Thin film, photoelectric device, display device and preparation method

Abstract

The invention provides a thin film, a photoelectric device, a display device and a preparation method. The preparation method of the thin film comprises the following steps: providing a solution containing a charged organic semiconductor material; placing the solution containing the charged organic semiconductor material between a first substrate and a second substrate which are oppositely arranged; and generating an electric field between the first substrate and the second substrate, and enabling the charged organic semiconductor material to move towards the first substrate or the second substrate under the driving of the electric field so as to form a thin film on the first substrate or the second substrate. The production cost can be reduced, and the quality of the film can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of display devices, and in particular to a thin film, an optoelectronic device, a display device and a preparation method thereof. Background Art

[0002] Optoelectronic devices in display devices, such as organic light-emitting diodes (OLEDs), organic photovoltaic devices (OPVs), and organic field effect transistors (OTFTs), have thin films, which may be light-emitting layers, hole transport layers, etc. However, the preparation cost of thin films in existing optoelectronic devices is high, and the quality of the prepared thin films is poor, resulting in a low yield of optoelectronic devices. Summary of the invention

[0003] Based on this, it is necessary to provide a method for preparing a thin film.

[0004] In addition, it is also necessary to provide a thin film, a method for preparing an optoelectronic device, an optoelectronic device and a display device.

[0005] At least one embodiment of the present application provides a method for preparing a thin film, comprising the following steps:

[0006] providing a solution containing a charged organic semiconductor material;

[0007] placing the solution containing the charged organic semiconductor material between a first substrate and a second substrate disposed opposite to each other; and

[0008] An electric field is generated between the first substrate and the second substrate, so that the charged organic semiconductor material moves toward the first substrate or the second substrate and forms a thin film on the first substrate or the second substrate.

[0009] In some embodiments, the charged organic semiconductor material is a doped semiconductor material, and the doped semiconductor material comprises an organic semiconductor material and a doping element; and / or

[0010] The solution containing the charged organic semiconductor material further comprises an organic solvent, wherein the dielectric constant of the organic solvent is greater than or equal to 20.

[0011] In some embodiments, the doping element is a halogen;

[0012] Wherein, the halogen includes at least one of iodine, fluorine, chlorine and bromine.

[0013] In some of the embodiments, in the doped semiconductor material, the mass ratio of the doping element to the organic semiconductor material is (1:10) to (3:2).

[0014] In some embodiments, the organic semiconductor material includes at least one of an organic hole functional material, an organic light emitting material, and an organic electronic functional material;

[0015] Wherein, the organic hole functional material includes at least one of polyvinyl carbazole, TFB, CuPc, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-Nphenylamino)triphenylamine and polyaniline; and / or

[0016] The organic light-emitting material includes at least one of 1,3-bis(N-carbazolyl)benzene, 4,4'-bis(N-carbazole)-1,1'-biphenyl, tris[2-(p-tolyl)pyridine-C2,N)iridium(III), 4,4',4"-tris(carbazole-9-yl)triphenylamine: tris[2-(p-tolyl)pyridine-C2,N)iridium, diaromatic anthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials and DBP fluorescent materials, polyacetylene and its derivatives, polyparaphenylene and its derivatives, polythiophene and its derivatives, and polyfluorene and its derivatives; and / or

[0017] The organic electronic functional material includes at least one of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene compounds, hydroxyquinoline compounds, polythiophene compounds, perylene imide compounds and fullerene compounds;

[0018] Wherein, the imidazole compound includes 1,3,5-tris(1-phenyl-1H-benzimidazole-2-yl)benzene;

[0019] Wherein, the fluorene-containing compound includes at least one of WPF-oxy-F, WPF-6-oxy-F, PF-EP, PFNBr, PFSO3Na, PFBTBr, 3TPA-FEP, PF-NS, PF-N-SOC8, FFiF, FPF, ZnO:PFN, PmP-NOH, PmP36F-NOH, PFBD, PEI:PF1, FCF and PF15-b-PDMAEMA75;

[0020] Wherein, the polythiophene compound includes at least one of P3HTN, PT3SB, PT2BTDPPSB, PT2NDISB, PT6N, PBTAZPOBr and PCPDTTPD-Im;

[0021] Wherein, the perylene imide compound includes at least one of PDINO, PDIP, PBI-H, FPDI, PDIN and PTCDI-C8;

[0022] Wherein, the fullerene compound includes at least one of DMAPA-C60, C60-ETA, C60-PEG, rGO-pyrene-PCBM, FPI-PEIE and Fullerenol; and / or

[0023] The solution containing the charged organic semiconductor material also includes an organic solvent, and the organic solvent includes acetonitrile, glycerol, furfural, ethylene glycol, nitromethane, nitrobenzene, methanol, propionitrile, o-nitrotoluene, benzonitrile, ethanol, chloroethanol, acetylacetone, propanol, acetone, chloroacetic acid, acetic anhydride, formamide, N-methylamide, DMSO, DMF, benzonitrile, acetic anhydride, n-propanol, butanone, xylene, n-hexanol, n-pentanol, cyclohexanone, methyl isobutyl ketone, diethyl ketone, N-methylmorpholine, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, N-methylpyrrolidone, dimethylacetamide, trichlorosulfuron At least one of phosphorus, carbon tetrachloride, bromoform, trichloroethylene, hydrazine, antimony tribromide, formic acid, hydrogen cyanide, trifluoroacetic acid, 2-chloroethane, nitroethane, epichlorohydrin, allyl alcohol, lactic acid, N,N-dimethylformamide, 1-nitropropane, 2-nitropropane, 1-propanol, 1,2-propylene glycol, 1,3-propylene glycol, maleic anhydride, succinonitrile, methyl cyanoacetate, 2-methylpropionitrile, bis(2-chloroethyl) ether, 2,4-pentanedione, o-chloronitrobenzene, m-chloronitrobenzene, o-nitroaniline, p-nitroaniline, hexanediol, benzonitrile, o-nitrotoluene, m-nitrotoluene and p-nitrotoluene.

[0024] In some embodiments, the first substrate and the second substrate are conductive substrates; and / or

[0025] Generating an electric field between the first substrate and the second substrate comprises the following steps:

[0026] Connecting one of the first substrate and the second substrate to the positive electrode of a power source, and connecting the other of the first substrate and the second substrate to the negative electrode of the power source; and / or

[0027] The electric field is a direct current electric field; and / or

[0028] The strength of the electric field is 1×10 4 V / m~1×10 8 V / m; and / or

[0029] The electric field is applied for a time period of 5s to 7200s.

[0030] In some embodiments, the first substrate and / or the second substrate has patterned electrodes thereon;

[0031] The electrode is selected from a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal single substance electrode or an alloy electrode;

[0032] The material of the doped metal oxide particle electrode includes one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide and aluminum-doped magnesium oxide.

[0033] Wherein, the composite electrode comprises 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 or ZnS / Al / ZnS;

[0034] Among them, the material of the metal single-element electrode includes one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg and Ba.

[0035] In some embodiments, the preparation of the solution containing the charged organic semiconductor material comprises the following steps:

[0036] Providing the organic semiconductor material and a first solvent, and mixing the organic semiconductor material and the first solvent to obtain a first mixed solution;

[0037] Providing a doping element single substance and a second solvent, and mixing the doping element single substance and the second solvent to obtain a second mixed solution;

[0038] Mixing the first mixed solution and the second mixed solution to obtain a third mixed solution containing a doped semiconductor material; and

[0039] The third mixed liquid and the organic solvent are mixed to obtain the solution containing the charged organic semiconductor material, wherein the solubility of the doped semiconductor material in the organic solvent is lower than the solubility of the doped semiconductor material in the first solvent and the second solvent.

[0040] In some embodiments, in the first mixed solution, the concentration of the organic semiconductor material is 0.5 g / L to 500 g / L; and / or

[0041] In the second mixed solution, the concentration of the doping element is 0.5 g / L to 500 g / L; and / or

[0042] In the step of mixing the first mixed solution and the second mixed solution, the volume ratio of the first mixed solution to the second mixed solution is (1:10) to (10:1); and / or

[0043] In the step of mixing the third mixed liquid and the organic solvent, the volume ratio of the third mixed liquid to the organic solvent is (1:10) to (10:1); and / or

[0044] The doping element is a halogen element, and the halogen element includes at least one of iodine, fluorine, chlorine and bromine.

[0045] In some embodiments, the boiling point of the organic solvent is greater than the boiling points of the first solvent and the second solvent; and / or

[0046] The first solvent and the second solvent independently include at least one of aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, alicyclic hydrocarbon compounds, halogenated hydrocarbon compounds, alcohol compounds, ether compounds, ester compounds and ketone compounds;

[0047] The aromatic hydrocarbon compounds include at least one of benzene, toluene, ethylbenzene, xylene, styrene, acetophenone, nitrobenzene, chlorobenzene, bromobenzene and iodobenzene; the aliphatic hydrocarbon compounds include at least one of pentane, hexane, heptane, octane, nonane, decane, tridecane, tetradecane, pentadecane and hexadecane; the alicyclic hydrocarbon compounds include at least one of cyclohexane, cyclopentane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cyclopentadecane, cyclohexadecane, cyclooctadecane and cycloeicosane; the halogenated hydrocarbon compounds include methyl chloride, dichloromethane, chloroform, carbon tetrachloride, methyl bromide, dibromomethane, bromoform, methyl iodide, diiodomethane and at least one of triiodomethane; the alcohol compound includes at least one of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol and decanol; the ether compound includes at least one of methyl ether, ethyl ether, propyl ether, butyl ether, pentyl ether, hexyl ether, heptyl ether, octyl ether, nonyl ether and decyl ether; the ester compound includes at least one of methyl formate, ethyl acetate, propyl propionate, butyl butyrate, pentyl valerate, hexyl hexanoate, heptyl heptanoate, octyl octanoate, nonyl nonanoate and decyl decanoate; the ketone compound includes at least one of acetone, butanone, pentanone, hexanone, heptanone, octanone, nonanone, decanone, undecanone and dodecanone.

[0048] In some embodiments, after mixing the third mixed solution and the organic solvent, the preparation of the solution containing the charged organic semiconductor material further comprises the following steps: mixing the third mixed solution and the organic solvent to obtain a fourth mixed solution;

[0049] heating the fourth mixed liquid; and

[0050] removing the agglomerates in the heated fourth mixed solution to obtain the solution containing the charged organic semiconductor material; and / or

[0051] The heating temperature is greater than the boiling points of the first solvent and the second solvent, and less than the boiling point of the organic solvent.

[0052] At least one embodiment of the present application provides a thin film, which is prepared by the above-mentioned preparation method.

[0053] At least one embodiment of the present application provides a method for preparing a photoelectric device, comprising the following steps:

[0054] Providing a first substrate and a second substrate, wherein the first substrate comprises a first electrode, and the first electrode and the second substrate are arranged opposite to each other;

[0055] preparing the thin film on the first electrode between the first substrate and the second substrate by using the preparation method according to any one of claims 1 to 11 to form an organic functional layer; and

[0056] A second electrode is prepared on the organic functional layer.

[0057] At least one embodiment of the present application provides a photoelectric device, including a first electrode and a second electrode arranged opposite to each other, wherein the thin film is arranged between the first electrode and the second electrode, and the thin film is prepared by the above-mentioned preparation method.

[0058] At least one embodiment of the present application provides a display device, including an optoelectronic device prepared by the above-mentioned preparation method, or the above-mentioned optoelectronic device.

[0059] The preparation method provided in the present application has simple steps, which can effectively reduce the preparation cost, and during the preparation, deposition is performed simultaneously at each point of the thin film, which effectively improves the consistency of the film layer and improves the quality of the film layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 The flow chart of the preparation of the film provided for this application. DETAILED DESCRIPTION

[0061] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the application content of the present application more thorough and comprehensive.

[0062] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art to which the present application belongs. The terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0063] At present, thin films such as light-emitting layers and hole transport layers in optoelectronic devices such as organic light-emitting diodes (OLEDs), organic photovoltaic devices (OPVs) and organic field effect transistors (OTFTs) are mostly prepared by vacuum evaporation or solution deposition. However, the evaporation equipment required by the vacuum evaporation method is relatively expensive, which will result in high production costs; the quality of thin films prepared by the solution method is poor, which ultimately leads to a low yield of the prepared optoelectronic devices.

[0064] To solve the above problems, see Figure 1 At least one embodiment of the present application provides a method for preparing a thin film, comprising the following steps:

[0065] Step S11: providing a solution containing a charged organic semiconductor material.

[0066] In one embodiment, the charged organic semiconductor material is a doped semiconductor material. In one embodiment, the doped semiconductor material comprises an organic semiconductor material and a doping element.

[0067] In one embodiment, the organic semiconductor material includes at least one of an organic hole functional material, an organic light emitting material, and an organic electronic functional material.

[0068] Specifically, by doping a small amount of elements into the organic semiconductor material, the organic semiconductor material is charged, so that it can move toward the first substrate and / or the second substrate and deposit on the substrate surface to form a thin film under the drive of the electric field between the first substrate and the second substrate.

[0069] In one embodiment, the organic hole functional material includes at least one of polyvinyl carbazole (PVK), TFB, CuPc, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-Nphenylamino)triphenylamine and polyaniline.

[0070] In one embodiment, the organic light-emitting material includes at least one of 1,3-bis(N-carbazolyl)benzene (mCP), 4,4'-bis(N-carbazole)-1,1'-biphenyl, tris[2-(p-tolyl)pyridine-C2,N)iridium(III), 4,4',4"-tri(carbazole-9-yl)triphenylamine: tris[2-(p-tolyl)pyridine-C2,N)iridium, diaromatic anthracene derivatives, distyrene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials and DBP fluorescent materials, polyacetylene and its derivatives, polyparaphenylene and its derivatives, polythiophene and its derivatives, and polyfluorene and its derivatives.

[0071] In one embodiment, the organic electronic functional material includes at least one of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene compounds, hydroxyquinoline compounds, polythiophene compounds, perylene imide compounds and fullerene compounds. In one embodiment, the imidazole compounds include 1,3,5-tris(1-phenyl-1H-benzimidazole-2-yl)benzene (TPBi). In one embodiment, the fluorene compounds include at least one of WPF-oxy-F, WPF-6-oxy-F, PF-EP, PFNBr, PFSO3Na, PFBTBr, 3TPA-FEP, PF-NS, PF-N-SOC8, FFiF, FPF, ZnO:PFN, PmP-NOH, PmP36F-NOH, PFBD, PEI:PF1, FCF and PF15-b-PDMAEMA75. In one embodiment, the polythiophene compound includes at least one of P3HTN, PT3SB, PT2BTDPPSB, PT2NDISB, PT6N, PBTAZPOBr and PCPDTTPD-Im. In one embodiment, the perylene imide compound includes at least one of PDINO, PDIP, PBI-H, FPDI, PDIN and PTCDI-C8. In one embodiment, the fullerene compound includes at least one of DMAPA-C60, C60-ETA, C60-PEG, rGO-pyrene-PCBM, FPI-PEIE and Fullerenol.

[0072] In one embodiment, the doping element is a halogen, that is, the organic semiconductor material is doped with a halogen so that the organic semiconductor material carries an electric charge.

[0073] In one embodiment, the halogen includes at least one of iodine, fluorine, chlorine and bromine.

[0074] Specifically, doping with halogen elements can obtain electrically p-type doped organic semiconductor materials, that is, the charged organic semiconductor material has electronegativity, and can move toward the substrate in a directional manner under the drive of an electric field to form a uniform and dense film.

[0075] In one embodiment, in the doped semiconductor material, the mass ratio of the doping element to the organic semiconductor material is (1:10) to (3:2).

[0076] Specifically, by changing the mass ratio of the doping element to the organic semiconductor material, the doping ratio in the doped semiconductor material can be changed, that is, the p-type doping degree in the doped semiconductor material can be changed, so that the charging degree of the doped semiconductor material can be adjusted, and then the movement speed of the doped semiconductor material in the electric field can be controlled, and by cooperating with the electric field, the deposition rate can be effectively adjusted to control the thickness and consistency of the prepared film. In one embodiment, the preparation of the solution containing the charged organic semiconductor material includes the following steps:

[0077] Step S111: providing the organic semiconductor material and a first solvent, and mixing the organic semiconductor material and the first solvent to obtain a first mixed solution.

[0078] Specifically, one, two or more organic semiconductor materials are dissolved in the first solvent at a first concentration to obtain the first mixed solution.

[0079] Wherein, the first solvent is a good solvent for the organic semiconductor material. That is, the organic semiconductor material has a high solubility in the first solvent. In one embodiment, the first solvent includes at least one of aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, alicyclic hydrocarbon compounds, halogenated hydrocarbon compounds, alcohol compounds, ether compounds, ester compounds and ketone compounds.

[0080] In one embodiment, the aromatic hydrocarbon compound includes at least one of benzene, toluene, ethylbenzene, xylene, styrene, acetophenone, nitrobenzene, chlorobenzene, bromobenzene and iodobenzene. In one embodiment, the aliphatic hydrocarbon compound includes at least one of pentane, hexane, heptane, octane, nonane, decane, tridecane, tetradecane, pentadecane and hexadecane. In one embodiment, the alicyclic hydrocarbon compound includes at least one of cyclohexane, cyclopentane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cyclopentadecane, cyclohexadecane, cyclooctadecane and cycloeicosane. In one embodiment, the halogenated hydrocarbon compound includes at least one of chloromethane, dichloromethane, chloroform, carbon tetrachloride, bromomethane, dibromomethane, bromoform, iodomethane, diiodomethane and triiodoform. In one embodiment, the alcohol compound includes at least one of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol and decanol. In one embodiment, the ether compound includes at least one of methyl ether, ethyl ether, propyl ether, butyl ether, pentyl ether, hexyl ether, heptyl ether, octyl ether, nonyl ether and decyl ether. In one embodiment, the ester compound includes at least one of methyl formate, ethyl acetate, propyl propionate, butyl butyrate, pentyl valerate, hexyl hexanoate, heptyl heptanoate, octyl octanoate, nonyl nonanoate and decyl decanoate. In one embodiment, the ketone compound includes at least one of acetone, butanone, pentanone, hexanone, heptanone, octanone, nonyl nonanoate, decanone, undecone and dodecanone.

[0081] In one embodiment, in the first mixed solution, the concentration of the organic semiconductor material is 0.5 g / L to 500 g / L to ensure that the solute is not too little to cause the subsequent formation of sufficient charged organic semiconductor material, and to avoid excessive solute causing the final charged organic semiconductor material solution to be too viscous and unable to be processed.

[0082] In one embodiment, during the process of dissolving the organic semiconductor material in the first solvent, the first solvent may be heated and stirred to accelerate the dissolution of the organic semiconductor material and to make the organic semiconductor material dissolve more thoroughly.

[0083] Step S112: providing a doping element single substance and a second solvent, and mixing the doping element single substance and the second solvent to obtain a second mixed solution.

[0084] Specifically, the doping element single substance is dissolved in the second solvent at a second concentration to obtain the second mixed solution containing the doping element single substance.

[0085] In one embodiment, after the doping element is dissolved in the second solvent, it is kept for a preset time to ensure that the doping element is dissolved completely and stably.

[0086] In one embodiment, the second solvent and the first solvent may be the same good solvent, that is, the second solvent may include at least one of aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, alicyclic hydrocarbon compounds, halogenated hydrocarbon compounds, alcohol compounds, ether compounds, ester compounds and ketone compounds.

[0087] In one embodiment, the aromatic hydrocarbon compound includes at least one of benzene, toluene, ethylbenzene, xylene, styrene, acetophenone, nitrobenzene, chlorobenzene, bromobenzene and iodobenzene. In one embodiment, the aliphatic hydrocarbon compound includes at least one of pentane, hexane, heptane, octane, nonane, decane, tridecane, tetradecane, pentadecane and hexadecane. In one embodiment, the alicyclic hydrocarbon compound includes at least one of cyclohexane, cyclopentane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cyclopentadecane, cyclohexadecane, cyclooctadecane and cycloeicosane. In one embodiment, the halogenated hydrocarbon compound includes at least one of chloromethane, dichloromethane, chloroform, carbon tetrachloride, bromomethane, dibromomethane, bromoform, iodomethane, diiodomethane and triiodoform. In one embodiment, the alcohol compound includes at least one of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol and decanol. In one embodiment, the ether compound includes at least one of methyl ether, ethyl ether, propyl ether, butyl ether, pentyl ether, hexyl ether, heptyl ether, octyl ether, nonyl ether and decyl ether. In one embodiment, the ester compound includes at least one of methyl formate, ethyl acetate, propyl propionate, butyl butyrate, pentyl valerate, hexyl hexanoate, heptyl heptanoate, octyl octanoate, nonyl nonanoate and decyl decanoate. In one embodiment, the ketone compound includes at least one of acetone, butanone, pentanone, hexanone, heptanone, octanone, nonyl nonanoate, decanone, undecone and dodecanone.

[0088] In another embodiment, the first solvent and the second solvent are different kinds of mutually soluble good solvents, that is, the first solvent and the second solvent only need to be good solvents for the organic semiconductor material and the doping element.

[0089] In one embodiment, in the second mixed solution, the concentration of the doping element is 0.5 g / L to 500 g / L to ensure that the solute is not too little to cause the subsequent formation of sufficient charged organic semiconductor material, and to avoid excessive solute causing the final charged organic semiconductor material solution to be too viscous and unable to be processed.

[0090] In one embodiment, the doping element is a halogen. In one embodiment, the halogen includes at least one of iodine, fluorine, chlorine and bromine.

[0091] Step S112 is now described by taking iodine as an example: dissolving iodine in chloroform (ie, the second solvent) at a concentration of 10 g / L, and stirring for 1 hour to obtain the second mixed solution.

[0092] Step S113: Mix the first mixed liquid and the second mixed liquid to obtain a third mixed liquid containing a doped semiconductor material.

[0093] Specifically, the first mixed liquid and the second mixed liquid are mixed at a volume ratio of (1:10) to (10:1), so that the doping element single substance dopes the organic semiconductor material to obtain the doped semiconductor material.

[0094] Among them, the mixing ratio of the first mixed liquid and the second mixed liquid is controlled to be (1:10) to (10:1) in order to ensure that there are enough doping elements to dope the organic semiconductor material and charge it, without introducing excessive doping elements to cause excessive impurity defects, thereby causing degradation of the performance of the final film.

[0095] By changing the mixing ratio of the first mixed liquid and the second mixed liquid, it is possible to achieve doping of the organic semiconductor material with different amounts of the doping element, that is, different doping ratios in the doped semiconductor material.

[0096] Step S114, mixing the third mixed liquid and an organic solvent to obtain a fourth mixed liquid.

[0097] The solubility of the doped semiconductor material in the organic solvent is lower than the solubility of the doped semiconductor material in the first solvent and the second solvent.

[0098] Specifically, the third mixed solution containing the doped semiconductor material is added to the organic solvent. Since the solubility of the doped semiconductor material in the organic solvent is less than the solubility of the doped semiconductor material in the first solvent and the second solvent, the doped semiconductor material will quickly form a nanoparticle dispersion in the organic solvent. At the same time, since the organic semiconductor material is electrochemically p-type doped with the halogen element, the obtained nanoparticle dispersion is negatively charged, so that the nanoparticle dispersion has an electrostatic repulsion effect, which inhibits the agglomeration of the nanoparticle dispersion, thereby stabilizing the nanoparticle dispersion.

[0099] In one embodiment, the third mixed liquid and the organic solvent are mixed in a volume ratio of (1:10) to (10:1). The volume ratio of the third mixed liquid and the organic solvent is controlled to be (1:10) to (10:1) to ensure that the charged organic semiconductor material can form a nanoparticle dispersion in an appropriate amount of anti-solvent without excessive anti-solvent causing it to quickly form agglomerates.

[0100] In one embodiment, the dielectric constant of the organic solvent is greater than or equal to 20. The organic solvent with a high dielectric constant selected in the present application is beneficial to stabilizing the charge and promoting the separation of counterions, thereby facilitating the improvement of the stability of the nanoparticle dispersion.

[0101] Wherein, the organic solvent is the anti-solvent of the doped semiconductor material. Wherein, the anti-solvent refers to a solvent that is insoluble in the doped semiconductor material. In one embodiment, the organic solvent includes acetonitrile, glycerol, furfural, ethylene glycol, nitromethane, nitrobenzene, methanol, propionitrile, o-nitrotoluene, benzonitrile, ethanol, chloroethanol, acetylacetone, propanol, acetone, chloroacetic acid, acetic anhydride, formamide, N-methylamide, DMSO, DMF, benzonitrile, acetic anhydride, n-propanol, butanone, xylene, n-hexanol, n-pentanol, cyclohexanone, methyl isobutyl ketone, diethyl ketone, N-methylmorpholine, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, N-methylpyrrolidone, dimethylacetamide, trichlorothiophosphorus, carbon tetrachloride, tribromo At least one of methane, trichloroethylene, hydrazine, antimony tribromide, formic acid, hydrogen cyanide, trifluoroacetic acid, 2-chloroethane, nitroethane, epichlorohydrin, allyl alcohol, lactic acid, N,N-dimethylformamide, 1-nitropropane, 2-nitropropane, 1-propanol, 1,2-propylene glycol, 1,3-propylene glycol, maleic anhydride, succinonitrile, methyl cyanoacetate, 2-methylpropionitrile, bis(2-chloroethyl) ether, 2,4-pentanedione, o-chloronitrobenzene, m-chloronitrobenzene, o-nitroaniline, p-nitroaniline, hexanediol, benzonitrile, o-nitrotoluene, m-nitrotoluene and p-nitrotoluene.

[0102] In one embodiment, during the process of injecting the third mixed solution containing the doped semiconductor material into the organic solvent, the organic solvent may be vigorously stirred to accelerate the formation of the nanoparticle dispersion. In one embodiment, under vigorous stirring, 1 mL of the third mixed solution with a concentration of 2 g / L may be injected into 7 mL of acetonitrile within 0.8 seconds.

[0103] Step S115, heating the fourth mixed liquid to remove the first solvent and the second solvent in the mixed liquid.

[0104] Specifically, the heating temperature is greater than the boiling points of the first solvent and the second solvent, and less than the boiling point of the organic solvent.

[0105] It is understood that in order to ensure that the first solvent and the second solvent can be removed by the heating method, while leaving the organic solvent, the boiling point of the organic solvent needs to be higher than the boiling points of the first solvent and the second solvent. For example, chloroform can be selected as the first solvent and the second solvent, and acetonitrile can be selected as the organic solvent. Since the boiling point of acetonitrile is higher than the boiling point of chloroform, the first solvent and the second solvent in the mixed solution can be removed by the heating method, while leaving the organic solvent.

[0106] In one embodiment, when chloroform is selected as the first solvent and the second solvent, and acetonitrile is selected as the organic solvent, the mixed solution can be heated at 70° C. until the chloroform in the mixed solution is removed. During the heating process, part of the acetonitrile will inevitably volatilize, and the concentration of the nanoparticle dispersion in the mixed solution will gradually increase.

[0107] Step S116, removing the agglomerates in the heated fourth mixed solution to obtain the solution containing the charged organic semiconductor material.

[0108] Specifically, the heated fourth mixed liquid is centrifuged to remove aggregates in the mixed liquid.

[0109] In one embodiment, in the solution containing the charged organic semiconductor material, at least a portion of the charged organic semiconductor material is a stable dispersion of the nanoparticles.

[0110] Step S12: placing the solution containing the charged organic semiconductor material between a first substrate and a second substrate that are oppositely disposed.

[0111] Specifically, a first substrate and a second substrate are provided, and the first substrate and the second substrate are placed in the solution containing the charged organic semiconductor material, and the first substrate and the second substrate are arranged relative to each other so that the charged organic semiconductor material is located between the first substrate and the second substrate.

[0112] In one embodiment, the first substrate and the second substrate are both conductive substrates. In one embodiment, the conductive substrate refers to a substrate with a conductive electrode. In one embodiment, the conductive electrode is selected from a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal single substance electrode or an alloy electrode.

[0113] In one embodiment, the first substrate and / or the second substrate has a patterned electrode. In one embodiment, the electrode is selected from a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal single substance electrode or an alloy electrode.

[0114] In one embodiment, the material of the doped metal oxide particle electrode includes one or more of indium doped tin oxide, fluorine doped tin oxide, antimony doped tin oxide, aluminum doped zinc oxide, gallium doped zinc oxide, indium doped zinc oxide, magnesium doped zinc oxide and aluminum doped magnesium oxide. In one embodiment, the composite electrode includes AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS or ZnS / Al / ZnS. In one embodiment, the material of the metal single substance electrode includes one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg and Ba.

[0115] Step S13: generating an electric field between the first substrate and the second substrate, and driving the charged organic semiconductor material to move toward the first substrate or the second substrate under the driving of the electric field to form a thin film on the first substrate or the second substrate.

[0116] Specifically, one of the first substrate and the second substrate is connected to the positive electrode of a power source, and the other of the first substrate and the second substrate is connected to the negative electrode of the power source to generate an electric field between the first substrate and the second substrate. Since the charged organic semiconductor material is negatively charged, the electric field can drive the negatively charged charged organic semiconductor material to move in a single direction toward the first substrate or the second substrate, and deposit on the first substrate or the second substrate, thereby forming the thin film.

[0117] In one embodiment, the first substrate has a patterned electrode, and when the first substrate is connected to the positive electrode of the power supply and the second substrate is connected to the negative electrode of the power supply, the electric field drives the negatively charged organic semiconductor material to move toward the first substrate in a directional manner, thereby forming the thin film on the first substrate.

[0118] In one embodiment, the electric field is a direct current electric field, wherein setting the electric field as a direct current electric field can ensure that the charged organic semiconductor material can move in a single direction toward the first substrate or the second substrate.

[0119] In one embodiment, the strength of the electric field is 1×10 4V / m~1×10 8 V / m. The thickness of the film can be adjusted by controlling the magnitude of the electric field.

[0120] In one embodiment, the application time of the electric field is 5s to 7200s. The thickness of the film can be adjusted by controlling the application time of the electric field.

[0121] In addition, the thickness, consistency and flatness of the film finally deposited on the first substrate or the second substrate can also be adjusted by changing the doping ratio of the doping elements in the doped semiconductor material and the concentration of the charged organic semiconductor material in the solution containing the charged organic semiconductor material.

[0122] Step S14, washing the film.

[0123] Specifically, the conductive substrate with the thin film deposited thereon is taken out from the solution containing the charged organic semiconductor material, and is placed in the organic solvent for washing for 1s to 600s under power-on conditions to remove residual organic matter and residual liquid that have not been deposited on the conductive substrate.

[0124] In one embodiment, after washing the thin film, the conductive substrate on which the thin film is deposited may be placed at a temperature of 40° C. to 250° C. and dried for 0 min to 300 min to remove the halogen atoms remaining on the thin film, and finally obtain the patterned thin film. In one embodiment, the drying temperature may be 80° C. and the drying time may be 20 min.

[0125] At least one embodiment of the present application provides a thin film, which is obtained by the above-mentioned thin film preparation method.

[0126] At least one embodiment of the present application provides a method for preparing a photoelectric device, comprising the following steps:

[0127] Step S21, providing a first substrate and a second substrate, wherein the first substrate includes a first electrode, and the first electrode and the second substrate are arranged opposite to each other.

[0128] In one embodiment, the first electrode may be an anode.

[0129] Step S22: Prepare the thin film on the first electrode between the first substrate and the second substrate using the above preparation method to form an organic functional layer. In one embodiment, the organic functional layer includes at least one of an organic hole functional layer, an organic light emitting layer and an organic electronic functional layer.

[0130] In one embodiment, the organic hole functional layer includes at least one of a hole transport layer, a hole injection layer and a hole blocking layer. In one embodiment, the organic electronic functional layer includes at least one of an electron transport layer and an electron blocking layer.

[0131] Step S23: preparing a second electrode on the organic functional layer, thereby obtaining a photoelectric device.

[0132] Specifically, the second substrate is used to cooperate with the first substrate to form an electric field. After the thin film is prepared, the second substrate can be removed and a second electrode can be prepared on the organic functional layer.

[0133] In one embodiment, the second electrode may be a cathode.

[0134] In one embodiment, the optoelectronic device includes at least one of an organic light emitting diode (OLED), an organic photovoltaic device (OPV), and an organic field effect transistor (OTFT).

[0135] At least one embodiment of the present application provides a photoelectric device, which includes the above-mentioned film and a first electrode and a second electrode located on two opposite surfaces of the film.

[0136] The preparation method provided in the present application first provides a solution containing a charged organic semiconductor material, and then places the solution containing the charged organic semiconductor material between a first substrate and a second substrate that are relatively arranged, and generates an electric field between the first substrate and the second substrate, and the charged organic semiconductor material moves toward the first substrate or the second substrate under the drive of the electric field to form a thin film on the first substrate or the second substrate. The equipment required for preparing the thin film in the present application is relatively simple and inexpensive, avoiding the introduction of expensive equipment such as evaporation machines, reducing production costs, simplifying production steps, and increasing production speed, and can be prepared on a large area. At the same time, since the deposition of all sites is carried out simultaneously when preparing the thin film, the consistency of the thin film is greatly improved, the quality of the thin film is improved, and thus the yield of the optoelectronic device is improved.

[0137] In addition, the preparation method provided in the present application only requires patterning of the electrodes on the conductive substrate to achieve patterning of all organic functional film layers on the conductive substrate.

[0138] Furthermore, an embodiment of the present application also provides a display device, which includes the above-mentioned optoelectronic device.

[0139] In one embodiment, the display device can be any electronic product with a display function, including but not limited to smart phones, tablet computers, laptop computers, digital cameras, digital video cameras, smart wearable devices, smart weighing electronic scales, car displays, televisions or e-book readers, among which smart wearable devices can be, for example, smart bracelets, smart watches, virtual reality (VR) helmets, etc.

[0140] The film and the preparation method thereof in the present application are described in detail below through examples and comparative examples.

[0141] Film Example 1

[0142] (1) Provide a clean conductive substrate with a patterned anode, and immerse the conductive substrate with the anode facing upward in a mixed solution of ODCB:H2O2, wherein the molar ratio of ODCB:H2O2 in the mixed solution is 1:1.5. Then, place the mixed solution without the conductive substrate under a UV lamp for UV ozone treatment for 5 minutes, then take the conductive substrate out of the mixed solution, and immerse it in an ethanol solution for 5 times, and then dry it. Then, place it in a UV ozone device to irradiate the anode surface for 15 minutes to completely remove the chlorocarbon residues on the anode surface, and obtain a surface chlorinated ITO anode.

[0143] (2) The material PVK was dissolved in chloroform at a concentration of 8 g / L, and then heated at 45°C and stirred for 20 minutes to obtain a first mixed solution. The iodine element was dissolved in chloroform at a concentration of 10 g / L and maintained for 1 hour to obtain a second mixed solution. 1.6 mL of the second mixed solution was added to 10 mL of the first mixed solution to obtain an intermediate mixed solution, and then 8.4 mL of chloroform was added to the intermediate mixed solution for dilution, and finally a third mixed solution containing doped semiconductor materials with a concentration of 4 g / L was obtained. Then, under vigorous stirring, 1 mL of the third mixed solution was injected into 7 mL of acetonitrile within 0.8 seconds. The mixed solution obtained by mixing the third mixed solution and acetonitrile was then heated at 70°C until the chloroform was removed and part (3 mL) of the acetonitrile volatilized, and finally a solution containing charged organic semiconductor materials with a concentration of 1 g / L was obtained.

[0144] (3) placing the conductive substrate with the patterned anode obtained in step (1) and another conductive substrate in a solution containing a charged organic semiconductor material, and placing them opposite to each other, and then connecting the conductive substrate with the patterned anode to the positive electrode of a power source, and connecting the other conductive substrate to the negative electrode of the power source, so as to generate a 9×10 4The electric field generated by the electric field drives the negatively charged organic semiconductor material to move toward the conductive substrate with the patterned anode and deposit on the patterned anode of the conductive substrate for 25 seconds. The conductive substrate with the thin film formed is taken out from the solution containing the charged organic semiconductor material and immersed in pure acetonitrile for 60 seconds under the condition of power on to remove the charged organic semiconductor material and the residual liquid that failed to be deposited on the anode. Subsequently, the conductive substrate with the thin film formed is dried at 100°C for 30 minutes to remove the acetonitrile solvent and the doped halogen atoms, and finally a dry film is obtained.

[0145] Film Example 2

[0146] The preparation method of film example 2 is substantially the same as that of film example 1, except that:

[0147] In step (2), the iodine element is replaced by chlorine element.

[0148] Film Example 3

[0149] The preparation method of film example 3 is substantially the same as that of film example 1, except that:

[0150] In step (2), the material PVK is dissolved in chloroform at a concentration of 8 g / L; and the iodine element is dissolved in chloroform at a concentration of 5 g / L.

[0151] Film Example 4

[0152] The preparation method of film example 4 is substantially the same as that of film example 1, except that:

[0153] In step (2), the material PVK is changed to mCP.

[0154] Film Example 5

[0155] The preparation method of film example 5 is substantially the same as that of film example 1, except that:

[0156] In step (3), the negatively charged organic semiconductor material moves directionally toward the conductive substrate with the patterned anode for 50 seconds.

[0157] Film Example 6

[0158] The preparation method of film example 6 is substantially the same as that of film example 1, except that:

[0159] In step (3), the strength of the electric field generated between the two conductive substrates is 12×10 4 V / m.

[0160] Film Comparative Example 1

[0161] (1) Provide a clean conductive substrate with a patterned anode, and immerse the conductive substrate with the anode facing upward in a mixed solution of ODCB:H2O2, wherein the molar ratio of ODCB:H2O2 in the mixed solution is 1:1.5. Then, place the mixed solution without the conductive substrate under a UV lamp for UV ozone treatment for 5 minutes, then take the conductive substrate out of the mixed solution, and immerse it in an ethanol solution for 5 times, and then dry it. Then, place it in a UV ozone device to irradiate the anode surface for 15 minutes to completely remove the chlorocarbon residues on the anode surface, and obtain a surface chlorinated ITO anode.

[0162] (2) A chloroform solution of PVK with a concentration of 15 g / L was spin-coated on the patterned anode of the conductive substrate at a spin coating speed of 2000 rpm using a spin coater, and then the conductive substrate was placed on a hot plate at 100° C. for annealing for 20 min to obtain a thin film made of PVK.

[0163] Film Comparative Example 2

[0164] The preparation method of the film comparative example 2 is substantially the same as the preparation method of the film example 1, except that:

[0165] The material PVK was dissolved in chloroform at a concentration of 0.1 g / L; the iodine element was dissolved in chloroform at a concentration of 0.1 g / L.

[0166] Film Comparative Example 3

[0167] The preparation method of the comparative film example 3 is substantially the same as that of the film example 1, except that:

[0168] In step (3), the time for the negatively charged organic semiconductor material to move directionally toward the conductive substrate with the patterned anode is 1 s.

[0169] Film Comparative Example 4

[0170] The preparation method of the comparative film example 4 is substantially the same as that of the film example 1, except that:

[0171] In step (3), the strength of the electric field generated between the two conductive substrates is 1×10 3 V / m.

[0172] The thickness, root mean square surface roughness and repeatability of the films prepared in Film Examples 1 to 6 and Film Comparative Examples 1 to 4 were tested respectively. The test results are shown in Table 1 below.

[0173] Table 1 Thickness, RMS Surface Roughness and Repeatability of Films Prepared from Film Examples 1 to 6 and Film Comparative Examples 1 to 4

[0174]

[0175]

[0176] Among them, the thickness and root mean square surface roughness Rq are obtained through AFM (atomic force microscope) test; the repeatability is calculated by counting the thickness of 50 films prepared by the same method. The calculation principle is: take the average value of the thickness of the 50 films as the reference value a, and among the 50 films, count the total number of all thicknesses with deviations from the reference value a less than or equal to ±3nm, set to b, and b / a is the film thickness repeatability value.

[0177] The smaller the root mean square surface roughness Rq, the more uniform the film and the better the quality. The larger the repeatability value, the better the process repeatability and the more stable it is.

[0178] As can be seen from Table 1 above, the thin film prepared in the thin film embodiment has higher flatness and uniformity than the thin film prepared by the solution method (i.e., spin coating method) in the thin film comparison example, and the thin film prepared in the thin film embodiment shows better film repeatability, indicating that the method adopted in the thin film embodiment is a stable thin film preparation method, which is conducive to improving the yield of the thin film. The comparison between different thin film embodiments shows that the change of doping material, electric field strength and time of applying the electric field can change the quality of the film, and different organic host materials have different film properties, so different processes need to be adopted.

[0179] Thin film comparative examples 2, 3, and 4 show that deviations from the specified condition range will affect the quality of the film. Specifically, low concentration, electric field strength, and application time will reduce the thickness of the film, seriously affecting the surface roughness and repeatability of the film deposition. Because the above conditions will cause the charged solute to be unable to be completely deposited on the substrate, the bonding force with the substrate is weak, the film is loose, and the compactness is poor. The optoelectronic device and its preparation method in this application are described in detail below through examples and comparative examples.

[0180] Device Example 1

[0181] (1) Provide a clean conductive substrate with a patterned anode, and immerse the conductive substrate with the anode facing upward in a mixed solution of ODCB:H2O2, wherein the molar ratio of ODCB:H2O2 in the mixed solution is 1:1.5. Then, place the mixed solution without the conductive substrate under a UV lamp for UV ozone treatment for 5 minutes, then take the conductive substrate out of the mixed solution, and immerse it in an ethanol solution for 5 times, and then dry it. Then, place it in a UV ozone device to irradiate the anode surface for 15 minutes to completely remove the chlorocarbon residues on the anode surface, and obtain a surface chlorinated ITO anode.

[0182] (2) The hole transport layer material PVK was dissolved in chloroform at a concentration of 8 g / L, and then heated at 45°C and stirred for 20 minutes to obtain a first mixed solution. The iodine element was dissolved in chloroform at a concentration of 10 g / L and maintained for 1 hour to obtain a second mixed solution. 1.6 mL of the second mixed solution was added to 10 mL of the first mixed solution to obtain an intermediate mixed solution, and then 8.4 mL of chloroform was added to the intermediate mixed solution for dilution, and finally a third mixed solution containing doped semiconductor materials with a concentration of 4 g / L was obtained. Then, under vigorous stirring, 1 mL of the third mixed solution was injected into 7 mL of acetonitrile within 0.8 seconds. The mixed solution obtained by mixing the third mixed solution and acetonitrile was heated at 70°C until the chloroform was removed and part (3 mL) of the acetonitrile volatilized, and finally a solution containing charged organic semiconductor materials with a concentration of 1 g / L was obtained.

[0183] (3) placing the conductive substrate with the patterned anode obtained in step (1) and another conductive substrate in a solution containing a charged organic semiconductor material, and placing them opposite to each other, and then connecting the conductive substrate with the patterned anode to the positive electrode of a power source, and connecting the other conductive substrate to the negative electrode of the power source, so as to generate a 9×10 4 The electric field is 100 V / m, and the generated electric field drives the negatively charged organic semiconductor material to move toward the conductive substrate with the patterned anode, and deposits on the patterned anode of the conductive substrate, and lasts for 25 seconds to form a 30nm thick hole transport layer on the patterned anode. The conductive substrate with the hole transport layer is taken out from the solution containing the charged organic semiconductor material, and is immersed in pure acetonitrile for 60 seconds under power-on conditions to remove the charged organic semiconductor material and residual liquid that failed to be deposited on the anode. Subsequently, the conductive substrate with the hole transport layer is dried at 100°C for 30 minutes to remove the acetonitrile solvent and the doped halogen atoms, and finally a dry hole transport layer is obtained.

[0184] (4) The light-emitting layer material mCP is dissolved in chloroform at a concentration of 8 g / L, and then heated at 45°C and stirred for 20 minutes to obtain a first mixed solution. The iodine element is dissolved in chloroform at a concentration of 10 g / L and maintained for 1 hour to obtain a second mixed solution. 1.6 mL of the second mixed solution is added to 10 mL of the first mixed solution to obtain an intermediate mixed solution, and then 8.4 mL of chloroform is added to the intermediate mixed solution for dilution, and finally a third mixed solution containing doped semiconductor materials with a concentration of 4 g / L is obtained. Then, under vigorous stirring, 1 mL of the third mixed solution is injected into 7 mL of acetonitrile within 0.8 seconds. The mixed solution obtained by mixing the third mixed solution and acetonitrile is then heated at 70°C until the chloroform is removed and part (3 mL) of the acetonitrile is volatilized, and finally a solution containing charged organic semiconductor materials with a concentration of 1 g / L is obtained.

[0185] (5) placing the conductive substrate with the hole transport layer obtained in step (3) and another conductive substrate in a solution containing a charged organic semiconductor material, and placing them opposite to each other, and then connecting the conductive substrate with the hole transport layer to the positive electrode of a power source, and connecting the other conductive substrate to the negative electrode of the power source, so as to generate a strength of 8.5×10 4 The electric field of 100 V / m is applied to the conductive substrate with a hole transport layer, and the generated electric field drives the negatively charged organic semiconductor material to move in a directional manner toward the conductive substrate with a hole transport layer, and deposits on the hole transport layer of the conductive substrate, and lasts for 35 seconds to form a 35 nm thick light-emitting layer on the hole transport layer. The conductive substrate with the light-emitting layer is taken out from the solution containing the charged organic semiconductor material, and is immersed in pure acetonitrile for washing for 60 seconds under power-on conditions to remove the charged organic semiconductor material and residual liquid that failed to be deposited on the hole transport layer. Subsequently, the conductive substrate with the light-emitting layer is dried at 100°C for 30 minutes to remove the acetonitrile solvent and the doped halogen atoms, and finally a dry light-emitting layer is obtained.

[0186] (6) The electron transport layer material TPBi was dissolved in chloroform at a concentration of 8 g / L, and then heated at 45°C and stirred for 20 minutes to obtain a first mixed solution. The iodine element was dissolved in chloroform at a concentration of 10 g / L and maintained for 1 hour to obtain a second mixed solution. 1.6 mL of the second mixed solution was added to 10 mL of the first mixed solution to obtain an intermediate mixed solution, and then 8.4 mL of chloroform was added to the intermediate mixed solution for dilution, and finally a third mixed solution containing doped semiconductor materials with a concentration of 4 g / L was obtained. Then, under vigorous stirring, 1 mL of the third mixed solution was injected into 7 mL of acetonitrile within 0.8 seconds. The mixed solution obtained by mixing the third mixed solution and acetonitrile was heated at 70°C until the chloroform was removed and part (3 mL) of the acetonitrile volatilized, and finally a solution containing charged organic semiconductor materials with a concentration of 1 g / L was obtained.

[0187] (7) placing the conductive substrate with the light-emitting layer obtained in step (5) and another conductive substrate in a solution containing a charged organic semiconductor material, and placing them opposite to each other, and then connecting the conductive substrate with the light-emitting layer to the positive electrode of a power source, and connecting the other conductive substrate to the negative electrode of the power source, so as to generate a light wave with an intensity of 8×10 4The electric field of 100 V / m is applied to the conductive substrate with the light-emitting layer, and the generated electric field drives the negatively charged organic semiconductor material to move in a directional manner toward the conductive substrate with the light-emitting layer, and deposits on the light-emitting layer of the conductive substrate, and lasts for 35 seconds to form a 40 nm thick electron transport layer on the light-emitting layer. The conductive substrate with the electron transport layer is taken out from the solution containing the charged organic semiconductor material, and is immersed in pure acetonitrile for washing for 60 seconds under power-on conditions to remove the charged organic semiconductor material and residual liquid that failed to be deposited on the electron transport layer. Subsequently, the conductive substrate with the electron transport layer is dried at 100°C for 30 minutes to remove the acetonitrile solvent and the doped halogen atoms, and finally a dry electron transport layer is obtained.

[0188] (8) placing the conductive substrate with the electron transport layer obtained in step (7) in a vapor deposition chamber, and thermally evaporating a layer of silver with a thickness of 100 nm on the electron transport layer through a mask plate as a cathode, thereby obtaining a photoelectric device.

[0189] Device Comparative Example 1

[0190] (1) Provide a clean conductive substrate with a patterned anode, and immerse the conductive substrate with the anode facing upward in a mixed solution of ODCB:H2O2, wherein the molar ratio of ODCB:H2O2 in the mixed solution is 1:1.5. Then, place the mixed solution without the conductive substrate under a UV lamp for UV ozone treatment for 5 minutes, then take the conductive substrate out of the mixed solution, and immerse it in an ethanol solution for 5 times, and then dry it. Then, place it in a UV ozone device to irradiate the anode surface for 15 minutes to completely remove the chlorocarbon residues on the anode surface, and obtain a surface chlorinated ITO anode.

[0191] (2) Spin coating a chloroform solution of PVK with a concentration of 15 g / L on the patterned anode of the conductive substrate at a spin coating speed of 2000 rpm, and then annealing the conductive substrate on a hot plate at 100° C. for 20 min to obtain a hole transport layer with a thickness of 30 nm. The material of the hole transport layer is PVK.

[0192] (3) Spin coating a chlorobenzene solution of mCP with a concentration of 40 g / L on the hole transport layer at a spin coating speed of 2500 rpm, and then annealing the conductive substrate on a hot plate at 100° C. for 20 min to form a 35 nm thick light-emitting layer, wherein the material of the light-emitting layer is mCP.

[0193] (4) Spin coating a TPBi toluene solution with a concentration of 35 g / L on the light-emitting layer at a spin coating speed of 2000 rpm, and then anneal the charged substrate on a hot plate at 100° C. for 20 min to form a 40 nm thick electron transport layer, wherein the material of the electron transport layer is TPBi.

[0194] (5) placing the conductive substrate with the electron transport layer obtained in step (4) in a vapor deposition chamber, and thermally evaporating a layer of silver with a thickness of 100 nm on the electron transport layer through a mask plate as a cathode, thereby obtaining a photoelectric device.

[0195] (I) The T95 lifespan of any six pixels on the optoelectronic devices prepared in Example 1 and Comparative Example 1 at a luminous brightness of 1000 nit was tested by a lifespan testing system. The test results are shown in Table 2 below.

[0196] Table 2 T95 lifespan of any six pixels on the optoelectronic devices prepared in device example 1 and device comparative example 1 at 1000 nit luminous brightness

[0197] Device Example 1 Device Comparison Example 1 The lifetime of the first pixel 64h 41h The life span of the second pixel 62 h 67h The life span of the third pixel 66 h 59h The life span of the fourth pixel 62 h 70h The lifespan of the fifth pixel 64 h 43h The lifespan of the sixth pixel 63 h 55h Average lifespan of six pixels 63.5h 55.83h Variance of the lifetime of six pixels <![CDATA[1.92h 2 ]]> <![CDATA[120.14h 2 ]]>

[0198] As shown in Table 2 above, the average T95 life of any six pixels of the optoelectronic device prepared in Device Example 1 at a luminous brightness of 1000 nit is 63.5 h, with a variance of only 1.92 h. 2 , while the average T95 life of any six pixels of the optoelectronic device prepared in device comparative example 1 at 1000nit luminous brightness is only 55.83h, and the variance is as high as 120.14h 2 This indicates that the optoelectronic device prepared in Device Example 1 has a longer lifespan and is more uniform and stable than the optoelectronic device prepared in Device Comparative Example 1, thereby reflecting that the quality of each organic functional layer in the optoelectronic device prepared in Device Example 1 is more consistent than that in Device Comparative Example 1, thereby being able to improve the yield of the optoelectronic device prepared in Device Example 1.

[0199] (ii) The maximum current efficiency (CEmax) of any six pixels on the optoelectronic devices prepared in device example 1 and device comparison example 1 was tested by an IV-L test system. The test results are shown in Table 3 below.

[0200] Table 3 Maximum current efficiency of any six pixels on the optoelectronic devices prepared in device example 1 and device comparative example 1

[0201]

[0202]

[0203] As shown in Table 3 above, the maximum current efficiency of any six pixels of the optoelectronic device prepared in Device Example 1 is 7.4 cd / A, and the variance is only 0.01 cd. 2 / A 2 , while the maximum current efficiency of any six pixels of the optoelectronic device prepared in device comparative example 1 is only 6.48 cd / A, and the variance is as high as 0.96 cd 2 / A2 This indicates that the maximum current efficiency of the optoelectronic device prepared in Device Example 1 is higher than that of the optoelectronic device prepared in Device Comparative Example 1, and is more uniform and stable, thereby reflecting that the quality of each organic functional layer in the optoelectronic device prepared in Device Example 1 is more consistent than that in Device Comparative Example 1, thereby being able to improve the yield of the optoelectronic device.

[0204] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0205] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A method for preparing a thin film, characterized in that: The following steps are involved: providing a solution containing a charged organic semiconductor material; placing the solution containing the charged organic semiconductor material between a first substrate and a second substrate that are oppositely disposed; as well as An electric field is generated between the first substrate and the second substrate, so that the charged organic semiconductor material moves toward the first substrate or the second substrate and forms a thin film on the first substrate or the second substrate.

2. The method for preparing a thin film according to claim 1, characterized in that: The charged organic semiconductor material is a doped semiconductor material, and the doped semiconductor material comprises an organic semiconductor material and a doping element; and / or The solution containing the charged organic semiconductor material further comprises an organic solvent, wherein the dielectric constant of the organic solvent is greater than or equal to 20.

3. The method for preparing a thin film according to claim 2, characterized in that: The doping element is a halogen; Wherein, the halogen includes at least one of iodine, fluorine, chlorine and bromine.

4. The method for preparing a thin film according to claim 2, characterized in that: In the doped semiconductor material, the mass ratio of the doping element to the organic semiconductor material is (1:10) to (3:2).

5. The method for preparing a thin film according to claim 2, characterized in that: The organic semiconductor material includes at least one of an organic hole functional material, an organic light emitting material and an organic electronic functional material; Wherein, the organic hole functional material includes at least one of polyvinyl carbazole, TFB, CuPc, Poly-TPD, PFB, DNTPD, TCATA, TCCA, CBP, TPD, NPB, NPD, PEDOT:PSS, TAPC, MCC, F4-TCNQ, HATCN, 4,4',4'-tris(N-3-methylphenyl-Nphenylamino)triphenylamine and polyaniline; and / or The organic light-emitting material includes at least one of 1,3-bis(N-carbazolyl)benzene, 4,4'-bis(N-carbazole)-1,1'-biphenyl, tris[2-(p-tolyl)pyridine-C2,N)iridium(III), 4,4',4"-tris(carbazole-9-yl)triphenylamine: tris[2-(p-tolyl)pyridine-C2,N)iridium, diaromatic anthracene derivatives, distilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent materials, TTPX fluorescent materials, TBRb fluorescent materials and DBP fluorescent materials, polyacetylene and its derivatives, polyparaphenylene and its derivatives, polythiophene and its derivatives, and polyfluorene and its derivatives; and / or The organic electronic functional material includes at least one of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene compounds, hydroxyquinoline compounds, polythiophene compounds, perylene imide compounds and fullerene compounds; Wherein, the imidazole compound includes 1,3,5-tris(1-phenyl-1H-benzimidazole-2-yl)benzene; Wherein, the fluorene-containing compound includes at least one of WPF-oxy-F, WPF-6-oxy-F, PF-EP, PFNBr, PFSO3Na, PFBTBr, 3TPA-FEP, PF-NS, PF-N-SOC8, FFiF, FPF, ZnO:PFN, PmP-NOH, PmP36F-NOH, PFBD, PEI:PF1, FCF and PF15-b-PDMAEMA75; Wherein, the polythiophene compound includes at least one of P3HTN, PT3SB, PT2BTDPPSB, PT2NDISB, PT6N, PBTAZPOBr and PCPDTTPD-Im; Wherein, the perylene imide compound includes at least one of PDINO, PDIP, PBI-H, FPDI, PDIN and PTCDI-C8; Wherein, the fullerene compound includes at least one of DMAPA-C60, C60-ETA, C60-PEG, rGO-pyrene-PCBM, FPI-PEIE and Fullerenol; and / or The organic solvent includes acetonitrile, glycerol, furfural, ethylene glycol, nitromethane, nitrobenzene, methanol, propionitrile, o-nitrotoluene, benzonitrile, ethanol, chloroethanol, acetylacetone, propanol, acetone, chloroacetic acid, acetic anhydride, formamide, N-methylamide, DMSO, DMF, benzonitrile, acetic anhydride, n-propanol, butanone, xylene, n-hexanol, n-pentanol, cyclohexanone, methyl isobutyl ketone, diethyl ketone, N-methylmorpholine, ethylene glycol monobutyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, N-methylpyrrolidone, dimethylacetamide, trichlorothiophosphorus, carbon tetrachloride, tribromoform, trichloroethane ... At least one of vinyl chloride, hydrazine, antimony tribromide, formic acid, hydrogen cyanide, trifluoroacetic acid, 2-chloroethane, nitroethane, epichlorohydrin, allyl alcohol, lactic acid, N,N-dimethylformamide, 1-nitropropane, 2-nitropropane, 1-propanol, 1,2-propylene glycol, 1,3-propylene glycol, maleic anhydride, succinonitrile, methyl cyanoacetate, 2-methylpropionitrile, bis(2-chloroethyl) ether, 2,4-pentanedione, o-chloronitrobenzene, m-chloronitrobenzene, o-nitroaniline, p-nitroaniline, hexanediol, benzonitrile, o-nitrotoluene, m-nitrotoluene and p-nitrotoluene.

6. The method for preparing a thin film according to claim 1, characterized in that: The first substrate and the second substrate are conductive substrates; and / or Generating an electric field between the first substrate and the second substrate comprises the following steps: Connecting one of the first substrate and the second substrate to the positive electrode of a power source, and connecting the other of the first substrate and the second substrate to the negative electrode of the power source; and / or The electric field is a direct current electric field; and / or The strength of the electric field is 1×10 4 V / m~1×10 8 V / m; and / or The electric field is applied for a time period of 5s to 7200s.

7. The method for preparing a thin film according to claim 1, characterized in that: The first substrate and / or the second substrate has patterned electrodes thereon; The electrode is selected from a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal single substance electrode or an alloy electrode; The material of the doped metal oxide particle electrode includes one or more of indium-doped tin oxide, fluorine-doped tin oxide, antimony-doped tin oxide, aluminum-doped zinc oxide, gallium-doped zinc oxide, indium-doped zinc oxide, magnesium-doped zinc oxide and aluminum-doped magnesium oxide. Wherein, the composite electrode comprises 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 or ZnS / Al / ZnS; Among them, the material of the metal single substance electrode includes one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg and Ba.

8. The method for preparing a thin film according to claim 2, characterized in that: The preparation of the solution containing the charged organic semiconductor material comprises the following steps: Providing the organic semiconductor material and a first solvent, and mixing the organic semiconductor material and the first solvent to obtain a first mixed solution; Providing a doping element single substance and a second solvent, and mixing the doping element single substance and the second solvent to obtain a second mixed solution; mixing the first mixed solution and the second mixed solution to obtain a third mixed solution containing a doped semiconductor material; and The third mixed liquid and the organic solvent are mixed to obtain the solution containing the charged organic semiconductor material, wherein the solubility of the doped semiconductor material in the organic solvent is lower than the solubility of the doped semiconductor material in the first solvent and the second solvent.

9. The method for preparing a thin film according to claim 8, characterized in that: In the first mixed solution, the concentration of the organic semiconductor material is 0.5 g / L to 500 g / L; and / or In the second mixed solution, the concentration of the doping element is 0.5 g / L to 500 g / L; and / or In the step of mixing the first mixed solution and the second mixed solution, the volume ratio of the first mixed solution to the second mixed solution is (1:10) to (10:1); and / or In the step of mixing the third mixed liquid and the organic solvent, the volume ratio of the third mixed liquid to the organic solvent is (1:10) to (10:1); and / or The doping element single substance is a halogen single substance, and the halogen single substance includes at least one of iodine single substance, fluorine single substance, chlorine single substance and bromine single substance.

10. The method for preparing a thin film according to claim 8, characterized in that: The boiling point of the organic solvent is greater than the boiling points of the first solvent and the second solvent; and / or The first solvent and the second solvent independently include at least one of aromatic hydrocarbon compounds, aliphatic hydrocarbon compounds, alicyclic hydrocarbon compounds, halogenated hydrocarbon compounds, alcohol compounds, ether compounds, ester compounds and ketone compounds; Wherein, the aromatic hydrocarbon compound includes at least one of benzene, toluene, ethylbenzene, xylene, styrene, acetophenone, nitrobenzene, chlorobenzene, bromobenzene and iodobenzene; The aliphatic hydrocarbon compound includes at least one of pentane, hexane, heptane, octane, nonane, decane, tridecane, tetradecane, pentadecane and hexadecane; The alicyclic hydrocarbon compound includes at least one of cyclohexane, cyclopentane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cyclopentadecane, cyclohexadecane, cyclooctadecane and cycloeicosane; The halogenated hydrocarbon compound includes at least one of methyl chloride, dichloromethane, chloroform, carbon tetrachloride, methyl bromide, dibromomethane, bromoform, methyl iodide, diiodomethane and triiodoform; The alcohol compound includes at least one of methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol and decanol; The ether compound includes at least one of methyl ether, ethyl ether, propyl ether, butyl ether, pentyl ether, hexyl ether, heptyl ether, octyl ether, nonyl ether and decyl ether; The ester compound comprises at least one of methyl formate, ethyl acetate, propyl propionate, butyl butyrate, pentyl valerate, hexyl hexanoate, heptyl heptanoate, octyl octanoate, nonyl nonanoate and decyl decanoate; The ketone compound includes at least one of acetone, butanone, pentanone, hexanone, heptanone, octanone, nonanone, decanone, undecanone and dodecanone.

11. The method for preparing a thin film according to claim 8, characterized in that: After the third mixed solution and the organic solvent are mixed, the preparation of the solution containing the charged organic semiconductor material further comprises the following steps: Mixing the third mixed liquid and an organic solvent to obtain a fourth mixed liquid; heating the fourth mixed liquid; and removing the agglomerates in the heated fourth mixed solution to obtain the solution containing the charged organic semiconductor material; and / or The heating temperature is greater than the boiling points of the first solvent and the second solvent, and less than the boiling point of the organic solvent.

12. A film, characterized in that: The film is prepared by the preparation method according to any one of claims 1 to 11.

13. A method for preparing a photoelectric device, characterized in that: The following steps are involved: Providing a first substrate and a second substrate, wherein the first substrate comprises a first electrode, and the first electrode and the second substrate are arranged opposite to each other; The thin film is prepared on the first electrode between the first substrate and the second substrate by using the preparation method as described in any one of claims 1 to 11 to form an organic functional layer; A second electrode is prepared on the organic functional layer.

14. A photoelectric device, characterized in that: The invention comprises a first electrode and a second electrode which are arranged opposite to each other, wherein a thin film is arranged between the first electrode and the second electrode, and the thin film is prepared by the preparation method according to any one of claims 1 to 11.

15. A display device, characterized in that: The invention comprises a photovoltaic device prepared by the preparation method according to claim 13, or a photovoltaic device according to claim 14.

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