A method for preparing a perovskite thin film and a perovskite thin film structure

Abstract

The application is suitable for the field of photovoltaic solar energy, and provides a preparation method of perovskite film and a perovskite film structure, the preparation method of perovskite film comprising mixing a compound with formula (I) with perovskite material to prepare a perovskite precursor solution; spin coating the perovskite precursor solution; performing anti-solvent treatment during the spin coating; and performing annealing treatment; in the formula (I), R1 and R2 are independently selected from H, F, Cl, Br, CH3, NO2, OCH3, Ph or Ac. The compound with formula (I) according to the application is added as a SAM material in the preparation process of perovskite film, and the finally formed SAM can not only serve as a protective layer of perovskite grain boundary, but also passivate defects of the grain boundary, so that the stability of the perovskite film can be improved.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic solar energy, and particularly relates to a method for preparing a perovskite thin film, a perovskite thin film structure, a method for preparing a perovskite solar cell, a perovskite solar cell, a solar cell module, and a solar photovoltaic system. Background Technology

[0002] Perovskite solar cells boast advantages such as high conversion efficiency and low cost, with their conversion efficiency leaping to over 25% in just 10 years, and even exceeding 30% for tandem cells with crystalline silicon. However, despite their high efficiency, perovskite solar cells are susceptible to light, water, and heat, hindering their commercial application beyond the laboratory. Therefore, maintaining the high efficiency of perovskite solar cells and maximizing their stability has become a significant research direction. The stability of perovskite solar cells depends to a certain extent on the stability of the perovskite thin film. In traditional perovskite thin film preparation methods, perovskite films prepared by solution methods typically contain numerous surface and grain boundary defects, allowing water and oxygen from the air to penetrate into the perovskite and decompose. Simultaneously, due to the unstable energy of interface defects, they are easily affected by external factors (such as light, electric fields, and heating), which can also accelerate the decomposition of the perovskite film. Therefore, protecting the grain boundaries of the perovskite is an effective method to improve the stability of the perovskite thin film.

[0003] In existing technologies, SAM (Self-assembled monolayer) is used to modify the interface between the perovskite thin film and other layers in perovskite solar cells. This effectively improves charge transport at the interfaces of each layer and passivates vacancy defects on the surface of each layer. For example, existing technologies have reported the use of PTAA(a) / 2PACz(b) (structure as follows). As a synthetic interface material (SAM), it is used to modify the interface between the ITO layer and the perovskite active layer, or the interface between the HTL layer and the perovskite active layer in organic solar cells (CCS Chem. 2022, Chemical Linkage and Passivation at Buried Interface for Thermally Stable Inverted Perovskite Solar Cells with Efficiency over 22%). SAM forms a self-assembled organic molecular film between itself and the perovskite film, which helps improve carrier transport, reduce energy loss caused by band mismatch, and thus improve cell efficiency. Furthermore, SAM can adjust the band structure of the interface, improve carrier transport efficiency, and reduce the impact of interface defects and impurities. Although the main role of SAM is modification at the interface, it can also indirectly improve the stability of the perovskite film and reduce the impact of environmental factors such as oxidation and humidity on the cell.

[0004] However, the existing SAM technology cannot meet the photovoltaic industry's requirements for photoelectric conversion efficiency and stability. Summary of the Invention

[0005] This invention provides a method for preparing a perovskite thin film, which aims to form a self-assembled monomolecular film, or SAM, at the grain boundaries of the perovskite, thereby forming a dense protective layer at the grain boundaries. This layer blocks the decomposition of the perovskite by external factors such as water and oxygen, thereby improving the stability and photoelectric conversion efficiency of the perovskite solar cell.

[0006] The present invention is implemented as follows: a method for preparing a perovskite thin film includes taking a compound having formula (I) Mixed with perovskite materials to prepare perovskite precursor solutions;

[0007] Spin-coating the perovskite precursor solution;

[0008] Solvent-removing treatment is performed during the spin coating process; and

[0009] Perform annealing treatment;

[0010] In the formula (I), R1 and R2 are independently selected from H, F, Cl, Br, CH3, NO2, OCH3, Ph or OAc.

[0011] Furthermore, the perovskite material has the general structural formula ABX3, wherein A is selected from one or more of methylamine ions, formamidinium ions, phenylethylamine ions, 1-naphthylmethylamine ions, and cesium ions; and B is selected from Pb. 2+ Sn 2+ and Ge 2+One or more of them; X is selected from I - ,Br - Cl - One or more of them.

[0012] In the perovskite precursor solution, the concentration of the compound having formula (I) is between 0.3 mg / mL and 1.5 mg / mL.

[0013] Furthermore, the spin coating is performed by first spin coating at a first speed for a first time period, and then spin coating at a second speed for a second time period; the first speed is less than the second speed, and the first time period is shorter than the second time period.

[0014] Furthermore, the first speed is 500 rpm to 700 rpm; the second speed is 4000 rpm to 5000 rpm; the first time period is 3 seconds to 8 seconds; and the second time period is 30 seconds to 50 seconds.

[0015] Furthermore, the antisolvent treatment conditions are as follows: 150 μL to 200 μL of antisolvent is added dropwise over a period of 1 to 3 seconds after spin coating begins, 10 to 15 seconds later.

[0016] Furthermore, the antisolvent is isopropanol, chlorobenzene, toluene, diethyl ether, or anisole.

[0017] Furthermore, the annealing conditions are: 50°C to 100°C for 3 to 30 minutes.

[0018] This invention also provides a perovskite thin film structure, including a perovskite thin film and a SAM covering the surface of the perovskite thin film, wherein the SAM is composed of a material having formula (I). The compound is prepared in the form of a compound, wherein R1 and R2 are independently selected from H, F, Cl, Br, CH3, NO2, OCH3, Ph or OAc.

[0019] This invention also provides a method for fabricating a perovskite solar cell, comprising:

[0020] An electron transport layer is fabricated on a substrate;

[0021] A perovskite thin film was prepared on the electron transport layer using the preparation method according to the present invention.

[0022] A hole transport layer is prepared on the perovskite thin film;

[0023] A metal electrode is fabricated on the hole transport layer.

[0024] Furthermore, the method for preparing the electron transport layer includes: mixing SnO2 dispersion and deionized water to obtain SnO2 precursor solution, and then depositing an electron transport layer with a thickness of 20 nm to 40 nm on the substrate by slit coating, blade coating, inkjet coating or spraying.

[0025] Furthermore, the method for preparing the hole transport layer includes: preparing a Spiro-oMeTad, PEDTO:PSS, or PTAA wet film by slit coating, blade coating, inkjet coating, or spraying, and heating and drying for 5 to 15 minutes to finally obtain a hole transport layer with a thickness of 100 nm to 150 nm.

[0026] Furthermore, the method for preparing the metal electrode includes: forming an Ag, Al, or Au electrode with a thickness of 80 nm to 120 nm on the hole transport layer by thermal evaporation under vacuum conditions.

[0027] This invention also provides a perovskite solar cell, comprising, from bottom to top, a substrate, a transparent conductive layer, an electron transport layer, a perovskite thin film, a hole transport layer, and a metal electrode. A first SAM (Sensitive Aperture Mass) is disposed between the perovskite thin film and the electron transport layer, and a second SAM is disposed between the perovskite thin film and the hole transport layer. The first SAM and the second SAM are formed by having formula (I). The compound is prepared in the form of a compound, wherein R1 and R2 are independently selected from H, F, Cl, Br, CH3, NO2, OCH3, Ph or OAc.

[0028] This invention also provides a solar cell module, including a perovskite solar cell according to the present invention.

[0029] This invention also provides a solar photovoltaic system, including a solar cell module according to the present invention.

[0030] The beneficial effects of this invention are as follows:

[0031] 1. Compounds having formula (I) possess hydroxyl and amino groups, wherein the hydroxyl group can react with B ions (such as Pb) at perovskite grain boundaries. 2+ Sn 2+ 、Ge 2+ Through coordination bonds, these molecules interact to form molecular locks, which can effectively regulate the crystallization kinetics of perovskite film formation.

[0032] 2. Thanks to the effective passivation of grain boundary defects in the perovskite film by the compound having formula (I), the perovskite film prepared by the method according to the present invention is uniform and dense without obvious pores, thereby improving the stability of the perovskite film.

[0033] 3. Furthermore, the amino group in formula (I) also reacts with halide ions (such as Cl-) in perovskite materials. - ,Br - I - Hydrogen bonds are formed between the perovskite particles, thus achieving a passivation effect. Simultaneously, due to the steric hindrance of perovskite crystallization, the compound with formula (I) ultimately forms a self-assembled monolayer (SAM) at the grain boundaries (i.e., the surface) of the perovskite film. This creates a dense protective layer at the grain boundaries, preventing the decomposition of the perovskite film by external factors such as water and oxygen, thereby improving the stability and photoelectric conversion efficiency of perovskite solar cells. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the perovskite solar cell provided in Example 4.

[0035] Reference numerals: Substrate S0, Transparent conductive layer S1, Electron transport layer S2, First SAM S31, Perovskite thin film S4, Second SAM S32, Hole transport layer S5, Metal electrode S6. Detailed Implementation

[0036] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0037] In compounds having formula (I) In this formula, R1 and R2 are independently selected from H, F, Cl, Br, CH3, NO2, OCH3, Ph, or OAc. Ph refers to phenyl, and Ac refers to acetyl.

[0038] Example 1

[0039] This embodiment provides a method for preparing perovskite thin films, specifically including:

[0040] 1) Compound P1 A perovskite precursor solution was prepared by mixing with the perovskite material FAPbI3. In compound P1, R1 in general formula (I) is H and R2 is H. The concentration of compound P1 in the perovskite precursor solution was 0.5 mg / mL.

[0041] It is understood that in other embodiments, the perovskite material is not limited to FAPbI3, and any suitable perovskite material having the general structural formula ABX3 can be selected, wherein A is selected from one or more of methylamine ions, formamidinium ions, phenylethylamine ions, 1-naphthylmethylamine ions, and cesium ions; and B is selected from Pb. 2+Sn 2+ and Ge 2+ One or more of them; X is selected from I - ,Br - Cl - One or more of them.

[0042] 2) Spin-coating the perovskite precursor solution obtained in the above steps: first, spin-coating at a first speed for a first time period, then spin-coating at a second speed for a second time period; the first speed is less than the second speed, and the first time period is shorter than the second time period. In this embodiment, the first speed is 600 rpm, and the first time period is 5 s; the second speed is 4500 rpm, and the second time period is 40 s. Crystallizing at two different speeds can adjust the nucleation and crystallization window time to achieve optimal film morphology.

[0043] 3) During the spin coating process, an anti-solvent treatment is performed. 12 seconds after the start of spin coating of the perovskite precursor solution, 170 μL of isopropanol is added dropwise within 2 seconds.

[0044] 4) After antisolvent treatment, perform annealing treatment. First, anneal at 55℃ for 3 minutes, and then anneal at 90℃ for 20 minutes.

[0045] The result is perovskite thin films with thicknesses ranging from 300 nm to 800 nm, such as 400 nm, 500 nm, 600 nm, and 700 nm.

[0046] Compound P1 has hydroxyl and amino groups, wherein the hydroxyl group can react with B ions (such as Pb) at perovskite grain boundaries. 2+ Sn 2+ 、Ge 2 + Through coordination bonds, amino groups (such as Cl-, etc.) interact to form molecular locks, effectively regulating the crystallization kinetics of perovskite film formation. Thanks to the effective passivation of grain boundary defects in the perovskite film by compound P1, the perovskite film prepared by this method is uniform and dense, without obvious pores, thus improving the stability of the perovskite film. Furthermore, amino groups also interact with halide ions (such as Cl-, etc.) in the perovskite material. - ,Br - I - Hydrogen bonds are formed between the perovskite particles, achieving a passivation effect. Simultaneously, due to the steric hindrance of perovskite crystallization, compound P1 ultimately forms a self-assembled monolayer (SAM) at the grain boundaries (i.e., the surface) of the perovskite. This creates a dense protective layer at the grain boundaries, preventing the decomposition of perovskite by external factors such as water and oxygen, thereby improving the stability of perovskite solar cells. The compound used to prepare SAM is called SAM material.

[0047] In summary, by adding the compound of formula (I) according to the present invention as a SAM material during the preparation of perovskite thin films, the resulting SAM can not only serve as a protective layer for perovskite grain boundaries, but also passivate grain boundary defects and synergistically improve the stability of perovskite thin films.

[0048] Example 2

[0049] This embodiment provides a method for preparing perovskite thin films, specifically including:

[0050] 1) Compound P2 A perovskite precursor solution was prepared by mixing with the perovskite material FAPbI3. In compound P2, R1 in general formula (I) is CH3 and R2 is Cl. The concentration of compound P2 in the perovskite precursor solution was 0.3 mg / mL.

[0051] 2) Spin-coat the perovskite precursor solution obtained in the above steps. First spin-coat at a speed of 500 rpm for 4 seconds, then spin-coat at a speed of 4000 rpm for 30 seconds.

[0052] 3) During the spin coating process, an anti-solvent treatment is performed. 10 seconds after the perovskite precursor solution begins spin coating, 150 μL of isopropanol is added dropwise within 1 second.

[0053] 4) Perform annealing treatment: first anneal at 55℃ for 3 minutes, and then anneal at 90℃ for 20 minutes.

[0054] Similar to Example 1 above, compound P2 in this example also has hydroxyl and amino groups. The hydroxyl groups can react with B ions (such as Pb) at the perovskite grain boundaries. 2+ Sn 2+ 、Ge 2+ The compounds P2 and P2 interact through coordination bonds to form molecular locks, effectively regulating the crystallization kinetics of perovskite film formation. Hydrogen bonds are formed between amino groups and surface iodides (iodide ions), achieving passivation. Due to the steric hindrance of perovskite crystallization, compound P2 ultimately forms a self-assembled monolayer (SAM) at the grain boundaries (i.e., the surface) of the perovskite film, thus forming a dense protective layer at the grain boundaries. This layer prevents the decomposition of perovskite by external factors such as water and oxygen, thereby improving the stability and photoelectric conversion efficiency of perovskite solar cells.

[0055] Example 3

[0056] This embodiment provides a method for preparing perovskite thin films, specifically including:

[0057] 1) Compound P3 A perovskite precursor solution was prepared by mixing with the perovskite material FAPbI3. In compound P3, R1 in general formula (I) is NO2 and R2 is Ph. The concentration of compound P3 in the perovskite precursor solution was 1.5 mg / mL.

[0058] 2) Spin-coat the perovskite precursor solution obtained in the above steps, first at 700 rpm for 8 seconds, then at 5000 rpm for 50 seconds. Using two different crystallization speeds allows adjustment of the nucleation and crystallization window time to optimize the film morphology. 3) Perform anti-solvent treatment during spin-coating: 15 seconds after the start of spin-coating of the perovskite precursor solution, add 200 μL of isopropanol dropwise within 3 seconds.

[0059] 4) Perform annealing treatment: first anneal at 55℃ for 3 minutes, and then anneal at 90℃ for 20 minutes.

[0060] Similar to Example 1 above, compound P3 in this example also has hydroxyl and amino groups. The hydroxyl groups can react with B ions (such as Pb) at the perovskite grain boundaries. 2+ Sn 2+ 、Ge 2+ The compounds P3 and P3 interact through coordination bonds to form molecular locks, effectively regulating the crystallization kinetics of perovskite film formation. Hydrogen bonds are formed between amino groups and surface iodides (iodide ions), achieving passivation. Due to the steric hindrance of perovskite crystallization, compound P3 ultimately forms a self-assembled monolayer (SAM) at the grain boundaries (i.e., the surface) of the perovskite film, creating a dense protective layer that blocks the decomposition of perovskite by external factors such as water and oxygen, thereby improving the stability and photoelectric conversion efficiency of perovskite solar cells.

[0061] Example 4

[0062] This embodiment provides a perovskite solar cell, such as Figure 1 As shown, from bottom to top, it includes: substrate S0, transparent conductive layer S1, electron transport layer S2, first SAM S31, perovskite thin film S4, second SAM S32, hole transport layer S5, and metal electrode S6.

[0063] The perovskite thin film S4 in this embodiment is obtained by the preparation method according to the present invention. Specifically, a compound having general formula (I) according to the present invention is added during the preparation of the perovskite precursor solution, and two SAM layers are preferably formed on the surface of the final perovskite thin film, namely, the first SAM S31 and the second SAM S32, respectively. These SAMs can not only serve as a protective layer for the perovskite grain boundaries, but also passivate grain boundary defects, thereby synergistically improving the stability of the perovskite thin film and the photoelectric conversion efficiency of the solar cell.

[0064] Example 5

[0065] This embodiment provides a method for preparing a perovskite solar cell, which specifically includes the following steps:

[0066] 1) Fabrication of electron transport layer

[0067] The transparent conductive layer was ultrasonically cleaned for 15 minutes each using detergent aqueous solution, deionized water, acetone, and isopropanol, respectively. After drying, the transparent conductive layer was treated in a UV / ozone cleaner for 10 minutes. An electron transport layer was then prepared on the treated FTO layer using a solution method. SnO2 nanoparticles were dispersed in 2% deionized water, and an electron transport layer with a thickness of 20 nm to 40 nm was deposited on the substrate using a slot coating method.

[0068] It is understood that, in other embodiments, the material of the electron transport layer is not limited to SnO2; any suitable material for preparing the electron transport layer in the prior art can be used, such as organic materials (e.g., fullerenes or fullerene derivatives PCBM) or inorganic materials (e.g., TiO2). Moreover, in other embodiments, other preparation methods, such as spin coating, can also be used to prepare the electron transport layer.

[0069] 2) Preparation of perovskite thin films

[0070] Will have equation (I) The compound and perovskite material FAPbI3I were dissolved in a mixed solvent of DMF and DMSO (4:1 v / v) and stirred at room temperature for 1 hour to obtain a precursor solution with a P1 concentration of 0.5 mg / mL. The precursor solution was then added dropwise to the electron transport layer prepared in the previous step. The layer was first spin-coated at 600 rpm for 5 seconds, then at 4500 rpm for 40 seconds. Finally, it was annealed at 55°C for 3 minutes, followed by annealing at 90°C for 20 minutes. 170 μL of isopropanol was added dropwise within 2 seconds 12 seconds after the start of spin-coating to obtain the perovskite film. The thickness of the perovskite film was between 300 nm and 800 nm. Finally, two SAM layers, namely the first SAM and the second SAM, were formed on the upper and lower surfaces of the perovskite film.

[0071] In this embodiment, compound P1 was used respectively. P2 P3 SAM was prepared.

[0072] 3) Fabrication of a hole transport layer

[0073] Spiro-oMeTad wet films were prepared by slit coating and then dried by heating for 10 min to obtain a hole transport layer with a thickness of 120 nm.

[0074] In other embodiments, the hole transport layer can also be prepared by blade coating, inkjet printing, or spraying, and the hole transport layer can also be made of any other suitable metal oxide material, such as NiO. X It can be made of CuSCN, CuI, V2O5 or Cu2O, or organic materials such as Spiro-oMeTad, PEDTO:PSS, PTAA or FDT.

[0075] 4) Fabrication of metal electrodes

[0076] Under high vacuum conditions (10) 4 Under the conditions of Pa), an Au electrode with a thickness of 100 nm is grown on the hole transport layer by thermal evaporation.

[0077] In other embodiments, the electrodes may also be made of other materials, such as Ag, Cu, Al, or carbon paste.

[0078] Ultimately, the result is as follows Figure 1 The perovskite solar cell shown.

[0079] Example 6

[0080] This embodiment provides a comparison between the perovskite solar cell device according to the present invention and Comparative Example 1.

[0081] Comparative Example 1

[0082] A perovskite solar cell, from bottom to top, includes a substrate, a transparent conductive layer, an electron transport layer, a perovskite thin film, a hole transport layer, and a metal electrode. The materials of the substrate, transparent conductive layer, electron transport layer, perovskite thin film, hole transport layer, and metal electrode are the same as those in Example 5. The difference from Example 5 is that Comparative Example 1 does not contain any SAM (Self-Activated Aqueous Metallic Aqueous Material).

[0083] The sample was subjected to AM1.5G, 100mW / cm 2 The JV performance curve of the battery was tested under illumination, and the following parameters were obtained: open-circuit voltage (Voc), short-circuit current density (Jsc), fill factor (FF), power conversion efficiency (PCE), and stability. The specific test results are shown in Table 1 below.

[0084] Table 1. Performance test results of solar cells

[0085]

[0086] The test results in Table 1 show that the photoelectric conversion efficiency of the perovskite solar cell prepared from the compound having general formula (I) according to the present invention is significantly improved compared with that of the perovskite solar cell without any SAM. The compound having formula (I) has hydroxyl and amino groups, wherein the hydroxyl group can react with B ions (such as Pb) at the perovskite grain boundaries. 2+ Sn 2+ 、Ge 2+ Through coordination bonds, these compounds form molecular locks, effectively regulating the crystallization kinetics of perovskite film formation. The compounds with general formula (I) effectively passivate grain boundary defects in perovskite films, resulting in uniform and dense films without obvious pores, thus improving the stability of the perovskite films. Furthermore, the amino groups in formula (I) also interact with halide ions (such as Cl-) in the perovskite material. - ,Br - I - Hydrogen bonds are formed between the perovskite particles, thus achieving a passivation effect. Simultaneously, due to the steric hindrance of perovskite crystallization, the compound with formula (I) ultimately forms a self-assembled monolayer (SAM) at the grain boundaries (i.e., the surface) of the perovskite film. This creates a dense protective layer at the grain boundaries, preventing the decomposition of the perovskite film by external factors such as water and oxygen, thereby improving the stability and photoelectric conversion efficiency of perovskite solar cells.

[0087] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a perovskite thin film, characterized in that, Including compounds having formula (I) Mixed with perovskite materials to prepare perovskite precursor solutions; The perovskite precursor solution was spin-coated onto the electron transport layer; During the spin coating process, anti-solvent treatment is performed. and Annealing is performed after antisolvent treatment; In the formula (I), R1 and R2 are independently selected from H, F, Cl, Br, CH3, NO2, OCH3, Ph or OAc; The perovskite material has the general structural formula ABX3, wherein A is selected from one or more of methylamine ions, formamidinium ions, phenylethylamine ions, 1-naphthylmethylamine ions, and cesium ions; and B is selected from Pb. 2+ Sn 2+ and Ge 2+ One or more of them; X is selected from I - ,Br - Cl - One or more of them.

2. The preparation method according to claim 1, characterized in that, In the perovskite precursor solution, the concentration of the compound having formula (I) is between 0.3 mg / mL and 1.5 mg / mL.

3. The preparation method according to claim 1, characterized in that, The spin coating is performed by first spin coating at a first speed for a first time period, and then spin coating at a second speed for a second time period; the first speed is less than the second speed, and the first time period is shorter than the second time period.

4. The preparation method according to claim 3, characterized in that, The first speed is 500 rpm to 700 rpm; the second speed is 4000 rpm to 5000 rpm; the first time period is 3 s to 8 s; and the second time period is 30 s to 50 s.

5. The preparation method according to claim 1, characterized in that, The antisolvent treatment conditions are as follows: 150 μL to 200 μL of antisolvent is added dropwise over a period of 1 to 3 seconds after spin coating begins, 10 to 15 seconds later.

6. The preparation method according to claim 5, characterized in that, The antisolvent is isopropanol, chlorobenzene, toluene, diethyl ether, or anisole.

7. The preparation method according to claim 1, characterized in that, The annealing conditions are: 50°C to 100°C for 3 to 30 minutes.

8. A perovskite thin film structure, characterized in that, It includes a perovskite film and a SAM covering the surface of the perovskite film, the SAM being composed of a material having formula (I). The perovskite film is made of a compound, wherein R1 and R2 are independently selected from H, F, Cl, Br, CH3, NO2, OCH3, Ph, or OAc in the formula (I); the perovskite film has the general structural formula ABX3, wherein A is selected from one or more of methylamine ion, formamidinium ion, phenethylamine ion, 1-naphthylmethylamine ion, and cesium ion; and B is selected from Pb. 2+ Sn 2+ and Ge 2+ One or more of them; X is selected from I - ,Br - Cl - One or more of them.

9. A method for fabricating a perovskite solar cell, characterized in that, include: An electron transport layer is fabricated on a substrate; A perovskite thin film is prepared on the electron transport layer by the preparation method according to any one of claims 1 to 7; A hole transport layer is prepared on the perovskite thin film; A metal electrode is fabricated on the hole transport layer.

10. The preparation method according to claim 9, characterized in that, The method for preparing the electron transport layer includes: mixing SnO2 dispersion and deionized water to obtain SnO2 precursor solution, and then depositing an electron transport layer with a thickness of 20 nm to 40 nm on the substrate by slit coating, blade coating, inkjet coating or spraying.

11. The preparation method according to claim 9, characterized in that, The method for preparing the hole transport layer includes: preparing a Spiro-oMeTad, PEDTO:PSS, or PTAA wet film by slit coating, blade coating, inkjet coating, or spraying, and heating and drying for 5 to 15 minutes to finally obtain a hole transport layer with a thickness of 100 nm to 150 nm.

12. The preparation method according to claim 9, characterized in that, The method for preparing the metal electrode includes: forming an Ag, Al, or Au electrode with a thickness of 80 nm to 120 nm on the hole transport layer by thermal evaporation under vacuum conditions.

13. A perovskite solar cell, characterized in that, From bottom to top, the structure includes a substrate, a transparent conductive layer, an electron transport layer, a perovskite thin film, a hole transport layer, and a metal electrode. A first SAM (Self-Agent Transporting Aperture) is disposed between the perovskite thin film and the electron transport layer, and a second SAM is disposed between the perovskite thin film and the hole transport layer. The first SAM and the second SAM are formed by having formula (I). The perovskite film is made of a compound, wherein R1 and R2 are independently selected from H, F, Cl, Br, CH3, NO2, OCH3, Ph, or OAc in the formula (I); the perovskite film has the general structural formula ABX3, wherein A is selected from one or more of methylamine ion, formamidinium ion, phenethylamine ion, 1-naphthylmethylamine ion, and cesium ion; and B is selected from Pb. 2+ Sn 2+ and Ge 2+ One or more of them; X is selected from I - ,Br - Cl - One or more of them.

14. A solar cell module, characterized in that, Including the perovskite solar cell as described in claim 13.

15. A solar photovoltaic system, characterized in that, Includes the solar cell module as described in claim 14.

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