Modified perovskite thin film, perovskite composite film, preparation method thereof and perovskite solar cell

Abstract

This invention discloses a modified perovskite thin film, a perovskite composite film, their preparation method, and a solar cell. This invention introduces a compound of formula I into perovskite, utilizing the hydrazine group on its structure to selectively reduce formula I. 0 This reduces the possibility of ion migration, thereby preventing performance degradation caused by ion migration. Simultaneously, it participates in the nucleation and crystallization regulation of perovskite; the O atoms with lone pairs of electrons can coordinate with Pb atoms, thus delaying the crystallization process of perovskite materials to a certain extent, contributing to the acquisition of high-quality perovskite thin films. This invention further modulates the Fermi level of the thin film through substituent design, reducing charge accumulation at the heterojunction and further improving device efficiency and operational stability, demonstrating great potential in improving the optoelectronic performance and stability of devices.

Description

Technical Field

[0001] This invention relates to the field of solar cell technology, specifically to a modified perovskite thin film, a perovskite composite film, their preparation methods, and a perovskite solar cell. Background Technology

[0002] In the forefront of optoelectronic technology exploration, metal halide perovskite solar cells (PSCs) have become a shining star in the photovoltaic field due to their outstanding performance and potential. Over the past decade, PSCs have achieved significant technological breakthroughs, with their certified power conversion efficiency (PCE) climbing to 26.7%, a figure gradually approaching and nearing the peak levels of industrialized crystalline silicon and Cu(In,Ga)Se2 photovoltaic technologies. However, like the shadow behind a brilliant star, PSCs, while pursuing high efficiency, also face severe challenges such as the stability and repeatability of perovskite-based electronic materials and devices.

[0003] However, despite significant progress in efficiency, the stability and reproducibility of perovskite-based electronic materials and devices remain crucial issues hindering their application. These challenges primarily stem from the oxidation of iodine and the reduction of lead under non-equilibrium conditions (such as light, heat, and electric fields), which not only affect performance and lifespan but also limit a deeper understanding of their intrinsic properties and the exploration of their practical application potential. In the path of research and production, the lack of reproducibility makes each experiment and manufacturing process fraught with unknowns and variables, undoubtedly increasing the complexity and uncertainty of R&D and production.

[0004] In particular, the perovskite light-absorbing layer, due to its ionic compound properties, has relatively weak intrinsic stability. At the interface with other semiconductor materials, ion migration (such as the migration of iodine and lead) becomes a difficult barrier to overcome, which not only weakens the performance of PSCs, but also makes it difficult for them to meet the stringent standards of commercial applications (typically requiring an operating life of 25 years to meet the IEC 61215 stability standard).

[0005] To address this, researchers have continuously explored and proposed various solutions. Among them, reducing agents and redox couples have become the two main strategies. Reducing agents such as benzylhydrazine hydrochloride (BHC), phenylhydrazine-4-sulfonic acid (PHPA), and 3-hydrazinobenzoic acid (3-HBA) can stabilize the precursor and inhibit the oxidation of iodide ions; while redox couples such as Eu... 3+ / Eu 2+ (Science 2019, 363, 265-270.) and ferrocene (Fc, Angew. Chem. Int. Ed. 2021, 60, 25567-25574.), etc., can repair Pb 0 and I 0Defects enable self-regeneration.

[0006] However, these solutions are not without flaws. For reducing agent strategies, the reducing agents have relatively singular functions and, as consumables, become ineffective after a period of aging, making it difficult to continuously restore defects over long-term aging. The design and development of reducing agents are often limited by existing chemical knowledge and technological conditions, making it difficult to integrate multiple functions on a single molecule. Reducing agents used in existing technologies often only target specific chemical reactions or defects, lacking versatility. This is mainly because the design of reducing agents is often based on specific redox reactions, making them inadequate for complex reaction systems or multiple defects. When participating in redox reactions, the chemical structure of the reducing agent changes, leading to reduced or lost activity. Furthermore, environmental factors such as temperature and humidity can accelerate the aging process of reducing agents. Reducing agents are gradually consumed during the reaction process, and their effectiveness and performance decrease with increasing use time, eventually losing their function. While redox pair strategies can inhibit the oxidation of iodide ions, their function is relatively singular. Existing redox strategies suffer from several drawbacks. First, Eu metal, being a rare element, is expensive due to limited mining availability. Furthermore, the high purity requirements for Eu metal further increase production costs, resulting in high Eu usage costs. Second, the redox kinetics of Pb and I are mismatched, with lower I defect formation and migration energies. This leads to a mismatch in the I ion defect concentration during the reaction, inducing I defect formation and making these defects more prone to diffusion and accumulation in the material. These defects degrade device performance and stability. Third, under practical operating conditions, hole accumulation may occur at the upper interface of perovskite solar cells. Hole accumulation leads to uneven charge distribution at the upper interface, causing changes in the local electric field. These changes promote I ion migration and I... 0 The formation of defects can affect the performance and stability of devices.

[0007] Therefore, the development of multifunctional additives has become a hot topic of common concern in scientific research and industry. This is not only key to improving the stability and reproducibility of PSCs, but also an important driving force for their continuous progress on the road to commercialization. Summary of the Invention

[0008] In order to overcome the shortcomings of the prior art, the present invention aims to provide a modified perovskite thin film, a perovskite composite film, a preparation method thereof, and a solar cell. The modified perovskite thin film / perovskite composite film can improve the problems of poor repeatability and many defects of perovskite thin films in the prior art, and can be used to improve device efficiency and stability.

[0009] A first aspect of the present invention provides a modified perovskite thin film comprising a perovskite material and a compound of formula I:

[0010]

[0011] In the compound of formula I, R is selected from -H, -OCH3, -CH3, -F, -Cl, -COOH, -CF3, and -SO2CF3.

[0012] A second aspect of the present invention provides a perovskite composite film, the perovskite composite film comprising a perovskite thin film formed of a perovskite material and a functional layer disposed on the perovskite thin film, the functional layer comprising a compound of formula I:

[0013]

[0014] In the compound of formula I, R is selected from -H, -OCH3, -CH3, -F, -Cl, -COOH, -CF3, and -SO2CF3.

[0015] According to the modified perovskite film of the first aspect or the perovskite composite film of the second aspect, wherein the perovskite material has the general formula ABX3, wherein A is one or more monovalent cations selected from amino, amidine, guanidinium, cesium, and rubidium; and B is Pb. 2+ Sn 2+ One or more of them; X is Cl - ,Br - I - SCN - CH3COO - One or more of the following; preferably, the molar fraction of lead ions in B is not less than 80%;

[0016] More preferably, in the modified perovskite film or perovskite composite film, the molar ratio of perovskite material to compound of formula I is 100:(0.1 to 1).

[0017] According to the modified perovskite film of the first aspect or the perovskite composite film of the second aspect, wherein the compound of Formula I is selected from one or more of 3-amino-phthalic acid hydrazide, 4-aminophthalic acid hydrazide, 3-amino-4-carboxyphthalic acid hydrazide, 3-amino-4-fluorophthalic acid hydrazide, and 3-amino-4-trifluoromethanesulfonic acid phthalic acid hydrazide.

[0018] A third aspect of the present invention provides a method for preparing the modified perovskite thin film of the first aspect, comprising:

[0019] (1) Prepare a perovskite precursor solution and add a compound of formula I to the perovskite precursor solution;

[0020] Preferably, the concentration of the compound of formula I in the perovskite precursor solution is 0.01–3 mg / mL;

[0021] (2) A wet film is formed by depositing a perovskite precursor solution, and the wet film is extracted using an antisolvent to form a modified perovskite film.

[0022] A fourth aspect of the present invention provides a method for preparing the perovskite composite film of the second aspect, the method comprising:

[0023] (1) Preparation of perovskite precursor solution;

[0024] (2) A wet film is formed by depositing a perovskite precursor solution, and the wet film is extracted by adding the antisolvent of compound I to form the perovskite composite film.

[0025] Preferably, the concentration of the compound of formula I in the antisolvent is 0.1 to 20 mg / mL.

[0026] The fifth aspect of the present invention provides a method for preparing the perovskite composite film of the second aspect, the method comprising:

[0027] (1) Preparation of perovskite precursor solution;

[0028] (2) A wet film is formed by depositing a perovskite precursor solution, and the wet film is extracted using an antisolvent and dried to obtain a perovskite thin film.

[0029] (3) A functional layer is prepared on the surface of the perovskite film obtained in step (2) using a surface modification solution containing compound I to form the perovskite composite film;

[0030] Preferably, the concentration of the compound of formula I in the surface modification solution is 0.1–20 mg / mL; and / or

[0031] Preferably, the solvent of the surface modification solution is selected from one or more of the following: dimethyl ether, isopropanol, m-xylene, toluene, 1,3,5-trimethylbutanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, ethyl acetate, butyl acrylate, diethyl ether, chlorobenzene, and toluene.

[0032] More preferably, the doping method is immersion and / or deposition;

[0033] More preferably, the soaking includes immersing the perovskite film in the surface modification solution for a soaking time of 5 to 600 seconds.

[0034] According to the method described in the third to fifth aspects, in step (2), the antisolvent is selected from one or more of anisole, isopropanol, m-xylene, toluene, 1,3,5-trimethylbutanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, ethyl acetate, butyl acrylate, diethyl ether, chlorobenzene, and toluene.

[0035] Preferably, the extraction method is soaking and / or deposition;

[0036] More preferably, the soaking includes immersing the wet film in an antisolvent for 5–600 s; and / or

[0037] More preferably, the deposition includes depositing an antisolvent on the wet film surface.

[0038] A sixth aspect of the present invention provides a perovskite solar cell, wherein the perovskite layer of the perovskite solar cell comprises a modified perovskite film of the first aspect or a modified perovskite film prepared according to the method of the third aspect.

[0039] The seventh aspect of the present invention provides a perovskite solar cell, wherein the perovskite layer of the perovskite solar cell comprises a perovskite composite film of the second aspect or a perovskite composite film prepared according to the method of the fifth or sixth aspect;

[0040] The functional layer of the perovskite composite film is disposed on one side of the hole transport layer of the perovskite solar cell.

[0041] According to the sixth or seventh aspect, the perovskite solar cell includes a conductive glass electrode layer, a first charge transport layer, a perovskite layer, a second charge transport layer, and a counter electrode layer; wherein, when the first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer; and when the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer.

[0042] Preferably, the electron transport layer material is an N-type semiconductor, preferably selected from C. 60 BCP, PC 61 BM, PC 71 One or more of BM, TiO2, ZnO, SnO2, and ZnTiO3, more preferably, the thickness of the electron transport layer is 5 to 120 nm;

[0043] Preferably, the hole transport layer material is a P-type semiconductor, preferably selected from one or more of nickel oxide, Spiro-OMeTAD, poly-TPD, copper phthalocyanine, nickel phthalocyanine, poly(triarylamine), and poly(3-hexylthiophene); more preferably, the thickness of the hole transport layer is 50-150 nm; and / or;

[0044] Preferably, the material of the counter electrode layer is selected from one or more of gold, silver, copper, and ITO, and the thickness of the counter electron layer is 60-300 nm.

[0045] The modified perovskite thin film / perovskite composite film of the present invention has, but is not limited to, the following beneficial effects:

[0046] This invention introduces a compound of formula I into perovskite, utilizing the hydrazine group on its structure to selectively reduce I. 0 This reduces the possibility of ion migration, thereby preventing performance degradation caused by ion migration. Simultaneously, it participates in the nucleation and crystallization regulation of perovskite; the O atoms with lone pairs of electrons can coordinate with Pb atoms, thus delaying the crystallization process of perovskite materials to a certain extent, contributing to the acquisition of high-quality perovskite thin films. This invention further modulates the Fermi level of the thin film through substituent design, reducing charge accumulation at the heterojunction and further improving device efficiency and operational stability, demonstrating great potential in improving the optoelectronic performance and stability of devices. Detailed Implementation

[0047] The present application will be further described in detail below through embodiments. Through these descriptions, the features and advantages of the present application will become clearer and more apparent.

[0048] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0049] Furthermore, the technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0050] This invention provides a modified perovskite thin film comprising a perovskite material and a compound of formula I:

[0051]

[0052] In the compound of formula I, R is selected from -H, -OCH3, -CH3, -F, -Cl, -COOH, -CF3, and -SO2CF3.

[0053] The present invention also provides a perovskite composite film, the perovskite composite film comprising a perovskite thin film formed of perovskite material and a functional layer disposed on the perovskite thin film, wherein the functional layer contains a compound of formula I:

[0054]

[0055] In the compound of formula I, R is selected from -H, -OCH3, -CH3, -F, -Cl, -COOH, -CF3, and -SO2CF3.

[0056] In the compound of formula I, -NH2 and R are substituents at any position on the benzene ring. When R is -H, the compound of formula I is luminol or isoluminol.

[0057] The core objective of this invention is to solve the problem of perovskite solar cells during operation due to I 0 This invention addresses stability issues caused by defects and improves the long-term reliability of devices through innovative strategies. By modifying the perovskite thin film in solar cells, this invention achieves the following effects:

[0058] 1. Solve the I problems in the work process 0 Defect stability problem

[0059] During the operation of perovskite solar cells, I 0 Defects are often a key factor leading to degraded device performance and insufficient stability. Therefore, this invention proposes using hydrazine-containing compounds to selectively oxidize and reduce these defects, thereby improving device stability and operating efficiency.

[0060] 2. Functional group design suppresses the generation of defects in thin films.

[0061] In addition to repairing existing defects, this invention can also introduce specific functional groups to suppress the formation of defects in perovskite films. These functional groups can form stable chemical bonds with key elements in the perovskite material, thereby preventing the formation of new defects during preparation and use. This strategy not only helps improve the initial performance of the device but also further extends its lifespan. When electron-donating groups are introduced, they shift the Fermi level of the perovskite downwards, making it more p-type, thus better matching the energy level structure of the hole transport layer; when electron-withdrawing groups are introduced, they shift the Fermi level of the perovskite downwards, making it more n-type, thus better matching the energy level structure of the electron transport layer.

[0062] 3. Modulate the Fermi level of the perovskite thin film to reduce charge accumulation at the heterojunction.

[0063] The Fermi level of perovskite thin films has a significant impact on their performance. This invention achieves precise control of the Fermi level of perovskite thin films by introducing substituents with different electron-withdrawing and electron-donating capabilities. This control optimizes the carrier dynamics of the device and reduces charge accumulation at the heterojunction, thereby further improving the device's performance and stability.

[0064] In one embodiment, the perovskite material has the general formula ABX3, wherein A is one or more monovalent cations selected from amino, amidine, guanidinium, cesium, and rubidium; and B is Pb. 2+ Sn 2+ One or more of them; X is Cl - ,Br - I - SCN - CH3COO -One or more of the following; preferably, the molar fraction of lead ions in B is not less than 80%;

[0065] More preferably, in the modified perovskite film or perovskite composite film, the molar ratio of perovskite material to compound of formula I is 100:(0.1 to 1).

[0066] This invention utilizes compounds of formula I to modify perovskite thin films. Compounds of formula I include luminol, isoluminol, and their derivatives. When R is -H, the compound of formula I is luminol or isoluminol, and the hydrazine group in its structure selectively reduces I. 0 This reduces the possibility of ion migration, thereby preventing performance degradation caused by ion migration. Simultaneously, it participates in the nucleation and crystallization regulation of perovskite; the O atoms with lone pairs of electrons can coordinate with Pb atoms, thus delaying the crystallization process of perovskite materials to a certain extent, contributing to the acquisition of high-quality perovskite thin films. This invention can further regulate the Fermi level of the thin film through the design of substituents. For example, R can be selected from -OCH3, -CH3, -F, -Cl (electron-donating groups, high Fermi level direction) and -COOH, -CF3, -SO2CF3 (electron-withdrawing groups, low Fermi level direction), reducing charge accumulation at the heterojunction and further improving device efficiency and operational stability.

[0067] Luminol, isoluminol, and their derivatives are shown below:

[0068] Luminol (3-amino-phenylenediamine):

[0069]

[0070] Isoluminol (4-aminophthalic acid hydrazide):

[0071]

[0072] In luminol derivatives, R1 refers to -NH2, and R2 refers to one of the following: -OCH3, -CH3, -F, -Cl (electron-donating group, in the direction of high Fermi level) and -COOH, -CF3, -SO2CF3 (electron-withdrawing group, in the direction of low Fermi level).

[0073]

[0074] In isoluminol derivatives, R3 refers to -NH2, and R4 refers to one of the following: -OCH3, -CH3, -F, -Cl (electron-donating group, in the direction of high Fermi level) and -COOH, -CF3, -SO2CF3 (electron-withdrawing group, in the direction of low Fermi level).

[0075]

[0076] In one embodiment, the compound of Formula I is selected from one or more of 3-amino-phthalic acid hydrazide, 4-aminophthalic acid hydrazide, 3-amino-4-carboxyphthalic acid hydrazide, 3-amino-4-fluorophthalic acid hydrazide, and 3-amino-4-trifluoromethanesulfonic acid phthalic acid hydrazide.

[0077] The present invention also provides a method for preparing the modified perovskite thin film, comprising:

[0078] (1) Prepare a perovskite precursor solution and add a compound of formula I to the perovskite precursor solution;

[0079] Preferably, the concentration of the compound of formula I in the perovskite precursor solution is 0.01–3 mg / mL;

[0080] (2) A wet film is formed by depositing a perovskite precursor solution, and the wet film is extracted using an antisolvent to form a modified perovskite film.

[0081] Specifically, a precursor solution containing the compound of formula I is deposited on a substrate to form a perovskite layer containing the compound of formula I, thereby allowing the compound of formula I to be directly doped into the perovskite and coated on the grain boundary surface.

[0082] The present invention also provides a method for preparing the perovskite composite film, comprising:

[0083] (1) Preparation of perovskite precursor solution;

[0084] (2) A wet film is formed by depositing a perovskite precursor solution, and the wet film is extracted by adding the antisolvent of compound I to form the perovskite composite film.

[0085] Preferably, the concentration of the compound of formula I in the antisolvent is 0.1 to 20 mg / mL.

[0086] Specifically, a perovskite precursor solution is deposited on a substrate to form a wet film; and the wet film is extracted using an antisolvent containing a compound of formula I to form a perovskite layer including the compound of formula I, thereby introducing the compound of formula I into the perovskite and coating it on the grain boundaries and the surface of the perovskite layer using the antisolvent.

[0087] The present invention also provides a method for preparing the perovskite composite film, comprising:

[0088] (1) Preparation of perovskite precursor solution;

[0089] (2) A wet film is formed by depositing a perovskite precursor solution, and the wet film is extracted using an antisolvent and dried to obtain a perovskite thin film.

[0090] (3) A functional layer is prepared on the surface of the perovskite film obtained in step (2) using a surface modification solution containing compound I to form the perovskite composite film;

[0091] Preferably, the concentration of the compound of formula I in the surface modification solution is 0.1–20 mg / mL; and / or

[0092] Preferably, the solvent of the surface modification solution is selected from one or more of the following: dimethyl ether, isopropanol, m-xylene, toluene, 1,3,5-trimethylbutanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, ethyl acetate, ethanol, butyl acrylate, diethyl ether, chlorobenzene, and toluene.

[0093] More preferably, the doping method is immersion and / or deposition;

[0094] More preferably, the soaking includes immersing the perovskite film in the surface modification solution for a soaking time of 5 to 600 seconds.

[0095] Specifically, a perovskite precursor solution is first deposited on a substrate, and after it dries to form a film, the dry film is then doped with the aforementioned surface modification solution to form a perovskite layer coated with a compound of formula I.

[0096] This invention relates to a method for preparing a highly stable modified perovskite thin film / perovskite composite film, comprising directly doping a compound of formula I onto the perovskite and coating it on the grain boundary surface, forming and coating the perovskite layer surface with a surface modification solution prepared from the compound of formula I, or introducing the perovskite into the grain boundary and coating it on the perovskite layer surface with an antisolvent containing the compound of formula I.

[0097] This invention utilizes an antisolvent to extract perovskite wet films, thereby achieving dual passivation of the perovskite surface and grain boundaries by luminol and its derivatives in one step.

[0098] In one specific embodiment, in step (1), the perovskite precursor solution is prepared by dissolving PbI2, FAI (formamidinium hydroiodide) and CsI in a solvent to obtain the perovskite precursor solution, wherein the solvent is a mixed liquid of NMP (N-methylpyrrolidone) and DMF (N,N-dimethylformamide) in a volume ratio of 1:5.

[0099] In one specific embodiment, in step (2), the antisolvent is selected from one or more of anisole, isopropanol, m-xylene, toluene, 1,3,5-trimethylbutanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, ethyl acetate, ethanol, butyl acrylate, diethyl ether, chlorobenzene, and toluene.

[0100] Preferably, the extraction method is soaking and / or deposition;

[0101] More preferably, the soaking includes immersing the wet film in an antisolvent for 5–600 s; and / or

[0102] More preferably, the deposition includes depositing an antisolvent on the wet film surface.

[0103] The present invention also provides a perovskite solar cell, wherein the perovskite layer of the perovskite solar cell includes the aforementioned modified perovskite thin film / perovskite composite film or the modified perovskite thin film / perovskite composite film prepared according to the aforementioned method.

[0104] The functional layer of the perovskite composite film is disposed on one side of the hole transport layer of the perovskite solar cell.

[0105] In one embodiment, the perovskite solar cell includes a conductive glass electrode layer, a first charge transport layer, a perovskite layer, a second charge transport layer, and a counter electrode layer; wherein, when the first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer; and when the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer.

[0106] Preferably, the electron transport layer material is an N-type semiconductor, preferably selected from C. 60 BCP, PC 61 BM, PC 71 One or more of BM, TiO2, ZnO, SnO2, and ZnTiO3, more preferably, the thickness of the electron transport layer is 5 to 120 nm;

[0107] Preferably, the hole transport layer material is a P-type semiconductor, preferably selected from one or more of nickel oxide, Spiro-OMeTAD, poly-TPD, copper phthalocyanine, nickel phthalocyanine, poly(triarylamine), and poly(3-hexylthiophene); more preferably, the thickness of the hole transport layer is 50-150 nm; and / or;

[0108] Preferably, the material of the counter electrode layer is selected from one or more of gold, silver, copper, and ITO, and the thickness of the counter electron layer is 60-120 nm.

[0109] The modified perovskite thin film / perovskite composite film of the present invention can be used in upright or inverted solar cells. When the perovskite solar cell is upright, the structure consists of, from bottom to top, a conductive glass electrode layer, an electron transport layer, a perovskite layer, a hole transport layer, and a counter electrode. When the perovskite solar cell is inverted, the structure consists of, from bottom to top, a conductive glass electrode layer, a hole transport layer, a perovskite layer, an electron transport layer, and a counter electrode layer.

[0110] This invention does not impose any special restrictions on the source of any raw materials; unless otherwise specified, they are all conventional products that can be obtained commercially.

[0111] Example 1

[0112] This embodiment illustrates the modification of perovskite thin films by doping luminol with precursors.

[0113] This embodiment provides a method for fabricating a perovskite solar cell with an upright structure, including:

[0114] Step S1: Preparation of electron transport layer: On a cleaned cathode (FTO glass), a titanium oxide layer is prepared by spray pyrolysis. The spraying temperature is 500℃, the number of spraying turns is 12, and the coating is annealed at 500℃ for 45 min. After natural cooling, an aqueous solution of KCl is spin-coated at 3000 rpm and annealed at 100℃ for 10 min. Thus, a TiO2 electron transport layer with a film thickness of 30 nm is obtained on the FTO glass.

[0115] Step S2 includes steps S2-1 to S2-2;

[0116] Step S2-1: Prepare a perovskite precursor solution containing luminol: Dissolve PbI2, FAI and CsI in a solvent (a mixture of NMP and DMF in a volume ratio of 1:5) with a molar ratio of 1:0.95:0.05, add 0.2 mg / mL of luminol, shake and mix well to obtain a precursor solution with a concentration of 1.5 mol / L.

[0117] Step S2-2: Preparation of luminol-doped perovskite layer: Spin-coat the precursor solution onto the electron transport layer obtained in step S1. The spin-coating conditions are 6000 rpm and the spin-coating time is 30 s. At the 25th s, add chlorobenzene solution as an anti-solvent for extraction. Anneal at 100℃ for 60 min and cool naturally to obtain the perovskite layer.

[0118] Step S3 includes steps S3-1 to S3-2;

[0119] Step S3-1: Prepare a chlorobenzene dispersion of Spiro-OMeTAD: Weigh 72 mg Spiro-OMeTAD and add it to 1 mL of chlorobenzene, then add 17.5 μL of Li-TFSI / ACN (520 mg / mL) and 28.8 μL of tBP, and sonicate for 10 min to prepare a chlorobenzene dispersion of Spiro-OMeTAD.

[0120] Step S3-2: Preparation of hole transport layer: The above-mentioned Spiro-OMeTAD chlorobenzene dispersion was spin-coated onto the perovskite layer using a solution method at a spin-coating speed of 3500 rpm and then naturally dried to obtain a hole transport layer with a film thickness of 130 nm.

[0121] Step S4: Prepare the anode: Deposit metallic silver on the hole transport layer to obtain the anode with a film thickness of 100 nm.

[0122] The perovskite solar cell with an upright structure provided in this embodiment is denoted as C-1.

[0123] Example 2

[0124] This example illustrates the modification of perovskite thin films by antisolvent doping with luminol.

[0125] The only difference between the method in this embodiment and the method in Embodiment 1 is that:

[0126] Step S2 includes steps S2-1 to S2-2;

[0127] Step S2-1: Prepare perovskite precursor solution: Dissolve PbI2, FAI and CsI in solvent (a mixed liquid of NMP and DMF in a volume ratio of 1:5) in a molar ratio of 1:0.95:0.05, shake and mix evenly to obtain a precursor solution with a concentration of 1.5 mol / L.

[0128] Step S2-2: Preparation of perovskite layer doped with luminol as an antisolvent: Spin-coat 50 μL of precursor solution onto the electron transport layer obtained in step S1 at 6000 rpm for 30 s. At 25 s, add 80 μL of chlorobenzene solution containing 0.5 mg / mL luminol as an antisolvent for extraction. Anneal at 100 °C for 60 min and allow to cool naturally to obtain the perovskite layer.

[0129] The perovskite solar cell with an upright structure provided in this embodiment is denoted as C-2.

[0130] Example 3

[0131] This embodiment illustrates the use of interface-modified luminol to modify perovskite thin films.

[0132] The only difference between the method in this embodiment and the method in Embodiment 1 is that:

[0133] Step S2 includes steps S2-1 to S2-3;

[0134] Step S2-1: Prepare perovskite precursor solution: Dissolve PbI2, FAI and CsI in a solvent (a mixture of NMP and DMF in a volume ratio of 1:5) with a molar ratio of 1:0.95:0.05, shake and mix evenly to obtain a precursor solution with a concentration of 1.5 mol / L.

[0135] Step S2-2: Preparation of unmodified perovskite layer: Spin-coat 50 μL of perovskite precursor solution onto the electron transport layer obtained in step S1. The spin-coating conditions are 6000 rpm and the spin-coating time is 35 s. At 28 s, chlorobenzene solution is added dropwise as an anti-solvent for extraction. Anneal at 100℃ for 45 min and cool naturally to obtain a dry film (unmodified perovskite layer).

[0136] Step S2-3: Preparation of luminol-modified perovskite layer: Spin-coat 20 μL of luminol isopropanol surface modification solution with a concentration of 0.3 mg / mL onto the unmodified perovskite layer obtained in step S2-2. The spin-coating conditions are 4000 rpm and the spin-coating time is 30 s. After natural cooling, the modified perovskite layer is obtained.

[0137] The perovskite solar cell with an upright structure provided in this embodiment is denoted as C-3.

[0138] Example 4

[0139] This embodiment illustrates the modification of perovskite thin films by doping a precursor with a luminol derivative-electron-withdrawing group (3-amino-4-trifluoromethanesulfonic acid phthalohydrazide).

[0140] The only difference between the method in this embodiment and the method in Embodiment 1 is that:

[0141] Step S2 includes steps S2-1 to S2-2;

[0142] Step S2-1: Prepare a perovskite precursor solution containing luminol derivatives: Dissolve PbI2, FAI and CsI in a solvent (a mixture of NMP and DMF in a volume ratio of 1:5) with a molar ratio of 1:0.95:0.05, add 0.2 mg / mL of 3-amino-4-trifluoromethanesulfonic acid phthalohydrazide, shake and mix well to obtain a precursor solution with a concentration of 1.5 mol / L;

[0143] Step S2-2: Preparation of luminol derivative-doped perovskite layer: Spin-coat the precursor solution onto the electron transport layer obtained in step S1. The spin-coating conditions are 6000 rpm and 30 s. At 25 s, add chlorobenzene solution as an anti-solvent for extraction. Anneal at 100℃ for 60 min and cool naturally to obtain the perovskite layer.

[0144] The perovskite solar cell with an upright structure provided in this embodiment is denoted as C-4.

[0145] Example 5

[0146] This embodiment illustrates the modification of perovskite thin films by doping the precursor with an isoluminol derivative-electron-withdrawing group (5-amino-4-trifluoromethanesulfonic acid phthalohydrazide).

[0147] The only difference between the method in this embodiment and the method in Embodiment 1 is that:

[0148] Step S2 includes steps S2-1 to S2-2;

[0149] Step S2-1: Prepare a perovskite precursor solution containing luminol derivatives: Dissolve PbI2, FAI and CsI in a solvent (a mixture of NMP and DMF in a volume ratio of 1:5) with a molar ratio of 1:0.95:0.05, add 0.2 mg / mL of 5-amino-4-trifluoromethanesulfonic acid phthalohydrazide, shake and mix well to obtain a precursor solution with a concentration of 1.5 mol / L;

[0150] Step S2-2: Preparation of isoluminol derivative-doped perovskite layer: Spin-coat the precursor solution onto the electron transport layer obtained in step S1. The spin-coating conditions are 6000 rpm and 30 s. At 25 s, add chlorobenzene solution as an antisolvent for extraction. Anneal at 100℃ for 60 min and cool naturally to obtain the perovskite layer.

[0151] The perovskite solar cell with an upright structure provided in this embodiment is denoted as C-5.

[0152] Example 6

[0153] This embodiment illustrates the modification of perovskite thin films by doping a precursor with a luminol derivative-electron-donating group (3-amino-4-methylphthalylhydrazide).

[0154] The only difference between the method in this embodiment and the method in Embodiment 1 is that:

[0155] Step S2 includes steps S2-1 to S2-2;

[0156] Step S2-1: Prepare a perovskite precursor solution containing luminol derivatives: Dissolve PbI2, FAI and CsI in a solvent (a mixture of NMP and DMF in a volume ratio of 1:5) with a molar ratio of 1:0.95:0.05, add 0.2 mg / mL of 3-amino-4-methylphthalic acid hydrazide, shake and mix well to obtain a precursor solution with a concentration of 1.5 mol / L;

[0157] Step S2-2: Preparation of luminol derivative-doped perovskite layer: Spin-coat the precursor solution onto the electron transport layer obtained in step S1. The spin-coating conditions are 6000 rpm and 30 s. At 25 s, add chlorobenzene solution as an anti-solvent for extraction. Anneal at 100℃ for 60 min and cool naturally to obtain the perovskite layer.

[0158] The perovskite solar cell with an upright structure provided in this embodiment is denoted as C-6.

[0159] Example 7

[0160] This embodiment illustrates the modification of perovskite thin films by doping the precursor with isoluminol.

[0161] The only difference between the method in this embodiment and the method in Embodiment 1 is that:

[0162] Step S2 includes steps S2-1 to S2-2;

[0163] Step S2-1: Prepare a perovskite precursor solution containing isoluminol: Dissolve PbI2, FAI and CsI in a solvent (a mixture of NMP and DMF in a volume ratio of 1:5) with a molar ratio of 1:0.95:0.05, add 0.2 mg / mL of isoluminol, shake and mix well to obtain a precursor solution with a concentration of 1.5 mol / L.

[0164] Step S2-2: Preparation of isoluminol-doped perovskite layer: Spin-coat the precursor solution onto the electron transport layer obtained in step S1. The spin-coating conditions are 6000 rpm and 30 s. At 25 s, add chlorobenzene solution as an antisolvent for extraction. Anneal at 100℃ for 60 min and cool naturally to obtain the perovskite layer.

[0165] The perovskite solar cell with an upright structure provided in this embodiment is denoted as C-7.

[0166] Example 8

[0167] This embodiment illustrates the modification of perovskite thin films by doping a precursor with a luminol derivative-electron-withdrawing group (3-amino-4-carboxyphthalohydrazide).

[0168] The only difference between the method in this embodiment and the method in Embodiment 1 is that:

[0169] Step S2 includes steps S2-1 to S2-2;

[0170] Step S2-1: Prepare a perovskite precursor solution containing luminol derivatives: Dissolve PbI2, FAI and CsI in a solvent (a mixture of NMP and DMF in a volume ratio of 1:5) with a molar ratio of 1:0.95:0.05, add 0.2 mg / mL of 3-amino-4-carboxyphthalic acid hydrazide, shake and mix well to obtain a precursor solution with a concentration of 1.5 mol / L;

[0171] Step S2-2: Preparation of luminol derivative-doped perovskite layer: Spin-coat the precursor solution onto the electron transport layer obtained in step S1. The spin-coating conditions are 6000 rpm and 30 s. At 25 s, add chlorobenzene solution as an anti-solvent for extraction. Anneal at 100℃ for 60 min and cool naturally to obtain the perovskite layer.

[0172] The perovskite solar cell with an upright structure provided in this embodiment is denoted as C-8.

[0173] Example 9

[0174] This embodiment illustrates the modification of perovskite thin films by doping a precursor with a luminol derivative-electron-donating group (3-amino-4-fluorobenzoylhydrazine).

[0175] The only difference between the method in this embodiment and the method in Embodiment 1 is that:

[0176] Step S2 includes steps S2-1 to S2-2;

[0177] Step S2-1: Prepare a perovskite precursor solution containing luminol derivatives: Dissolve PbI2, FAI and CsI in a solvent (a mixture of NMP and DMF in a volume ratio of 1:5) with a molar ratio of 1:0.95:0.05, add 0.2 mg / mL of 3-amino-4-fluorobenzoylhydrazine, shake and mix well to obtain a precursor solution with a concentration of 1.5 mol / L;

[0178] Step S2-2: Preparation of luminol derivative-doped perovskite layer: Spin-coat the precursor solution onto the electron transport layer obtained in step S1. The spin-coating conditions are 6000 rpm and 30 s. At 25 s, add chlorobenzene solution as an anti-solvent for extraction. Anneal at 100℃ for 60 min and cool naturally to obtain the perovskite layer.

[0179] The perovskite solar cell with an upright structure provided in this embodiment is denoted as C-9.

[0180] Comparative Example 1

[0181] This comparative example illustrates a method for preparing solar cells without modifying the perovskite thin film.

[0182] The only difference between this comparative method and the method in Example 1 is that:

[0183] Step S2 includes steps S2-1 to S2-2;

[0184] Step S2-1: Prepare perovskite precursor solution: Dissolve PbI2, FAI and CsI in a solvent (a mixture of NMP and DMF in a volume ratio of 1:5) with a molar ratio of 1:0.95:0.05, shake and mix evenly to obtain a precursor solution with a concentration of 1.5 mol / L.

[0185] Step S2-2: Preparation of unmodified perovskite layer: Spin-coat perovskite solution onto the electron transport layer obtained in step S1. The spin-coating conditions are 6000 rpm and 35 s. At 28 s, add chlorobenzene solution as an antisolvent for extraction. Anneal at 100℃ for 45 min and cool naturally to obtain a dry film (unmodified perovskite layer).

[0186] The perovskite solar cell with an upright structure provided in this comparative example is denoted as C-10.

[0187] The electrochemical performance of the perovskite solar cells prepared in the above examples and comparative examples was tested, and the results are shown in Table 1.

[0188] Table 1

[0189]

[0190]

[0191]

[0192] *Among them, the aging conditions for the retention rate of photoelectric conversion efficiency of the device after 1000h aging are 65℃ nitrogen atmosphere conditions.

[0193] As can be seen from the data in Table 1, compared with the device of Comparative Example 1 (i.e., without luminol material added to the perovskite layer), the present invention significantly improves the photoelectric conversion efficiency and thermal stability of the device by introducing luminol material into the perovskite layer. The modified perovskite films in Examples 1-9 all exhibited beneficial stability, and the photoelectric conversion efficiency retention rate after 1000h aging was significantly improved compared with the unmodified Comparative Example 1. Further comparison of Example 1 (using precursor solution to introduce luminol material), Example 2 (using antisolvent to introduce luminol material), and Example 3 (using surface modification solution to introduce luminol material) shows that the perovskite solar cell prepared by introducing luminol material through precursor solution exhibits superior photoelectric performance. This is because the precursor solution introduction method can ensure the uniform distribution and efficient function of the compound of Formula I in the perovskite layer. Furthermore, after comparing Examples 1 with Examples 4 to 9, it can be observed that in the upright device structure, the luminol derivatives designed with electron-withdrawing functional groups (Examples 4, 5, and 8) exhibit more optimized performance in terms of photoelectric properties and stability compared to designs with electron-donating groups (Examples 6 and 9).

[0194] The present application has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present application based on these embodiments, all of which fall within the protection scope of the present application.

Claims

1. A modified perovskite thin film comprising a perovskite material and a compound of formula I: Equation I; in, In the compound of formula I, R is selected from -H, -OCH3, -CH3, -F, -Cl, -COOH, -CF3, and -SO2CF3.

2. A perovskite composite membrane, characterized in that, The perovskite composite film comprises a perovskite film formed of perovskite material and a functional layer disposed on the perovskite film, wherein the functional layer contains a compound of formula I: Equation I; In the compound of formula I, R is selected from -H, -OCH3, -CH3, -F, -Cl, -COOH, -CF3, and -SO2CF3.

3. The modified perovskite film according to claim 1 or the perovskite composite film according to claim 2, characterized in that, The perovskite material has the general formula ABX3, where A is one or more monovalent cations selected from amino, amidine, guanidinium, cesium, and rubidium; and B is Pb. 2+ Sn 2+ One or more of them; X is Cl - ,Br - I - SCN - CH3COO - One or more of them.

4. The modified perovskite film or perovskite composite film according to claim 3, characterized in that, The molar fraction of lead ions in component B is not less than 80%.

5. The modified perovskite film or perovskite composite film according to claim 3, characterized in that, In the modified perovskite film or perovskite composite film, the molar ratio of perovskite material to compound of formula I is 100:(0.1~1).

6. The modified perovskite film according to claim 1 or the perovskite composite film according to claim 2, characterized in that, The compound of Formula I is selected from one or more of 3-amino-phthaloyl hydrazide, 4-aminophthaloyl hydrazide, 3-amino-4-carboxyphthaloyl hydrazide, 3-amino-4-fluorophthaloyl hydrazide, and 3-amino-4-trifluoromethanesulfonic acid phthaloyl hydrazide.

7. The method for preparing the modified perovskite thin film according to claim 1, 3, 4, 5 or 6, characterized in that, The method includes: (1) Prepare a perovskite precursor solution and add a compound of formula I to the perovskite precursor solution; (2) A wet film is formed by depositing a perovskite precursor solution, and the wet film is extracted using an antisolvent to form a modified perovskite film.

8. The method for preparing the modified perovskite thin film according to claim 7, characterized in that, In the perovskite precursor solution, the concentration of compound I is 0.01~3 mg / mL.

9. The method for preparing the perovskite composite film according to any one of claims 2 to 6, characterized in that, The method includes: (1) Preparation of perovskite precursor solution; (2) A wet film is formed by depositing a perovskite precursor solution, and the wet film is extracted by adding the antisolvent of compound I to form the perovskite composite film.

10. The method for preparing the perovskite composite film according to claim 9, characterized in that, In the antisolvent, the concentration of compound of formula I is 0.1~20 mg / mL.

11. The method for preparing the perovskite composite film according to any one of claims 2 to 6, characterized in that, The method includes: (1) Preparation of perovskite precursor solution; (2) A wet film is formed by depositing a perovskite precursor solution, and the wet film is extracted using an antisolvent and dried to obtain a perovskite thin film; (3) A functional layer is prepared by doping the surface of the perovskite film obtained in step (2) using a surface modification solution containing compound I, thereby forming the perovskite composite film.

12. The method for preparing the perovskite composite film according to claim 11, characterized in that, In the surface modification solution, the concentration of compound of formula I is 0.1~20 mg / mL.

13. The method for preparing the perovskite composite film according to claim 11, characterized in that, The solvent of the surface modification solution is selected from one or more of the following: dimethyl ether, isopropanol, m-xylene, toluene, 1,3,5-trimethylbutanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, ethyl acetate, butyl acrylate, diethyl ether, chlorobenzene, and toluene.

14. The method for preparing the perovskite composite film according to claim 11, characterized in that, The doping method is immersion and / or deposition.

15. The method for preparing the perovskite composite film according to claim 14, characterized in that, The immersion involves immersing the perovskite film in the surface modification solution for 5-600 seconds.

16. The method according to any one of claims 7-15, characterized in that, In step (2), the antisolvent is selected from one or more of the following: anisole, isopropanol, m-xylene, toluene, 1,3,5-trimethylbutanol, 1,2-dichlorobenzene, ethyl acrylate, chloroform, ethyl acetate, butyl acrylate, diethyl ether, chlorobenzene, and toluene.

17. The method according to claim 16, characterized in that, The extraction method is soaking and / or deposition.

18. The method according to claim 17, characterized in that, The soaking process involves immersing the wet film in an antisolvent for 5 to 600 seconds.

19. The method according to claim 17, characterized in that, The deposition includes depositing an antisolvent on the wet film surface.

20. A perovskite solar cell, characterized in that, The perovskite layer of the perovskite solar cell includes the modified perovskite film according to claim 1, 3, 4, 5 or 6, or the modified perovskite film prepared according to the method according to claim 7, 16, 17, 18 or 19.

21. A perovskite solar cell, characterized in that, The perovskite layer of the perovskite solar cell comprises a perovskite composite film according to any one of claims 2 to 6 or a perovskite composite film prepared according to any one of claims 9 to 19; The functional layer of the perovskite composite film is disposed on one side of the hole transport layer of the perovskite solar cell.

22. The perovskite solar cell according to claim 20 or 21, characterized in that, The perovskite solar cell includes a conductive glass electrode layer, a first charge transport layer, a perovskite layer, a second charge transport layer, and a counter electrode layer; wherein, when the first charge transport layer is an electron transport layer, the second charge transport layer is a hole transport layer; and when the first charge transport layer is a hole transport layer, the second charge transport layer is an electron transport layer.

23. The perovskite solar cell according to claim 22, characterized in that, The electron transport layer material is an N-type semiconductor.

24. The perovskite solar cell according to claim 22, characterized in that, The electron transport layer material is selected from C. 60 BCP, PC 61 BM, PC 71 One or more of BM, TiO2, ZnO, SnO2, and ZnTiO3.

25. The perovskite solar cell according to claim 22, characterized in that, The thickness of the electron transport layer is 5~120 nm.

26. The perovskite solar cell according to claim 22, characterized in that, The hole transport layer material is a P-type semiconductor.

27. The perovskite solar cell according to claim 22, characterized in that, The hole transport layer material is selected from one or more of nickel oxide, Spiro-OMeTAD, poly-TPD, copper phthalocyanine, nickel phthalocyanine, poly(triarylamine), and poly(3-hexylthiophene).

28. The perovskite solar cell according to claim 22, characterized in that, The thickness of the hole transport layer is 50~150 nm.

29. The perovskite solar cell according to claim 22, characterized in that, The material of the counter electrode layer is selected from one or more of gold, silver, copper, and ITO, and the thickness of the counter electrode layer is 60~300 nm.

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