Method for preparing solar cells assisted by (trifluoroacetyl)benzotriazole

Abstract

The invention discloses a method for preparing a solar cell assisted by (trifluoroacetyl) benzotriazole, and relates to the field of solar cells. The active light-absorbing layer of the solar cell of the invention is a perovskite semiconductor material APbX3 assisted by the additive trifluoroacetyl (benzotriazole), wherein A is at least one of alkylamine, alkyl amidine or alkali element, and X is at least one of iodine, bromine and chlorine. The invention regulates the film morphology and crystallinity of the perovskite active layer by adding a trace amount of trifluoroacetyl (benzotriazole) to the perovskite solution, improves the transmission and collection of carriers; passivates the bulk defects of the perovskite light-absorbing layer, utilizes the ultraviolet isomerization properties of the material, and improves the ultraviolet stability of the perovskite film and the device; improves the difference between the forward and reverse scans of the perovskite solar cell, ensures steady-state output, improves the efficiency and repeatability of the cell, and significantly improves the photoelectric conversion of the cell.

Description

Technical Field

[0001] The present invention relates to the technical field of solar cells, and specifically to an additive-assisted high-efficiency perovskite solar cell that is stable under ultraviolet light and a preparation method thereof. Background Art

[0002] Organic-inorganic halide perovskite solar cells have attracted much attention in the past decade due to their rapidly developing certified conversion efficiency in small-area devices. However, they are easily affected by environmental factors, resulting in loss of device efficiency. Therefore, the literature reports that interface engineering, hydrophobic treatment, and encapsulation have been used to delay the degradation of perovskites and extend the life of devices. However, their stability under light (especially ultraviolet light) is rarely reported. Ultraviolet light can easily introduce vacancies into perovskites, causing increased ion migration and even degradation of organic ions. Therefore, there is an urgent need to find a method that can protect perovskites from long-term ultraviolet damage for a long time.

[0003] According to previous articles, perovskite body doping has been proven to be an effective method to improve the UV resistance of perovskite absorption layer. In addition to improving the stability of perovskite solar cells under ultraviolet light, this method also introduces functional groups with passivation effects to further improve the quality of perovskite films, thereby improving the overall performance of perovskite solar cells. For example, Wang Zhaokui et al. from Soochow University used the classic photoisomerization molecular spiropyran, whose front and back isomers meet the requirements of two different configurations to achieve state conversion and dynamic capture of continuous update defects once photoinduced defects appear during subsequent operations (YR Shi, KL Wang, YH Lou, GL Liu, CH Chen, J. Chen, L. Zhang and Z. K. Wang, Adv Mater 34 (50), e2205338 (2022)). The team of Yang Wang and Yanlin Song from the Institute of Chemistry, Chinese Academy of Sciences, proposed a tautomerism passivation strategy for molecular isomerization passivation, namely 2,3-bis(2,4,5-trimethyl-3-thienyl)maleimide (DAE), to passivate defects and prepare light-stable perovskite solar modules with sustainable UV protection (Yang Wang, Hua Yang, Kun Zhang, Mingquan Tao, Mingzhu Li, and Yanlin Song, ACS Energy Letters, 20227(10), 3646-3652). These studies show that effective chemical doping strategies can improve the UV stability and device performance of perovskite solar cells.

[0004] In summary, the problems of perovskite solar cells can be summarized as follows:

[0005] (i) The defect density of perovskite films is still very high;

[0006] (2) The stability of perovskite films and devices under ultraviolet light is still not ideal. Summary of the invention

[0007] In order to overcome the above-mentioned shortcomings of the prior art, the present invention provides a high-efficiency perovskite solar cell that is stable under ultraviolet light and a preparation method thereof, by adding a trace amount of trifluoroacetyl (benzotriazole) to the perovskite solution

[0008] The additive method regulates the film morphology and crystallinity of the perovskite active layer, improves the transport and collection of carriers, and passivates the bulk defects of the perovskite light-absorbing layer; utilizes the ultraviolet heterogeneous properties of the material to improve the ultraviolet stability of the perovskite film and device; improves the forward and reverse scanning differences of the perovskite solar cell, ensures steady-state output, improves the cell efficiency and repeatability, and significantly improves the photoelectric conversion of the cell.

[0009] The technical solution provided by the present invention is:

[0010] A method for preparing solar cells assisted by (trifluoroacetyl)benzotriazole, a perovskite solar cell, which includes, from bottom to top, a bottom substrate, a bottom transparent conductive layer, a bottom carrier transport layer, a perovskite layer, a top carrier transport layer and a top metal electrode layer; the bottom transparent conductive layer is grown on the upper surface of the bottom substrate by magnetron sputtering; the bottom carrier transport layer is grown on a glass substrate by solution spin coating; the perovskite layer is grown on the bottom transparent conductive layer by solution spin coating, and is connected in the middle by the bottom carrier transport layer; the top carrier transport layer and the top metal electrode layer are sequentially placed on the upper side of the active perovskite layer; the perovskite layer is a perovskite semiconductor material APbX3 grown with the assistance of the additive trifluoroacetyl (benzotriazole), wherein A is at least one of alkylamine, alkyl amidine and alkali element, the Pb element is derived from PbI2 or PbBr2, and X is at least one of iodine, bromine and chlorine; the additive is trifluoroacetyl (benzotriazole).

[0011] For the above-mentioned UV-stable high-efficiency perovskite solar cell, further, under the premise of keeping the main structure of the device unchanged, an additional functional layer can be selectively added between the bottom transparent conductive layer and the bottom carrier transport layer, or between the bottom carrier transport layer and the perovskite layer, or between the perovskite layer and the top carrier transport layer, or between the top carrier transport layer and the top metal electrode layer. For example, a buffer modification layer material including polyvinyl carbazole (PVK) and poly[bis(4-phenyl)(4-butylphenyl)amine] (Poly-TPD) can be selectively added between the bottom carrier transport layer and the active layer perovskite; a buffer modification layer: 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline (BCP) can be selectively added to the inner side of the top metal electrode.

[0012] For the above-mentioned UV-stable high-efficiency perovskite solar cell, further, the cell structure is PIN, the bottom substrate is transparent glass, the bottom transparent conductive layer is an ITO transparent electrode, the bottom carrier transport layer and the top carrier transport layer are respectively one or more of nickel oxide, fullerene derivatives, and self-limiting monolayers, the perovskite layer is a wide bandgap perovskite, and the top metal electrode layer is a metal electrode.

[0013] Furthermore, the perovskite precursor solution is a mixed solution of the perovskite semiconductor material APbX3 and the solvent in a volume ratio of DMF:DMSO=1:1, and the concentration of the added trifluoroacetyl (benzotriazole) is 0.5-2.5 molar percent.

[0014] Furthermore, the perovskite layer was prepared by pouring ethyl acetate on a rotating substrate at a spin coating speed of 5000 rpm for 50 seconds, and then annealing on a hot plate at 100 degrees Celsius for 30 minutes 26 seconds before the end of the spin coating.

[0015] Advantages and positive effects of this method:

[0016] This method can achieve excellent photoelectric performance on a glass substrate by introducing trifluoroacetyl (benzotriazole) (C8H4F3N3O) as a perovskite precursor solution additive to regulate the growth of perovskite crystals. C8H4F3N3O coordinates with lead iodide and FAI to form hydrogen bonds and passivate perovskite phase defects, resulting in better crystallinity of the perovskite film. The isomerization characteristics of trifluoroacetyl (benzotriazole) make the perovskite stable under ultraviolet light, so that the perovskite film has excellent ultraviolet stability. Under the synergistic effect of C=O group doping and C-F3 group doping to assist crystallization, the intrinsic defect density of the perovskite film is greatly reduced, and the carrier lifetime is greatly improved, thereby increasing the photoelectric conversion efficiency of the battery and improving the stability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the invention.

[0018] Figure 1 The JV curve of the wide bandgap organic-inorganic perovskite solar cell shown in Example 1;

[0019] Figure 2 is a JV curve diagram of the wide bandgap organic-inorganic perovskite solar cell shown in Example 2;

[0020] Figure 3 is a JV curve diagram of the wide bandgap organic-inorganic perovskite solar cell shown in Example 3;

[0021] Figure 4 is a JV curve diagram of the wide bandgap organic-inorganic perovskite solar cell shown in Example 4;

[0022] Figure 5 This is the structure diagram of the single-junction perovskite solar cell device of the present invention;

[0023] Figure 6 The SEM images of the control sample and the perovskite film doped with trifluoroacetyl (benzotriazole);

[0024] Figure 7 Steady-state PL images of the Control sample and the sample doped with trifluoroacetyl (benzotriazole);

[0025] Figure 8 JV diagram of the control sample and the perovskite single-junction PIN device doped with trifluoroacetyl (benzotriazole);

[0026] Fig. 9 Long-term stability of the control sample and the perovskite single-junction PIN device doped with trifluoroacetyl (benzotriazole) under UVa irradiation from the glass surface (a) and from the silver electrode surface (b), respectively.

[0027] Fig.10 The stability of the control sample and the perovskite single-junction PIN device doped with trifluoroacetyl (benzotriazole) after 1400 hours in a nitrogen environment.

[0028] The above films and devices are not packaged. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0030] The present invention provides a high-quality perovskite film that is stable under ultraviolet light and prepared with the aid of an additive trifluoroacetyl (benzotriazole), and a perovskite cell having the film. Figure 5 The perovskite solar cell of the present invention comprises, from bottom to top, a bottom substrate (1), a bottom transparent conductive layer (2), a bottom carrier transport layer (3), a perovskite layer (4), a top carrier transport layer (5) and a top metal electrode layer (6); the bottom transparent conductive layer is grown on the upper surface of the bottom substrate (1) by magnetron sputtering; the perovskite layer (4) is grown on the bottom transparent conductive layer (2) by solution spin coating, and is connected in the middle by the bottom carrier transport layer (3); the top carrier transport layer (5) and the top metal electrode layer (6) are sequentially placed on the upper side of the active perovskite layer (4).

[0031] The perovskite layer (4) of the present invention is a perovskite semiconductor material APbX3 assisted by the additive trifluoroacetyl (benzotriazole), wherein A is at least one of alkylamine, alkylamidine or alkali element, the Pb element is derived from PbI2 or PbBr2, and X is at least one of iodine, bromine and chlorine; the additive is trifluoroacetyl (benzotriazole). 0.83 Cs 0.17 Pb(I 0.8 Br 0.2 )3 The perovskite material is described, which is not used to limit the technical solution protected by the present invention, but only to better illustrate the technical concept of the present invention and compare the technical effects. Other choices of the perovskite semiconductor material APbX3 defined by the technical solution of the present invention have the same technical effects as the embodiments of the present invention.

[0032] Embodiment 1:

[0033] The invention provides a method for preparing a wide bandgap organic-inorganic hybrid perovskite solar cell with a (trifluoroacetyl)benzotriazole material body passivation. The (trifluoroacetyl)benzotriazole material is introduced into a wide bandgap organic-inorganic hybrid perovskite film to effectively passivate the body defects of the perovskite film, improve the quality of the wide bandgap organic-inorganic perovskite film, and improve the photoelectric conversion efficiency of the wide bandgap organic-inorganic perovskite solar cell.

[0034] Step 1: ultrasonically clean the glass / ITO substrate with detergent, deionized water and isopropyl alcohol for 15 minutes each in sequence for use, wherein the square resistance of the ITO layer is 7-15 ohms.

[0035] Step 2: Dry the cleaned glass / ITO substrate with nitrogen, treat it with UV for 20 minutes, and then spin-coat NiO on the glass / ITO substrate. x Solution, by controlling the spin coating speed to adjust NiO x The thickness of the hole transport layer film was then annealed on a hot plate at 100 degrees Celsius for 10 minutes in air.

[0036] Step 3: Spin coat 1.3M FA in a nitrogen glove box using a one-step method 0.83 Cs 0.17 Pb(I 0.8 Br 0.2 )3 Perovskite solution, the solvent is a mixed solution of DMF:DMSO (volume ratio 1:1), the concentration of (trifluoroacetyl)benzotriazole is 0.5 mol%, the spin coating speed is 5000 rpm, the time is 50 seconds, and 26 seconds before the end, ethyl acetate (200 μL) is poured on the rotating substrate. Then it is placed on a hot plate at 100 degrees Celsius for annealing for 30 minutes. The thickness of the perovskite film is about 400 nanometers.

[0037] Step 4: Use the solution spin coating method to spin-coat PCBM and BCP electron transport layers on the perovskite layer in sequence. PCBM is dissolved in chlorobenzene with a concentration of 20 mg / ml, and the spin coating speed is 2000 rpm for 30 seconds; BCP is dissolved in isopropanol with a concentration of 0.5 mg / ml, and the spin coating speed is 5000 rpm for 30 seconds.

[0038] Step 6: Using a thermal evaporation process, evaporate a metal silver electrode on the electron transport layer with a thickness of 80 nanometers.

[0039] Experimental results: The structure of perovskite battery is as follows Figure 5 As shown in FIG. 1 , under the irradiation of AM1.5, 100 mW / cm2 standard light intensity, the solar cell prepared in this embodiment has an open circuit voltage of 1.14 V, a short circuit current of 20.48 mA / cm2, a fill factor of 79.4%, and an efficiency of 18.53% ( Figure 1 ).

[0040] Embodiment 2:

[0041] The invention provides a method for preparing a wide bandgap organic-inorganic hybrid perovskite solar cell with a (trifluoroacetyl)benzotriazole material body passivation. The (trifluoroacetyl)benzotriazole material is introduced into a wide bandgap organic-inorganic hybrid perovskite film to effectively passivate the body defects of the perovskite film, improve the quality of the wide bandgap organic-inorganic perovskite film, and improve the photoelectric conversion efficiency of the wide bandgap organic-inorganic perovskite solar cell.

[0042] Step 1: ultrasonically clean the glass / ITO substrate with detergent, deionized water and isopropyl alcohol for 15 minutes each in sequence for use, wherein the square resistance of the ITO layer is 7-15 ohms.

[0043] Step 2: Dry the cleaned glass / ITO substrate with nitrogen, treat it with UV for 20 minutes, and then spin-coat NiO on the glass / ITO substrate. x Solution, by controlling the spin coating speed to adjust NiO x The thickness of the hole transport layer film was then annealed on a hot plate at 100 degrees Celsius for 10 minutes in air.

[0044] Step 3: Spin coat 1.3M FA in a nitrogen glove box using a one-step method 0.83 Cs 0.17 Pb(I 0.8 Br 0.2)3 Perovskite solution, the solvent is a mixed solution of DMF:DMSO (volume ratio 1:1), the concentration of (trifluoroacetyl)benzotriazole is 1.5 mol%, the spin coating speed is 5000 rpm, the time is 50 seconds, and 26 seconds before the end, ethyl acetate (200 μL) is poured on the rotating substrate. Then it is placed on a hot plate at 100 degrees Celsius for annealing for 30 minutes. The thickness of the perovskite film is about 400 nanometers.

[0045] Step 4: Use the solution spin coating method to spin-coat PCBM and BCP electron transport layers on the perovskite layer in sequence. PCBM is dissolved in chlorobenzene with a concentration of 20 mg / ml, and the spin coating speed is 2000 rpm for 30 seconds; BCP is dissolved in isopropanol with a concentration of 0.5 mg / ml, and the spin coating speed is 5000 rpm for 30 seconds.

[0046] Step 6: Using a thermal evaporation process, evaporate a metal silver electrode on the electron transport layer with a thickness of 80 nanometers.

[0047] Experimental results: The structure of perovskite battery is as follows Figure 5 As shown in FIG. 1 , under the irradiation of AM1.5, 100 mW / cm2 standard light intensity, the solar cell prepared in this embodiment has an open circuit voltage of 1.17 V, a short circuit current of 21.78 mA / cm2, a fill factor of 84.33%, and an efficiency of 21.54% ( Figure 2 ).

[0048] Embodiment 3:

[0049] The invention provides a method for preparing a wide bandgap organic-inorganic hybrid perovskite solar cell with a (trifluoroacetyl)benzotriazole material body passivation. The (trifluoroacetyl)benzotriazole material is introduced into a wide bandgap organic-inorganic hybrid perovskite film to effectively passivate the body defects of the perovskite film, improve the quality of the wide bandgap organic-inorganic perovskite film, and improve the photoelectric conversion efficiency of the wide bandgap organic-inorganic perovskite solar cell.

[0050] Step 1: ultrasonically clean the glass / ITO substrate with detergent, deionized water and isopropyl alcohol for 15 minutes each in sequence for use, wherein the square resistance of the ITO layer is 7-15 ohms.

[0051] Step 2: Dry the cleaned glass / ITO substrate with nitrogen, treat it with UV for 20 minutes, and then spin-coat NiO on the glass / ITO substrate. x Solution, by controlling the spin coating speed to adjust NiO x The thickness of the hole transport layer film was then annealed on a hot plate at 100 degrees Celsius for 10 minutes in air.

[0052] Step 3: Spin coat 1.3M FA in a nitrogen glove box using a one-step method0.83 Cs 0.17 Pb(I 0.8 Br 0.2 )3 Perovskite solution, the solvent is a mixed solution of DMF:DMSO (volume ratio 1:1), the concentration of (trifluoroacetyl)benzotriazole is 2.5 mol%, the spin coating speed is 5000 rpm, the time is 50 seconds, and 26 seconds before the end, ethyl acetate (200 μL) is poured on the rotating substrate. Then it is placed on a hot plate at 100 degrees Celsius for annealing for 30 minutes, and the thickness of the perovskite film is about 400 nanometers.

[0053] Step 4: Use the solution spin coating method to spin-coat PCBM and BCP electron transport layers on the perovskite layer in sequence. PCBM is dissolved in chlorobenzene with a concentration of 20 mg / ml, and the spin coating speed is 2000 rpm for 30 seconds; BCP is dissolved in isopropanol with a concentration of 0.5 mg / ml, and the spin coating speed is 5000 rpm for 30 seconds.

[0054] Step 6: Using a thermal evaporation process, evaporate a metal silver electrode on the electron transport layer with a thickness of 80 nanometers.

[0055] Experimental results: The structure of perovskite battery is as follows Figure 5 As shown in FIG. 1 , under the irradiation of AM1.5, 100 mW / cm2 standard light intensity, the solar cell prepared in this embodiment has an open circuit voltage of 1.16 V, a short circuit current of 20.63 mA / cm2, a fill factor of 80.89%, and an efficiency of 19.36% ( Figure 3 ).

[0056] Embodiment 4 (comparative example):

[0057] The present invention provides a method for preparing a wide bandgap organic-inorganic hybrid perovskite solar cell with a body passivation of a (trifluoroacetyl)benzotriazole material. The (trifluoroacetyl)benzotriazole material is introduced into a wide bandgap organic-inorganic hybrid perovskite film to effectively passivate body defects of the perovskite film, improve the quality of the wide bandgap organic-inorganic perovskite film, and improve the photoelectric conversion efficiency of the wide bandgap organic-inorganic perovskite solar cell. The (trifluoroacetyl)benzotriazole material is not introduced in this embodiment, and the technical effect achieved by the present invention is illustrated by comparing this comparative embodiment with the technical solution of the present invention.

[0058] Step 1: ultrasonically clean the glass / ITO substrate with detergent, deionized water and isopropyl alcohol for 15 minutes each in sequence for use, wherein the square resistance of the ITO layer is 7-15 ohms.

[0059] Step 2: Dry the cleaned glass / ITO substrate with nitrogen, treat it with UV for 20 minutes, and then spin-coat NiO on the glass / ITO substrate. xSolution, by controlling the spin coating speed to adjust NiO x The thickness of the hole transport layer film was then annealed on a hot plate at 100 degrees Celsius for 10 minutes in air.

[0060] Step 3: Spin coat 1.3M FA in a nitrogen glove box using a one-step method 0.83 Cs 0.17 Pb(I 0.8 Br 0.2 )3 Perovskite solution, the solvent is a mixed solution of DMF:DMSO (volume ratio 1:1), the spin coating speed is 5000 rpm, the time is 50s, and 26 seconds before the end, ethyl acetate (200 μl) is poured on the rotating substrate. Then it is placed on a hot plate at 100 degrees Celsius for annealing for 30 minutes. The thickness of the perovskite film is about 400 nanometers.

[0061] Step 4: Use the solution spin coating method to spin-coat PCBM and BCP electron transport layers on the perovskite layer in sequence. PCBM is dissolved in chlorobenzene with a concentration of 20 mg / ml, and the spin coating speed is 2000 rpm for 30 seconds; BCP is dissolved in isopropanol with a concentration of 0.5 mg / ml, and the spin coating speed is 5000 rpm for 30 seconds.

[0062] Step 6: Using a thermal evaporation process, evaporate a metal silver electrode on the electron transport layer with a thickness of 80 nanometers.

[0063] Experimental results: The structure of perovskite battery is as follows Figure 5 As shown in FIG. 1 , under the irradiation of AM1.5, 100 mW / cm2 standard light intensity, the solar cell prepared in this embodiment has an open circuit voltage of 1.13 V, a short circuit current of 19.88 mA / cm2, a fill factor of 81.7%, and an efficiency of 18.36% ( Figure 4 ). By comparing the comparative examples with Examples 1-3 of the present invention, the open circuit voltage, short circuit current and efficiency of the solar cells prepared without introducing the (trifluoroacetyl)benzotriazole material are significantly lower than those of the embodiments of the present invention.

[0064] According to the embodiment of the present invention, the perovskite film obtained after doping with trifluoroacetyl (benzotriazole) has larger grains, such as Figure 6 As shown. And it effectively inhibits the generation of defects in perovskite films, such as Figure 7 Complete Figure 5 The cell preparation shown in the figure was tested under a standard solar intensity (AM1.5, 100 mW / cm2) irradiation, as shown in the figure. Figure 8As shown in Figure 2, the device performance is greatly improved after doping with trifluoroacetyl (benzotriazole). In order to study the device stability, the devices with and without trifluoroacetyl (benzotriazole) were tested under ultraviolet (UVa 365nm, 60mW / cm2) irradiation without a UV filter, as shown in Figure 2. Fig. 9 As shown in Figure 2, after doping, the UV stability of the device has been significantly improved. Fig.10 As shown, after being stored in nitrogen for 1400 hours, the doped device almost maintained its original performance.

[0065] In summary, the present invention provides a method for preparing a high-quality perovskite film. By introducing trifluoroacetyl (benzotriazole) as an additive and utilizing the ultraviolet isomerization characteristics, the perovskite film and the device remain stable, the defects of the perovskite are eliminated to the greatest extent, and the efficiency of the perovskite solar cell is significantly improved. The method is simple and easy to implement.

[0066] The above is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for preparing solar cells with the aid of (trifluoroacetyl)benzotriazole, the method comprising: A perovskite solar cell comprises, from bottom to top, a bottom substrate (1), a bottom transparent conductive layer (2), a bottom carrier transport layer (3), a perovskite layer (4), a top carrier transport layer (5) and a top metal electrode layer (6); the bottom transparent conductive layer (2) is grown on the upper surface of the bottom substrate (1) by magnetron sputtering; the bottom carrier transport layer (3) is grown on the bottom substrate (1) by solution spin coating; the perovskite layer (4) is grown on the bottom transparent conductive layer (2) by solution spin coating, and is connected in the middle by the bottom carrier transport layer (3); the top carrier transport layer (5) and the top metal electrode layer (6) are sequentially placed on the upper side of the perovskite layer (4); The perovskite layer (4) is a perovskite semiconductor material APbX3 grown with the aid of an additive (trifluoroacetyl)benzotriazole, A is at least one of an alkylamine, an alkyl amidine or an alkali element, the Pb element is derived from PbI2 or PbBr2, and X is at least one of iodine, bromine or chlorine; (trifluoroacetyl)benzotriazole and a perovskite precursor solution are mixed in a certain ratio, and then spin-coated and annealed to prepare the perovskite layer (4); The precursor solution is a mixed solution of perovskite semiconductor material APbX3 and solvent in a volume ratio of DMF:DMSO=1:1, and the concentration of added (trifluoroacetyl)benzotriazole is 0.5-2.5 mole percent; The spin coating speed was 5000 rpm for 50 seconds. 26 seconds before the end of the coating, ethyl acetate was poured onto the rotating substrate, and then the substrate was placed on a hot plate at 100 degrees Celsius for annealing for 30 minutes to prepare a perovskite layer (4).

2. The method for preparing solar cells with the aid of (trifluoroacetyl)benzotriazole as claimed in claim 1, characterized in that: The battery structure is PIN.

3. The method for preparing solar cells with the aid of (trifluoroacetyl)benzotriazole as claimed in claim 1, characterized in that: The bottom substrate (1) is transparent glass.

4. The method for preparing solar cells with the aid of (trifluoroacetyl)benzotriazole as claimed in claim 1, characterized in that: The bottom transparent conductive layer (2) is an ITO transparent electrode.

5. The method for preparing solar cells with the aid of (trifluoroacetyl)benzotriazole as claimed in claim 1, characterized in that: The perovskite layer (4) is a wide bandgap perovskite.

6. The method for preparing solar cells with the aid of (trifluoroacetyl)benzotriazole as claimed in claim 1, characterized in that: The top metal electrode layer (6) is a metal electrode.

7. The method for preparing solar cells with the aid of (trifluoroacetyl)benzotriazole as claimed in claim 1, characterized in that: The bottom carrier transport layer (3) and the top carrier transport layer (5) are respectively one or more of nickel oxide, fullerene derivatives, and self-limiting monolayers.

8. The method for preparing solar cells with the aid of (trifluoroacetyl)benzotriazole as claimed in claim 1, characterized in that: The perovskite solar cell comprises buffer modification layer materials added between a bottom carrier transport layer (3) and a perovskite layer (4), and between a top carrier transport layer (5) and a top metal electrode layer (6), respectively, wherein the buffer modification layer material between the bottom carrier transport layer (3) and the perovskite layer (4) is polyvinyl carbazole or poly[bis(4-phenyl)(4-butylphenyl)amine], and the buffer modification layer material between the top carrier transport layer (5) and the top metal electrode layer (6) is 2,9-dimethyl-4,7-biphenyl-1,10-phenanthroline.

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