Perovskite thin film modifier, modification method and perovskite solar cell

Abstract

The invention provides a perovskite thin film modifier, a modification method and a perovskite solar cell. The perovskite thin film modifier comprises a volatile first substance providing an electron donor group; the electron donor group enables uncoordinated lead ion defects in the perovskite thin film to be passivated; the electron donor group is a carbon-oxygen bond. The electron donor group in the modifier passivates uncoordinated Pb < 2 + > defects on the surface of the secondary perovskite thin film; the modifier not only can clean the surface of the perovskite thin film, but also has a synergistic effect of cooperating with subsurface defect passivation, so that non-radiative recombination at an interface is greatly reduced, and an ion migration path is eliminated. The modifier provided by the invention is suitable for large-area preparation of the perovskite thin film, and the perovskite solar cell with the perovskite thin film applied has better photoelectric conversion performance and stability.

Description

Technical Field

[0001] The present application relates to the technical field of perovskite solar cell preparation, and particularly to a perovskite thin film modifier, a modification method and a perovskite solar cell. Background Art

[0002] The related research on perovskite solar cells (PSCs) has developed rapidly, and its photoelectric conversion efficiency has reached an astonishing 26.1% in just a few decades. However, its stability problem faces severe challenges and is still far from meeting the standards of industrial applications. As the core material layer of PSCs, the quality of metal halide perovskite directly determines the development of device performance and stability. Considering the soft lattice characteristics of the perovskite thin film and the problem of stoichiometric deviation caused by the rapid crystallization process, there will inevitably be metastable nanoscale impurity phases, including isolated nanocrystals, solvent compounds, non-stoichiometric phases and amorphous phases. These impurity phases can not only trap photo-generated charges as deep-level defects, but also serve as the invasion sites of external water and oxygen, and at the same time act as the channels for ion migration inside the thin film, inducing and accelerating the degradation of the perovskite thin film, and ultimately leading to the reduction of the stability of PSCs (perovskite solar cells). Summary of the Invention

[0003] The present application aims to solve at least one of the technical problems in the related art to some extent. The present application provides a perovskite thin film modifier, a modification method and a perovskite solar cell.

[0004] To achieve the above object, according to the first aspect of the present application, a perovskite thin film modifier is provided, which includes a volatile first substance providing an electron donor group; the electron donor group passivates the uncoordinated lead ion defects in the perovskite thin film; the electron donor group is a carbon-oxygen bond.

[0005] In some embodiments, the first substance includes isopropyl alcohol and chlorobenzene with a volume ratio of (0.1 - 9):1.

[0006] In some embodiments, the modifier further includes a second substance; the second substance includes guanidoacetic acid and / or poly(2-ethyl-2-oxazoline); the concentration of the second substance in the modifier does not exceed 1 mg / ml.

[0007] According to the second aspect of the present application, a method for modifying a perovskite thin film is provided, which uses the modifier described in any of the above embodiments for modification.

[0008] In some embodiments, the method includes the following steps:

[0009] Coat the modifier described in any of the above embodiments on the surface of the perovskite thin film to form a liquid film;

[0010] The liquid film is subjected to vacuum or purge treatment until the first substance volatilizes and then dried.

[0011] In some embodiments, the modifier forms the liquid film by coating or doctor blading; when doctor blading is used, the gap of the doctor blading parameter is 100 nm - 500 μm, and the speed is 5 - 50 mm / s.

[0012] In some embodiments, the thickness of the liquid film is 100 nm - 500 μm.

[0013] According to a third aspect of the present application, a perovskite film is provided, which is prepared by using the modification method described in any of the above embodiments.

[0014] According to a fourth aspect of the present application, a perovskite solar cell is provided, which includes the perovskite film described in any of the above embodiments.

[0015] In some embodiments, the perovskite solar cell further includes a substrate, a semiconductor material layer, a perovskite layer, a charge transport layer, and a metal layer.

[0016] Additional aspects and advantages of the present application will be given in part in the following description, become apparent in part from the following description, or be learned through the practice of the present application. Description of the Drawings

[0017] The above and / or additional aspects and advantages of the present application will become apparent and be readily understood from the following description of the embodiments in conjunction with the drawings, where:

[0018] Figure 1 is a flowchart of a method for modifying a perovskite film in an embodiment of the present application. Detailed Description of the Embodiments

[0019] Embodiments of the present application will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the drawings are exemplary only for explaining the present application and should not be construed as limiting the present application. On the contrary, the embodiments of the present application include all changes, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0020] This application is an improvement based on the following related technologies: Considering the soft lattice characteristics of perovskite thin films and the problem of stoichiometric deviation caused by the rapid crystallization process, there will inevitably be metastable nanoscale impurity phases, including isolated nanocrystals, solvent compounds, non-stoichiometric phases, and amorphous phases. These impurity phases can not only trap photo-generated charges as deep-level defects, but also serve as invasion sites for external water and oxygen, and at the same time act as channels for ion migration inside the thin film, inducing and accelerating the degradation of perovskite thin films, ultimately leading to a decrease in the stability of PSCs (perovskite solar cells).

[0021] This application aims to at least partly solve one of the technical problems in the related technologies. To achieve the above object, according to the first aspect of this application, a perovskite thin film modifier is proposed, which includes a volatile first substance that provides an electron donor group; the electron donor group passivates the uncoordinated lead ion defects in the perovskite thin film; the electron donor group is a carbon-oxygen bond.

[0022] In the related technologies, the preparation of the perovskite absorption layer will inevitably have metastable nanoscale impurity phases, including isolated nanocrystals, solvent compounds, non-stoichiometric phases, and amorphous phases, etc. The generation of these defects will lead to an increase in radiation at the perovskite interface, etc., resulting in poor conversion characteristics of the battery, and serving as invasion sites for external water and oxygen, and at the same time acting as channels for ion migration inside the thin film, inducing and accelerating the degradation of perovskite thin films, ultimately leading to a decrease in the stability of PSCs (perovskite solar cells).

[0023] This application proposes a perovskite thin film modifier, which includes a first substance for providing an electron donor group, where the electron donor group is a carbon-oxygen bond (C═O), and the electron donor group passivates the uncoordinated lead ion defects in the perovskite thin film. In addition, the first substance is volatile, and the first substance can clean the perovskite thin film, and at the same time increase the mass difference on the perovskite thin film and the removal effect of defect sites through the volatility of the first substance.

[0024] In some embodiments, the first substance comprises isopropanol and chlorobenzene with a volume ratio of (0.1 - 9):1. The first substance includes isopropanol and chlorobenzene, and the volume ratio of isopropanol to chlorobenzene is (0.1 - 9):1. Exemplary volume ratios of isopropanol to chlorobenzene can be (0.1, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9):1. The main functions of isopropanol are as follows: Isopropanol has a relatively high polarity and may help interact with the polar regions on the perovskite surface; as a good cleaner, isopropanol may help remove surface contaminants or residual solvents. The main function of chlorobenzene is that its low polarity may play a role in non-polar regions, jointly promoting the uniform distribution of the modifier on the entire film surface, thereby more effectively passivating lead ion defects. If the volume ratio of isopropanol to chlorobenzene is too high, such as higher than 9, the electron donor group (carbon-oxygen bond) may combine with the uncoordinated Pb 2 + through the hydroxyl group (-OH) in isopropanol or the chlorine atom in chlorobenzene to form a stable coordination structure, reducing defect states, thereby inhibiting non-radiative recombination and ion migration, and the synergistic effect is poor; if the volume ratio of isopropanol to chlorobenzene is too low, such as lower than 0.1, the synergistic effect is also poor.

[0025] In some embodiments, the modifier further comprises a second substance; the second substance comprises guanidoacetic acid and / or poly(2-ethyl-2-oxazoline); the concentration of the second substance in the modifier does not exceed 1 mg / ml.

[0026] Among them, the modifier in this embodiment further comprises a second substance. The second substance can be guanidoacetic acid, or the second substance can be poly(2-ethyl-2-oxazoline), or the second substance can be poly(2-ethyl-2-oxazoline) and guanidoacetic acid. The main function of guanidoacetic acid is that the guanidine group usually has a strong coordination ability and may be able to bind to lead ions in the perovskite, thereby passivating the uncoordinated Pb 2 + defects; the main function of poly(2-ethyl-2-oxazoline) is that the guanidine group usually has a strong coordination ability and may be able to bind to lead ions in the perovskite, thereby passivating the uncoordinated Pb 2 + defects. The concentration of the second substance in the modifier does not exceed 1 mg / ml. When the concentration of the second substance in the modifier is too high, such as higher than 1 mg / ml, the carrier interface transport effect will be reduced.

[0027] The modifier in this application cleans the surface of the perovskite film, and at the same time uses the volatility of the first substance to remove the poor-quality parts and defect sites on the perovskite film. In addition, the second substance in the modifier in this embodiment can passivate the surface defects of the perovskite film, greatly reducing non-radiative recombination at the interface and eliminating the ion migration path.

[0028] According to a second aspect of the present application, a method for modifying a perovskite thin film is provided, which uses the modifier in any of the above embodiments for modification.

[0029] In some embodiments, the method for modifying a perovskite thin film is as Figure 1 shown, and includes the following steps:

[0030] S1: Coating the modifier in any of the above embodiments on the surface of the perovskite thin film to form a liquid film;

[0031] S2: Performing vacuum or purge treatment on the liquid film until the first substance volatilizes and then drying.

[0032] Among them, in S1, the modifier in any of the above embodiments is used to form a uniform and stable liquid film on the surface of the perovskite film layer through methods such as coating and doctor blading. The modifier forms a liquid film by coating or doctor blading; when using the doctor blading method, the gap of the doctor blading parameter is 100 nm - 500 μm, and the speed is 5 - 50 mm / s; the thickness of the liquid film is 100 nm - 500 μm.

[0033] Among them, in S2, the liquid film is subjected to vacuum or purge treatment. During the vacuum treatment or purge treatment of the liquid film, solvents such as isopropanol and chlorobenzene quickly volatilize, which will carry away poor-quality and defective sites. At the same time, the added second substance forms a bond with the uncoordinated Pb 2+ defect passivation on the subsurface of the perovskite thin film. Therefore, vacuum or purge treatment can make the first substance volatilize quickly and uniformly, ensuring the treatment effect.

[0034] According to a third aspect of the present application, a perovskite thin film is provided, which is prepared by using the modification method in any of the above embodiments.

[0035] According to a fourth aspect of the present application, a perovskite solar cell is provided, which includes the perovskite thin film in any of the above embodiments.

[0036] In some embodiments, the perovskite solar cell further includes a substrate, a semiconductor material layer, a perovskite layer, a charge transport layer, and a metal layer. The substrate can be an FTO thin film, and the semiconductor material layer can be a NiO x thin film (thickness 20 nm, x ≤ 1), the perovskite layer is a conventional device in the art, the charge transport layer is a C60 electron transport layer, and the metal layer is an Au electrode.

[0037] To facilitate further understanding of the present application, the solutions of the present application will be further described below in conjunction with embodiments. Those skilled in the art will understand that only some embodiments are described in the present application, and any other suitable specific embodiments are within the scope of the present application.

[0038] Example 1

[0039] This embodiment provides a perovskite thin film modifier and a method for modifying a perovskite thin film using the perovskite thin film modifier. The specific composition and preparation method are as follows: Measure 1 ml of isopropanol and 1 ml of chlorobenzene, mix them evenly and stir to form a homogeneous solution as the perovskite thin film modifier.

[0040] Clean the 10*10 cm FTO thin film (glass thickness 2 mm, FTO film layer thickness 100 nm) glass. Use magnetron sputtering to sputter a dense NiO x thin film (thickness 20 nm, x≤1) on the surface layer of the FTO thin film glass, with a sputtering power of 80 W for 30 min. Treat the sputtered thin film with oxygen plasma for 10 min at a power of 2 kW. Weigh 4.61 g of PbI2 and 1.50 g of MAI, dissolve them in 6 mL of DMF, heat and stir at 70 °C for 15 minutes to fully dissolve, obtaining a perovskite precursor solution A; Take 200 μL of the perovskite precursor solution and evenly spread it on one side of the substrate to be spin-coated, use a scraper to form a film with a gap of 300 μm and a speed of 15 mm / s, and then transfer the thin film to a hot stage at 130 °C for annealing for 15 min to obtain a perovskite thin film (400 nm).

[0041] Take 400 μL of the perovskite thin film modifier and evenly spread it on one end of the surface of the prepared perovskite thin film, use a scraper to form a film with a gap of 500 μm and a speed of 10 mm / s; Subsequently, place the thin film in a vacuum device, quickly evacuate to 5 Pa, and stay for 5 minutes to obtain a treated perovskite thin film.

[0042] Evaporate a layer of C60 electron transport layer (40 nm) on the surface of the perovskite thin film prepared above to obtain a perovskite solar cell. Transfer the electron transport layer to a thermal evaporation device, and start evaporating the gold electrode (Au) under the condition that the vacuum degree reaches 1×10 -5 Pa, with a thickness of 100 nm; Obtain a perovskite solar cell.

[0043] Example 2

[0044] This embodiment provides a perovskite thin film modifier and a method for modifying a perovskite thin film using the perovskite thin film modifier. The specific composition and preparation method are as follows: Measure an isopropanol and chlorobenzene solution with a volume ratio of 1:2, and prepare 1 mg / ml guanidinoacetic acid as the perovskite thin film modifier.

[0045] Clean the 10*10 cm FTO thin film (glass thickness 2 mm, FTO film layer thickness 100 nm) glass. Use magnetron sputtering to sputter a dense NiO xA thin film (thickness 20 nm, x ≤ 1), sputtering power 80 W, for 30 min. The above sputtered thin film was treated with oxygen plasma for 10 min, power 2 kW. Weigh 4.61 g of PbI2 and 1.50 g of MAI and dissolve them in 6 mL of DMF, heat and stir at 70 °C for 15 minutes to fully dissolve, obtaining perovskite precursor solution A; take 200 μL of perovskite precursor solution and evenly spread it on one side of the substrate to be spin-coated, use a doctor blade to form a film, gap 400 μm, speed 25 mm / s, and then transfer the thin film to a hot stage at 130 °C for annealing for 15 min, obtaining a perovskite thin film (400 nm).

[0046] Take 400 μL of perovskite thin film modifier and evenly spread it on one end of the surface of the prepared perovskite thin film, use a doctor blade to form a film, gap 500 μm, speed 10 mm / s; then place the thin film in a vacuum device, quickly evacuate to 5 Pa, and stay for 5 minutes to obtain the treated perovskite thin film. Evaporate a layer of C60 electron transport layer (40 nm) on the surface of the above-prepared perovskite thin film to obtain a perovskite solar cell. Transfer the electron transport layer to a thermal evaporation device, and start evaporating the electrode (Au) under the condition that the vacuum degree reaches 1×10 -5 Pa, with a thickness of 100 nm to obtain a perovskite solar cell.

[0047] Example 3

[0048] This example provides a perovskite thin film modifier and a method for modifying a perovskite thin film using the perovskite thin film modifier. The specific composition and preparation method are as follows: Measure isopropanol and chlorobenzene solution with a volume ratio of 9:1, and prepare a poly(2-ethyl-2-oxazoline) solution with a concentration of 0.1 mg / ml as the perovskite thin film modifier.

[0049] Clean the 10*10 cm FTO thin film (glass thickness 2 mm, FTO film layer thickness 100 nm) glass. Use magnetron sputtering method to sputter a dense NiO x thin film (thickness 20 nm, x ≤ 1) on the surface layer of the FTO thin film glass, sputtering power 80 W, for 30 min. The above sputtered thin film was treated with oxygen plasma for 10 min, power 2 kW. Weigh 4.61 g of PbI2 and 1.50 g of MAI and dissolve them in 6 mL of DMF, heat and stir at 70 °C for 15 minutes to fully dissolve, obtaining perovskite precursor solution A; take 200 μL of perovskite precursor solution and evenly spread it on one side of the substrate to be spin-coated, use a doctor blade to form a film, gap 400 μm, speed 25 mm / s, and then transfer the thin film to a hot stage at 130 °C for annealing for 15 min, obtaining a perovskite thin film (400 nm).

[0050] Take 400 μL of the perovskite film modifier and evenly spread it on one end of the surface of the prepared perovskite film. Use a scraper to form a film with a gap of 500 μm and a speed of 10 mm / s. Subsequently, place the film in a vacuum device and quickly evacuate to 5 Pa, and stay for 5 minutes to obtain the treated perovskite film. Evaporate a layer of C60 electron transport layer (40 nm) on the surface of the above-prepared perovskite film to obtain a perovskite solar cell. Transfer the electron transport layer to a thermal evaporation device and start evaporating the electrode (Au) under the condition that the vacuum degree reaches 1×10 -5 Pa, and obtain a perovskite solar cell with a thickness of 100 nm.

[0051] Example 4

[0052] This example provides a perovskite film modifier and a method for modifying a perovskite film using the perovskite film modifier. The specific composition and preparation method are as follows: Measure isopropanol and chlorobenzene solution with a volume ratio of 0.1:1, and prepare a 0.5 mg / ml guanidine acetate perovskite film modifier.

[0053] Clean the 10*10 cm FTO film (glass thickness 2 mm, FTO film layer thickness 100 nm) glass. Use magnetron sputtering method to sputter a dense NiO x film (thickness 20 nm, x≤1) on the surface layer of the FTO film glass, with a sputtering power of 80 W for 30 min. Treat the above-sputtered film with oxygen plasma for 10 min with a power of 2 kW. Weigh 4.61 g of PbI2 and 1.50 g of MAI and dissolve them in 6 mL of DMF, heat and stir at 70 °C for 15 minutes to fully dissolve, to obtain perovskite precursor solution A; Take 200 μL of the perovskite precursor solution and evenly spread it on one side of the substrate to be spin-coated. Use a scraper to form a film with a gap of 400 μm and a speed of 25 mm / s, and then transfer the film to a 130 °C hot stage for annealing for 15 min to obtain a perovskite film (400 nm).

[0054] Take 400 μL of the perovskite film modifier and evenly spread it on one end of the surface of the prepared perovskite film. Use a scraper to form a film with a gap of 500 μm and a speed of 10 mm / s. Subsequently, place the film in a vacuum device and quickly evacuate to 5 Pa, and stay for 5 minutes to obtain the treated perovskite film. Evaporate a layer of C60 electron transport layer (40 nm) on the surface of the above-prepared perovskite film to obtain a perovskite solar cell. Transfer the electron transport layer to a thermal evaporation device and start evaporating the electrode (Au) under the condition that the vacuum degree reaches 1×10 -5 Pa, and obtain a perovskite solar cell with a thickness of 100 nm.

[0055] Comparative Example 1

[0056] In this comparative example, a perovskite solar cell composed of an unmodified perovskite film was provided. The 10*10 cm FTO film (glass thickness 2 mm, FTO film layer thickness 100 nm) glass was cleaned. A dense NiOx film (thickness 20 nm, x≤1) was sputtered on the surface layer of the FTO film glass by magnetron sputtering method, with a sputtering power of 80 W for 30 min. The above sputtered film was treated with oxygen plasma for 10 min at a power of 2 kW. Weigh 4.61 g of PbI2 and 1.50 g of MAI and dissolve them in 6 mL of DMF, and heat and stir at 70 °C for 15 minutes to fully dissolve them to obtain perovskite precursor solution A; take 200 μL of perovskite precursor solution and evenly spread it on one side of the substrate to be spin-coated, use a scraper to form a film, with a gap of 300 μm and a speed of 15 mm / s, and then transfer the film to a hot stage at 130 °C for annealing for 15 min to obtain a perovskite film (400 nm).

[0057] Take 400 μL of perovskite film modifier and evenly spread it on one end of the surface of the prepared perovskite film, use a scraper to form a film, with a gap of 500 μm and a speed of 10 mm / s; then place the film in a vacuum device, quickly evacuate to 5 Pa, and stay for 5 minutes to obtain a treated perovskite film. Evaporate a layer of C60 electron transport layer (40 nm) on the surface of the above-prepared perovskite film to obtain a perovskite solar cell. Transfer the electron transport layer to a thermal evaporation device, and start evaporating the electrode (Au) under the condition that the vacuum degree reaches 1×10 -5 Pa, with a thickness of 100 nm to obtain a perovskite solar cell.

[0058] Comparative Example 2

[0059] This example provides a perovskite film modifier and a method for modifying a perovskite film with the perovskite film modifier. The specific composition and preparation method are as follows: Measure 1 ml of isopropanol and 1 ml of chlorobenzene, mix them evenly and stir to form a uniform perovskite film modifier.

[0060] Clean the 10*10 cm FTO film (glass thickness 2 mm, FTO film layer thickness 100 nm) glass. A dense NiO xThin film (thickness 20 nm, x ≤ 1), sputtering power 80 W, for 30 min. The above sputtered thin film was treated with oxygen plasma for 10 min, power 2 kW. Weigh 4.61 g of PbI2 and 1.50 g of MAI and dissolve them in 6 mL of DMF, heat and stir at 70 °C for 15 minutes to fully dissolve, obtaining perovskite precursor solution A; take 200 μL of perovskite precursor solution and evenly spread it on one side of the substrate to be spin-coated, use a doctor blade to form a film, gap 300 μm, speed 15 mm / s, and then transfer the thin film to a hot stage at 130 °C for annealing for 15 min to obtain a perovskite thin film (400 nm). Take 400 μL of perovskite thin film modifier and evenly spread it on one end of the surface of the prepared perovskite thin film, use a doctor blade to form a film, gap 500 μm, speed 10 mm / s; then place the thin film in the air to dry completely naturally.

[0061] Evaporate a layer of C60 electron transport layer (40 nm) on the surface of the perovskite thin film prepared above to obtain a perovskite solar cell. Transfer the electron transport layer to a thermal evaporation equipment, and start evaporating the gold electrode (Au) under the condition that the vacuum degree reaches 1×10 -5 Pa, with a thickness of 100 nm; obtain a perovskite solar cell.

[0062] Comparative Example 3

[0063] This example provides a perovskite thin film modifier and a method for modifying a perovskite thin film using the perovskite thin film modifier. The specific composition and preparation method are as follows: Measure 1 ml of isopropanol as the perovskite thin film modifier.

[0064] Clean the 10*10 cm FTO thin film (glass thickness 2 mm, FTO film layer thickness 100 nm) glass. Use the magnetron sputtering method to sputter a dense NiO x Thin film (thickness 20 nm, x ≤ 1), sputtering power 80 W, for 30 min. The above sputtered thin film was treated with oxygen plasma for 10 min, power 2 kW. Weigh 4.61 g of PbI2 and 1.50 g of MAI and dissolve them in 6 mL of DMF, heat and stir at 70 °C for 15 minutes to fully dissolve, obtaining perovskite precursor solution A; take 200 μL of perovskite precursor solution and evenly spread it on one side of the substrate to be spin-coated, use a doctor blade to form a film, gap 300 μm, speed 15 mm / s, and then transfer the thin film to a hot stage at 130 °C for annealing for 15 min to obtain a perovskite thin film (400 nm).

[0065] Evaporate a layer of C60 electron transport layer (40 nm) on the surface of the perovskite thin film prepared above to obtain a perovskite solar cell. Transfer the electron transport layer to a thermal evaporation equipment, and the vacuum degree reaches 1×10 -5Under the condition of Pa, start evaporating and depositing a gold electrode (Au) with a thickness of 100 nm; obtain a perovskite solar cell.

[0066] Comparative Example 4

[0067] This example provides a perovskite thin film modifier and a method for modifying a perovskite thin film using the perovskite thin film modifier. The specific composition and preparation method are as follows: Measure isopropanol and chlorobenzene solution with a volume ratio of 1:2, and prepare a 2 mg / ml guanidinium acetate perovskite thin film modifier.

[0068] Clean a 10*10 cm FTO thin film (glass thickness 2 mm, FTO film layer thickness 100 nm) glass. Use magnetron sputtering method to sputter a dense NiO x thin film (thickness 20 nm, x≤1) on the surface of the FTO thin film glass, with a sputtering power of 80 W for 30 min. Treat the sputtered thin film with oxygen plasma for 10 min at a power of 2 kW. Weigh 4.61 g of PbI2 and 1.50 g of MAI and dissolve them in 6 mL of DMF, heat and stir at 70 °C for 15 minutes to fully dissolve, obtaining a perovskite precursor solution A; take 200 μL of the perovskite precursor solution and evenly spread it on one side of the substrate to be spin-coated, use a scraper to form a film with a gap of 300 μm and a speed of 15 mm / s, and then transfer the thin film to a 130 °C hot stage for annealing for 15 min to obtain a perovskite thin film (400 nm).

[0069] Evaporate and deposit a C60 electron transport layer (40 nm) on the surface of the perovskite thin film prepared above to obtain a perovskite solar cell. Transfer the electron transport layer to a thermal evaporation device, and when the vacuum reaches 1×10 -5 Pa, start evaporating and depositing a gold electrode (Au) with a thickness of 100 nm; obtain a perovskite solar cell.

[0070] Experimental Example

[0071] Use PCE to test the current density-voltage (JV) curves of the perovskite solar cells prepared in Examples 1-2 and Comparative Examples 1-2. The test is completed on a kethley 2400 system; test conditions: simulated light intensity is 100 mW cm -2 (AM1.5G), the scanning rate is 0.1 V s -1 (step size is 0.02 V, time delay is 200 ms), the scanning range is from 1.2 V to -0.2 V, and the power output of the xenon lamp is calibrated by a NERL (National Renewable Energy Laboratory) standard KG5 standard Si perovskite solar cell. The test results are shown in Table 1.

[0072] Table 1 Detection Results of Perovskite Solar Cells in Each Example and Comparative Example

[0073]

[0074] As can be seen from Table 1, the volume ratio of isopropanol to chlorobenzene realizes surface cleaning and uniform film formation by adjusting the evaporation rate and polarity complementarity; guanidine acetic acid passivates lead ion defects through strong coordination of the guanidine group, reduces non-radiative recombination, and improves the open-circuit voltage and fill factor. Vacuum treatment accelerates solvent evaporation and removes defects, indicating that solvent synergy and precise concentration control are the keys. This modification strategy provides a feasible solution for highly efficient and stable perovskite cells through interface optimization and defect passivation.

[0075] It should be noted that in the description of the present application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0076] Any process or method description shown in the flowchart or described in other ways herein can be understood to represent a module, segment, or part of code including one or more executable instructions for implementing a specific logical function or process. The scope of the preferred embodiments of the present application includes additional implementations, where the functions may be executed in a substantially simultaneous manner or in the reverse order according to the functions involved, rather than in the order shown or discussed, which should be understood by those skilled in the technical field to which the embodiments of the present application belong.

[0077] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0078] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present application.

Claims

1. A perovskite film modifier, characterized in that: The invention comprises a volatile first substance which provides an electron donor group; the electron donor group passivates the uncoordinated lead ion defects in the perovskite film; and the electron donor group is a carbon-oxygen bond.

2. The modifier according to claim 1, characterized in that The first substance includes isopropanol and chlorobenzene in a volume ratio of (0.1-9):

1.

3. The modifier according to claim 1, characterized in that The modifier further comprises a second substance; the second substance comprises guanidinoacetic acid and / or poly(2-ethyl-2-oxazoline); and the concentration of the second substance in the modifier does not exceed 1 mg / ml.

4. A method for modifying a perovskite film, characterized in that: The modification is carried out using the modifying agent described in any one of claims 1 to 3.

5. The method according to claim 4, characterized in that The steps include: Applying the modifier described in any one of claims 1 to 3 on the surface of the perovskite film to form a liquid film; The liquid film is vacuum treated or blown to dry after the first substance is volatilized.

6. The method according to claim 5, characterized in that The modifying agent forms the liquid film by coating or scraping. When scraping is adopted, the scraping parameter gap is 100nm-500μm and the speed is 5-50mm / s.

7. The method according to claim 5, characterized in that The thickness of the liquid film is 100nm-500μm.

8. A perovskite film, characterized in that: Prepared by the modification method described in any one of claims 4 to 7.

9. A perovskite solar cell, characterized in that: The method comprises utilizing the perovskite film described in claim 8.

10. The perovskite solar cell according to claim 9, characterized in that: The perovskite solar cell also includes a substrate, a semiconductor material layer, a perovskite layer, a charge transport layer and a metal layer.

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