Trans-perovskite solar cell device and preparation method thereof

Abstract

The invention relates to a trans-perovskite solar cell device and a preparation method thereof. The structure of the trans-perovskite solar cell device comprises a transparent conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, a cathode buffer layer and a metal back electrode layer which are sequentially stacked from bottom to top, the perovskite solar cell is characterized in that an interface modification layer formed by imidazole ring-containing acetate molecules is introduced between the hole transport layer and the perovskite layer. According to the trans-perovskite solar cell, an interface modification layer formed by imidazole ring acetate molecules (1-butyl-3-methyl-imidazole acetate) is introduced between a hole transport layer and a perovskite layer in the trans-perovskite solar cell, and interface contact between the perovskite layer and the hole transport layer is increased; therefore, the interface adhesive force between the perovskite film and the hole transport layer is improved, the defects of the perovskite layer are effectively reduced, the non-radiative recombination of photon-generated carriers is reduced, and the purpose of effectively improving the photoelectric conversion efficiency and stability of the device is achieved.

Description

Technical Field

[0001] The present invention relates to the field of solar photovoltaic technology, in particular to an inverted perovskite solar cell device and a preparation method thereof. Background Art

[0002] As a third-generation solar cell technology, perovskite solar cells have made rapid progress over the past decade, with their photoelectric conversion efficiency constantly reaching new heights, now rivaling that of crystalline silicon solar cells. In recent years, inverted perovskite solar cells have attracted considerable attention due to their advantages, including simple fabrication, low-temperature film formation, low hysteresis, and suitability for combining with traditional solar cells to create stacked devices.

[0003] An important prerequisite for high-efficiency perovskite solar cells is a hole transport layer with superior uniformity and surface morphology, which affects the interface contact between the two surfaces of electrode / hole transport layer / perovskite and affects the quality of perovskite morphology.

[0004] Perovskite films are usually prepared by evaporating solvents from precursor solutions through a spin coating process. During the preparation process, perovskite films are prone to uneven distribution, resulting in low bonding strength between the perovskite film layer and the hole transport layer and insufficient adhesion, which affects the quality of the perovskite film and, in turn, the performance and stability of perovskite solar cells.

[0005] Both inverted and regular solar cells suffer from the problem of poor adhesion between the perovskite film and the hole transport layer, and this problem is more prominent in inverted solar cells. The poor wettability of the hole transport layer surface leads to poor contact between the hole transport layer and the perovskite interface, which not only affects hole extraction at the interface but also affects the nucleation and growth of perovskite crystals, and easily generates defects at the grain boundaries and surface during the crystallization process. Interface defect states exacerbate the non-radiative recombination of photogenerated carriers, thereby seriously affecting the energy conversion efficiency and stability of the device. This has become a major factor limiting the further improvement of the photovoltaic performance of inverted perovskite solar cells. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide an inverted perovskite solar cell device and a preparation method thereof, aiming to solve the problem of reduced device performance and stability caused by interface defects in existing inverted solar cells.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions: An inverted perovskite solar cell device, whose structure includes a transparent conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, a cathode buffer layer and a metal back electrode layer stacked in sequence from bottom to top; characterized in that an interface modification layer formed by imidazole cycloacetate molecules is introduced between the hole transport layer and the perovskite layer.

[0008] Furthermore, the imidazole cycloacetate molecule is 1-butyl-3-methyl-imidazole acetate, which includes the following two groups of anions and cations: .

[0009] In some embodiments, the interface modification layer is an interface modification layer containing 1-butyl-3-methyl-imidazole acetate prepared on the surface of the hole transport layer, and is obtained by adding a solution of 1-butyl-3-methyl-imidazole acetate to the hole transport layer of the conductive substrate and annealing.

[0010] In some embodiments, the concentration of the 1-butyl-3-methyl-imidazole acetate solution is in the range of 0.1 to 2 µL / mL.

[0011] In some embodiments, the interface modification layer is prepared by dissolving 1-butyl-3-methyl-imidazole acetate in a DMF solution and uniformly mixing the mixture; filtering the mixed solution to obtain a filtrate; dripping the filtrate onto the hole transport layer of the conductive substrate to cover the hole transport layer, and then spin coating, followed by annealing to obtain the interface modification layer.

[0012] In some embodiments, the hole transport layer is made of an organic or inorganic hole transport material solution.

[0013] Preferably, the organic hole transport material solution includes one or both of a PTAA solution and a PEDOT:PSS solution.

[0014] Preferably, the inorganic hole transport material solution is one or both of nickel oxide and copper oxide solutions.

[0015] In some embodiments, the main body of the perovskite layer is ABX3, wherein A includes one or more of methylamine cations, cesium cations, and formamidinium cations; B includes lead cations; and X includes chloride anions and iodide anions.

[0016] In some embodiments, the perovskite layer is made of a perovskite layer solution, and the perovskite layer solution is configured in two parts, the first part is a lead iodide solution, and the second part is an organic halide solution.

[0017] Preferably, the organic halide solution comprises one or more of FAI, MACl, and MAI; Preferably, the solvent of the lead iodide solution is one or more of dimethyl sulfoxide, N,N-dimethylformamide, r-butyrolactone, and N-methylpyrrolidone; the solute of the organic halide solution in the perovskite solution is a salt of formamidine or methylamine hydroiodide or methylamine hydrochloride or methylamine hydrobromide, and the solvent is isopropanol.

[0018] In some embodiments, the perovskite layer is prepared by a two-step spin coating method, comprising the following steps: Spin coating a lead iodide solution on the interface modification layer, and then performing a first annealing treatment; and An organic halide solution is spin-coated on the surface of the lead iodide layer, and then a second annealing treatment is performed.

[0019] In some embodiments, the inverted perovskite solar cell device comprises a perovskite layer based on 3MAI:PbAc2·xH2O, where 0≤x≤3. The preparation method comprises: heating lead acetate trihydrate in a nitrogen atmosphere to remove water to obtain anhydrous acetic acid. The anhydrous lead acetate and lead acetate trihydrate are then mixed in a certain ratio to prepare lead acetate PbAc2·xH2O with an adjustable hydration level. This is then dissolved in DMF with methylamine iodide (MAI) to prepare a perovskite precursor solution containing 30%-50% by weight. The substrate and perovskite solution are heated, and the perovskite layer is formed by a one-step spin coating process, followed by annealing in a nitrogen atmosphere.

[0020] The present invention provides a preparation method for preparing the above-mentioned inverse perovskite solar cell device, comprising the following steps: S101, providing a conductive substrate; S102, preparing a hole transport layer on the surface of the conductive substrate; S103, preparing an interface modification layer containing imidazole cycloacetate molecules on the surface of the hole transport layer; S104, preparing a perovskite layer on the surface of the interface modification layer containing imidazole cycloacetate molecules; S105, preparing an electron transport layer on the surface of the perovskite layer; S106, preparing a cathode buffer layer on the surface of the electron transport layer; and S107, preparing an electrode on the surface of the cathode buffer layer.

[0021] In which, in step S101, the conductive substrate is a transparent rigid conductive substrate or a transparent flexible conductive substrate, the transparent rigid conductive substrate is one of an ITO substrate, an FTO substrate, etc., and the transparent flexible conductive substrate is one of a PET substrate and a PEN substrate; step S101 includes cleaning the conductive substrate: ultrasonically cleaning the conductive substrate in deionized water and a detergent solution, and / or, ultrasonically cleaning the conductive substrate with deionized water, and / or, ultrasonically treating the conductive substrate in an isopropyl alcohol solution, then taking it out and drying it with nitrogen, and then performing ultraviolet ozone treatment.

[0022] The step S102 includes the following two steps: S1021, preparing a hole transport material and an electron transport material solution; the hole transport material solution is an organic or inorganic hole transport material solution, the organic hole transport material solution is one or both of a PTAA solution and a PEDOT:PSS solution; the inorganic hole transport material solution is one or both of a nickel oxide solution and a copper oxide solution; and S1022, coating the hole transport material solution on the surface of the conductive substrate by a solution method, and annealing to obtain the hole transport layer.

[0023] The step S103 includes the following two steps: S1031, preparing a 1-butyl-3-methyl-imidazole acetate solution; filtering the solution to obtain a filtrate, and spin-coating the filtrate on the hole transport layer to cover the hole transport layer; and S1032, annealing treatment to obtain an interface modification layer.

[0024] The step S104 includes the following two steps: S1041, spin-coating a lead iodide solution onto the interface modification layer, and then performing a first annealing treatment to form a lead iodide layer, wherein the spin-coating parameters include: a rotation speed of 1000-5000 rpm, a time of 20-100 seconds, and a process of the first annealing treatment: setting a temperature range of 50-120° C., performing the annealing treatment in a nitrogen environment, and an annealing time of 50-150 seconds; and S1042, spin-coating an organic halide solution on the surface of the lead iodide layer, and then performing a second annealing treatment: wherein the organic halide solution includes FAI, MACl, and MAI, and the mass ratio of the FAI, MACl, and MAI is (60-90):(3-10):(3-10); the spin-coating parameters include: a rotation speed of 1000-3000 rpm; the process of the second annealing treatment is: setting the temperature to 80-150°C, performing the treatment in a drying oven environment, and performing the treatment for 5-15 minutes.

[0025] The step S105 includes the following two steps: S1051, providing an electron transport material solution; the electron transport material solution is an organic electron transport material solution, and the organic electron transport material solution is one or both of a C60 solution and a PC61BM solution; and S1052, coating the electron transport material solution on the surface of the perovskite layer by a solution method, and performing annealing treatment to form the electron transport layer.

[0026] In the step S106, a BCP solution is prepared, wherein the solvent is isopropyl alcohol, and the solution is filtered to obtain a filtrate; the filtrate is dropped onto the perovskite layer for spin coating, followed by annealing.

[0027] In step S107, a metal electrode is prepared on the surface of the cathode buffer layer by evaporation, and the material of the metal back electrode layer is one of Au, Ag, Al, Ti, Ni, Pd, Cu, Cr or a low-temperature carbon electrode.

[0028] The beneficial effects of the present invention are: The inverted perovskite solar cell device of the present invention selects an effective interface passivation material, namely an acetate molecule containing an imidazole ring, which increases the interface contact between the perovskite film and the hole transport layer, thereby improving the interface wettability between the perovskite film and the hole transport layer, reducing interface defects, and optimizing the performance and stability of the inverted device.

[0029] Specifically, the inverted perovskite solar cell device of the present invention uses 1-butyl-3-methyl-imidazolium acetate containing imidazole cycloacetate molecules as an interface modification layer, which improves the wettability of lead iodide on the hole transport layer, improves the interface contact between the hole transport layer and the perovskite layer, improves the crystallinity of the perovskite layer, and forms a perovskite film with a larger grain size; at the same time, the interface defects between the perovskite and the hole transport layer are passivated, the mobility and lifetime of the carriers are improved, the non-radiative recombination is significantly reduced, and the charge transport is promoted; at the same time, due to the uniform coverage of the imidazole acetate molecules at the interface, a dipole is formed at the interface, which effectively improves charge transport, reduces the interface opening voltage loss, and improves the photoelectric conversion efficiency of the perovskite solar cell. Further, the present invention uses 1-butyl-3-methyl-imidazolium acetate containing imidazole cycloacetate molecules as an interface modification layer, which reacts with the lead iodide remaining at the interface, effectively reducing the residual amount of lead iodide at the interface, forming a high-quality film, and improving the stability of the device.

[0030] To more clearly illustrate the embodiments of the present invention, the following describes the embodiments of the present invention or compares them with the prior art in conjunction with the accompanying drawings. Obviously, the following drawings only describe some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without inventive effort. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a flow chart of preparing an inverted perovskite solar cell device according to an embodiment of the present invention.

[0032] Figure 2 Schematic diagram of the structure of an inverted perovskite solar cell device according to an embodiment of the present invention.

[0033] Figure 3 3 is a photoelectric conversion efficiency curve of the inverted perovskite solar cell device of Example 3 of the present invention and the control example.

[0034] Figure 4 This is a comparison of atomic force microscopy scans before and after PTAA modification.

[0035] Figure 5 The figure shows the contact angle test between the lead iodide solution and the control hole transport layer and the hole transport layer after interface modification with imidazole cycloacetate molecule 1-butyl-3-methyl-imidazolium acetate.

[0036] Figure 6 These are SEM images of the control perovskite film and the perovskite film after interface modification with imidazole cycloacetate molecules 1-butyl-3-methyl-imidazolium acetate. DETAILED DESCRIPTION

[0037] The following describes exemplary embodiments of the present application in more detail with reference to the accompanying drawings. Although exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments described herein. Instead, these embodiments are provided to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0038] It should be understood that the terms used herein are for the purpose of describing specific example embodiments only and are not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "one", "an" and "said" as used herein may also be meant to include plural forms. The terms "comprise", "include", "contain" and "have" are inclusive and therefore specify the presence of stated features, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, steps, operations, elements, parts, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring them to be performed in the specific order described or illustrated, unless the order of execution is clearly indicated. It should also be understood that additional or alternative steps may be used.

[0039] The experimental methods described in the following examples, unless otherwise specified, are conventional methods; the reagents and materials described, unless otherwise specified, can be obtained from commercial channels.

[0040] The endpoints and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to form one or more new numerical ranges, and these numerical ranges should be considered to be specifically disclosed herein.

[0041] The present invention relates to a trans-perovskite solar cell device based on imidazole cycloacetate molecules and a preparation method thereof. Figure 2 The structure of the inverted perovskite solar cell device includes a transparent conductive substrate 1, a hole transport layer 2, a perovskite layer 4, an electron transport layer 5, a cathode buffer layer 6, and a metal back electrode layer 7, which are stacked in sequence from bottom to top. The present invention introduces an interface modification layer 3 formed by imidazole cycloacetate molecules (1-butyl-3-methyl-imidazolium acetate) between the hole transport layer 2 and the perovskite layer 4 of the inverted perovskite solar cell device. By increasing the interfacial contact between the perovskite layer 4 and the hole transport layer 2, the interfacial adhesion between the perovskite film 4 and the hole transport layer 2 is improved, the defects of the perovskite layer 4 are effectively reduced, and the non-radiative recombination of photogenerated carriers is reduced, thereby effectively improving the photoelectric conversion efficiency and stability of the device.

[0042] The first aspect of the present invention provides a method for preparing an inverse perovskite solar cell containing an acetate molecule containing an imidazole ring, comprising the following steps S101 to S107, referring to Figure 1 : S101, providing a conductive substrate; S102, preparing a hole transport layer on the surface of the conductive substrate; S103, preparing an interface modification layer containing imidazole cycloacetate molecules 1-butyl-3-methyl-imidazolium acetate on the surface of the hole transport layer; S104, preparing a perovskite layer on the surface of the 1-butyl-3-methyl-imidazolium acetate interface modification layer containing imidazolium cycloacetate molecules; S105, preparing an electron transport layer on the surface of the perovskite layer; S106, preparing a cathode buffer layer on the surface of the electron transport layer; and S107, preparing an electrode on the surface of the cathode buffer layer.

[0043] In some embodiments, the conductive substrate in step S101 is a transparent rigid conductive substrate or a transparent flexible conductive substrate. The transparent rigid conductive substrate may be an ITO substrate, an FTO substrate, or the like. The transparent flexible conductive substrate may be a PET substrate, a PEN substrate, or the like. The conductive substrate may also be made of other materials known in the art.

[0044] In some embodiments, the conductive substrate, such as an ITO substrate, undergoes cleaning and UV treatment. Specifically, the conductive substrate is first cleaned; then, the cleaned conductive substrate is subjected to UV treatment to increase the hydrophilicity of the conductive substrate. The cleaning steps may include ultrasonically cleaning the conductive substrate using a mixture of deionized water and detergent, then deionized water and isopropyl alcohol, followed by drying with nitrogen.

[0045] In some embodiments, the step of preparing the hole transport layer 2 on the surface of the conductive substrate 1 in step S102 specifically includes the following two steps: S1021, preparing a hole transport material solution; and S1022, coating the hole transport material solution on the surface of the conductive substrate by a solution method (such as spin coating), and annealing to obtain the hole transport layer.

[0046] In S1021, the hole transport material solution of the hole transport layer can be an organic hole transport material solution, such as one or both of a PTAA solution and a PEDOT:PSS solution; or an inorganic hole transport material solution, such as a nickel oxide or copper oxide solution. The preparation method can be spin coating, spray coating, or a chemical bath. PTAA is poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine); PEDOT is a polymer of EDOT (3,4-ethylenedioxythiophene); and PSS is polystyrene sulfonate.

[0047] In S1022, a spin coating and annealing process is used. For example, a 2.5 mg / mL PTAA chlorobenzene solution is spin-coated on a clean ITO conductive substrate at a rotation speed of 5000 rpm and an acceleration of 5000 rpm / s for 30 seconds, and then annealed in a nitrogen atmosphere at 100°C for 10 minutes.

[0048] Step S103 includes the following two steps: S1031, adding a 1-butyl-3-methyl-imidazole acetate solution dropwise onto the hole transport layer of the conductive substrate until the hole transport layer is completely covered; S1032, annealing treatment to obtain an interface modification layer.

[0049] In some embodiments, in S1031, specifically, 1-butyl-3-methyl-imidazole acetate is dissolved in a DMF solution and uniformly mixed to obtain a 1-butyl-3-methyl-imidazole acetate solution, wherein the concentration of the 1-butyl-3-methyl-imidazole acetate is 0.1 to 2 µL / mL. The 1-butyl-3-methyl-imidazole acetate solution is filtered to obtain a filtrate; the filtrate is dropwise added to the hole transport layer of the conductive substrate until the hole transport layer is completely covered, and then spin coating is performed; illustratively, the spin coating is performed at a rotation speed of 5000 rpm and an acceleration of 5000 rpm / s for 30 seconds.

[0050] In S1032, for example, annealing was performed at 90°C for 10 min.

[0051] The present invention introduces an interface modification layer 3 formed by imidazole cycloacetate molecules 1-butyl-3-methyl-imidazole acetate between the hole transport layer 2 and the perovskite layer 4 in the inverted perovskite solar cell, thereby increasing the interface contact between the perovskite film and the hole transport layer, thereby improving the interface adhesion between the perovskite film and the hole transport layer, effectively reducing the defects of the perovskite layer, reducing the non-radiative recombination of photogenerated carriers, and effectively improving the photoelectric conversion efficiency and stability of the device.

[0052] In step S104, the perovskite body is ABX3, wherein A includes methylamine cations, cesium cations, and formamidinium cations; B includes lead cations; and X includes bromide ions, chloride anions, and iodide anions. This embodiment uses a two-step spin coating method to prepare the perovskite layer: S1041, spin-coating a 1.5 mol lead iodide solution on the interface modification layer, and then performing an annealing treatment (first annealing); S1042, spin-coating an organic halide solution on the surface of the lead iodide layer, and then performing an annealing (second annealing) process.

[0053] The present invention prepares a perovskite layer solution in two parts: a lead iodide solution and an organic halide solution. After weighing the chemicals, solvents are added to each solution and dissolved evenly to obtain the lead iodide solution and the organic halide solution, respectively. The perovskite layer is then obtained by spin coating and annealing.

[0054] As some embodiments, in S104, the solvent of the PbI2 solution can be one or more of dimethyl sulfoxide, N,N-dimethylformamide, r-butyrolactone, N-methylpyrrolidone, etc.; the solute of the perovskite organic halide solution is formamidine or methylamine hydroiodide (chloride or bromide), etc., and the solvent is isopropyl alcohol (IPA).

[0055] In S1041, the lead iodide solution is spin-coated on the interface modification layer. The spin-coating parameters include a rotation speed of 1000-5000 rpm and a time of 20-100 s. This step also includes an annealing (first annealing) process. The first annealing process is performed in a nitrogen environment in a glove box at a set temperature of 50-120°C, preferably 70°C, for 50-150 s, preferably 60 s.

[0056] In one embodiment, the organic halide solution in S1042 may be a solution containing formamidinium iodide (FAI), methylammonium chloride (MACl), and methylammonium iodide (MAI). The solvent may be, but is not limited to, isopropyl alcohol (IPA). Using mixed cations and halogens is more conducive to the transformation of the perovskite phase and inhibits the formation of a non-perovskite phase.

[0057] Furthermore, the mass ratio of FAI, MACl, and MAI is (60-90):(3-10):(3-10). Using mixed cations and halogens within this mass ratio range is more conducive to the transformation of the perovskite phase and inhibits the formation of the non-perovskite phase.

[0058] In one embodiment, in the step of spin-coating the organic halide solution onto the surface of the lead iodide layer (S1042), the spin-coating parameters include a rotation speed of 1000-3000 rpm and a time of 30 seconds. This step also includes an annealing (second annealing) process. In one embodiment, the second annealing process is performed in a closed environment at different humidity levels (humidity controlled between 20% and 30%) at a temperature of 80-150°C, preferably 150°C, for 5-15 minutes.

[0059] This invention utilizes a two-step spin-coating process to prepare the perovskite layer. This method eliminates the prior art drop-coating process involving antisolvents such as chlorobenzene. Furthermore, by independently controlling the deposition parameters of the lead halide and organic halide (e.g., annealing temperature, spin-coating speed, and separate control of the lead iodide and organic halide concentrations), the perovskite film can be enhanced. This method produces perovskite films with larger grains and higher quality, making them suitable for the fabrication of high-efficiency perovskite solar cells. Furthermore, this spin-coating process is mature, simple, and highly reproducible.

[0060] The present invention uses a two-step spin-coating technique to prepare the perovskite layer. The interface modification layer containing imidazole cycloacetate molecules strongly interacts with the lead iodide remaining at the interface. The imidazole ring (C=N) of the cation and the C=O of the anion of the molecule chemically interact with PbI2, thereby delaying the crystallization process of the perovskite and allowing the lead iodide to more completely transform into the perovskite phase. This synergistic regulation increases the grain size of the resulting perovskite film and reduces the amount of lead iodide remaining at the interface, forming a high-quality film and improving the stability of the device.

[0061] In step S105, an electron transport layer is prepared. In one embodiment, the step of preparing the electron transport layer on the surface of the perovskite layer specifically includes: S1051, providing an electron transport material solution; S1052, coating the electron transport material solution on the surface of the perovskite layer by a solution method (such as spin coating), and annealing to form the electron transport layer.

[0062] In one embodiment, the electron transport material solution may be an organic electron transport material solution, such as C 60 Solutions, PCBM solutions, PC61BM solutions, etc. can be prepared by spin coating, spray coating, chemical bath coating, etc. Specifically, a 20 mg / mL PCBM solution is prepared using chlorobenzene as the solvent, and the solution is filtered through a filter to obtain a filtrate. PC61BM, whose molecular formula is [6,6]-phenyl-C61-butyric acid methyl ester, is also known as [6,6]-phenyl-C61-butyric acid isomethyl ester.

[0063] In step S106, a cathode buffer layer is prepared. In one embodiment, the cathode buffer layer is BCP. BCP (bathocuproine), commonly known as bathocuproine, has the chemical name 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline. Specifically, a 1 mg / mL BCP solution is prepared in isopropanol. The solution is filtered through a filter to obtain a filtrate. The filtrate is then dripped onto the perovskite layer, followed by spin coating (at a speed of 4000 rpm and an acceleration of 4000 rpm / s), followed by annealing (100°C for 1 minute).

[0064] In step S107, an electrode is prepared. A metal electrode can be prepared on the surface of the cathode buffer layer by evaporation, and the material of the metal back electrode layer is one of Au, Ag, Al, Ti, Ni, Pd, Cu, Cr or a low-temperature carbon electrode.

[0065] The present invention uses 1-butyl-3-methyl-imidazole acetate containing imidazole cycloacetate molecules as an interface modification layer, which improves the wettability of lead iodide on the hole transport layer, improves the interfacial contact between the hole transport layer and the perovskite layer, and enhances the crystallinity of the perovskite layer, forming a perovskite film with enlarged grain size. Simultaneously, the interface defects between the perovskite and the hole transport layer are passivated, improving the mobility and lifetime of carriers, significantly reducing non-radiative recombination, and promoting charge transfer. Furthermore, due to the uniform coverage of the imidazole acetate molecules at the interface, a dipole is formed at the interface, effectively enhancing charge transfer and reducing the interface's turn-on voltage loss. This improves the photoelectric conversion efficiency of the perovskite solar cell.

[0066] The present invention uses 1-butyl-3-methyl-imidazole acetate containing imidazole cycloacetate molecules as an interface modification layer, which strongly interacts with the lead iodide remaining at the interface, thereby delaying the crystallization process of the perovskite, allowing the lead iodide to be more completely converted into the perovskite phase, effectively reducing the residual amount of lead iodide at the interface, forming a high-quality film, and improving the stability of the device.

[0067] The acetate molecule containing an imidazole ring designed by the present invention comprises the following groups: .

[0068] The inverse perovskite solar cell device structure of the present invention is shown in FIG. Figure 2 The structure includes a transparent conductive substrate 1, a hole transport layer 2, an interface modification layer 3, a perovskite layer 4, an electron transport layer 5, a cathode buffer layer 6 and a metal back electrode layer 7 stacked in sequence from bottom to top. Figure 3 The typical materials or compositions of each layer are marked.

[0069] The transparent conductive substrate 1 is the aforementioned conductive substrate, which can be a transparent rigid conductive substrate or a transparent flexible conductive substrate, and is exemplified by a rigid conductive ITO substrate.

[0070] The hole transport layer 2 is formed by forming the aforementioned organic hole transport material solution or the aforementioned inorganic hole transport material solution on the transparent conductive substrate 1 by a solution method and then annealing. For example, the organic hole transport material solution PTAA is used.

[0071] The interface modification layer 3 is prepared on the surface of the hole transport layer 2, comprising an imidazole cycloacetate molecule, 1-butyl-3-methyl-imidazolium acetate. Specifically, 1-butyl-3-methyl-imidazolium acetate is dissolved in a DMF solution and uniformly mixed. The mixed solution is filtered to obtain a filtrate. The filtrate is then dripped onto the hole transport layer of the conductive substrate until the hole transport layer is completely covered. The layer is then spin-coated and annealed. The concentration of the 1-butyl-3-methyl-imidazolium acetate ranges from 0.1 to 2 µL / mL.

[0072] The perovskite layer 4 , whose perovskite body is the aforementioned ABX 3 , is formed on the interface modification layer by sequentially spin-coating a lead iodide solution and an organic halide solution using a two-step spin-coating method and annealing.

[0073] The electron transport layer 5 is formed by coating the electron transport material solution on the surface of the perovskite layer and annealing the solution. The electron transport material solution is exemplified by a PCBM solution.

[0074] The cathode buffer layer 6 is illustratively a BCP.

[0075] The metal back electrode layer 7 can be formed by evaporating a metal electrode on the surface of the cathode buffer layer. The material of the metal back electrode layer is one of Au, Ag, Al, Ti, Ni, Pd, Cu, Cr, or a low-temperature carbon electrode. For example, the metal back electrode layer 7 is a silver electrode.

[0076] The present invention is described in detail below with reference to specific comparative examples and embodiments, but these embodiments do not limit the scope of protection of the present invention in any way. In the control example, the preparation method of the inverse perovskite solar cell includes the following steps (1) to (6) in sequence:

[0077] (1) Cleaning of rigid conductive ITO substrate: Soak in detergent aqueous solution, deionized water and isopropyl alcohol for ultrasonic cleaning for 15 minutes respectively. After completion, blow dry with nitrogen. Place the treated ITO transparent substrate in a UV instrument and treat with ozone for 30 minutes.

[0078] (2) Preparation of hole transport layer: A 2.5 mg / mL poly(bis(4-phenyl)(2,4,6-trimethylphenyl)amine)PTAA chlorobenzene solution was spin-coated on a clean ITO conductive substrate for 30 seconds and then annealed in a nitrogen atmosphere at 100°C for 10 minutes. The spin-coating process was as follows: the spin-coating speed was 5000 rpm, the acceleration was 5000 rpm / s, and the spin-coating time was 30 seconds.

[0079] (3) The perovskite layer is prepared by a two-step spin coating method. The specific preparation steps are as follows: To prepare the perovskite layer solution: Dissolve 1.5 mol of lead iodide in a mixture of 900 μL of DMF and 100 μL of DMSO to obtain a lead iodide solution. Dissolve FAI, MACl, and MAI in isopropyl alcohol (IPA) and stir to obtain an organic halide solution with mass concentrations of 90 mg / mL, 6.39 mg / mL, and 9 mg / mL, respectively. The preparation of the perovskite layer is divided into two steps: the first step is to drop lead iodide solution on the surface of the hole transport layer and spin-coat it at a speed of 1500 rpm and an acceleration of 1000 rpm / s. The sample is annealed at 70°C for 1 minute and then cooled for use. The second step is to add an organic halide solution based on the first step and spin-coat it at a speed of 1500 rpm and 1000 rpm / s. After the spin coating is completed, the sample is placed on a heating table, annealed at 150°C for 30 minutes, and then cooled for use.

[0080] (4) Preparation of electron transport layer: prepare a 20 mg / mL PCBM solution with chlorobenzene as solvent and stir for 15 min; filter the solution to obtain a filtrate; drop the filtrate onto the perovskite layer and then spin coat the layer; the spin coating speed is 1000 rpm, the acceleration is 1000 rpm / s, the spin coating time is 30 s, and the layer is annealed at 70°C for 1 min.

[0081] (5) Cathode buffer layer: prepare a 1 mg / mL BCP solution with isopropanol as the solvent and stir for 15 min; filter the solution with a filter to obtain a filtrate; drop the filtrate onto the perovskite layer and then spin coat it; the spin coating speed is 4000 rpm, the acceleration is 4000 rpm / s, the spin coating time is 30 s, and the layer is annealed at 100°C for 1 min.

[0082] (6) Preparation of electrodes: 6×10 -4 Pa, a 100 nm thick Ag electrode was evaporated on the cathode buffer layer to produce a highly efficient and stable inverse perovskite solar cell. Example 1

[0083] In Example 1, a trans-perovskite solar cell device containing an acetate molecule containing an imidazole ring is prepared by a method comprising the following steps (1) to (7): (1) Cleaning of rigid conductive ITO substrate: Soak in detergent aqueous solution, deionized water and isopropyl alcohol for ultrasonic cleaning for 15 minutes respectively. After completion, blow dry with nitrogen. Place the treated ITO transparent substrate in a UV instrument and treat with ozone for 30 minutes.

[0084] (2) Preparation of hole transport layer: Spin coat a 2.5 mg / mL PTAA chlorobenzene solution on a clean ITO conductive substrate for 30 seconds and anneal in a nitrogen atmosphere at 100°C for 10 minutes. Spin coating process: Spin speed 5000 rpm, acceleration 5000 rpm / s, spin coating for 30 seconds, and spin coating time 30 seconds.

[0085] (3) Preparation of an interface modification layer of acetate molecules containing imidazole rings: Prepare a 0.1 μL / mL solution of acetate molecules containing imidazole rings in DMF as the solvent, stir for 15 min, and filter the solution to obtain a filtrate. Add the filtrate to the PTAA hole transport layer on the conductive substrate until the PTAA hole transport layer is completely covered, and then spin coat the substrate; the spin coating speed is 5000 rpm, the acceleration is 5000 rpm / s, the spin coating time is 30 s, and the substrate is annealed in a nitrogen atmosphere at 100°C for 10 min.

[0086] (4) Prepare the perovskite layer by two-step spin coating. The specific preparation steps are as follows: To prepare the perovskite layer solution, dissolve 1.5 mol of lead iodide in a mixture of 900 μL of DMF and 100 μL of DMSO to obtain a lead iodide solution. Dissolve FAI, MACl, and MAI in IPA and stir to obtain an organic halide solution with mass concentrations of 90 mg / mL, 6.39 mg / mL, and 9 mg / mL, respectively.

[0087] The preparation of the perovskite layer is divided into two steps: the first step is to drop lead iodide solution on the surface of the hole transport layer for spin coating, the spin coating speed is 1500 rpm, the acceleration is 1000 rpm / s, the spin coating time is 30 s, and the sample is annealed at 70°C for 1 min and then cooled for use; the second step is to add organic halide solution based on the first step, the spin coating speed is 2000 rpm, the acceleration is 3000 rpm / s, and the spin coating time is 30 s. After the spin coating is completed, the sample is placed on a heating table, annealed at 150°C for 30 min, and then cooled for use.

[0088] (5) Preparation of electron transport layer: Prepare a 20 mg / mL PCBM solution in chlorobenzene as solvent, stir for 15 min, filter the solution through a filter to obtain a filtrate. Add the filtrate dropwise onto the perovskite layer, and then spin-coat the layer at a speed of 1000 rpm, an acceleration of 1000 rpm / s, and a spin-coating time of 30 s. Anneal the layer at 70°C for 1 min.

[0089] (6) Cathode buffer layer: Prepare a 1 mg / mL BCP solution in isopropanol and stir for 15 min. Filter the solution to obtain a filtrate. Add the filtrate dropwise onto the perovskite layer and then spin-coat the layer at a speed of 4000 rpm, an acceleration of 4000 rpm / s, and a spin-coating time of 30 s. Anneal the layer at 100°C for 1 min.

[0090] (7) Preparation of electrodes: 6×10 -4Pa, a 100 nm thick Ag electrode was evaporated on the cathode buffer layer to produce an efficient and stable inverse perovskite solar cell.

[0091] The preparation method of the unmodified trans perovskite solar cell device of the control example is the same as the steps in Example 1. The only difference is that the interface modification layer of acetate molecules containing imidazole rings is not included in the trans perovskite solar cell of the control example. Example 2

[0092] In Example 2, a trans-perovskite solar cell device containing an acetate molecule containing an imidazole ring is prepared by a method comprising the following steps (1) to (7): Steps (1)-(2) and (4)-(7) are the same as in Example 1, except for step (3): Step (3): Prepare an interface modification layer of acetate molecules containing imidazole rings. Prepare a 0.5 μL / mL solution of acetate molecules containing imidazole rings, using DMF as the solvent, and stir for 15 minutes. Filter the solution with a filter to obtain a filtrate. Add the filtrate to the PTAA hole transport layer on the conductive substrate until the PTAA hole transport layer is completely covered, and then spin coat the substrate; the spin coating speed is 5000 rpm, the acceleration is 5000 rpm / s, the spin coating time is 30 seconds, and the substrate is annealed in a nitrogen atmosphere at 100°C for 10 minutes. Example 3

[0093] In Example 3, a trans-perovskite solar cell device containing an acetate molecule containing an imidazole ring is prepared by a method comprising the following steps (1) to (7): Steps (1)-(2) and (4)-(7) are the same as in Example 1, except for step (3): Step (3): Prepare an interface modification layer of acetate molecules containing imidazole rings. Prepare a 1 μL / mL solution of acetate molecules containing imidazole rings, using DMF as the solvent, and stir for 15 minutes. Filter the solution with a filter to obtain a filtrate. Add the filtrate to the PTAA hole transport layer on the conductive substrate until the PTAA hole transport layer is completely covered, and then spin coat the substrate; the spin coating speed is 5000 rpm, the acceleration is 5000 rpm / s, the spin coating time is 30 seconds, and the substrate is annealed in a nitrogen atmosphere at 100°C for 10 minutes. Example 4

[0094] In Example 4, a method for preparing a trans-perovskite solar cell device containing an acetate molecule containing an imidazole ring comprises the following steps: Steps (1)-(2) and (4)-(7) are the same as in Example 1, except for step (3): Step (3): Prepare an interface modification layer of acetate molecules containing imidazole rings. Prepare a 2 μL / mL solution of acetate molecules containing imidazole rings, using DMF as the solvent, and stir for 15 minutes. Filter the solution with a filter to obtain a filtrate. Add the filtrate to the PTAA hole transport layer on the conductive substrate until the PTAA hole transport layer is completely covered, and then spin coat the substrate; the spin coating speed is 5000 rpm, the acceleration is 5000 rpm / s, the spin coating time is 30 seconds, and the substrate is annealed in a nitrogen atmosphere at 100°C for 10 minutes. Example 5

[0095] In this embodiment, a method for preparing an inverted perovskite solar cell based on a PEDOT:PSS hole transport layer specifically includes the following steps (1) to (7): Steps (1), (3)-(7) are the same as in Example 1, except for step (2): Step (2): Preparation of hole transport layer: Spin coat the PEDOT:PSS solution on a clean ITO conductive substrate for 30 seconds and anneal in a nitrogen atmosphere at 100°C for 10 minutes. Spin coating process: Spin at 5000 rpm, 5000 rpm / s for 30 seconds. Spin coat the PEDOT:PSS aqueous solution filtered through a 0.45 μm filter on a clean ITO conductive substrate at 4000 rpm for 50 seconds (acceleration of 4000 rpm / s) and anneal in air at 130°C for 20 minutes. Example 6

[0096] In this embodiment, a method for preparing an inverted perovskite solar cell device based on a NiOx hole transport layer includes the following steps (1) to (7): Steps (1), (3)-(7) are the same as in Example 1, except for step (2): Step (2): Preparation of hole transport layer: Spin-coat 5 mg / mL NiOx solution (solvent H2O:IPA=3:1) on a clean ITO conductive substrate and anneal in air at 100°C for 10 min. Spin-coating process: rotation speed 3000 rpm, acceleration 3000 rpm / s, spin-coating time 30 s. In this embodiment, x has no specific value, mainly because NiO x The chemical composition of MgO is non-stoichiometric (i.e., the oxygen content is variable), and its actual oxygen content is significantly affected by the preparation conditions and doping state. Example 7

[0097] In this embodiment, an inverted perovskite solar cell device based on the new perovskite material 3MAI:PbAc2·xH2O (0≤x≤3) is prepared by a method comprising the following steps (1) to (7): Steps (1)-(3) and (5)-(7) are the same as in Example 1, except for step (4): To prepare the perovskite layer solution, lead acetate trihydrate (99.99% purity) was heated at 100°C for 12 hours in a nitrogen atmosphere to remove water and obtain anhydrous lead acetate. By adjusting the mixing ratio of anhydrous lead acetate (PbAc2) and lead acetate trihydrate (PbAc2·3H2O), a hydration-adjustable lead acetate (PbAc2·xH2O, 0 ≤ x ≤ 3) was prepared, with x = 2.8 being the optimal ratio. This was used to prepare the perovskite precursor solution. A 30%-50% mass fraction perovskite precursor solution was prepared by dissolving 1.2 mol of lead acetate (PbAc2·xH2O) (0 ≤ x ≤ 3) and methylamine iodine (MAI) in DMF at a molar ratio of 1:3, with x = 2.8. The perovskite layer was deposited by heating the substrate and perovskite solution at low temperature (<100°C), using heat-assisted spin coating (HASP). The substrate was heated at 90°C for 5 minutes. The perovskite solution was heated at 60-80°C for 5-10 minutes. After one-step spin coating, it was annealed at 100°C in a nitrogen atmosphere for 10 minutes. Spin coating was performed at a speed of 3000 rpm, an acceleration of 3000 rpm / s, and a spin coating time of 30 seconds. Example 8

[0098] In this embodiment, a flexible inverse perovskite solar cell device based on the new perovskite material 3MAI:PbAc2·xH2O (0≤x≤3) is prepared by a method comprising the following steps (1) to (7): Steps (2), (3), (5)-(7) are the same as those in Example 1, except for steps (1) and (4): In step (1), the flexible conductive ITO-PET substrate is cleaned by soaking it in a detergent aqueous solution, deionized water and isopropyl alcohol for ultrasonic cleaning for 15 minutes respectively. After completion, it is blown dry with nitrogen. The treated ITO transparent substrate is placed in a UV instrument and treated with ozone for 30 minutes.

[0099] To prepare the perovskite layer solution, lead acetate trihydrate (99.99% purity) was heated at 100°C for 12 h in a nitrogen atmosphere to remove water and obtain anhydrous lead acetate. By adjusting the mixing ratio of anhydrous lead acetate (PbAc2) and lead acetate trihydrate (PbAc2·3H2O), a hydration-adjustable lead acetate (PbAc2·xH2O, 0 ≤ x ≤ 3) was prepared, with x=2 being the optimal ratio. This was used to prepare the perovskite precursor solution. A 30%-50% mass fraction perovskite precursor solution was prepared by dissolving 1.2 mol of lead acetate (PbAc2·xH2O) (0 ≤ x ≤ 3) and methylamine iodide (MAI) in DMF at a molar ratio of 1:3, with x=2.8 being the optimal ratio. The perovskite layer was deposited by heating the substrate and perovskite solution at low temperature (<100°C), using heat-assisted spin coating (HASP). The substrate was heated at 90°C for 5 min. The perovskite solution was heated at 60-80°C for 5-10 minutes. After one-step spin coating, it was annealed at 100°C in a nitrogen atmosphere for 10 minutes. Spin coating was performed at a speed of 3000 rpm, an acceleration of 3000 rpm / s, and a spin coating time of 30 seconds.

[0100] The photoelectric conversion efficiency of the inverse perovskite solar cell devices prepared in the Examples and Control Examples was tested using a steady-state calibrated solar simulator. The test results are shown in Table 1. Table 1 shows that the inverse perovskite solar cell with interface modification using imidazole cycloacetate molecules, 1-butyl-3-methyl-imidazolium acetate, has reduced defects and improved interface transport performance. This indicates that modifying the interface between the hole transport layer and the perovskite film using imidazole cycloacetate molecules, 1-butyl-3-methyl-imidazolium acetate, can effectively improve its photoelectric conversion efficiency.

[0101] Table 1. Performance of perovskite solar cell devices prepared in various embodiments and comparative examples

[0102] Reference Figure 2 , a schematic structural diagram of an inverted perovskite solar cell device in an embodiment, with reference to the aforementioned description of the inverted perovskite solar cell device structure.

[0103] Reference Figure 3 , a graph showing the photoelectric conversion efficiency of the solar cell device of the control example and embodiment 3, wherein the solar cell device of embodiment 3 is a perovskite film modified with an imidazole cycloacetate molecule 1-butyl-3-methyl-imidazolium acetate interface, and the control example solar cell device does not contain the interface modification, Figure 3 It can be seen that the solar cell device contains a perovskite film with an interface modified by imidazole cycloacetate molecules 1-butyl-3-methyl-imidazolium acetate, and its photoelectric conversion efficiency is effectively improved.

[0104] Figure 4 The middle is the atomic force microscope scanning comparison before and after PTAA modification, Figure 4 It can be seen that the surface morphology of the PTAA film modified with 1-butyl-3-methyl-imidazole acetate molecules is smoother and denser, which is conducive to the subsequent preparation of perovskite films.

[0105] Figure 5 The figure shows the contact angle test of lead iodide with the control hole transport layer and the hole transport layer modified with the imidazole cycloacetate molecule 1-butyl-3-methyl-imidazolium acetate. Figure 5 It can be seen that the contact angles of PbI2 solution on the unmodified and 1-butyl-3-methyl-imidazole acetate interface-modified PTAA substrates are 42.15° and 18.64°, respectively, confirming that the wettability of PTAA is significantly improved after 1-butyl-3-methyl-imidazole acetate treatment.

[0106] Figure 6 The middle is a control example, and the SEM image of the perovskite film after interface modification with imidazole cycloacetate molecules 1-butyl-3-methyl-imidazolium acetate. Figure 6 Compared with the control perovskite film, the perovskite film prepared after interface modification with 1-butyl-3-methyl-imidazole acetate has a more uniform surface morphology and larger grain size, which improves the quality of the perovskite film and effectively reduces non-radiative recombination.

[0107] The perovskite layer of the inverse perovskite solar cell device of the present invention is prepared by a two-step spin coating method, wherein a lead iodide solution and an organic halide solution are spin-coated step by step, and an interface modification layer reacts with residual lead iodide to reduce defects.

[0108] The perovskite layer of the inverted perovskite solar cell device of the present invention comprises FAI, MACl, MAI mixed cations, and halogen, avoiding a single component. The present invention demonstrates that the inverted perovskite solar cell device has a maximum photoelectric conversion efficiency of 23.71%, significantly higher than that of existing inverted perovskite solar cell devices. Furthermore, data such as AFM images, interface contact angle measurements, and SEM images demonstrate that the inverted perovskite solar cell device of the present invention exhibits advantages in interface wettability and film quality.

[0109] The perovskite layer of the inverted perovskite solar cell device in this embodiment utilizes a novel perovskite material, 3MAI:PbAc2·xH2O (0≤x≤3). This layer is prepared at low temperatures (<100°C) by rapidly preheating the substrate and heating the perovskite precursor solution, known as heat-assisted spin coating (HASP). This technique increases the perovskite grain size and reduces defects between grains, significantly improving the efficiency of the perovskite cell. The resulting cell device achieves a photoelectric conversion efficiency exceeding 20%, with a flexible device achieving an efficiency of 19.10%, and exhibits no hysteresis. This preparation method holds great promise for future applications.

[0110] The hole transport layer of the inverted perovskite solar cell device of an embodiment of the present invention comprises PEDOT:PSS and NiOx. The surface of the PEDOT:PSS and NiOx hole transport layer is modified with an imidazole-based ionic liquid of 1-butyl-3-methyl-imidazolium acetate. The modified surface morphology is smoother, which is beneficial to suppressing the recombination of dark current.

[0111] In summary, the present invention provides an inverted perovskite solar cell device and a preparation method thereof. The present invention introduces an interface modification layer formed by an acetate containing an imidazole ring, 1-butyl-3-methyl-imidazolium acetate, between the hole transport layer and the perovskite layer in the inverted perovskite solar cell, thereby increasing the interface contact between the perovskite film and the hole transport layer. Through the interaction between the acetate molecules containing the imidazole ring and the hole transport layer, the wettability of lead iodide on the hole transport layer is improved, the interface contact between the hole transport layer and the perovskite layer is improved, and the crystallinity and film quality of the perovskite layer are improved; the defects of the perovskite layer are effectively reduced, the non-radiative recombination of photogenerated carriers is reduced, and the photoelectric conversion efficiency of the device is effectively improved. The interface reacts with the lead iodide remaining at the interface, effectively reducing the residual amount of lead iodide at the interface, forming a high-quality film, and improving the stability of the device.

[0112] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention, and that the scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An inverted perovskite solar cell device, comprising a transparent conductive substrate, a hole transport layer, a perovskite layer, an electron transport layer, a cathode buffer layer, and a metal back electrode layer stacked in sequence from bottom to top; characterized in that: An interface modification layer containing imidazole cycloacetate molecules is introduced between the hole transport layer and the perovskite layer.

2. The inverted perovskite solar cell device according to claim 1, wherein: The imidazole cycloacetate molecule is 1-butyl-3-methyl-imidazole acetate, which includes the following two groups: anion and cation: 。 3. The inverted perovskite solar cell device according to claim 2, wherein: The interface modification layer is prepared on the surface of the hole transport layer and contains 1-butyl-3-methyl-imidazole acetate, and is obtained by adding a solution of 1-butyl-3-methyl-imidazole acetate to the hole transport layer of the conductive substrate and then annealing.

4. The inverse perovskite solar cell device according to claim 3, wherein: The concentration range of the 1-butyl-3-methyl-imidazole acetate solution is 0.1-2 μL / mL.

5. The inverted perovskite solar cell device according to claim 4, wherein: The preparation method of the interface modification layer comprises the following steps: dissolving 1-butyl-3-methyl-imidazole acetate in a DMF solution and uniformly mixing the mixture; filtering the mixed solution to obtain a filtrate; dripping the filtrate onto a hole transport layer of a conductive substrate to cover the hole transport layer, and then performing spin coating, followed by annealing to obtain the interface modification layer.

6. The inverted perovskite solar cell device according to claim 2, wherein: The hole transport layer is made of an organic or inorganic hole transport material solution; The organic hole transport material solution includes one or two of a PTAA solution and a PEDOT:PSS solution; The inorganic hole transport material solution is one or both of nickel oxide and copper oxide solutions.

7. The inverted perovskite solar cell device according to claim 2, wherein: The main body of the perovskite layer is ABX3, wherein A includes one or more of methylamine cations, cesium cations, and formamidinium cations; B includes lead cations; and X includes chloride anions and iodide anions. The perovskite layer is made of a perovskite layer solution, and the perovskite layer solution is configured in two parts, the first part is a lead iodide solution, and the second part is an organic halide solution; The organic halide solution includes FAI, MACl, and MAI; The solvent of the lead iodide solution is one or more of dimethyl sulfoxide, N,N-dimethylformamide, r-butyrolactone, and N-methylpyrrolidone; the solute of the organic halide solution in the perovskite solution is a salt of formamidine, methylamine hydroiodide, methylamine hydrochloride, or methylamine hydrobromide, and the solvent is isopropyl alcohol; The perovskite layer is prepared by a two-step spin coating method, comprising the following steps: Spin coating a lead iodide solution on the interface modification layer, and then performing a first annealing treatment; An organic halide solution is spin-coated on the surface of the lead iodide layer, and then a second annealing treatment is performed.

8. The inverted perovskite solar cell device according to claim 1, wherein: The perovskite layer is made from 3MAI:PbAc2·xH2O, where 0≤x≤3. The preparation method involves heating lead acetate trihydrate in a nitrogen atmosphere to remove water to produce anhydrous acetic acid. The anhydrous lead acetate and lead acetate trihydrate are then mixed in a specific ratio to prepare lead acetate (PbAc2·xH2O) with an adjustable hydration level. The prepared lead acetate (PbAc2·xH2O) and methylamine iodide (MAI) are then dissolved in DMF to create a 30%-50% by weight perovskite precursor solution. The substrate and perovskite solution are heated, and the perovskite layer is formed by a one-step spin coating process. The perovskite layer is then annealed in a nitrogen atmosphere.

9. A preparation method for preparing the inverse perovskite solar cell device according to any one of claims 1 to 8, comprising the following steps: S101, providing a conductive substrate; S102, preparing a hole transport layer on the surface of the conductive substrate; S103, preparing an interface modification layer containing imidazole cycloacetate molecules on the surface of the hole transport layer; S104, preparing a perovskite layer on the surface of the interface modification layer containing imidazole cycloacetate molecules; S105, preparing an electron transport layer on the surface of the perovskite layer; S106, preparing a cathode buffer layer on the surface of the electron transport layer; as well as S107, preparing an electrode on the surface of the cathode buffer layer.

10. The preparation method according to claim 9, wherein: In step S101, the conductive substrate is a transparent rigid conductive substrate or a transparent flexible conductive substrate, the transparent rigid conductive substrate is one of an ITO substrate, an FTO substrate, etc., and the transparent flexible conductive substrate is one of a PET substrate, a PEN substrate; step S101 comprises cleaning the conductive substrate: ultrasonically cleaning the conductive substrate in a deionized water and detergent solution, and / or ultrasonically cleaning the conductive substrate with deionized water, and / or ultrasonically treating the conductive substrate in an isopropyl alcohol solution, then removing the conductive substrate and drying it with nitrogen, and then performing ultraviolet ozone treatment; The step S102 includes the following two steps: S1021, preparing a hole transport material and an electron transport material solution; the hole transport material solution is an organic or inorganic hole transport material solution, the organic hole transport material solution is one or both of a PTAA solution and a PEDOT:PSS solution; the inorganic hole transport material solution is one or both of a nickel oxide solution and a copper oxide solution; as well as S1022, coating the hole transport material solution on the surface of the conductive substrate by a solution method, and annealing the substrate to obtain the hole transport layer; The step S103 includes the following two steps: S1031, preparing a 1-butyl-3-methyl-imidazole acetate solution; filtering the solution to obtain a filtrate, and spin-coating the filtrate on the hole transport layer to cover the hole transport layer; and S1032, annealing treatment to obtain an interface modification layer; The step S104 includes the following two steps: S1041, spin-coating a lead iodide solution onto the interface modification layer, and then performing a first annealing treatment to form a lead iodide layer, wherein the spin-coating parameters include: a rotation speed of 1000-5000 rpm, a time of 20-100 seconds, and a process of the first annealing treatment: setting a temperature range of 50-120° C., performing the annealing treatment in a nitrogen environment, and an annealing time of 50-150 seconds; and S1042, spin-coating an organic halide solution on the surface of the lead iodide layer, and then performing a second annealing treatment: wherein the organic halide solution includes FAI, MACl, and MAI, and the mass ratio of the FAI, MACl, and MAI is (60-90):(3-10):(3-10); the spin-coating parameters include: a rotation speed of 1000-3000 rpm; the second annealing process is as follows: setting the temperature to 80-150° C., performing in a drying oven environment, and performing the annealing for 5-15 minutes; The step S105 includes the following two steps: S1051, providing an electron transport material solution; the electron transport material solution is an organic electron transport material solution, and the organic electron transport material solution is one or both of a C60 solution and a PC61BM solution; and S1052, coating the electron transport material solution on the surface of the perovskite layer by a solution method, and performing annealing treatment to form the electron transport layer; In step S106, a BCP solution is prepared, wherein the solvent is isopropyl alcohol, and the solution is filtered to obtain a filtrate; the filtrate is dropped onto the perovskite layer for spin coating, followed by annealing; In step S107, a metal electrode is prepared on the surface of the cathode buffer layer by evaporation, and the material of the metal back electrode layer is one of Au, Ag, Al, Ti, Ni, Pd, Cu, Cr or a low-temperature carbon electrode.

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