Perovskite solar cell based on 2-aminoethyl sulfuric acid interface modification and preparation method thereof

Abstract

The invention relates to the technical field of solar cells, in particular to a perovskite solar cell based on 2-aminoethyl sulfuric acid interface modification and a preparation method thereof, and the perovskite solar cell sequentially comprises a conductive substrate layer, an electron transport layer, a perovskite light absorption layer, a hole transport layer and a back electrode layer from bottom to top; an interface between the electron transport layer and the perovskite light absorption layer is modified through amphoteric molecules, the amphoteric molecules are 2-aminoethyl sulfuric acid, and the molecular formula of the amphoteric molecules is C2H7NO4S. Wherein sulfate ions in the amphoteric molecules can passivate oxygen vacancy defects in a manner of forming covalent bonds with the oxygen vacancy defects on the surface of the metal oxide, and ammonium ions in the amphoteric molecules can passivate organic acupoints of the perovskite in a manner of forming ionic bonds with PbI3 <-> in the perovskite; meanwhile, the interface energy level of the electron transport layer / perovskite light absorption layer and the quality of the perovskite thin film are improved, and finally the purpose of improving the efficiency and the stability of the perovskite solar cell is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and in particular to a perovskite solar cell based on 2-aminoethylsulfate interface modification and a preparation method thereof. Background Art

[0002] Perovskite solar cells have attracted considerable attention due to their abundant raw materials, simple preparation, low cost, and high photoelectric conversion efficiency. Currently, the highest certified efficiency of a single-cell perovskite solar cell has reached 27%, roughly comparable to the 27.3% efficiency of silicon-based cells. Furthermore, the lifespan of perovskite solar cells has also met the minimum standards required for commercialization. Therefore, perovskite solar cells demonstrate significant potential as a replacement for silicon-based cells.

[0003] In nip-type perovskite solar cells, the electron transport layer materials currently used are mainly metal oxide materials, such as TiO2, SnO2, ZnO, etc. Studies have shown that the electron transport layer / perovskite light absorption layer interface prepared using these metal oxides has a large number of defects, which can lead to serious non-radiative recombination of carriers, thereby affecting the efficiency and stability of perovskite solar cells. Therefore, it is very important to develop suitable surface modification materials to passivate defects at the interface and suppress non-radiative recombination of carriers. In addition, studies have shown that some interface modification materials can also improve the interface energy level or enhance the film quality of perovskite. Based on this, we use suitable amphiphilic molecules for interface modification, which not only achieves the passivation of interface defects and improves the quality of perovskite films, but also achieves the effect of improving the interface energy level. Summary of the Invention

[0004] The purpose of the present invention is to provide a perovskite solar cell based on 2-aminoethylsulfuric acid interface modification and a preparation method thereof, wherein amphiphilic molecules are grown on the metal oxide electron transport layer, wherein the sulfate ions in the amphiphilic molecules can passivate the oxygen vacancy defects by forming covalent bonds with the oxygen vacancy defects on the metal oxide surface, and the ammonium ions in the amphiphilic molecules can passivate the oxygen vacancy defects by forming covalent bonds with the PbI3 in the perovskite. - The organic holes of the perovskite are passivated by forming ionic bonds, while also improving the interface energy level of the electron transport layer / perovskite light absorption layer and the quality of the perovskite film, ultimately achieving the goal of improving the efficiency and stability of perovskite solar cells.

[0005] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

[0006] The perovskite solar cell based on 2-aminoethylsulfate interface modification comprises, from bottom to top, a conductive substrate layer, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a back electrode layer; the interface between the electron transport layer and the perovskite light-absorbing layer is modified by an amphiphilic molecule, wherein the amphiphilic molecule is 2-aminoethylsulfate with a molecular formula of C2H7NO4S.

[0007] The amphiphilic molecular interface modification layer is formed by sulfate (SO4 2- ) combines with the oxygen vacancy defects on the metal oxide surface in the electron transport layer and through ammonium radicals (NH3 + ) and PbI3 in the perovskite light absorbing layer - combination.

[0008] Furthermore, the conductive substrate layer is made of indium tin oxide (ITO) or fluorine-doped tin oxide (FTO);

[0009] The material of the electron transport layer is one of SnO2, TiO2 or ZnO;

[0010] The perovskite light absorbing layer material is of ABX3 type, wherein A is Rb + 、Cs + 、CH3NH3 + 、HC(NH2)2 + One or more of, B is Pb 2+ and Sn 2+ One or more of, X is Cl - Br - , I - One or more of;

[0011] The hole transport layer material is Spiro-OMeTAD, P3HT, PTAA, CuI, CuSCN, NiO x and MoO x One or more of;

[0012] The back electrode layer material is one of Au, Ag and low-temperature carbon.

[0013] In another aspect, the present invention provides a method for preparing the above-mentioned perovskite solar cell, comprising the following steps:

[0014] S1: Pretreatment of the conductive substrate: The conductive substrate was ultrasonically cleaned with a solution containing 2-5% Decon 90, deionized water, and ethanol for 15 minutes, and dried with nitrogen gas;

[0015] S2: Preparation of electron transport layer: dilute SnO2 colloidal solution and spin-coat it on the substrate surface, followed by annealing;

[0016] S3: Preparation of an amphiphilic interface modification layer: Immerse the electron transport layer from step S2 in a 2-aminoethylsulfuric acid solution, wash, and dry;

[0017] S4: Preparation of perovskite light-absorbing layer: spin-coating the perovskite precursor solution on the surface of the modified layer, adding anti-solvent and annealing;

[0018] S5: Preparation of hole transport layer: spin coating the hole transport material solution on the surface of the perovskite layer;

[0019] S6: Preparation of back electrode: Deposit the back electrode layer by evaporation or solution method.

[0020] Furthermore, in step S2, a 2-10% mass fraction of an electron transport layer material solution is dropped onto the conductive substrate treated in step S1, spin-coated at a speed of 2000-6000 rpm for 20-60 seconds, and then annealed at 50-200° C. for 10-60 minutes to obtain an electron transport layer.

[0021] Furthermore, in step S3, the electron transport layer obtained in S2 is placed in a 2-aminoethylsulfuric acid solution with a concentration of 0.001-10 mg / mL, immersed for 1-30 hours, and then washed with a solvent for preparing the amphiphilic molecules to obtain an amphiphilic molecule interface modification layer.

[0022] Furthermore, the solvent for preparing the amphiphilic molecule solution is one or more of secondary deionized water, ethanol, and isopropanol.

[0023] Furthermore, in step S4, a perovskite precursor solution with a concentration of 0.6-1.7 mol / L is added dropwise to the interface modification layer in step S3, and spin-coated at a speed of 1000-6000 rpm for 20-60 seconds. 0.06-1 mL of anti-solvent is added dropwise in the 5th to 25th second, and then annealed at 50-150° C. for 10-60 minutes to obtain a perovskite light-absorbing layer.

[0024] Furthermore, in step S5, a hole transport layer material solution with a concentration of 10-100 mg / mL is added dropwise to the perovskite light absorbing layer prepared in step S4, and spin-coated at a rotation speed of 1000-5000 rpm for 20-60 seconds to prepare a hole transport layer.

[0025] Furthermore, in step S6, the back electrode material is prepared by evaporation, spin coating, blade coating, etc. to obtain a back electrode layer with a thickness of 60-200 nm.

[0026] Beneficial effects of the present invention:

[0027] The present invention uses amphiphilic molecules to modify the interface of SnO2 / perovskite. The sulfate ions in the amphiphilic molecules passivate the oxygen vacancies on the surface of the SnO2 film by forming covalent bonds with the oxygen vacancies in SnO2, while the ammonium ions in the amphiphilic molecules passivate the oxygen vacancies on the surface of the SnO2 film by forming covalent bonds with the PbI3 in the perovskite. - By forming ionic bonds, the organic holes of the perovskite are passivated, while also improving the interface energy level of the electron transport layer / perovskite absorption layer and improving the quality of the perovskite film. Ultimately, the efficiency of the perovskite solar cell was increased from 20.54% to 23.74%.

[0028] After the invention is modified by amphiphilic molecules, the dipole effect of the amphiphilic molecules improves the SnO2 / perovskite interface energy pole, thereby reducing the interface potential loss, which is beneficial to the improvement of the device open circuit voltage. At the same time, the ammonium ions in the amphiphilic molecules react with the PbI3 in the perovskite precursor solution. - The interaction between ions can promote the rapid nucleation of perovskite, thereby improving the uniformity of the perovskite crystallization process, resulting in fewer holes on the film surface, more uniform and compact particles, fewer internal defects in the film, and enhanced optical and electrical properties of the film. This not only improves the carrier transmission efficiency, but also reduces the recombination loss of carriers within the film, promoting the improvement of photoelectric conversion efficiency.

[0029] The perovskite solar cell of the present invention exhibits significant enhancements in photoelectric performance. Interface modification improves the carrier transport path and current extraction efficiency, resulting in an increase in open-circuit voltage, short-circuit current density, and fill factor, and an enhancement in the overall photoelectric conversion efficiency. Amphiphilic molecule modification and passivation not only improves the initial performance of the battery, but also significantly enhances the environmental stability of the device. The constructed unencapsulated perovskite solar cell can still maintain 95% of its initial efficiency after aging for 500 hours in an environment with 15-30% air humidity. At the same time, the perovskite solar cell can still maintain 85% of its initial efficiency after aging for 100 hours at 85°C.

[0030] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1Figure 2 shows the structure of a perovskite solar cell device and the interaction between amphiphilic molecules and SnO2 and FAPbI3 perovskites; (a) is the structure of a perovskite solar cell device; (b) is a schematic diagram of the internal mechanism of amphiphilic molecules;

[0033] Figure 2 X-ray photoelectron spectra of SnO2 films without modification, after modification with amphiphilic molecules, and amphiphilic molecule films; (a) is the Sn 3d peak; (b) is the O1s peak diagram;

[0034] Figure 3 X-ray photoelectron spectra of perovskite film, amphiphilic film, and perovskite:amphiphilic mixed film; (a) is the Pb 4f peak; (b) is the N1s peak;

[0035] Figure 4 (a) and (b) are the UV photoelectron spectra of SnO2 film and perovskite film after unmodified and amphiphilic molecule modification, and (c) is the Tauc plot of perovskite film;

[0036] Figure 5 (a) and (b) are scanning electron micrographs of the unmodified and amphiphilic molecule-modified perovskite films, and (c) is a schematic diagram of the X-ray diffraction spectrum.

[0037] Figure 6 UV-visible absorption spectra (a) and fluorescence spectra (b) of unmodified and amphiphilic molecule-modified ITO / SnO2 / perovskite films;

[0038] Figure 7 The light intensity-open circuit voltage (V oc ) curve (a) and the space charge limited current curve of the single electron device (b);

[0039] Figure 8 The current density-voltage curves of unmodified and amphiphilic molecule-modified perovskite solar cells;

[0040] Figure 9 Figure 2 shows the solar air environment stability (a) and thermal stability test diagram (b) of the unmodified and amphiphilic molecule modified perovskite. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] Example 1

[0043] The perovskite solar cell based on 2-aminoethylsulfate interface modification described in this embodiment comprises, from bottom to top, a conductive substrate layer, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a back electrode layer; the interface between the electron transport layer and the perovskite light-absorbing layer is modified by an amphiphilic molecule, wherein the amphiphilic molecule is 2-aminoethylsulfate with a molecular formula of C2H7NO4S.

[0044] The amphiphilic molecular interface modification layer is formed by sulfate (SO4 2- ) combines with the oxygen vacancy defects on the metal oxide surface in the electron transport layer and through ammonium radicals (NH3 + ) and PbI3 in the perovskite light absorbing layer - combination.

[0045] In this embodiment, the conductive base layer is made of indium tin oxide (ITO) or fluorine-doped tin oxide (FTO);

[0046] The material of the electron transport layer is one of SnO2, TiO2 or ZnO;

[0047] The perovskite light absorbing layer material is of ABX3 type, wherein A is Rb + 、Cs + 、CH3NH3 + 、HC(NH2)2 + One or more of, B is Pb 2+ and Sn 2+ One or more of, X is Cl - Br - , I - One or more of;

[0048] The hole transport layer material is Spiro-OMeTAD, P3HT, PTAA, CuI, CuSCN, NiO x and MoO x One or more of;

[0049] The back electrode layer material is one of Au, Ag and low-temperature carbon.

[0050] Example 2

[0051] The method for preparing an unmodified perovskite solar cell as described in this embodiment comprises the following steps:

[0052] S1: The ITO conductive substrate was cleaned in sequence with 2-5% Decon 90 solution, secondary deionized water, ethanol, secondary deionized water, and secondary deionized water ultrasonically for 15 minutes, and then blown dry with a nitrogen gun for later use;

[0053] S2: Add secondary deionized water to a 15% SnO2 solution at a volume ratio of 1 / 7 to dilute it. After filtering through a 0.22μm water filter, take 45μL and dropwise add it onto the ITO conductive substrate treated in step S1. First, spin coat it at a speed of 400rpm / min for 3s, then at a speed of 6000rpm / min for 40s, and then heat and anneal on a hot plate at 150℃ for 30min to prepare an electron transport layer.

[0054] S3: Dissolve 707 mg PbI2, 245 mg FAI, 8.4 mg MABr, 27.5 mg PbBr2, and 33.7 mg MACl in a mixed solution of 1 ml DMF and DMSO (V DMF :V DMSO =4:1), stirred at room temperature for 2 hours, filtered through a 0.22 μm organic filter head, 40 μL of the perovskite precursor solution was spread evenly on the electron transport layer in step S2, first spin-coated at a low speed of 1000 rpm / min for 5 seconds, and then spin-coated at a high speed of 4000 rpm / min for 20 seconds. When the high-speed spin coating ran for 10 seconds, 100 μL of chlorobenzene was quickly added dropwise, and then heated and annealed on a hot plate at 150°C for 10 minutes to obtain a perovskite light-absorbing layer.

[0055] S4: Dissolve 72.5 mg of Spiro-OMeTAD in 1 mL of chlorobenzene, add 22.5 μL of tBP and 18.5 μL of LiTFSI solution (concentration of 520 mg / mL, solvent: acetonitrile), stir well, and filter with a 0.22 μm organic filter. Spread 30 μL of the solution on the perovskite light-absorbing layer in step S3, and spin coat at 4500 rpm / min for 35 seconds to prepare a hole transport layer.

[0056] S5: Under high vacuum conditions, a 100 nm Ag electrode is deposited on the hole transport layer in step S4 by thermal evaporation.

[0057] Example 3

[0058] The method for preparing the amphiphilic molecule-modified perovskite solar cell described in this embodiment comprises the following steps:

[0059] Unlike unmodified perovskite solar cells, after completing step S2, a layer of amphiphilic interface modification material is first grown on the electron transport layer and then spin-coated to form the perovskite light-absorbing layer. The specific method for growing the amphiphilic interface modification material is as follows: the electron transport layer prepared in step S2 is immersed in a 0.05 mg / mL aqueous solution of amphiphilic molecules. After 12 hours, the layer is removed and rinsed with secondary deionized water, then blown dry with a nitrogen gun to obtain the amphiphilic interface modification layer.

[0060] Figure 1 This is a diagram of the structure of a perovskite solar cell device and a schematic diagram of the interaction between amphiphilic molecules and SnO2 and FAPbI3 perovskites. Figure 1 a is the structure diagram of perovskite solar cell device. Figure 1 b indicates that the sulfate ions in the amphiphilic molecules can form lipid bonds with the oxygen vacancies in SnO2 to passivate the oxygen vacancy defects; the ammonium ions in the amphiphilic molecules can form lipid bonds with the PbI3 - Electrostatic interactions occur, passivating the organic vacancies in perovskite.

[0061] Figure 2 X-ray photoelectron spectra of unmodified and amphiphilic SnO2 films and amphiphilic film. Figure 2 a shows that the Sn 3d peak shifted 0.53 eV toward the high binding energy direction after amphiphilic molecule modification. Figure 2 b is the O1s peak diagram. After modification with amphiphilic molecules, the O peak of the oxygen vacancy (SnO) in SnO2 disappeared, and a new peak appeared at 530.9eV, which is not at the same position as the O peak in the amphiphilic molecules. The appearance of these results indicates that the sulfate ions in the amphiphilic molecules form Sn-OS bonds with the oxygen vacancies in SnO2.

[0062] Figure 3 These are the X-ray photoelectron spectra of perovskite film, amphiphilic film, and perovskite:amphiphilic mixed film. Figure 3 a shows that the Pb 4f peak shifted 0.47 eV toward the high binding energy direction after amphiphilic molecule modification. Figure 3 b shows that the N1s peak shifts to a lower binding energy of 0.45 eV after mixing with the amphiphilic molecules, and the position of the N1s peak is different from that of the pure amphiphilic molecules. The above results indicate that the ammonium ions in the amphiphilic molecules and the PbI3 in the perovskite - An interaction occurred.

[0063] Figure 4 The UV photoelectron spectra of unmodified SnO2 films and perovskite films after modification with amphiphilic molecules, as well as the Tauc plot of the perovskite film. Figure 4 a shows that the work function of SnO2 film is reduced from 4.38eV to 4.22eV after modification with amphiphilic molecules. Figure 4 b shows that the energy starting edge and cutoff edge of the perovskite film are 1.14eV and 16.92eV respectively. The valence band of the perovskite is -5.44eV obtained from 21.22-16.92+1.14. Figure 4Figure c is a tauc plot converted from the UV-visible absorption spectrum, showing the perovskite film's optical bandwidth of 1.53 eV. The perovskite's conduction band, calculated from 5.44-1.53, is -3.91 eV. Because the work function of the SnO2 film, modified with amphiphilic molecules, is closer to the perovskite's conduction band, potential losses at the interface are reduced, thereby improving the interface energy level.

[0064] Figure 5 Scanning electron microscopy morphology and X-ray diffraction spectra of unmodified and amphiphilic molecule modified perovskite films. Figure 5 a shows that the unmodified perovskite film has many holes. Figure 5 b shows that the holes in the perovskite film after modification with amphiphilic molecules are almost invisible. Figure 5 c shows that the peak intensity of the perovskite film increases after the amphiphilic molecules are modified, indicating that the crystallinity is enhanced. The above results indicate that the quality of the perovskite film is improved after the amphiphilic molecules are modified.

[0065] Figure 6 UV-visible absorption and fluorescence spectra of unmodified and amphiphilic molecule modified ITO / SnO2 / perovskite films. Figure 6 a shows that the UV-visible absorption spectra of the modified and unmodified samples are almost identical, indicating that the amphiphilic molecule modification has almost no effect on the light absorption of the perovskite. Figure 6 b shows that the fluorescence intensity decreases after modification with amphiphilic molecules, indicating that electrons are more easily transferred to the ITO / SnO2 thin film layer after modification.

[0066] Figure 7 The light intensity-open circuit voltage (V oc ) curve and the space charge limited current curve of the single electron device. Figure 7 a shows the modified light intensity -V oc The ideal factor of the curve dropped from 1.71 to 1.31, indicating that the carrier recombination form in the battery device changed from non-radiative recombination to radiative recombination, that is, the defects of the device were reduced. Figure 7 b shows that after modification with amphiphilic molecules, the defect filling limit voltage is reduced from 0.37V to 0.15V, indicating that the defects in the perovskite film are reduced.

[0067] Figure 8 The current density-voltage curves for unmodified and amphiphilic perovskite solar cells are shown in Table 1. The modified perovskite solar cells exhibit improved performance parameters, with conversion efficiency increasing from 20.54% to 23.74%.

[0068] Table 1

[0069]

[0070] Figure 9 The graph shows the air environment stability and thermal stability test of perovskite solar cells after unmodified and amphiphilic molecule modification. Figure 9 a shows that the unencapsulated perovskite solar cell in the modified embodiment can still maintain 90% of the initial efficiency after aging for 1350 hours in an environment with an air humidity of 10-30%. Figure 9 b shows that the unencapsulated perovskite solar cell in the embodiment can still maintain 85% of the initial efficiency after aging at 85°C for 100 hours.

[0071] In summary, the amphiphilic molecules of the present invention possess both sulfate and ammonium ions. Their application to modifying the interface between the metal oxide electron transport layer and the perovskite layer improves the interface energy level, passivates interface defects, and enhances the quality of the perovskite film, thereby suppressing non-radiative carrier recombination and enhancing electron extraction, thereby significantly improving the photoelectric conversion efficiency and long-term stability of perovskite solar cells. The present method is simple and practical, and can effectively promote the large-scale commercialization of perovskite solar cells.

[0072] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A perovskite solar cell based on 2-aminoethylsulfate interface modification, characterized in that: From bottom to top, they are the conductive substrate layer, electron transport layer, perovskite light-absorbing layer, hole transport layer, and back electrode layer; the interface between the electron transport layer and the perovskite light-absorbing layer is modified by an amphiphilic molecule, which is 2-aminoethylsulfate with a molecular formula of C2H7NO4S.

2. The perovskite solar cell based on 2-aminoethylsulfate interface modification according to claim 1, characterized in that: The conductive base layer is made of indium tin oxide or fluorine-doped tin oxide; The material of the electron transport layer is one of SnO2, TiO2 or ZnO; The perovskite light absorbing layer material is of ABX3 type, wherein A is Rb + 、Cs + 、CH3NH3 + 、HC(NH2)2 + One or more of, B is Pb 2+ and Sn 2+ One or more of, X is Cl - Br - , I - One or more of; The hole transport layer material is Spiro-OMeTAD, P3HT, PTAA, CuI, CuSCN, NiO x and MoO x One or more of; The back electrode layer material is one of Au, Ag and low-temperature carbon.

3. The method for preparing a perovskite solar cell according to claim 1 or 2, wherein: The following steps are involved: S1: The conductive substrate was ultrasonically cleaned with a solution containing 2-5% Decon 90, deionized water, and ethanol for 15 minutes, and dried with nitrogen gas. S2: Dilute the SnO2 colloidal solution and spin-coat it on the substrate surface, followed by annealing. S3: Soaking the electron transport layer in 2-aminoethylsulfuric acid solution, washing and drying; S4: Spin-coating the perovskite precursor solution on the surface of the modified layer, adding anti-solvent and then annealing; S5: spin coating the hole transport material solution on the surface of the perovskite layer; S6: Depositing a back electrode layer by evaporation or solution method.

4. The preparation method according to claim 3, wherein: In step S2, a 2-10% mass fraction of an electron transport layer material solution is dropped onto the conductive substrate treated in step S1, spin-coated at a speed of 2000-6000 rpm for 20-60 seconds, and then annealed at 50-200° C. for 10-60 minutes to prepare an electron transport layer.

5. The preparation method according to claim 3, wherein: In step S3, the electron transport layer obtained in S2 is placed in a 2-aminoethylsulfuric acid solution with a concentration of 0.001-10 mg / mL, immersed for 1-30 hours, and then washed with a solvent for preparing the amphiphilic molecules to obtain an amphiphilic molecule interface modification layer.

6. The preparation method according to claim 3, wherein: The solvent for preparing the amphiphilic molecule solution is one or more of secondary deionized water, ethanol, and isopropanol.

7. The preparation method according to claim 3, wherein: In step S4, a perovskite precursor solution with a concentration of 0.6-1.7 mol / L is added dropwise to the interface modification layer in step S3, and spin-coated at a speed of 1000-6000 rpm for 20-60 seconds. 0.06-1 mL of anti-solvent is added dropwise in the 5th to 25th second, and then annealed at 50-150° C. for 10-60 minutes to obtain a perovskite light-absorbing layer.

8. The preparation method according to claim 3, wherein: In step S5, a hole transport layer material solution with a concentration of 10-100 mg / mL is added dropwise to the perovskite light absorbing layer prepared in step S4, and spin-coated at a rotation speed of 1000-5000 rpm for 20-60 seconds to prepare a hole transport layer.

9. The preparation method according to claim 3, wherein: In step S6, the back electrode material is prepared by evaporation, spin coating, blade coating, etc. to obtain a back electrode layer with a thickness of 60-200 nm.

Images