 5s to 60min. Specifically, the second preset time period may be 5～60s、1～5min、5～50min、10～50min、10～40min、20～40min、20～30min、5～10min、10～20min、20～30min、30～40min、40～50min、50～60min or the like.

In an embodiment, the start time of the second preset time period is earlier than the end time of the first preset time period, that is, the start time of the ultraviolet irradiation treatment is earlier than the end time of the atmosphere treatment.

In this embodiment, before the atmosphere treatment is finished, the ultraviolet irradiation treatment is started, so that the impurity solvent bonded and connected with the inorganic particles and the connection between the first ligand and the inorganic particles can be damaged, and more sites on the surface of the inorganic particles are exposed, thereby promoting the exchange and connection of the target ligand, greatly improving the specific surface area of ligand exchange, and greatly improving the ligand exchange efficiency. And simultaneously, the residues of the impurity solvents in the film are reduced, and the negative influence of the impurity solvents and the like on the performance of the film is reduced, so that the performance of the film is improved.

In one embodiment, the ultraviolet irradiation treatment is performed first, and after the ultraviolet irradiation treatment is finished, the atmosphere treatment is started to perform ligand exchange. I.e. the ending time of the second preset time period is earlier than or equal to the starting time of the first preset time period. Specifically, the interval time between the ultraviolet irradiation treatment and the atmosphere treatment is greater than 0 and less than or equal to 60s, and specifically may be: more than 0 and less than 5s, 5-10 s, 10-20 s, 20-30 s, 30-40 s, 40-50 s, 50-60 s, etc.

In this embodiment, the impurity solvent bonded and connected to the inorganic particles is destroyed by the ultraviolet irradiation treatment, and the connection between the first ligand and the inorganic particles is destroyed, so that more sites on the surface of the inorganic particles are exposed, and then the first atmosphere containing the target ligand is subjected to atmosphere treatment, so as to promote the exchange and connection of the target ligand, greatly improve the specific surface area of ligand exchange, and greatly improve the ligand exchange efficiency.

In another specific embodiment, the first preset time period at least partially coincides with the second preset time period. In this embodiment, the start time and the end time of the atmosphere treatment and the ultraviolet irradiation treatment may not be limited, that is, the atmosphere treatment may be started first, the ultraviolet irradiation treatment may be started first, the atmosphere treatment may be ended first, or the ultraviolet irradiation treatment may be ended first, it is only necessary to satisfy at least partial time overlapping of the two treatments, and in the overlapping time period, the two treatments further promote a substantial improvement of the ligand exchange efficiency under the dual function of the two treatments.

Further, in an embodiment, the time when the first preset time period coincides with the second preset time period is a third preset time, where the third preset time is greater than 0s and less than or equal to 3600s, and in at least some embodiments, the third preset time is 5 to 3600s, that is, 5s to 60min. Specifically, the third preset time may be 5～60s、1～5min、5～50min、10～50min、10～40min、20～40min、20～30min、5～10min、10～20min、20～30min、30～40min、40～50min、50～60min or the like. It will be appreciated that the time for the dual action of placing the first film layer in the first atmosphere for the atmosphere treatment and applying the ultraviolet irradiation treatment to the first film layer is 5s to 60min. In this embodiment, the first preset time period and the second preset time period may not be limited, or the first time period during which the first film layer is placed in the first atmosphere and the second time period during which the first film layer is placed in the second atmosphere and the third time period may be equal to or greater than the third time period, but the overlapping time is required to be within a range of 5-60 min, so that the great improvement of the ligand exchange efficiency is further promoted.

In one embodiment, before the first film layer is placed in the first atmosphere for ligand exchange treatment, the method further includes: a first atmosphere is provided. In particular, the providing of the first atmosphere may be achieved by a sealable container.

In a specific embodiment, the target ligand is in a gaseous state at normal temperature and pressure, for example, 1-aminoethane, at this time, the gas of the target ligand may be introduced into a closed container to obtain a required vapor pressure, and in another embodiment, the target ligand is in a liquid state or a solid state at normal temperature and pressure, for example, pyridine, 1, 2-propane diamine, etc., the target ligand may be placed in the closed container first, then an environment with a certain temperature and/or pressure is provided in the closed container, the transition of the target ligand from the liquid phase to the gas phase is promoted, and the gas exchange is performed in the closed container, so as to remove the original impurity gas in the closed container, thereby obtaining the first atmosphere of the target ligand, and obtaining the vapor pressure of the target.

In an embodiment, the providing a first film layer in step S11 includes:

step S111: providing inorganic particles and a first solvent, and mixing to obtain an inorganic particle solution;

step S112: providing a substrate, and arranging the inorganic particle solution on the substrate to form the first film layer.

In an embodiment, the first solvent includes an alcohol solvent, which may be one or more of ethanol, butanol, triethylene glycol, tetraethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, 3-methoxybutanol, etc.

The inorganic particle solution may be a dispersion of the inorganic particles or a colloidal solution of the inorganic particles. The concentration of the inorganic particle solution may be 1 to 120mg/mL, specifically 1～100mg/mL、5～100mg/mL、5～80mg/mL、10～80mg/mL、10～70mg/mL、20～70mg/mL、20～60mg/mL、30～60mg/mL、30～50mg/mL、40～50mg/mL or the like. This concentration can uniformly disperse the zinc oxide particles and can uniformly spread out on the substrate.

In an embodiment, the first film layer may be a liquid film, that is, the first film layer is a liquid film formed by the inorganic particle solution, and the ligand exchange treatment in step S12 is performed in a liquid film state.

In another embodiment, the first film layer may be a solid film, that is, after the inorganic particle solution is disposed on the substrate to form a liquid film, the solid, main material formed after the solvent is removed is the first film layer of the inorganic particles through a drying process, with respect to the liquid film or the liquid film.

The drying treatment may be vacuum drying or heat drying, so as to remove the first solvent in the inorganic particle solution as much as possible. Specifically, the vacuum drying pressure can be 0.01-10 Pa, and the time is 5-30 min. Specifically, the vacuum drying pressure may be 0.01 to 0.1Pa, 0.1 to 1Pa, 1 to 5Pa, 5 to 10Pa, etc., and the time may be 5 to 10 minutes, 10 to 20 minutes, 20 to 30 minutes, etc. The heating and drying temperature can be 40-140 ℃ and the time is 5-60 min. Specifically, the temperature of the heating and drying may be 40 to 12 ℃,60 to 120 ℃,60 to 100 ℃, 80 to 100 ℃, etc., and the time may be 5 to 10min, 10 to 20min, 20 to 30min, 30 to 40min, 40 to 50min, 50 to 60min, etc.

In an embodiment, in step S112, the disposing the inorganic particle solution on the substrate may be specifically disposed by a solution method. The solution method may be spin coating, printing, inkjet printing, knife coating, printing, dip-coating, dipping, spraying, roll coating, casting, slit coating, bar coating, or the like.

The application provides a film, which is prepared by the preparation method of the film. The film includes inorganic particles having the target ligand attached thereto.

The film prepared by the preparation method of the film provided by the application has higher ligand exchange rate, namely, more target ligands are connected to the inorganic particles, so that the surface defects of the inorganic particles are greatly reduced, and the performances of the film, such as electron transmission efficiency, hole transmission efficiency, luminous efficiency and the like, are improved. That is, the thin film may have electron transporting property, hole transporting property, or light emitting property.

Further, the inorganic particles are connected with the first ligand in addition to the target ligand. It can be understood that the ligand exchange treatment provided by the application can improve the ligand exchange efficiency, improve the number of the target ligands connected to the surfaces of the inorganic particles and reduce the surface defects of the inorganic particles. However, the ligand exchange is not entirely performed but there is an equilibrium, and thus, the movement of the equilibrium toward the attachment of the target ligand to the inorganic particle may be promoted by the ligand exchange treatment placed in the first atmosphere, but the surface of the inorganic particle after the ligand exchange treatment may still have a part of the first ligand attached thereto.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a light emitting device according to an embodiment of the application. The present application also provides a light emitting device 100 including a first electrode 10, a second electrode 20, and a functional layer 30, wherein the first electrode 10 and the second electrode 20 are disposed opposite to each other, and the functional layer 30 is disposed between the first electrode 10 and the second electrode 20. Wherein the functional layer 30 includes the above-mentioned thin film or a thin film prepared by the preparation method of the above-mentioned thin film.

In this embodiment, the functional layer 30 includes the thin film provided by the present application or includes the thin film prepared by the method for preparing a thin film provided by the present application, which greatly reduces the defects of inorganic particles in the thin film, and improves the performance of the functional layer 30 including the thin film, thereby improving the performance such as the light emitting performance and the lifetime of the light emitting device 100 including the functional layer 30. Such as current density, external quantum efficiency EQE, etc., and lifetime, etc.

It is understood that when the functional layer 30 has a single-layer structure, the functional layer 30 may be the above-described film or include a film prepared by the above-described film preparation method. When the functional layer 30 includes two or more film layers, one or more of the functional layers 30 may be the above film or may include a film prepared by the above film preparation method.

In an embodiment, the functional layer 30 may include one or more of a light emitting layer 31, an electron functional layer 32, and a hole functional layer 33. That is, the thin film prepared by the method for preparing a thin film provided by the present application may be one or more of the light-emitting layer 31, the electron functional layer 32, and the hole functional layer 33.

Wherein the first electrode 10 and the second electrode 20 are a pair of electrodes, the first electrode 10 is an anode, and the second electrode 20 is a cathode; the first electrode 10 is a cathode, and the second electrode 20 is an anode.

In a specific embodiment, the functional layer 30 includes an electron functional layer 32, and the electron functional layer 32 includes an electron transport layer and/or an electron injection layer, and the electron injection layer is disposed near the cathode. The electron transport layer and/or the electron injection layer may be the above film or include a film prepared by the above film preparation method.

In a specific embodiment, the functional layer 30 includes a hole functional layer 33, and the hole functional layer 33 is disposed between the anode and the light emitting layer 31. The hole function layer 33 may include a hole injection layer and/or a hole transport layer. When the hole function layer 33 includes two layers of a hole injection layer and a hole transport layer, the hole injection layer is disposed near the anode side, and the hole transport layer is disposed near the light emitting layer 31 side. The hole injection layer and/or the hole transport layer can be the film or a film prepared by the preparation method of the film.

The material of the hole transport layer may include poly (9, 9-dioctylfluorene-CO-N- (4-butylphenyl) diphenylamine) (TFB), polyvinylcarbazole (PVK), poly (N, N '-bis (4-butylphenyl) -N, N' -bis (phenyl) benzidine) (poly-TPD), poly (9, 9-dioctylfluorene-CO-bis-N, N-phenyl-1, 4-Phenylenediamine) (PFB), 4',4 "-tris (carbazole-9-yl) triphenylamine (TCATA), 4' -bis (9-Carbazole) Biphenyl (CBP), N '-diphenyl-N, N' -bis (3-methylphenyl) -1,1 '-biphenyl-4, 4' -diamine (TPD), N '-diphenyl-N, N' - (1-naphtyl) -1,1 '-biphenyl-4, 4' -diamine (NPB), poly (3, 4-ethylenedioxythiophene) -poly (styrenesulfonic acid) (PEDOT: PSS), spiro-NPB, spiro-TPD, doped or undoped NiO, moO ₃、WO₃、V₂O₅, P-gallium nitride, crO ₃、CuO、MoS₂、MoSe₂、WS₃、WSe₃, cuS, cuSCN.

The hole injection layer is made of a material with hole injection capability and can comprise one or more of poly (3, 4-ethylenedioxythiophene) -polystyrene sulfonic acid (PEDOT: PSS), 2,3,5, 6-tetrafluoro-7, 7', 8' -tetracyanoquinone-dimethane (F4-TCNQ), 2,3,6,7,10, 11-hexacyano-1, 4,5,8,9, 12-Hexaazabenzophenanthrene (HATCN), copper phthalocyanine (CuPc), transition metal oxide and transition metal chalcogenide; wherein the transition metal oxide comprises one or more of NiO, moO ₂、WO₃ and CuO; the metal chalcogenide comprises one or more of MoS ₂、MoSe₂、WS₃、WSe₃ and CuS.

In an embodiment, the material of the light emitting layer 31 may be selected from one or more of organic light emitting materials or quantum dots; the organic luminescent material is at least one selected from a biaryl anthracene derivative, a stilbene aromatic derivative, a pyrene derivative or a fluorene derivative, a TBPe luminescent material emitting blue light, a TTPA luminescent material emitting green light, a TBRb luminescent material emitting orange light and a DBP luminescent material emitting red light; the quantum dot is selected from at least one of single-structure quantum dot, core-shell structure quantum dot and perovskite type semiconductor material, the single-structure quantum dot is selected from at least one of II-VI compound, IV-VI compound, III-V compound and I-III-VI compound, the II-VI compound is 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 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、SnPbSTe, The III-V compound is at least one selected from GaN、GaP、GaAs、GaSb、AlN、AlP、AlAs、AlSb、InN、InP、InAs、InSb、GaNP、GaNAs、GaNSb、GaPAs、GaPSb、AlNP、AlNAs、AlNSb、AlPAs、AlPSb、InNP、InNAs、InNSb、InPAs、InPSb、GaAlNP、GaAlNAs、GaAlNSb、GaAlPAs、GaAlPSb、GaInNP、GaInNAs、GaInNSb、GaInPAs、GaInPSb、InAlNP、InAlNAs、InAlNSb、InAlPAs and InAlPSb, and the I-III-VI compound is at least one selected from CuInS, cuInSe and AgInS; The core of the quantum dot with the core-shell structure is selected from any one of the quantum dots with the single structure, and the shell material of the quantum dot with the core-shell structure is selected from at least one of CdS, cdTe, cdSeTe, cdZnSe, cdZnS, cdSeS, znSe, znSeS and ZnS; the perovskite type semiconductor material is selected from doped or undoped inorganic perovskite type semiconductor or organic-inorganic hybrid perovskite type semiconductor; The structural general formula of the inorganic perovskite semiconductor is AMX ₃, wherein A is Cs ⁺ ion, M is divalent metal cation, at least one of Pb²⁺、Sn²⁺、Cu²⁺、Ni²⁺、Cd²⁺、Cr²⁺、Mn²⁺、Co²⁺、Fe²⁺、Ge²⁺、Yb²⁺、Eu²⁺ and X is halogen anion, at least one of Cl ^-、Br^-、I^-; The structural general formula of the organic-inorganic hybrid perovskite semiconductor is BMX ₃, wherein B is an organic amine cation selected from CH ₃(CH₂)_n-2NH₃ ⁺ or [ NH ₃(CH₂)_nNH₃]²⁺ ], wherein n is more than or equal to 2, M is a divalent metal cation selected from at least one of Pb²⁺、Sn²⁺、Cu²⁺、Ni²⁺、Cd²⁺、Cr²⁺、Mn²⁺、Co²⁺、Fe²⁺、Ge²⁺、Yb²⁺、Eu²⁺, x is halogen anion and is selected from at least one of Cl ^-、Br^-、I^-.

It is understood that when the material of the light emitting layer 31 is an organic light emitting material, the light emitting device 100 is an organic electroluminescent device. When the material of the light emitting layer 31 is a quantum dot light emitting material, the light emitting device 100 is a quantum dot electroluminescent device.

It can be understood that, when one or more of the light emitting layer 31, the electron functional layer 32, and the hole functional layer 33 is the above film or a film prepared by the above film preparation method, the material of the film is selected from inorganic particulate materials.

In one embodiment, the first electrode 10 and the second electrode 20 are independently selected from 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 at least one selected from Al, ag, cu, mo, au, ba, ca and Mg; the material of the carbon electrode is at least one selected from graphite, carbon nano tube, graphene and carbon fiber; the material of the doped or undoped metal oxide electrode is at least one selected from ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO; the material of the composite electrode is at least one 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 and ZnS/Al/ZnS. Wherein "/" represents a laminated structure, for example, the composite electrode AZO/Ag/AZO represents an electrode of a composite structure in which AZO layers, ag layers, and AZO layers are laminated in three layers.

It will be appreciated that, in addition to the above functional layers, functional layers that are conventionally used in light emitting devices and help to improve the performance of the light emitting device, such as an electron blocking layer, an electron injection layer, a hole blocking layer, and/or an interface modification layer, may be added to the light emitting device 100.

It will be appreciated that the materials and thicknesses of the layers of the light emitting device 100 may be set and adjusted accordingly to the light emitting requirements of the light emitting device 100.

The light emitting device 100 further includes a substrate (not shown). The substrate may be a rigid substrate or a flexible substrate. The rigid substrate can be ceramic material or various glass materials and the like. The flexible substrate may be a substrate formed of a material such as a polyimide film (PI) and its derivatives, polyethylene naphthalate (PEN), phosphoenolpyruvic acid (PEP), or diphenylene ether resin.

It is understood that the light emitting device 100 may be a front-up light emitting device or an inverted light emitting device. When the light emitting device 100 is a front light emitting device, the substrate is bonded to a side of the anode remote from the light emitting layer 31. When the light emitting device 100 is an inverted light emitting device, the substrate is bonded to a side of the cathode remote from the light emitting layer 31.

It will be appreciated that, in addition to the above functional layers, functional layers that are conventionally used in light emitting devices and help to improve the performance of the light emitting device, such as an electron blocking layer, an electron injection layer, a hole blocking layer, and/or an interface modification layer, may be added to the light emitting device 100.

It will be appreciated that the materials and thicknesses of the layers of the light emitting device 100 may be set and adjusted accordingly to the light emitting requirements of the light emitting device 100.

The application also provides a preparation method of the light-emitting device. In one embodiment, a method of manufacturing a light emitting device includes the steps of:

step S31: providing a prefabricated device, the prefabricated device comprising a first electrode;

Step S32: forming a functional layer on the prefabricated device;

Step S33: a second electrode is formed on the functional layer.

Wherein the functional layer may include one or more of a light emitting layer, an electron functional layer, and a hole functional layer. The functional layer comprises a film prepared by the preparation method of the film provided by the application, or the film provided by the application. Namely, one or more film layers of the light-emitting layer, the electron functional layer and the hole functional layer can be prepared by the preparation method of the film provided by the application.

In one embodiment, the first electrode is a cathode and the second electrode is an anode. The light emitting device prepared in this embodiment is an inverted light emitting device.

Further, in an embodiment, the functional layer includes an electronic functional layer, and the electronic functional layer is prepared by the preparation method of the thin film provided by the application. Specifically, the step of forming the electronically functional layer on the cathode includes: forming a first film layer on the cathode, wherein the inorganic particles are connected with a first ligand; then placing the first film layer in a first atmosphere for atmosphere treatment, and applying ultraviolet irradiation treatment to the first film layer to obtain a film; and in the first atmosphere containing the target ligand, gas molecules of the target ligand permeate from the surface of the first film layer far away from the cathode to the surface close to the cathode side to exchange the ligand.

In this embodiment, the inorganic particles near the anode in the electronic functional layer are connected with more target ligands, and the inorganic particles near the cathode are connected with relatively less target ligands, so as to provide a certain promoting or slowing effect for the carriers and a certain guiding effect for the electron transmission direction.

In another embodiment, the first electrode is an anode and the second electrode is a cathode. The front-end light emitting device prepared in this example.

Further, in an embodiment, the functional layer includes an electronic functional layer, and the electronic functional layer is prepared by the preparation method of the thin film provided by the application. Specifically, the step of forming the electronic functional layer on the anode includes: a first film layer is formed on the anode, and a first ligand is connected to the inorganic particles; then placing the first film layer in a first atmosphere for atmosphere treatment, and applying ultraviolet irradiation treatment to the first film layer to obtain a film; and in the first atmosphere containing the target ligand, gas molecules of the target ligand permeate from the surface of the first film layer far away from the anode to the surface close to one side of the anode to exchange the ligand.

In this embodiment, the inorganic particles near the cathode in the electronic functional layer are connected with more target ligands, and the inorganic particles near the anode are connected with relatively less target ligands, so as to provide a certain promoting or slowing effect for the carriers and a certain guiding effect for the electron transmission direction.

It is understood that the method for manufacturing the light emitting device may further include a packaging step, and the packaging material used for packaging may be at least one selected from UV paste, metal film, glass paste, and the like. In a specific embodiment, the encapsulation material may be an acrylic resin or an epoxy resin. The packaging can be machine packaging or manual packaging, ultraviolet curing glue sealing can be adopted, and the concentration of oxygen and water in the environment where the packaging step is carried out is lower than 0.1ppm so as to ensure the stability of the light-emitting device.

In the preparation method of the light-emitting device provided by the application, the preparation methods of the anode, the hole functional layer, the light-emitting layer and the cathode can be realized by adopting conventional technologies in the field, such as a chemical method or a physical method. Wherein, the chemical method comprises chemical vapor deposition, continuous ion layer adsorption and reaction, anodic oxidation, electrolytic deposition and coprecipitation. Physical methods include physical plating methods and solution methods, wherein the physical plating methods include: thermal evaporation plating, electron beam evaporation plating, magnetron sputtering, multi-arc ion plating, physical vapor deposition, atomic layer deposition, pulsed laser deposition, etc.; the solution method may be spin coating, printing, ink jet printing, knife coating, printing, dip-coating, dipping, spray coating, roll coating, casting, slit coating, bar coating, or the like.

It is understood that when the light emitting device further includes an electron injection layer, an electron blocking layer, a hole blocking layer, and/or an interface modification layer, the above two preparation methods further include a step of forming the above corresponding layers using the above chemical method or physical method.

The application also relates to a display device comprising the light emitting device provided by the application. The display device may be any electronic product with a display function, including but 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 set or an electronic book reader, wherein the smart wearable device may be, for example, a smart bracelet, a smart watch, a Virtual Reality (VR) helmet, etc.

The present application will now be described in more detail by way of the following examples, which are intended to be illustrative of the application and not limiting thereof.

Example 1

A film and a preparation method thereof are provided, comprising the following steps:

step 1, preparing a standard zinc oxide solution with the concentration of 30mg/mL.

And 2, preparing a zinc oxide nanocrystalline film layer on the white glass substrate by adopting the zinc oxide solution through spin coating, and performing vacuum drying treatment under the condition of 1Pa for 5min to obtain a first film layer. And then placing the first film layer in a first atmosphere of ethylamine ligand for ligand exchange, and performing ultraviolet irradiation treatment on the upper part of the prefabricated device to obtain the film. Wherein the vapor pressure of the ethylamine ligand is 3atm; the wavelength of ultraviolet irradiation treatment is 355nm, and the power is 4W; the two treatments were started simultaneously, the irradiation time period of the ultraviolet irradiation treatment was 15min, and the treatment time period of the ligand exchange in the first atmosphere of the ethylamine ligand was 30min.

Comparative example 1

This comparative example is substantially the same as example 1, except that: and step 2, spin-coating a zinc oxide nanocrystalline film layer and drying to obtain a first film layer, and carrying out no subsequent operation.

And (3) testing: XPS characterization test was performed on comparative example 1 and experimental example 1, and the O1s peak of the test result was subjected to peak separation to obtain oxygen vacancy O _V data, see Table 1.

TABLE 1

	Comparative example 1	Experimental example 1
			OV	2.53	1.61

As can be seen from table 1, the thin film prepared by the thin film preparation method of the present application can reduce defects such as oxygen vacancy defects on the surface of nano zinc oxide.

Example 2

A film and a preparation method thereof are provided, comprising the following steps:

s1, preparing a standard zinc oxide solution A with the concentration of 30mg/mL.

S2, preparing a zinc oxide film layer on the white glass substrate by adopting solution A spin coating, and then drying for 30min at 80 ℃. The prefabricated device was then subjected to ligand exchange in a first atmosphere of mercaptoethylamine (vapor pressure 5 atm), and an ultraviolet light irradiation treatment was given above the prefabricated device. The wavelength of ultraviolet irradiation treatment is 365nm, and the power is 4W; both treatments started simultaneously and ended simultaneously, with a treatment duration of 10min.

Comparative example 2

This comparative example is substantially identical to example 2, except that: and S2, preparing a zinc oxide film layer on the white glass substrate by adopting solution A spin coating, and then drying at 80 ℃ for 30min to obtain a film, wherein subsequent ligand exchange in the mercaptoethylamine steam atmosphere is not performed.

Comparative example 3

This comparative example is substantially identical to example 2, except that: in step S1, a bottle of solution identical to the standard zinc oxide solution A was prepared, and the concentration was 30mg/mL as well. To this, 10wt% of mercaptoethylamine ligand, labeled as zinc oxide solution B, was added. And preparing a zinc oxide film layer by adopting the solution B spin coating, and then drying for 30min at 80 ℃ to obtain the film.

Comparative example 4

This comparative example is substantially identical to example 2, except that: a zinc oxide film was prepared on a white glass substrate by spin coating with solution A, followed by drying at 80℃for 30min. Then, the prefabricated device was subjected to ligand exchange in a vapor atmosphere of mercaptoethylamine under conditions of 5atm for 10 minutes to obtain a thin film.

And (3) testing: the films of comparative examples 2 to 4 and example 2 were subjected to XPS characterization test, and S (sulfur) element analysis was performed, and the results are shown in Table 2 below.

TABLE 2

	Comparative example 2	Comparative example 3	Comparative example 4	Example 2
					S element content	0.16％	2.7％	5.9％	6.5％

As can be seen from table 2, in the method for preparing a thin film of example 2, compared with comparative examples 2 to 4, the method for preparing a thin film of the present application, in which the ligand exchange is performed by placing the thin film in a first atmosphere of mercaptoethylamine (vapor pressure 5 atm) and simultaneously performing the ultraviolet irradiation treatment on the prefabricated device, the content of S element is large, indicates that the method for preparing a thin film of the present application has high ligand exchange efficiency, more mercaptoethylamine is coordinately connected with zinc oxide particles, and can reduce the falling off of the ligand and improve the exchange efficiency of the target ligand compared with the method for preparing a thin film of comparative example 3, in which the ligand exchange is performed in the solution.

Device example 1

The embodiment of the device provides a quantum dot light emitting diode and a preparation method thereof, and the method specifically comprises the following steps.

Step 1: preparing an ITO layer on a transparent substrate by adopting an evaporation method to obtain an ITO electrode;

Step 2: and sequentially preparing a hole injection layer, a hole transport layer and a luminescent layer on the ITO electrode by adopting ink-jet printing to obtain the prefabricated device. The hole injection layer is made of PEDOT: PSS, thickness 30nm. The hole transport layer is made of TFB and has a thickness of 20nm. The quantum dot luminescent layer material is CdZnSe/ZnSe/ZnS/CdZnS/ZnS, and the thickness is 40nm.

Step 3: setting ZnO solution on a light-emitting layer of a prefabricated device through ink-jet printing, and then drying at 80 ℃ for 30min to obtain a first film layer; and placing the prefabricated device with the first film layer in a first atmosphere of ethylamine ligand for ligand exchange, and applying ultraviolet irradiation treatment above the prefabricated device to obtain the film. Wherein the vapor pressure of the ethylamine ligand is 3atm; the wavelength of ultraviolet irradiation treatment is 355nm, and the power is 4W; the two treatments were started simultaneously, the irradiation time period of the ultraviolet irradiation treatment was 15min, and the treatment time period of the ligand exchange in the first atmosphere of the ethylamine ligand was 30min.

Step 4: and (3) evaporating Al on the electronic functional layer at a speed of 1 angstrom/second for 200s by thermal evaporation, wherein the vacuum degree is not higher than 3×10 ^-4 Pa, obtaining a cathode with a thickness of 20nm, and packaging to obtain the quantum dot light-emitting diode.

Device example 2

The present device embodiment is substantially identical to device embodiment 1, except that: in step 3, the vapor pressure of the ethylamine ligand is 10atm.

Device example 3

The present device embodiment is substantially identical to device embodiment 1, except that: in step 3, the vapor pressure of the ethylamine ligand was 1atm.

Device example 4

The present device embodiment is substantially identical to device embodiment 1, except that: in the step 3, the wavelength of ultraviolet irradiation treatment is 365nm, the power is 1W, and the irradiation time of ultraviolet irradiation treatment is 30min.

Device example 5

The present device embodiment is substantially identical to device embodiment 4, except that: in step 3, the first film layer is placed in a first atmosphere of pyridine ligands while an ultraviolet light irradiation treatment is given above the prefabricated device. The vapor pressure of the pyridine ligand was 6atm, the wavelength of the ultraviolet irradiation treatment was 365nm, the power was 1W, and both treatments were started and ended simultaneously, with a treatment duration of 40min.

Device example 6

The present device embodiment is substantially identical to device embodiment 1, except that: the ultraviolet irradiation treatment was first performed for 15min, and then the ligand exchange treatment was performed in the first atmosphere of ethylamine ligand for 30min.

Device comparative example 1

The present device embodiment is substantially identical to device embodiment 1, except that: in step 3, 10wt% of ethylamine ligand was added to a standard zinc oxide solution A having a concentration of 30mg/mL, and the resulting zinc oxide solution B was mixed, and the zinc oxide solution B was coated on the light-emitting layer, followed by drying at 80℃for 30 minutes to conduct solvent removal, to obtain an electron transport layer having a thickness of 40 nm.

Device comparative example 2

The present device embodiment is substantially identical to device embodiment 1, except that: in step 3, when the prefabricated device with the first film layer formed is placed in the first atmosphere of the ethylamine ligand for treatment, ultraviolet irradiation treatment is not performed.

And (3) testing: the quantum dot light emitting diodes of device examples 1-6 and device comparative examples 1-2 were subjected to an operating life test and an external quantum efficiency EQE test. Specifically, the working life of each quantum dot light emitting diode piece was determined using a constant current drive of 2mA, and the test results are given in table 3 below. Wherein, when T95_1K (h) is 1000nit, the brightness is attenuated to 95% for a time. The external quantum efficiency EQE is measured by an EQE optical test instrument, and the luminous efficiency of the whole device can be reflected.

TABLE 3 Table 3

As can be seen from table 3, compared with the device comparative example 1, the quantum dot light emitting diode of the device examples 1 to 6 has better external quantum efficiency EQE and t95@1knits, probably because the preparation method of the thin film provided by the application can improve the exchange efficiency of the target ligand and reduce the defect of the zinc oxide surface, thereby having better electron transmission performance and further improving the light emitting performance and service life of the quantum dot light emitting diode.

Compared with the device comparative example 2, the quantum dot light-emitting diode of the device example 1 has better external quantum efficiency EQE and T95@1knits, probably because the preparation method of the film provided by the application avoids the falling of the ligand during ligand exchange in the solution, improves the exchange efficiency of the target ligand, reduces the defect of the zinc oxide surface, has better electron transmission performance, and further improves the light-emitting performance and the service life of the quantum dot light-emitting diode.

As can be seen from device examples 1-3, the external quantum efficiency EQE and t95@1knits of the quantum dot light emitting diode elements of device examples 2 and 3 are relatively small, possibly due to the fact that the vapor pressure is small (such as 1 atm), the ligand exchange efficiency of zinc oxide in the electron transport layer is relatively low, and the surface defects are relatively large, which affects the electron transport performance of the electron transport layer, thereby affecting the light emitting performance and the lifetime of the quantum dot light emitting diode element; when the vapor pressure is high (e.g., 10 atm), the electron transport layer may be damaged to some extent, such as cracks or pores, and the compactness of the electron transport layer is damaged, thereby affecting the light emitting performance and the service life of the quantum dot light emitting diode.

The preparation method of the thin film, the light-emitting device, the preparation method thereof and the display device provided by the embodiment of the application are described in detail, and specific examples are applied to illustrate the principle and the implementation of the application, and the description of the above examples is only used for helping to understand the method and the core idea of the application; meanwhile, as those skilled in the art will have variations in the specific embodiments and application scope in light of the ideas of the present application, the present description should not be construed as limiting the present application.

Claims (13)

1. A method of producing a film comprising:

providing a first film layer, wherein the first film layer comprises inorganic particles, and the inorganic particles are connected with first ligands;

placing the first film layer in a first atmosphere for first treatment in a first preset time period, and applying ultraviolet irradiation to the first film layer for second treatment in a second preset time period to obtain the film;

Wherein the first atmosphere contains a target ligand.

2. The method of claim 1, wherein,

The first atmosphere is composed of the target ligand in a gaseous state; and/or

In the first atmosphere, the vapor pressure of the target ligand is 1-10 atm; and/or

The power of the ultraviolet irradiation treatment is 1-5000 mW; and/or

The first preset time period is 5-3600 s; and/or

The second preset time period is 5-3600 s; and/or

The start time of the second preset time period is earlier than the end time of the first preset time period; and/or

The average particle diameter of the inorganic particles is 2-10 nm; and/or

The target ligand comprises one or more of halogen ligand, amino ligand, sulfhydryl ligand, carboxyl ligand, pyridine ligand and the like.

3. The method of claim 2, wherein,

The time of the first preset time period overlapping with the second preset time period is a third preset time, and the third preset time is more than 0s and less than or equal to 3600s; or alternatively

After the second process is finished, the first process is started at intervals of a fourth time, and the fourth time is more than 0 and less than or equal to 60s.

4. The method of claim 2, wherein,

The inorganic particles comprise at least one of metal oxide, doped metal oxide, II-VI semiconductor material, III-V semiconductor material and I-III-VI semiconductor material, and the metal oxide is at least one of ZnO, baO, tiO ₂、SnO₂; the metal oxide in the doped metal oxide is at least one of ZnO and TiO ₂、SnO₂, the doping element is at least one of Al, mg, li, in, ga, co, mn, and the II-VI semiconductor material is at least one of ZnS, znSe, cdS; the III-V semiconductor material is at least one selected from InP and GaP; the I-III-VI semiconductor material is at least one of CuInS and CuGaS; and/or

The inorganic particles comprise one of LiF,LiF/Yb、MgP,MgF₂,Al₂O₃、Ga₂O₃、ZnO、Cs₂CO₃、Rb₂CO₃、RbBr; and/or

The inorganic particles comprise at least one quantum dot selected from single-structure quantum dots, core-shell structure quantum dots and perovskite type semiconductor materials, wherein the single-structure quantum dots are selected from at least one of II-VI compounds, IV-VI compounds, III-V compounds and I-III-VI compounds, the II-VI 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 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、SnPbSTe, The III-V compound is at least one selected from GaN、GaP、GaAs、GaSb、AlN、AlP、AlAs、AlSb、InN、InP、InAs、InSb、GaNP、GaNAs、GaNSb、GaPAs、GaPSb、AlNP、AlNAs、AlNSb、AlPAs、AlPSb、InNP、InNAs、InNSb、InPAs、InPSb、GaAlNP、GaAlNAs、GaAlNSb、GaAlPAs、GaAlPSb、GaInNP、GaInNAs、GaInNSb、GaInPAs、GaInPSb、InAlNP、InAlNAs、InAlNSb、InAlPAs and InAlPSb, and the I-III-VI compound is at least one selected from CuInS, cuInSe and AgInS; The core of the quantum dot with the core-shell structure is selected from any one of the quantum dots with the single structure, and the shell material of the quantum dot with the core-shell structure is selected from at least one of CdS, cdTe, cdSeTe, cdZnSe, cdZnS, cdSeS, znSe, znSeS and ZnS; the perovskite type semiconductor material is selected from doped or undoped inorganic perovskite type semiconductor or organic-inorganic hybrid perovskite type semiconductor; The structural general formula of the inorganic perovskite semiconductor is AMX ₃, wherein A is Cs ⁺ ion, M is divalent metal cation, at least one of Pb²⁺、Sn^{2 +}、Cu²⁺、Ni²⁺、Cd²⁺、Cr²⁺、Mn²⁺、Co²⁺、Fe²⁺、Ge²⁺、Yb²⁺、Eu²⁺ and X is halogen anion, at least one of Cl ^-、Br^-、I^-; The structural general formula of the organic-inorganic hybrid perovskite semiconductor is BMX ₃, wherein B is an organic amine cation selected from CH ₃(CH₂)_n-2NH₃ ⁺ or [ NH ₃(CH₂)_nNH₃]²⁺ ], wherein n is more than or equal to 2, M is a divalent metal cation selected from at least one of Pb²⁺、Sn²⁺、Cu²⁺、Ni²⁺、Cd²⁺、Cr²⁺、Mn²⁺、Co²⁺、Fe²⁺、Ge²⁺、Yb²⁺、Eu²⁺, X is halogen anion, which is selected from at least one of Cl ^-、Br^-、I^-; And/or

The inorganic particles include one or more of doped or undoped NiO、V₂O₅、CrO₃、CuO、CuS、MoO₃、MoS₂、MoSe₂、WO₃、WS₂、WSe₂ and CuSCN; and/or

The halogen ligand comprises one or more of fluorine, chlorine, bromine and iodine; and/or

The amino ligand comprises one or more of ethylamine, 1-octylamine, 1, 2-propylene diamine, 1, 4-butylene diamine, 9-octadecylene amine, aniline, p-phenylenediamine and o-phenylenediamine; and/or

The sulfhydryl ligand comprises one or more of ethanethiol, octanethiol, mercaptoethylamine and 3-sulfhydryl-1-propylamine; and/or

The carboxyl ligand comprises one or more of propionic acid, butyric acid, (Z) -9-octadecenoic acid and thioglycollic acid; and/or

The pyridine ligand comprises one or more of pyridine and picoline.

5. The method of manufacturing of claim 1, wherein providing the first film layer comprises:

Providing inorganic particles and a first solvent, and mixing to obtain an inorganic particle solution;

Providing a substrate, and arranging the inorganic particle solution on the substrate to form the first film layer.

6. The method of manufacturing according to claim 5, further comprising, after disposing the inorganic particle solution on the substrate: drying to form a solid first film layer;

wherein the drying treatment is vacuum drying or heating drying; the pressure of the vacuum drying is 0.001-10 Pa; the temperature of the heating and drying is 40-140 ℃.

7. The method of preparing according to claim 6, wherein the first solvent comprises one or more of alcohol solvents; and/or

The concentration of the inorganic particle solution is 1-120 mg/mL.

8. A film prepared by the method of any one of claims 1-7.

9. A light emitting device, comprising:

A first electrode and a second electrode disposed opposite to each other;

A functional layer disposed between the first electrode and the second electrode; wherein the functional layer comprises the film prepared by the method for preparing a film according to any one of claims 1 to 7 or comprises the film according to claim 8.

10. A light-emitting device according to claim 9, wherein,

The functional layer comprises a light-emitting layer, wherein the light-emitting layer is a film prepared by the preparation method of the film of any one of claims 1-7 or the film of claim 8; and/or

The functional layer comprises an electronic functional layer, wherein the electronic functional layer comprises an electron transport layer and/or an electron injection layer, and the electron transport layer and/or the electron injection layer are/is a film prepared by the preparation method of the film according to any one of claims 1-7 or the film according to claim 8; and/or

The functional layer comprises a hole functional layer, and the hole functional layer comprises a hole injection layer and/or a hole transport layer; wherein the hole injection layer and/or the hole transport layer is/are a film prepared by the method for preparing a film according to any one of claims 1 to 7, or a film according to claim 8; and/or

The first electrode and the second electrode are independently selected from 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 at least one selected from Al, ag, cu, mo, au, ba, ca and Mg; the material of the carbon electrode is at least one selected from graphite, carbon nano tube, graphene and carbon fiber; the material of the doped or undoped metal oxide electrode is at least one selected from ITO, FTO, ATO, AZO, GZO, IZO, MZO and AMO; the material of the composite electrode is at least one 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 and ZnS/Al/ZnS.

11. A method of manufacturing a light emitting device, comprising:

Providing a prefabricated device, the prefabricated device comprising a first electrode;

Forming a functional layer on the prefabricated device, wherein the functional layer is prepared by the preparation method of the film according to any one of claims 1 to 7; and

And forming a second electrode on the functional layer to obtain the light-emitting device.

12. The method for manufacturing a light-emitting device according to claim 11, wherein,

The functional layer comprises an electronic functional layer, wherein the electronic functional layer comprises an electronic transmission layer and/or an electronic injection layer; and/or

The functional layer comprises a hole functional layer, and the hole functional layer comprises a hole injection layer and/or a hole transport layer; and/or

The functional layer includes a light emitting layer.

13. A display device, characterized in that the display device comprises a light emitting device according to any one of claims 9-10.