Composite material, thin film, preparation method of thin film, photoelectric device and display device

Abstract

The invention discloses a composite material, a film, a preparation method of the film, a photoelectric device and a display device, the composite material comprises an elastic ferroelectric polymer and ionic liquid, and the elastic ferroelectric polymer is formed by crosslinking a ferroelectric material and a crosslinking agent. The composite material disclosed by the invention not only has ferroelectric characteristics, but also has relatively good flexibility.

Description

Technical Field

[0001] The present application relates to the field of display technologies, and particularly to a composite material, a film, a preparation method thereof, an optoelectronic device, and a display device. Background Art

[0002] Currently, the widely used optoelectronic devices are organic light-emitting devices (OLEDs) and quantum dot light-emitting devices (QLEDs). Due to their excellent display performances such as self-luminescence, simple structure, ultra-thinness, fast response speed, wide viewing angle, low power consumption, and flexible display, OLEDs have become the mainstream technology in the field of display technologies. QLEDs have the advantages of saturated emission light color, adjustable wavelength, low turn-on voltage, good solution processability, easy fine control of quantum dots, etc., and have high photoluminescence and electroluminescence quantum yields, and have become a strong competitor to OLEDs in recent years.

[0003] The structures of traditional OLED and QLED devices generally include an anode, a hole injection layer, a hole transport layer, a light-emitting layer, an electron transport layer, an electron injection layer, and a cathode. Under the action of an electric field, the holes generated by the anode and the electrons generated by the cathode of the optoelectronic device move, are respectively injected into the hole transport layer and the electron transport layer, and finally migrate to the light-emitting layer. When the two meet in the light-emitting layer, energy excitons are generated, thereby exciting the light-emitting molecules to finally generate visible light.

[0004] However, the light emission uniformity of existing optoelectronic devices is poor. Summary of the Invention

[0005] In view of this, the present application provides a composite material, a film, a preparation method thereof, an optoelectronic device, and a display device.

[0006] The embodiment of the present application is implemented as follows. A composite material includes an elastic ferroelectric polymer and an ionic liquid, wherein the elastic ferroelectric polymer is formed by cross-linking a ferroelectric material and a cross-linking agent.

[0007] Optionally, in some embodiments of the present application, the composite material is composed of the elastic ferroelectric polymer and the ionic liquid.

[0008] Optionally, in some embodiments of the present application, the ferroelectric material includes a linear ferroelectric material, and the linear ferroelectric material includes a polyvinylidene fluoride-based compound; and / or

[0009] The cross-linking agent includes a flexible cross-linking agent, and the flexible cross-linking agent includes one or more of a polyamine-based flexible cross-linking agent, a polyether-based flexible cross-linking agent, and a polyester-based flexible cross-linking agent; and / or

[0010] The ionic liquid includes a methylimidazole-based ionic liquid.

[0011] Optionally, in some embodiments of the present application, the polyvinylidene fluoride-based compound includes one or more of poly(vinylidene fluoride-trifluoroethylene), polyvinylidene difluoride, polyvinylidene fluoride, poly(vinylidene difluoride-co-trifluoroethylene), poly(vinylidene difluoride-co-hexafluoropropylene); and / or

[0012] The polyamine-based flexible crosslinking agent includes one or more of polyethylene oxide diamine, polyethyleneimine, and polyethylene glycol diamine. The polyether-based flexible crosslinking agent includes polyethylene glycol, and the polyester-based flexible crosslinking agent includes one or more of polycaprolactone; and / or

[0013] The methylimidazole-based ionic liquid includes one or more of 1-butyl-3-methylimidazole cyanide, 1-propyl-3-methylimidazole bromide, 1-propyl-3-methylimidazole iodide, 1-butyl-3-methylimidazole chloride, and 1-ethyl-3-methylimidazole bromide.

[0014] Optionally, in some embodiments of the present application, the mass ratio of the ferroelectric material to the crosslinking agent is (50-100):1; and / or

[0015] The mass ratio of the ferroelectric material to the ionic liquid is (20-50):1; and / or

[0016] The crosslinking density of the elastic ferroelectric polymer is 1-2%.

[0017] Correspondingly, an embodiment of the present application further provides a film including the composite material.

[0018] Correspondingly, an embodiment of the present application further provides a method for preparing a film, including the following steps:

[0019] Providing a mixed solution including a ferroelectric material, a crosslinking agent, an ionic liquid, and a solvent; and

[0020] Depositing the mixed solution and heating to obtain a film.

[0021] Optionally, in some embodiments of the present application, the solvent includes one or more of N,N-dimethylformamide, isopropanol, ethanol, dimethyl sulfoxide, N-methylpyrrolidone, chlorobenzene, toluene, xylene, and acetone; and / or

[0022] The mass ratio of the ferroelectric material to the crosslinking agent is (50-100):1; and / or

[0023] The mass ratio of the ferroelectric material to the ionic liquid is (20-50):1; and / or

[0024] The temperature of the heating is 100-120 °C, and the time is 10-20 min; and / or

[0025] The ferroelectric material includes a linear ferroelectric material, the linear ferroelectric material includes a polyvinylidene fluoride-based compound, and the polyvinylidene fluoride-based compound includes one or more of poly(vinylidene fluoride-trifluoroethylene), polyvinylidene difluoride, polyvinylidene fluoride, poly(vinylidene difluoride-co-trifluoroethylene), and poly(vinylidene difluoride-co-hexafluoropropylene); and / or

[0026] The crosslinking agent includes a flexible crosslinking agent, the flexible crosslinking agent includes one or more of a polyamine-based flexible crosslinking agent, a polyether-based flexible crosslinking agent, and a polyester-based flexible crosslinking agent. Among them, the polyamine-based flexible crosslinking agent includes one or more of polyethylene oxide diamine, polyethyleneimine, and polyethylene glycol diamine, the polyether-based flexible crosslinking agent includes polyethylene glycol, and the polyester-based flexible crosslinking agent includes one or more of polycaprolactone; and / or

[0027] The ionic liquid includes a methylimidazole-based ionic liquid, and the methylimidazole-based ionic liquid includes one or more of 1-butyl-3-methylimidazole cyanide, 1-propyl-3-methylimidazole bromide, 1-propyl-3-methylimidazole iodide, 1-butyl-3-methylimidazole chloride, and 1-ethyl-3-methylimidazole bromide.

[0028] Correspondingly, an embodiment of the present application further provides an optoelectronic device, including an anode and a cathode disposed opposite to each other, and a functional layer disposed between the anode and the cathode, where

[0029] A first ferroelectric layer is disposed between the anode and the functional layer, and the material of the first ferroelectric layer includes a first composite material, and the first composite material includes a first elastic ferroelectric polymer and a first ionic liquid. Among them, the first elastic ferroelectric polymer is formed by crosslinking a first ferroelectric material and a first crosslinking agent; and / or

[0030] A second ferroelectric layer is disposed between the cathode and the functional layer, and the material of the second ferroelectric layer includes a second composite material, and the second composite material includes a second elastic ferroelectric polymer and a second ionic liquid. Among them, the second elastic ferroelectric polymer is formed by crosslinking a second ferroelectric material and a second crosslinking agent.

[0031] Optionally, in some embodiments of the present application, the functional layer includes m sub-functional layers, and the optoelectronic device further includes n third ferroelectric layers, where m≥2, m - n≥1, and each third ferroelectric layer is located between two adjacent sub-functional layers. The material of the third ferroelectric layer includes a third composite material, and the third composite material includes a third elastic ferroelectric polymer and a third ionic liquid. Among them, the third elastic ferroelectric polymer is formed by crosslinking a third ferroelectric material and a third crosslinking agent.

[0032] Optionally, in some embodiments of the present application, the first ferroelectric material, the second ferroelectric material, and the third ferroelectric material each independently include a linear ferroelectric material, and the linear ferroelectric material includes a polyvinylidene fluoride-based compound; and / or

[0033] The first crosslinking agent, the second crosslinking agent, and the third crosslinking agent each independently include a flexible crosslinking agent, and the flexible crosslinking agent includes one or more of a polyamine-based flexible crosslinking agent, a polyether-based flexible crosslinking agent, and a polyester-based flexible crosslinking agent; and / or

[0034] The first ionic liquid, the second ionic liquid, and the third ionic liquid each independently include a methylimidazole-based ionic liquid.

[0035] Optionally, in some embodiments of the present application, the polyvinylidene fluoride-based compound includes one or more of poly(vinylidene fluoride-trifluoroethylene), polyvinylidene difluoride, polyvinylidene fluoride, poly(vinylidene difluoride-co-trifluoroethylene), and poly(vinylidene difluoride-co-hexafluoropropylene); and / or

[0036] The polyamine-based flexible crosslinking agent includes one or more of polyethylene oxide diamine, polyethyleneimine, and polyethylene glycol diamine, the polyether-based flexible crosslinking agent includes polyethylene glycol, and the polyester-based flexible crosslinking agent includes one or more of polycaprolactone; and / or

[0037] The methylimidazole-based ionic liquid includes one or more of 1-butyl-3-methylimidazole cyanide, 1-propyl-3-methylimidazole bromide, 1-propyl-3-methylimidazole iodide, 1-butyl-3-methylimidazole chloride, and 1-ethyl-3-methylimidazole bromide; and / or

[0038] The first ferroelectric material, the second ferroelectric material, and the third ferroelectric material are the same or different; and / or

[0039] The first crosslinking agent, the second crosslinking agent, and the third crosslinking agent are the same or different; and / or

[0040] The first ionic liquid, the second ionic liquid, and the third ionic liquid are the same or different.

[0041] Optionally, in some embodiments of the present application, the mass ratio of the ferroelectric material to the crosslinking agent is (50-100):1; and / or

[0042] The mass ratio of the ferroelectric material to the ionic liquid is (20-50):1; and / or

[0043] The crosslinking density of the elastic ferroelectric polymer is 1-2%; and / or

[0044] The thickness of the first ferroelectric layer, the thickness of the second ferroelectric layer, and the thickness of the third ferroelectric layer are each independently 10 to 20 nm.

[0045] Optionally, in some embodiments of the present application, the functional layer includes a sub-functional layer, and the sub-functional layer is a light-emitting layer; or

[0046] The functional layer includes two sub-functional layers, and the two sub-functional layers are a light-emitting layer and an electron transport layer respectively, and the electron transport layer is located between the light-emitting layer and the cathode; or

[0047] The functional layer includes two sub-functional layers, and the two sub-functional layers are a light-emitting layer and a hole transport layer respectively, and the hole transport layer is located between the light-emitting layer and the anode; or

[0048] The functional layer includes three sub-functional layers, and the three sub-functional layers are a light-emitting layer, a hole transport layer, and a hole injection layer respectively, wherein the hole transport layer is located between the light-emitting layer and the anode, and the hole injection layer is located between the hole transport layer and the anode; or

[0049] The functional layer includes three sub-functional layers, and the three sub-functional layers are a light-emitting layer, an electron transport layer, and a hole transport layer respectively, wherein the electron transport layer is located between the light-emitting layer and the cathode 20, and the hole transport layer is located between the light-emitting layer and the anode; or

[0050] The functional layer includes four sub-functional layers, and the four sub-functional layers are a light-emitting layer, an electron transport layer, a hole transport layer, and a hole injection layer respectively, wherein the electron transport layer is located between the light-emitting layer and the cathode, the hole transport layer is located between the light-emitting layer and the anode, and the hole injection layer is located between the hole transport layer and the anode.

[0051] Optionally, in some embodiments of the present application, the anode and the cathode each independently include a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal single-element 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. The composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, or ZnS / Al / ZnS. The material of the metal single-element electrode includes one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg, and Ba; and / or

[0052] The material of the light-emitting layer includes one or more of an organic light-emitting material and a quantum dot light-emitting material. The organic light-emitting material includes one or more of 4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridineiridium(III)], 4,4',4''-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridineiridium, diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent material, TTPX fluorescent material, TBRb fluorescent material, DBP fluorescent material, delayed fluorescence material, TTA material, thermally activated delayed material, a polymer containing a B-N covalent bond, a hybrid local charge transfer excited state material, an exciplex luminescent material, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives;The quantum dot light-emitting material includes one or more of single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials. The shell layer of the core-shell structure quantum dots includes one or more layers. The materials of the single-structure quantum dots, the core materials of the core-shell structure quantum dots, and the shell layer materials of the core-shell structure quantum dots are each independently selected from one or more of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The II-VI group compounds include one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds include one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds include one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds include one or more of CuInS2, CuInSe2, and AgInS2. The perovskite semiconductor material includes doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors. The structural general formula of the inorganic perovskite semiconductor is AMX3, where A is Cs; + ions, M is a divalent metal cation, including Pb 2+ and Sn 2+, Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ One or more of, X is a halogen anion, including Cl - , Br - , I - One or more of; the structural general formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, where B is an organic amine cation, including CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation, including Pb 2+ , Sn 2+ , Cu 2+ , Ni 2 + , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ One or more of, X is a halogen anion, including Cl - , Br - , I - One or more of; and / or

[0053] The materials of the hole transport layer include one or more of 4,4'-N,N'-dicarbazolyl-biphenyl, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(N-vinylcarbazole) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine, spiro-NPB, poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline], 1,3-bis(carbazol-9-yl)benzene, polyaniline, polypyrrole, poly(p-phenylene vinylene), aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, doped graphene, undoped graphene, C60, doped or undoped NiO, doped or undoped MoO3, doped or undoped WO3, doped or undoped V2O5, doped or undoped p-type gallium nitride, doped or undoped CrO3, doped or undoped CuO; the materials of the hole injection layer include one or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, PEDOT, PEDOT:PSS, derivatives of PEDOT:PSS doped with s-MoO3, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, tetracyanoquinodimethane, copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide and copper oxide; and / or

[0054] The material of the hole injection layer includes one or more of 2,3,6,7,10,11 - hexacyano - 1,4,5,8,9,12 - hexaazatriphenylene, PEDOT, PEDOT:PSS, derivatives of PEDOT:PSS doped with s - MoO3, 4,4',4' - tris(N - 3 - methylphenyl - N - phenylamino)triphenylamine, tetracyanoquinodimethane, copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide; and / or

[0055] The material of the electron transport layer includes one or more of inorganic electron transport materials and organic electron transport materials. The inorganic electron transport materials include one or more of metal oxides, doped metal oxides, IIB - VIA group semiconductor materials, IIIA - VA group semiconductor materials, and IB - IIIA - VIA group semiconductor materials. The metal oxides include one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5; the metal oxides in the doped metal oxides include one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, Al2O3, and the dopants in the doped metal oxides include one or several of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, Sn; the IIB - VIA group semiconductor materials include one or more of ZnS, ZnSe, CdS; the IIIA - VA group semiconductor materials include one or more of InP, GaP; the IB - IIIA - VIA group semiconductor materials include one or more of CuInS, CuGaS; the organic electron transport materials include one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene - containing compounds, and hydroxyquinoline compounds.

[0056] Correspondingly, the embodiment of the present application further provides a display device, and the display device includes the above - mentioned optoelectronic device.

[0057] The composite material described in the present application includes the elastic ferroelectric polymer and the ionic liquid. The elastic ferroelectric polymer is formed by cross - linking the ferroelectric material and the cross - linker. The composite material has both ferroelectric properties and good flexibility. Description of the Drawings

[0058] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0059] Figure 1It is a flowchart of a method for preparing a thin film provided by an embodiment of the present application;

[0060] Figure 2 It is a schematic structural diagram of a first optoelectronic device provided by an embodiment of the present application;

[0061] Figure 3 It is a schematic structural diagram of a second optoelectronic device provided by an embodiment of the present application;

[0062] Figure 4 It is a schematic structural diagram of a third optoelectronic device provided by an embodiment of the present application;

[0063] Figure 5 It is a schematic structural diagram of a fourth optoelectronic device provided by an embodiment of the present application;

[0064] Figure 6 It is a schematic structural diagram of a fifth optoelectronic device provided by an embodiment of the present application;

[0065] Figure 7 It is a schematic structural diagram of a sixth optoelectronic device provided by an embodiment of the present application;

[0066] Figure 8 It is a flowchart of a method for preparing an optoelectronic device provided by an embodiment of the present application;

[0067] Figure 9 It is a flowchart of another method for preparing an optoelectronic device provided by an embodiment of the present application.

[0068] Reference numerals:

[0069] Optoelectronic device 100; Anode 10; Cathode 20; Functional layer 30; Light-emitting layer 31; Electron transport layer 32; Hole transport layer 33; Hole injection layer 34; First ferroelectric layer 40; Second ferroelectric layer 50; Third ferroelectric layer 60. Detailed implementation manners

[0070] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts fall within the protection scope of the present application. In addition, it should be understood that the specific implementation manners described herein are only used to illustrate and explain the present application, and are not used to limit the present application.

[0071] In this application, unless otherwise stated, the orientation terms such as "upper" and "lower" generally refer to the upper and lower directions in the actual use or working state of the device, specifically the drawing directions in the attached drawings; while "inner" and "outer" refer to the outline of the device. Additionally, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc. are only used as labels without imposing numerical requirements or establishing an order.

[0072] In this application, "and / or" describes the association relationship of associated objects and indicates that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Here, A and B can be singular or plural.

[0073] In this application, "at least one" means one or more, and "a plurality" means two or more. "At least one kind", "at least one of the following items (pieces)" or similar expressions refer to any combination of these items, including any combination of single items (pieces) or plural items (pieces). For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both represent: a, b, c, a - b (i.e., a and b), a - c, b - c, or a - b - c, where a, b, and c can be single or multiple respectively.

[0074] In this application, when forming another layer "on" a certain layer, the so-called "on" is a broad concept, which can mean that the formed another layer is adjacent to the certain layer, or there can be other spacer structure layers between the another layer and the certain layer. For example, when forming a cathode "on" the first charge transport layer, the so-called "on" can mean that the formed cathode is adjacent to the first charge transport layer, or there can be other spacer structure layers between the cathode and the first charge transport layer, such as a light-emitting layer.

[0075] The various embodiments of this application can exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be construed as a rigid limitation on the scope of this application; therefore, it should be considered that the description of the range has specifically disclosed all possible sub-ranges and the individual values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and the individual numbers within that range, such as 1, 2, 3, 4, 5, and 6, which applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0076] The technical solution of this application is as follows:

[0077] In a first aspect, an embodiment of the present application provides a composite material, including an elastic ferroelectric polymer and an ionic liquid. Among them, the elastic ferroelectric polymer is formed by crosslinking a ferroelectric material and a crosslinking agent.

[0078] The ionic liquid is doped in the elastic ferroelectric polymer.

[0079] In some embodiments, the composite material consists of the elastic ferroelectric polymer and the ionic liquid.

[0080] The composite material described in the present application includes the elastic ferroelectric polymer and the ionic liquid. The elastic ferroelectric polymer is formed by crosslinking the ferroelectric material and the crosslinking agent. The composite material not only has ferroelectric properties, can undergo electrode polarization under the action of an external electric field, generate a charge distribution on its surface, form polarization charges, and improve the charge distribution, but also has good flexibility and bendability, and also has good electrical conductivity.

[0081] The ferroelectric material can be a linear ferroelectric material, and the linear ferroelectric material includes but is not limited to polyvinylidene fluoride-based compounds. Further, the polyvinylidene fluoride-based compounds include but are not limited to poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)), polyvinylidene fluoride (PVDF), polyvinylidene fluoride, poly(vinylidene fluoride-co-trifluoroethylene), poly(vinylidene fluoride-co-hexafluoropropylene) (a polymer of 1,1,2,3,3,3-hexafluoro-1-propene and 1,1-difluoroethylene), etc. The ferroelectric material not only has excellent ferroelectricity but also can form a crosslinked network under the action of a crosslinking agent, thereby improving flexibility and stability.

[0082] The crosslinking agent includes a flexible crosslinking agent. Further, the flexible crosslinking agent includes but is not limited to one or more of polyamine-based flexible crosslinking agents, polyether-based flexible crosslinking agents, and polyester-based flexible crosslinking agents. Further, the polyamine-based flexible crosslinking agents include but are not limited to one or more of polyethylene oxide diamine (PEG-diamine), polyethyleneimine, and polyethylene glycol diamine. The polyether-based flexible crosslinking agent includes but is not limited to polyethylene glycol (PEG). The polyester-based flexible crosslinking agent includes but is not limited to one or more of polycaprolactone (PCL). The crosslinking agent can effectively bind the molecular chains of the ferroelectric material together to form a three-dimensional network structure, thereby enhancing the performance and stability of the material.

[0083] The ionic liquid includes but is not limited to methylimidazole-based ionic liquids. Further, the methylimidazole ionic liquid includes 1-butyl-3-methylimidazole cyanide (BMIM + CN -) One or more of 1 - propyl - 3 - methylimidazolium bromide, 1 - propyl - 3 - methylimidazolium iodide, 1 - butyl - 3 - methylimidazolium chloride, and 1 - ethyl - 3 - methylimidazolium bromide. The ionic liquid can effectively improve the conductivity and ferroelectricity of the composite material.

[0084] In some embodiments, the mass ratio of the ferroelectric material to the cross - linker is (50 - 100):1. For example, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, 85:1, 90:1, 95:1, 100:1, etc. Within this mass ratio range, the linear ferroelectric polymer material can be given elasticity, and the elastic ferroelectric polymer can maintain a high degree of crystallinity.

[0085] In some embodiments, the mass ratio of the ferroelectric material to the ionic liquid is (20 - 50):1. For example, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, etc. Within this mass ratio range, the composite material can have both ferroelectric properties, good flexibility and bendability, and good conductivity.

[0086] In some embodiments, the cross - linking density of the elastic ferroelectric polymer is 1 - 2%. For example, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2%, etc. Within this cross - linking density range, the linear ferroelectric polymer material can be given elasticity, and the elastic ferroelectric polymer can maintain a high degree of crystallinity.

[0087] In a second aspect, the present application also provides a film, including the composite material described above.

[0088] The film has ferroelectric properties due to the composite material, and also has good flexibility, bendability and conductivity.

[0089] In a third aspect, please refer to Figure 1 , the present application also provides a method for preparing a film, including the following steps:

[0090] Step S11: Provide a mixed solution containing a ferroelectric material, a cross - linker, an ionic liquid and a solvent;

[0091] Step S12: Deposit the mixed solution and heat it to cross - link the ferroelectric material and the cross - linker to form a composite material, thereby obtaining a film.

[0092] It can be understood that the film includes the composite material described above.

[0093] The ferroelectric material, the cross - linker and the ionic liquid are as described above, and will not be elaborated here.

[0094] The solvents include, but are not limited to, one or more of N,N-dimethylformamide, isopropanol, ethanol, DMSO (dimethyl sulfoxide), NMP (N-methylpyrrolidone), chlorobenzene, toluene, xylene, and acetone.

[0095] It can be understood that the amount of the solvent is not limited as long as it can fully dissolve and disperse the ferroelectric material, crosslinking agent, and ionic liquid.

[0096] In some embodiments, the mass ratio of the ferroelectric material to the crosslinking agent is (50 - 100):1, for example, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, 85:1, 90:1, 95:1, 100:1, etc.

[0097] In some embodiments, the mass ratio of the ferroelectric material to the ionic liquid is (20 - 50):1, for example, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, etc.

[0098] In some embodiments, the heating temperature range is 100 - 120 °C, for example, 100 °C, 105 °C, 110 °C, 115 °C, 120 °C, etc., and the time range is 10 - 20 min, for example, 10 min, 12 min, 15 min, 16 min, 18 min, 20 min, etc. Within this range, it is beneficial for the full crosslinking of the ferroelectric material and the crosslinking agent, and it is also beneficial for the composite material to have good ferroelectric properties, flexibility, bendability, and conductivity.

[0099] In some embodiments, depositing the mixed solution includes: depositing the mixed solution on a film-forming substrate.

[0100] The film-forming substrate can be a substrate known for thin film preparation, such as one or more of a glass substrate, a silicon wafer substrate, a polycarbonate substrate, a polymethyl methacrylate substrate, a polyethylene terephthalate substrate, a polyethylene naphthalate substrate, a polyamide, and a polyethersulfone substrate.

[0101] In some other embodiments, depositing the mixed solution includes: depositing the mixed solution on an electrode or a functional layer of an optoelectronic device. It can be understood that the electrode can be a cathode or an anode, and the functional layer can be a light-emitting layer, an electron transport layer, a hole transport layer, or a hole injection layer.

[0102] Fourth aspect, please refer to Figures 2 to 7, embodiments of the present application further provide an optoelectronic device 100, including an anode 10 and a cathode 20 disposed opposite to each other, and a functional layer 30 disposed between the anode 10 and the cathode 20, where the functional layer 30 includes one or more sub-functional layers stacked. A first ferroelectric layer 40 is disposed between the anode 10 and the functional layer 30, and / or a second ferroelectric layer 50 is disposed between the cathode 20 and the functional layer 30.

[0103] The material of the first ferroelectric layer 40 includes a first composite material, and the first composite material includes a first elastic ferroelectric polymer and a first ionic liquid. Among them, the first elastic ferroelectric polymer is formed by cross-linking a first ferroelectric material and a first cross-linking agent.

[0104] The material of the second ferroelectric layer 50 includes a second composite material, and the second composite material includes a second elastic ferroelectric polymer and a second ionic liquid. Among them, the second elastic ferroelectric polymer is formed by cross-linking a second ferroelectric material and a second cross-linking agent.

[0105] The functional layer 30 includes m sub-functional layers, and the optoelectronic device further includes n third ferroelectric layers 60, where m≥2, m - n≥1, and each third ferroelectric layer 60 is located between two adjacent sub-functional layers.

[0106] The material of the third ferroelectric layer 60 includes a third composite material, and the third composite material includes a third elastic ferroelectric polymer and a third ionic liquid. Among them, the third elastic ferroelectric polymer is formed by cross-linking a third ferroelectric material and a third cross-linking agent.

[0107] The first ferroelectric material, the second ferroelectric material, and the third ferroelectric material each independently include the linear ferroelectric material described above. It can be understood that the first ferroelectric material, the second ferroelectric material, and the third ferroelectric material may be the same or different.

[0108] The first cross-linking agent, the second cross-linking agent, and the third cross-linking agent each independently include the flexible cross-linking agent described above. It can be understood that the first cross-linking agent, the second cross-linking agent, and the third cross-linking agent may be the same or different.

[0109] The first ionic liquid, the second ionic liquid, and the third ionic liquid each independently include the methylimidazole-based ionic liquid described above. It can be understood that the first ionic liquid, the second ionic liquid, and the third ionic liquid may be the same or different.

[0110] It can be understood that when there are multiple third ferroelectric layers 60, the materials of the multiple third ferroelectric layers 60 may be the same or different.

[0111] The optoelectronic device 100 includes at least one of the first ferroelectric layer 40, the second ferroelectric layer 50, and the third ferroelectric layer 60. Thus, under the action of an externally applied electric field, the elastic ferroelectric polymer in the ferroelectric layer can undergo an electrode polarization phenomenon, generating a charge distribution on its surface to form polarization charges, thereby improving the charge distribution and further enhancing the light emission uniformity of the optoelectronic device 100. Further, the ferroelectric layer also has good flexibility, bendability, and conductivity, which can effectively improve the flexibility, bendability, light emission efficiency, and lifespan of the optoelectronic device and other properties.

[0112] Taking the first ferroelectric layer 40 located between the anode 10 and the functional layer 30 as an example, the elastic ferroelectric polymer in the first ferroelectric layer 40 can undergo an electrode polarization phenomenon under the action of an externally applied electric field, generating a charge distribution on its surface to form polarization charges, and improving the distribution uniformity of holes in the hole functional layer and the light-emitting layer. Further, the light emission uniformity of the optoelectronic device 100 is enhanced.

[0113] It can be understood that the ferroelectric layer located between the light-emitting layer and the anode can improve the distribution uniformity of holes in the hole functional layer and the light-emitting layer, while the ferroelectric layer located between the light-emitting layer and the cathode can improve the distribution uniformity of electrons in the electron functional layer and the light-emitting layer.

[0114] In some embodiments, the thickness of the first ferroelectric layer 40, the thickness of the second ferroelectric layer 50, and the thickness of the third ferroelectric layer 60 are each independently 10 - 20 nm. For example, 10 nm, 12 nm, 13 nm, 15 nm, 16 nm, 18 nm, 20 nm, etc. Within this thickness range, the flexibility, bendability, light emission uniformity, light emission efficiency, lifespan, and other properties of the optoelectronic device can be effectively improved.

[0115] It can be understood that the thickness of the first ferroelectric layer 40, the thickness of the second ferroelectric layer 50, and the thickness of the third ferroelectric layer 60 can be the same or different.

[0116] It can be understood that when there are multiple third ferroelectric layers 60, the thicknesses of the multiple ferroelectric layers 60 can be the same or different.

[0117] Please refer to Figure 2 , in some embodiments, the functional layer 30 includes one sub-functional layer, and the sub-functional layer is the light-emitting layer 31.

[0118] Please refer to Figure 3 , in some embodiments, the functional layer 30 includes two sub-functional layers, the two sub-functional layers are respectively the light-emitting layer 31 and the electron transport layer 32, and the electron transport layer 32 is located between the light-emitting layer 31 and the cathode 20.

[0119] Please refer to Figure 4, in some embodiments, the functional layer 30 includes two sub-functional layers, namely a light-emitting layer 31 and a hole-transporting layer 33, and the hole-transporting layer 33 is located between the light-emitting layer 31 and the anode 10.

[0120] Please refer to Figure 5 , in some embodiments, the functional layer 30 includes three sub-functional layers, namely a light-emitting layer 31, a hole-transporting layer 33, and a hole-injecting layer 34. Among them, the hole-transporting layer 33 is located between the light-emitting layer 31 and the anode 10, and the hole-injecting layer 34 is located between the hole-transporting layer 33 and the anode 10.

[0121] Please refer to Figure 6 , in some embodiments, the functional layer 30 includes three sub-functional layers, namely a light-emitting layer 31, an electron-transporting layer 32, and a hole-transporting layer 33. Among them, the electron-transporting layer 32 is located between the light-emitting layer 31 and the cathode 20, and the hole-transporting layer 33 is located between the light-emitting layer 31 and the anode 10.

[0122] Please refer to Figure 7 , in some embodiments, the functional layer 30 includes four sub-functional layers, namely a light-emitting layer 31, an electron-transporting layer 32, a hole-transporting layer 33, and a hole-injecting layer 34. Among them, the electron-transporting layer 32 is located between the light-emitting layer 31 and the cathode 20, the hole-transporting layer 33 is located between the light-emitting layer 31 and the anode 10, and the hole-injecting layer 34 is located between the hole-transporting layer 33 and the anode 10.

[0123] The anode 10 and the cathode 20 are electrodes known in the art for optoelectronic devices. For example, they can independently include but are not limited to doped metal oxide electrodes, composite electrodes, graphene electrodes, carbon nanotube electrodes, elemental metal electrodes, or alloy electrodes. The materials of the doped metal oxide electrodes can include but are not limited to one or more of indium-doped tin oxide (ITO), fluorine-doped tin oxide (FTO), antimony-doped tin oxide (ATO), aluminum-doped zinc oxide (AZO), gallium-doped zinc oxide (GZO), indium-doped zinc oxide (IZO), magnesium-doped zinc oxide (MZO), aluminum-doped magnesium oxide (AMO), and cadmium-doped zinc oxide. The composite electrode is an electrode formed by laminating two or more layers of conductive materials. For example, AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS, ZnS / Al / ZnS, Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc. Herein, " / " represents a laminated structure. For example, AZO / Ag / AZO represents a composite electrode including an AZO layer, an Ag layer, and an AZO layer laminated in sequence. The materials of the elemental metal electrodes can include but are not limited to one or more of Ag, Ni, Pt, Au, Ir, Cu, Mo, Al, Ca, Mg, and Ba. The alloy electrodes include but are not limited to Au:Mg alloy electrodes and Ag:Mg alloy electrodes.

[0124] In some embodiments, the anode 10 is an electrode with a relatively high work function. For example, it can include but is not limited to a doped metal oxide electrode with a relatively high work function, an elemental metal electrode with a relatively high work function, and a carbon nanotube electrode. The elemental metal electrode with a relatively high work function can be selected from but is not limited to Ni, Pt, Au, Ag, Ir, etc.

[0125] In some embodiments, the cathode 20 is an electrode with a relatively low work function. For example, it can include but is not limited to an elemental metal electrode with a relatively low work function, a composite electrode with a relatively low work function, and an alloy electrode with a relatively low work function. The elemental metal electrode with a relatively low work function can be Ca, Ba, Al, Mg, etc. The composite electrode with a relatively low work function can be Ca / Al, LiF / Ca, LiF / Al, BaF2 / Al, CsF / Al, CaCO3 / Al, BaF2 / Ca / Al, etc. The alloy electrodes with a relatively low work function are Au:Mg and Ag:Mg, etc.

[0126] The materials of the light-emitting layer 31 can include but are not limited to one or more of organic light-emitting materials and quantum dot light-emitting materials.

[0127] The organic light-emitting material may include, but is not limited to, CBP:Ir(mppy)3 (4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridine iridium(III)]), TCTX:Ir(mmpy) (4,4',4”-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridine iridium]), diaryl anthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent material, TTPX fluorescent material, TBRb fluorescent material, DBP fluorescent material, delayed fluorescence material, TTA material, TADF (thermally activated delayed fluorescence) material, polymer containing B-N covalent bond, HLCT (hybrid local charge transfer excited state) material, Exciplex (excited complex) light-emitting material, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives, or one or more of them.

[0128] The quantum dot light-emitting material may include, but is not limited to, one or more of single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials.

[0129] It can be understood that the shell layer of the core-shell structure quantum dots includes one or more layers.

[0130] The materials of the single-structure quantum dots, the core materials of the core-shell structure quantum dots, and the shell materials of the core-shell structure quantum dots may respectively include, but are not limited to, one or more of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The II-VI group compounds may include, but are not limited to, one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds may include, but are not limited to, one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds may include, but are not limited to, one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds may include, but are not limited to, one or more of CuInS2, CuInSe2, and AgInS2.

[0131] As an example, the quantum dots of the core-shell structure may include, but are not limited to, one or more of CdSe / CdSeS / CdS, InP / ZnSeS / ZnS, CdZnSe / ZnSe / ZnS, CdSeS / ZnSeS / ZnS, CdSe / ZnS, CdSe / ZnSe / ZnS, ZnSe / ZnS, ZnSeTe / ZnS, CdSe / CdZnSeS / ZnS, and InP / ZnSe / ZnS.

[0132] The perovskite semiconductor material may include, but is not limited to, doped or undoped inorganic perovskite semiconductors, or organic-inorganic hybrid perovskite semiconductors. The general structural formula of the inorganic perovskite semiconductor is AMX3, where A is a Cs + ion, M is a divalent metal cation, including Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ and one or more of the like, and X is a halogen anion, including Cl - , Br - , I - and one or more of the like. The general structural formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, where B is an organic amine cation, including CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation, including Pb 2+ , Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ and one or more of the like, and X is a halogen anion, including Cl - , Br - , I - and one or more of the like.

[0133] In some embodiments, ligands are connected to the surface of the quantum dots. In at least some embodiments, the ligands include, but are not limited to, one or more of acid ligands, thiol ligands, amine ligands, (oxy)phosphine ligands, phospholipids, lecithins, polyvinylpyridines, etc. As a specific embodiment, the acid ligands include, but are not limited to, one or more of decanoic acid, undecylenic acid, myristic acid, oleic acid, stearic acid; the thiol ligands include, but are not limited to, one or more of octyl mercaptan, dodecyl mercaptan, octadecyl mercaptan; the amine ligands include, but are not limited to, one or more of oleylamine, octadecylamine, octylamine; the (oxy)phosphine ligands include, but are not limited to, one or more of trioctylphosphine, trioctylphosphine oxide.

[0134] In some embodiments, the average particle size of the quantum dots ranges from 5 to 50 nm.

[0135] The material of the electron transport layer 32 may include, but is not limited to, one or more of inorganic electron transport materials and organic electron transport materials.

[0136] The inorganic electron transport materials include inorganic semiconductor particles, and the inorganic semiconductor particles include, but are not limited to, one or more of doped metal oxide particles, undoped metal oxide particles, IIB-VIA group semiconductor materials, IIIA-VA group semiconductor materials, and IB-IIIA-VIA group semiconductor materials. The metal oxides in the undoped metal oxide particles include, but are not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5. The metal oxides in the doped metal oxides include, but are not limited to, one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, Al2O3, and the doping elements in the doped metal oxides include, but are not limited to, one or more of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, Sn. As an example, the doped metal oxides can be aluminum-doped zinc oxide (AZO), lithium-doped zinc oxide (LZO), magnesium-doped zinc oxide (MZO), tin-doped zinc oxide (Sn-ZnO), etc. The IIB-VIA group semiconductor materials include, but are not limited to, one or more of ZnS, ZnSe, CdS. The IIIA-VA group semiconductor materials include, but are not limited to, one or more of InP, GaP. The IB-IIIA-VIA group semiconductor materials include, but are not limited to, one or more of CuInS, CuGaS.

[0137] The average particle size of the inorganic semiconductor particles ranges from 5 to 50 nm.

[0138] The organic electron transport materials may include, but are not limited to, one or more of quinoxaline compounds, imidazole compounds, triazine compounds, fluorene-containing compounds, hydroxyquinoline compounds.

[0139] The material of the hole transport layer 33 may be a material known in the art for hole transport layers. For example, it may be selected from, but not limited to, 4,4'-N,N'-dicarbazolyl-biphenyl (CBP), poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] (PTAA), N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine (α-NPD), N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine (TPD), poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine) (Poly-TPD), N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro(spiro-TPD), N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine (DNTPD), 4,4',4'-tris(N-carbazolyl)-triphenylamine (TCTA), 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine (m-MTDATA), poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))] (TFB), poly(N-vinylcarbazole) (PVK) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine (NPB), spiro-NPB, poly(phenylene vinylene) (PPV), poly[2-methoxy-5-(2-ethylhexoxy)-1,4-phenylene vinylene] (MEH-PPV), poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene] (MOMO-PPV), 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene (spiro-omeTAD), 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline] (TAPC), 1,3-bis(carbazol-9-yl)benzene (MCP), polyaniline, polypyrrole, poly(p-phenylene vinylene), aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, doped graphene, undoped graphene, C60, doped or undoped NiO, doped or undoped MoO3, doped or undoped WO3, doped or undoped V2O5, doped or undoped p-type gallium nitride, doped or undoped CrO3, doped or undoped CuO, one or more of them.

[0140] The material of the hole injection layer 34 can be a material known in the art for hole injection layers, and can be selected from, but not limited to, 2,3,6,7,10,11 - hexacyano - 1,4,5,8,9,12 - hexaazatriphenylene (HAT - CN), PEDOT, PEDOT:PSS, a derivative of PEDOT:PSS doped with s - MoO3 (PEDOT:PSS:s - MoO3), 4,4',4' - tris(N - 3 - methylphenyl - N - phenylamino)triphenylamine (m - MTDATA), tetracyanoquinodimethane (F4 - TCQN), copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide, or one or more of them.

[0141] It can be understood that the optoelectronic device 100 can also be provided with some sub - functional layers that are conventionally used in optoelectronic devices and are helpful for improving the performance of optoelectronic devices, such as an electron blocking layer, a hole blocking layer, an electron injection layer, an interface modification layer, etc.

[0142] It can be understood that the materials of the respective layers of the optoelectronic device 100 can be adjusted according to the light - emitting requirements of the optoelectronic device 100.

[0143] It can be understood that the optoelectronic device 100 can be a normal - structure optoelectronic device or an inverted - structure optoelectronic device. The optoelectronic device 100 can be a quantum dot optoelectronic device (QLED), an organic light - emitting device, a solar cell, a thin - film transistor, etc.

[0144] In a fifth aspect, please refer to Figure 8 , an embodiment of the present application provides a method for manufacturing an optoelectronic device, including the following steps:

[0145] Step S21: Provide the anode 10;

[0146] Step S22: Prepare one or more stacked sub - functional layers on the anode 10 to obtain the functional layer 30;

[0147] Step S23: Prepare the cathode 20 on the functional layer 30 to obtain the optoelectronic device 100.

[0148] The manufacturing method further includes:

[0149] Prepare the first ferroelectric layer 40 on the anode 10 by using the thin - film manufacturing method described above; and / or,

[0150] Prepare the second ferroelectric layer 50 on the functional layer 30 by using the thin - film manufacturing method described above; and / or,

[0151] After at least one of the one or more stacked sub - functional layers is prepared, prepare the third ferroelectric layer 60 on the sub - functional layer by using the thin - film manufacturing method described above.

[0152] For a seventh aspect, please refer to Figure 9 , an embodiment of the present application provides another method for manufacturing an optoelectronic device, including the following steps:

[0153] Step S31: Provide a cathode 20;

[0154] Step S32: Prepare one or more stacked sub-functional layers on the cathode 20 to obtain a functional layer 30;

[0155] Step S33: Prepare an anode 10 on the functional layer 30 to obtain an optoelectronic device 100.

[0156] The manufacturing method further includes:

[0157] Prepare a second ferroelectric layer 50 on the cathode 20 using the thin film manufacturing method described above; and / or,

[0158] Prepare a first ferroelectric layer 40 on the functional layer 30 using the thin film manufacturing method described above; and / or,

[0159] After at least one of the one or more stacked sub-functional layers is prepared, prepare a third ferroelectric layer 60 on the sub-functional layer using the thin film manufacturing method described above.

[0160] In the above two manufacturing methods:

[0161] The one or more stacked sub-functional layers include one or more of a light-emitting layer 31, an electron transport layer 32, a hole transport layer 33, and a hole injection layer 34.

[0162] The methods for manufacturing the anode 10 and the cathode 20 can be implemented using conventional techniques in the art, such as chemical methods or physical methods. Among them, chemical methods include chemical vapor deposition, sequential ionic layer adsorption and reaction, anodic oxidation, electrolytic deposition, and coprecipitation. Physical methods include physical coating methods and solution methods. Among them, physical coating methods include: thermal evaporation coating, electron beam evaporation coating, magnetron sputtering, multi-arc ion coating, physical vapor deposition, atomic layer deposition, pulsed laser deposition, etc.; solution methods can be spin coating, printing, inkjet printing, blade coating, printing, dip coating, immersion, spraying, roll coating, casting, slot die coating, and bar coating, etc.

[0163] In some embodiments, a substrate is further disposed on one side of the anode 10 away from the functional layer 30 or on one side of the cathode 20 away from the functional layer 30. The substrate may be a rigid substrate or a flexible substrate. In some embodiments, the material of the substrate may include, but is not limited to, one or more of glass, silicon wafer, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyethylene naphthalate, polyamide, and polyethersulfone.

[0164] It can be understood that when the optoelectronic device 100 further includes functional layers that are conventionally used in optoelectronic devices and are helpful for improving the performance of the optoelectronic device, such as an electron blocking layer, a hole blocking layer, an electron injection layer, an interface modification layer, etc., the preparation method of the optoelectronic device 100 may further include the step of preparing the above functional layers by using conventional techniques in the art.

[0165] It should be noted that the electronic functional layer described in the present application may be an electron injection layer, or an electron transport layer, or a stacked electron injection layer and electron transport layer, and the hole functional layer described in the present application may be a hole injection layer, or a hole transport layer, or a stacked hole injection layer and hole transport layer.

[0166] In an eighth aspect, the present application also relates to a display device, and the display device includes the optoelectronic device 100.

[0167] The display device may be any electronic product having a display function, and the electronic product includes, but is not limited to, a smart phone, a tablet computer, a notebook computer, a digital camera, a digital video camera, a smart wearable device, a smart weighing electronic scale, a vehicle-mounted display, a television, or an e-book reader. Among them, the smart wearable device may be, for example, a smart bracelet, a smart watch, a virtual reality (VR) helmet, etc.

[0168] The present application will be specifically described below through specific embodiments. The following embodiments are only partial embodiments of the present application and do not limit the present application.

[0169] Material Example 1

[0170] 100 mg of poly(vinylidene fluoride-trifluoroethylene) (ferroelectric material) and 10 mg of polyethylene oxide diamine (crosslinking agent) are mixed and dispersed in 50 mL of N,N-dimethylformamide, and then 20 mg of 1-propyl-3-methylimidazolium bromide (ionic liquid) is added and dispersed evenly to obtain a mixed solution;

[0171] The mixed solution is heated at a constant temperature of 110°C for 10 min to obtain a composite material.

[0172] Material Example 2

[0173] This example is basically the same as Material Example 1, except that in this example, polyvinylidene fluoride is used to replace poly(vinylidene fluoride-trifluoroethylene) in Material Example 1, and polyethylene glycol is used to replace polyethylene oxide diamine in Example 1.

[0174] Material Example 3

[0175] This example is basically the same as Material Example 1, except that in this example, poly(vinylidene fluoride-co-trifluoroethylene) is used to replace poly(vinylidene fluoride-trifluoroethylene) in Material Example 1, and polycaprolactone is used to replace polyethylene oxide diamine in Material Example 1.

[0176] Material Example 4

[0177] This example is basically the same as Material Example 1, except that in this example, 1-propyl-3-methylimidazolium bromide is used to replace 1-butyl-3-methylimidazolium cyanide in Material Example 1.

[0178] Material Example 5

[0179] This example is basically the same as Material Example 1, except that in this example, 1-butyl-3-methylimidazolium chloride is used to replace 1-butyl-3-methylimidazolium cyanide in Material Example 1.

[0180] Material Example 6

[0181] This example is basically the same as Material Example 1, except that in this example, the mass ratio of the ferroelectric material to the crosslinking agent is 50:1.

[0182] Material Example 7

[0183] This example is basically the same as Material Example 1, except that in this example, the mass ratio of the ferroelectric material to the crosslinking agent is 100:1.

[0184] Material Example 8

[0185] This example is basically the same as Material Example 1, except that in this example, the mass ratio of the ferroelectric material to the ionic liquid is 20:1.

[0186] Material Example 9

[0187] This example is basically the same as Material Example 1, except that in this example, the mass ratio of the ferroelectric material to the ionic liquid is 50:1.

[0188] Material Example 10

[0189] This example is basically the same as Material Example 1, except that in this example, the heating temperature is 100 °C.

[0190] Material Example 11

[0191] This example is basically the same as Material Example 1, except that the heating temperature in this example is 120 °C.

[0192] Material Comparative Example 1

[0193] This comparative example is basically the same as Example 1, except that no crosslinking agent and ionic liquid were added during the preparation of the material in this example. That is, the material in this example is poly(vinylidene fluoride-trifluoroethylene).

[0194] Material Comparative Example 2

[0195] This comparative example is basically the same as Material Example 1, except that no ionic liquid was added during the preparation of the material of the optoelectronic device in this example. That is, the material in this example is a crosslinked product of poly(vinylidene fluoride-trifluoroethylene).

[0196] The flexibility of the materials of Material Examples 1 to 11 and Material Comparative Examples 1 to 2 was tested. The flexibility of the materials can be characterized by the radius of curvature of the film prepared therefrom. Specifically, the materials of Material Examples 1 to 11 and Material Comparative Examples 1 to 2 were respectively prepared into films with a thickness of 15 nm, and then the radius of curvature of the films was tested. The test results are shown in Table 1.

[0197] Among them, the radius of curvature is the rate of rotation of the tangent direction angle of a certain point on the curve with respect to the arc length, that is, the numerical value of the bending radius. For example, a curvature of 4000R refers to the degree of bending of a circle with a radius of 4 m. Similarly, 3000R refers to the degree of bending of a circle with a radius of 3 m. The smaller the radius of curvature, the better its flexibility.

[0198] Table 1:

[0199]

[0200]

[0201] As can be seen from Table 1:

[0202] Compared with the materials of Material Comparative Example 1, the materials of Material Examples 1 to 11 have significantly lower radii of curvature. It can be seen that the composite materials of the present application have good flexibility and good bendability. The reason may be that the materials in Material Examples 1 to 11 have an elastic ferroelectric polymer formed by crosslinking a ferroelectric material and a crosslinking agent;

[0203] Compared with the materials of Material Comparative Example 2, the materials of Material Examples 1 to 11 have similar or even lower radii of curvature. It can be seen that the flexibility is still good after doping ionic liquid into the elastic ferroelectric polymer.

[0204] Device Example 1

[0205] Provide an ITO anode with a thickness of 80 nm;

[0206] Spin-coat PEDOT:PSS material on the anode and anneal at 150 °C for 30 min to obtain a hole injection layer with a thickness of 25 nm;

[0207] Spin-coat TFB material on the hole injection layer and anneal at 200 °C for 30 min to obtain a hole transport layer with a thickness of 25 nm;

[0208] Ink-jet print CdZnSe quantum dot material on the hole transport layer to obtain a light-emitting layer with a thickness of 40 nm;

[0209] Ink-jet print an ethanol solution of ZnO on the light-emitting layer and anneal at 80 °C for 30 min to obtain an electron transport layer with a thickness of 35 nm;

[0210] Prepare a ferroelectric layer with a thickness of 15 nm on the electron transport layer, where the material of the ferroelectric layer is the composite material in Example 1;

[0211] Evaporate Ag on the ferroelectric layer to obtain a cathode with a thickness of 100 nm;

[0212] Encapsulate to obtain an optoelectronic device.

[0213] Device Examples 2-11

[0214] Device Examples 2-11 are basically the same as Device Example 1, except that the materials of the ferroelectric layers in Device Examples 2-11 are the composite materials in Material Examples 2-11, respectively.

[0215] Device Example 12

[0216] This example is basically the same as Example 1, except that no ferroelectric layer is provided between the electron transport layer and the cathode in this example. Instead, the ferroelectric layer in Example 1 is provided between the light-emitting layer and the electron transport layer.

[0217] Device Example 13

[0218] This example is basically the same as Example 1, except that no ferroelectric layer is provided between the electron transport layer and the cathode in this example. Instead, the ferroelectric layer in Example 1 is provided between the light-emitting layer and the hole transport layer.

[0219] Device Example 14

[0220] This embodiment is basically the same as Embodiment 1, except that no ferroelectric layer is provided between the electron transport layer and the cathode in this embodiment. Instead, the ferroelectric layer in Embodiment 1 is provided between the hole transport layer and the hole injection layer.

[0221] Device Embodiment 15

[0222] This embodiment is basically the same as Embodiment 1, except that no ferroelectric layer is provided between the electron transport layer and the cathode in this embodiment. Instead, the ferroelectric layer in Embodiment 1 is provided between the anode and the hole injection layer.

[0223] Device Embodiment 16

[0224] This embodiment is basically the same as Embodiment 1, except that the ferroelectric layer in Embodiment 1 is provided between the light-emitting layer and the electron transport layer, between the light-emitting layer and the hole transport layer, between the hole transport layer and the hole injection layer, and between the anode and the hole injection layer in this embodiment.

[0225] Device Comparative Example 1

[0226] This comparative example is basically the same as Device Embodiment 1, except that the optoelectronic device in this comparative example does not include a ferroelectric layer.

[0227] Device Comparative Examples 2 - 3

[0228] Device Comparative Examples 2 - 3 are basically the same as Device Embodiment 1, except that the materials of the ferroelectric layers in Device Comparative Examples 2 - 3 are the materials of Material Comparative Examples 1 - 2 respectively.

[0229] The optoelectronic devices of Device Embodiments 1 - 16 and Device Comparative Examples 1 - 3 are respectively tested for luminous uniformity, external quantum efficiency EQE, lifetime T95@1000nit, and flexibility. The test results are shown in Table 1.

[0230] The test method for luminous uniformity is as follows: Nine points are evenly taken in the light-emitting area, and their luminous intensities are measured. Then, normalization is performed according to the average of the nine points, and the variance is calculated. The smaller the variance, the higher the luminous uniformity.

[0231] The test method for external quantum efficiency EQE is as follows: Using a Fosda FPD optical property measurement device, an efficiency test system built by controlling a QE PRO spectrometer, a Keithley 2400, and a Keithley 6485 through LabView, parameters such as voltage, current, brightness, and emission spectrum are measured, and the external quantum efficiency EQE of the device is calculated through calculation.

[0232] The test method for the lifetime T95@1000nit is as follows: In CDA gas, under the drive of a constant current or voltage, the time it takes for the brightness of the device to decay to a certain proportion of the maximum brightness is measured. The time when the brightness decays to 95% of the maximum brightness is defined as T95, and this lifetime is the measured lifetime. To shorten the lifetime test cycle, the device lifetime test is usually carried out by accelerating the device aging at high brightness, and the lifetime at low brightness is obtained by fitting through the decay fitting formula. For example, the lifetime at 1000nits is denoted as T95@1000nits, and the calculation formula is:

[0233]

[0234] where T95 L is the lifetime at low brightness, generally taking the lifetime at 1000nits, and T95 H is the lifetime at high brightness, that is, the measured lifetime, and L H is the maximum brightness to which the device is accelerated, and L L is generally 1000nits, A is the acceleration factor, taking 1.7. Among them, the constant current is 2mA.

[0235] Table 1:

[0236]

[0237]

[0238] It can be seen from Table 1 that:

[0239] Compared with the optoelectronic devices of Comparative Examples 1-2 of the device, the optoelectronic devices of Examples 1-16 of the device have better flexibility. It can be seen that setting the ferroelectric layer of the present application in the optoelectronic device can effectively improve the flexibility of the device. The reason may be that the ferroelectric layer in the optoelectronic devices of Examples 1-16 of the device has better flexibility;

[0240] Compared with the optoelectronic device of Comparative Example 3 of the device, the optoelectronic devices of Examples 1-16 of the device have a similar or even lower radius of curvature. It can be seen that setting the ferroelectric layer composed of an elastic ferroelectric polymer and an ionic liquid of the present application in the optoelectronic device can have a flexibility similar to or even better than that of the ferroelectric layer composed of only the cross-linked product of a linear polymer;

[0241] Compared with the optoelectronic devices of Device Comparative Example 1, the optoelectronic devices of Device Examples 1 to 16 have better luminescence uniformity, higher efficiency, and longer lifespan. It can be seen that setting the ferroelectric layer of the present application in the optoelectronic device can effectively improve the luminescence uniformity of the device. The reason may be that Device Examples 1 to 16 include a ferroelectric layer, and the ferroelectric layer includes an elastic ferroelectric polymer. Under the action of an external electric field, the elastic ferroelectric polymer in the ferroelectric layer can undergo an electrode polarization phenomenon, generating a charge distribution on its surface to form polarization charges, thereby improving the charge distribution and further enhancing the luminescence uniformity of the optoelectronic device;

[0242] Compared with the optoelectronic devices of Device Comparative Example 2, the optoelectronic devices of Device Examples 1 to 16 have better luminescence uniformity, higher efficiency, and longer lifespan. It can be seen that setting the ferroelectric layer of the present application in the optoelectronic device can effectively improve the luminescence uniformity of the device. The reason may be that the ferroelectric layer of Device Examples 1 to 16 includes an elastic ferroelectric polymer crosslinked from the ferroelectric material and the crosslinking agent, which has better ferroelectric properties and can undergo an electrode polarization phenomenon under the action of an external electric field, generating a charge distribution on its surface to form polarization charges, improving the charge distribution, and further enhancing the luminescence uniformity of the optoelectronic device;

[0243] Compared with the optoelectronic devices of Device Comparative Example 3, the optoelectronic devices of Device Examples 1 to 16 have better luminescence uniformity, higher efficiency, and longer lifespan. It can be seen that setting the ferroelectric layer of the present application in the optoelectronic device can effectively improve the luminescence uniformity of the device. The reason may be that the ferroelectric layer of Device Examples 1 to 16 includes an elastic ferroelectric polymer crosslinked from the ferroelectric material and the crosslinking agent and an ionic liquid, and the ionic liquid can enhance the ferroelectricity and conductivity of the composite material.

[0244] The technical solutions provided in the embodiments of the present application have been introduced in detail above. Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those skilled in the art, based on the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A composite material, characterized in that, Comprising an elastic ferroelectric polymer and an ionic liquid, wherein the elastic ferroelectric polymer is formed by cross-linking a ferroelectric material and a cross-linking agent.

2. The composite material according to claim 1, characterized in that The composite material is composed of the elastic ferroelectric polymer and the ionic liquid.

3. The composite material according to claim 1 or 2, characterized in that the ferroelectric material includes a linear ferroelectric material, and the linear ferroelectric material includes a polyvinylidene fluoride-based compound; and / or the cross-linking agent includes a flexible cross-linking agent, and the flexible cross-linking agent includes one or more of a polyamine-based flexible cross-linking agent, a polyether-based flexible cross-linking agent, and a polyester-based flexible cross-linking agent; and / or the ionic liquid includes a methylimidazole-based ionic liquid.

4. The composite material according to claim 3, characterized in that the polyvinylidene fluoride-based compound includes one or more of poly(vinylidene fluoride-trifluoroethylene), polyvinylidene difluoride, polyvinylidene fluoride, poly(vinylidene difluoride-co-trifluoroethylene), and poly(vinylidene difluoride-co-hexafluoropropylene); and / or the polyamine-based flexible cross-linking agent includes one or more of polyethylene oxide diamine, polyethyleneimine, and polyethylene glycol diamine, the polyether-based flexible cross-linking agent includes polyethylene glycol, and the polyester-based flexible cross-linking agent includes one or more of polycaprolactone; and / or the methylimidazole-based ionic liquid includes one or more of 1-butyl-3-methylimidazole cyanide, 1-propyl-3-methylimidazole bromide, 1-propyl-3-methylimidazole iodide, 1-butyl-3-methylimidazole chloride, and 1-ethyl-3-methylimidazole bromide.

5. The composite material according to claim 1 or 2, characterized in that the mass ratio of the ferroelectric material to the cross-linking agent is (50-100):1; and / or the mass ratio of the ferroelectric material to the ionic liquid is (20-50):1; and / or the cross-linking density of the elastic ferroelectric polymer is 1-2%.

6. A film, characterized in that, Comprising the composite material according to any one of claims 1-5.

7. A method for preparing a thin film, characterized in that, Comprising the following steps: Providing a mixed solution containing a ferroelectric material, a cross-linking agent, an ionic liquid, and a solvent; and Depositing the mixed solution and heating to obtain a thin film.

8. The preparation method according to claim 7, characterized in that the solvent includes one or more of N,N-dimethylformamide, isopropanol, ethanol, dimethyl sulfoxide, N-methylpyrrolidone, chlorobenzene, toluene, xylene, and acetone; and / or the mass ratio of the ferroelectric material to the cross-linking agent is (50-100):1; and / or the mass ratio of the ferroelectric material to the ionic liquid is (20-50):1; and / or the heating temperature is 100-120 °C and the time is 10-20 min; and / or the ferroelectric material includes a linear ferroelectric material, the linear ferroelectric material includes a polyvinylidene fluoride-based compound, and the polyvinylidene fluoride-based compound includes one or more of poly(vinylidene fluoride-trifluoroethylene), polyvinylidene difluoride, polyvinylidene fluoride, poly(vinylidene difluoride-co-trifluoroethylene), and poly(vinylidene difluoride-co-hexafluoropropylene); and / or The crosslinking agent includes a flexible crosslinking agent, and the flexible crosslinking agent includes one or more of a polyamine-based flexible crosslinking agent, a polyether-based flexible crosslinking agent, and a polyester-based flexible crosslinking agent. Among them, the polyamine-based flexible crosslinking agent includes one or more of polyethylene oxide diamine, polyethyleneimine, and polyethylene glycol diamine; the polyether-based flexible crosslinking agent includes polyethylene glycol; and the polyester-based flexible crosslinking agent includes one or more of polycaprolactone; and / or The ionic liquid includes a methylimidazole-based ionic liquid, and the methylimidazole-based ionic liquid includes one or more of 1-butyl-3-methylimidazole cyanide, 1-propyl-3-methylimidazole bromide, 1-propyl-3-methylimidazole iodide, 1-butyl-3-methylimidazole chloride, and 1-ethyl-3-methylimidazole bromide.

9. An optoelectronic device, characterized in that, It includes an anode and a cathode arranged oppositely, and a functional layer arranged between the anode and the cathode, where A first ferroelectric layer is arranged between the anode and the functional layer. The material of the first ferroelectric layer includes a first composite material, and the first composite material includes a first elastic ferroelectric polymer and a first ionic liquid. Among them, the first elastic ferroelectric polymer is formed by crosslinking a first ferroelectric material and a first crosslinking agent; and / or A second ferroelectric layer is arranged between the cathode and the functional layer. The material of the second ferroelectric layer includes a second composite material, and the second composite material includes a second elastic ferroelectric polymer and a second ionic liquid. Among them, the second elastic ferroelectric polymer is formed by crosslinking a second ferroelectric material and a second crosslinking agent.

10. The optoelectronic device according to claim 9, characterized in that, The functional layer includes m sub-functional layers, and the optoelectronic device further includes n third ferroelectric layers, where m≥2, m - n≥1. Each third ferroelectric layer is located between two adjacent sub-functional layers. The material of the third ferroelectric layer includes a third composite material, and the third composite material includes a third elastic ferroelectric polymer and a third ionic liquid. Among them, the third elastic ferroelectric polymer is formed by crosslinking a third ferroelectric material and a third crosslinking agent.

11. The optoelectronic device according to claim 10, wherein The first ferroelectric material, the second ferroelectric material, and the third ferroelectric material each independently include a linear ferroelectric material, and the linear ferroelectric material includes a polyvinylidene fluoride-based compound; and / or The first crosslinking agent, the second crosslinking agent, and the third crosslinking agent each independently include a flexible crosslinking agent, and the flexible crosslinking agent includes one or more of a polyamine-based flexible crosslinking agent, a polyether-based flexible crosslinking agent, and a polyester-based flexible crosslinking agent; and / or The first ionic liquid, the second ionic liquid, and the third ionic liquid each independently include a methylimidazole-based ionic liquid.

12. The optoelectronic device according to claim 11, wherein The polyvinylidene fluoride-based compound includes one or more of poly(vinylidene fluoride-trifluoroethylene), polyvinylidene difluoride, polyvinylidene fluoride, poly(vinylidene difluoride-co-trifluoroethylene), and poly(vinylidene difluoride-co-hexafluoropropylene); and / or The polyamine-based flexible crosslinking agent includes one or more of polyethylene oxide diamine, polyethyleneimine, and polyethylene glycol diamine; the polyether-based flexible crosslinking agent includes polyethylene glycol; the polyester-based flexible crosslinking agent includes one or more of polycaprolactone; and / or The methylimidazole-based ionic liquid includes one or more of 1-butyl-3-methylimidazole cyanide, 1-propyl-3-methylimidazole bromide, 1-propyl-3-methylimidazole iodide, 1-butyl-3-methylimidazole chloride, and 1-ethyl-3-methylimidazole bromide; and / or The first ferroelectric material, the second ferroelectric material, and the third ferroelectric material are the same or different; and / or The first crosslinking agent, the second crosslinking agent, and the third crosslinking agent are the same or different; and / or The first ionic liquid, the second ionic liquid, and the third ionic liquid are the same or different.

13. The optoelectronic device according to claim 10, wherein The mass ratio of the ferroelectric material to the crosslinking agent is (50-100):1; and / or The mass ratio of the ferroelectric material to the ionic liquid is (20-50):1; and / or The crosslinking density of the elastic ferroelectric polymer is 1-2%; and / or The thicknesses of the first ferroelectric layer, the second ferroelectric layer, and the third ferroelectric layer are each independently 10-20 nm.

14. The optoelectronic device according to claim 9, wherein The functional layer includes one sub-functional layer, and the sub-functional layer is a light-emitting layer; or The functional layer includes two sub-functional layers, which are a light-emitting layer and an electron transport layer respectively, and the electron transport layer is located between the light-emitting layer and the cathode; or The functional layer includes two sub-functional layers, which are a light-emitting layer and a hole transport layer respectively, and the hole transport layer is located between the light-emitting layer and the anode; or The functional layer includes three sub-functional layers, which are a light-emitting layer, a hole transport layer, and a hole injection layer respectively. Among them, the hole transport layer is located between the light-emitting layer and the anode, and the hole injection layer is located between the hole transport layer and the anode; or The functional layer includes three sub-functional layers, which are a light-emitting layer, an electron transport layer, and a hole transport layer respectively. Among them, the electron transport layer is located between the light-emitting layer and the cathode, and the hole transport layer is located between the light-emitting layer and the anode; or The functional layer includes four sub-functional layers, which are a light-emitting layer, an electron transport layer, a hole transport layer, and a hole injection layer respectively. Among them, the electron transport layer is located between the light-emitting layer and the cathode, the hole transport layer is located between the light-emitting layer and the anode, and the hole injection layer is located between the hole transport layer and the anode.

15. The optoelectronic device according to claim 14, wherein The anode and the cathode each independently include a doped metal oxide particle electrode, a composite electrode, a graphene electrode, a carbon nanotube electrode, a metal elemental 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. The composite electrode includes one or more of AZO / Ag / AZO, AZO / Al / AZO, ITO / Ag / ITO, ITO / Al / ITO, ZnO / Ag / ZnO, ZnO / Al / ZnO, TiO2 / Ag / TiO2, TiO2 / Al / TiO2, ZnS / Ag / ZnS or ZnS / Al / ZnS. The material of the metal elemental electrode includes one or more of Ag, Al, Cu, Mo, Au, Pt, Ca, Mg, and Ba; and / or The material of the light-emitting layer includes one or more of an organic light-emitting material and a quantum dot light-emitting material. The organic light-emitting material includes one or more of 4,4'-bis(N-carbazolyl)-1,1'-biphenyl: tris[2-(p-tolyl)pyridineiridium(III)], 4,4',4''-tris(carbazol-9-yl)triphenylamine: tris[2-(p-tolyl)pyridineiridium], diarylanthracene derivatives, stilbene aromatic derivatives, pyrene derivatives, fluorene derivatives, TBPe fluorescent material, TTPX fluorescent material, TBRb fluorescent material, DBP fluorescent material, delayed fluorescence material, TTA material, thermally activated delayed material, polymer containing B-N covalent bond, hybrid local charge transfer excited state material, exciplex luminescent material, polyacetylene and its derivatives, poly(p-phenylene) and its derivatives, polythiophene and its derivatives, polyfluorene and its derivatives;The quantum dot light-emitting material includes one or more of single-structure quantum dots, core-shell structure quantum dots, and perovskite semiconductor materials. The materials of the single-structure quantum dots, the core materials of the core-shell structure quantum dots, and the shell materials of the core-shell structure quantum dots are each independently selected from one or more of II-VI group compounds, IV-VI group compounds, III-V group compounds, and I-III-VI group compounds. The shell of the core-shell structure quantum dot includes one or more layers. The II-VI group compounds include one or more of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, and HgZnSTe. The IV-VI group compounds include one or more of SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, and SnPbSTe. The III-V group compounds include one or more of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, and InAlPSb. The I-III-VI group compounds include one or more of CuInS2, CuInSe2, and AgInS2. The perovskite semiconductor material includes doped or undoped inorganic perovskite semiconductors or organic-inorganic hybrid perovskite semiconductors. The structural general formula of the inorganic perovskite semiconductor is AMX3, where A is Cs; + ions, M is a divalent metal cation, including Pb 2+ and Sn 2+ , Cu 2+ , Ni 2+ , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ One or more of, X is a halogen anion, including Cl - , Br - , I - One or more of; the structural general formula of the organic-inorganic hybrid perovskite semiconductor is BMX3, where B is an organic amine cation, including CH3(CH2) n-2 NH3 + or [NH3(CH2) n NH3] 2+ , where n≥2, M is a divalent metal cation, including Pb 2+ , Sn 2+ , Cu 2+ , Ni 2 + , Cd 2+ , Cr 2+ , Mn 2+ , Co 2+ , Fe 2+ , Ge 2+ , Yb 2+ , Eu 2+ One or more of, X is a halogen anion, including Cl - , Br - , I - One or more of; and / or The materials of the hole transport layer include one or more of 4,4'-N,N'-dicarbazolyl-biphenyl, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], N,N'-diphenyl-N,N'-bis(1-naphthyl)-1,1'-biphenyl-4,4”-diamine, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-(1,1'-biphenyl)-4,4'-diamine, poly(N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine), N,N'-bis(3-methylphenyl)-N,N'-bis(phenyl)-spiro, N,N'-bis(4-(N,N'-diphenyl-amino)phenyl)-N,N'-diphenylbenzidine, 4,4',4'-tris(N-carbazolyl)-triphenylamine, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, poly[(9,9'-dioctylfluorene-2,7-diyl)-co-(4,4'-(N-(4-sec-butylphenyl)diphenylamine))], poly(N-vinylcarbazole) and its derivatives, N,N'-bis(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4-4'-diamine, spiro-NPB, poly(phenylene vinylene), poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylene vinylene], poly[2-methoxy-5-(3',7'-dimethyloctyloxy)-1,4-phenylene vinylene], 2,2',7,7'-tetrakis[N,N-bis(4-methoxyphenyl)amino]-9,9'-spirobifluorene, 4,4'-cyclohexylbis[N,N-bis(4-methylphenyl)aniline], 1,3-bis(carbazol-9-yl)benzene, polyaniline, polypyrrole, poly(p-phenylene vinylene), aromatic tertiary amines, polynuclear aromatic tertiary amines, 4,4'-bis(p-carbazolyl)-1,1'-biphenyl compounds, N,N,N',N'-tetraarylbenzidine, PEDOT:PSS and its derivatives, polymethacrylate and its derivatives, poly(9,9-octylfluorene) and its derivatives, poly(spirofluorene) and its derivatives, doped graphene, undoped graphene, C60, doped or undoped NiO, doped or undoped MoO3, doped or undoped WO3, doped or undoped V2O5, doped or undoped p-type gallium nitride, doped or undoped CrO3, doped or undoped CuO; the materials of the hole injection layer include one or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, PEDOT, PEDOT:PSS, derivatives of PEDOT:PSS doped with s-MoO3, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, tetracyanoquinodimethane, copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide and copper oxide; and / or The material of the hole injection layer includes one or more of 2,3,6,7,10,11-hexacyano-1,4,5,8,9,12-hexaazatriphenylene, PEDOT, PEDOT:PSS, a derivative of PEDOT:PSS doped with s-MoO3, 4,4',4'-tris(N-3-methylphenyl-N-phenylamino)triphenylamine, tetracyanoquinodimethane, copper phthalocyanine, nickel oxide, molybdenum oxide, tungsten oxide, vanadium oxide, molybdenum sulfide, tungsten sulfide, and copper oxide; and / or The material of the electron transport layer includes one or more of an inorganic electron transport material and an organic electron transport material. The inorganic electron transport material includes one or more of a metal oxide, a doped metal oxide, a IIB-VIA group semiconductor material, a IIIA-VA group semiconductor material, and a IB-IIIA-VIA group semiconductor material. The metal oxide includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5. The metal oxide in the doped metal oxide includes one or more of ZnO, TiO2, SnO2, ZrO2, Ta2O5, Al2O3, and the dopant in the doped metal oxide includes one or several of Al, Mg, Li, Mn, Y, La, Cu, Ni, Zr, Ce, In, Ga, Sn. The IIB-VIA group semiconductor material includes one or more of ZnS, ZnSe, CdS. The IIIA-VA group semiconductor material includes one or more of InP, GaP. The IB-IIIA-VIA group semiconductor material includes one or more of CuInS, CuGaS. The organic electron transport material includes one or more of a quinoxaline compound, an imidazole compound, a triazine compound, a fluorene-containing compound, and a hydroxyquinoline compound.

16. A display device, characterized in that, The display device includes the optoelectronic device according to any one of claims 9 to 15.

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