Preparation method of aromatic hydrocarbon-based benzodiazole one-dimensional structure-perovskite composite film and solar cell

Abstract

The application belongs to the technical field of solar cells, and proposes a preparation method of an aromatic hydrocarbon-based benzoxazole one-dimensional structure-perovskite composite film and a solar cell, which are sequentially from bottom to top: a transparent conductive glass substrate, an electron transport layer, an aromatic hydrocarbon-based benzoxazole one-dimensional structure-perovskite composite layer, a hole transport layer, and a metal electrode; the aromatic hydrocarbon-based benzoxazole one-dimensional structure-perovskite composite layer is; the general formula of the aromatic hydrocarbon-based benzoxazole one-dimensional structure is MBX n , wherein M is an aromatic hydrocarbon-based benzoxazole. The application can form a one-dimensional passivation structure of π-π stacking at the grain boundary of a perovskite film and the surface of a perovskite film in situ, accelerate the charge extraction and transmission at the grain boundary / interface, and further improve the photoelectric conversion efficiency of the device; meanwhile, due to the existence of the aromatic hydrocarbon group in the structure, the one-dimensional passivation structure has abundant π-conjugated system hydrophobic structures, and the stability of the device is effectively improved.

Description

Technical Field

[0001] This invention belongs to the field of solar cell technology, specifically relating to a method for preparing an aromatic hydrocarbon-based benzodiazole one-dimensional structure-perovskite composite thin film and a solar cell. Background Technology

[0002] Organic-inorganic hybrid perovskite solar cells have attracted significant research attention in academia and industry in recent years due to their continuously improving efficiency, solution preparation processes, and low raw material costs. The efficiency of perovskite solar cells has increased from 3.8% in 2009 to the current 26.1%. However, the stability of perovskite solar cells is one of the major challenges for future commercial applications. This is primarily due to the inherently weak bonding of halide perovskite polycrystalline thin films, especially at grain boundaries where dislocations, dangling bonds, and unsaturated coordination defects are more likely to form. These sites exacerbate halide diffusion, leading to the decomposition of the three-dimensional perovskite structure and a decline in device performance (particularly under conditions of strong light and high humidity). Therefore, achieving simultaneous improvement in the efficiency and stability of perovskite solar cells is crucial for their commercial application.

[0003] Introducing a low-dimensional perovskite protective layer is currently an effective strategy to improve the stability of perovskite layers. Common methods include two-dimensional and one-dimensional structural modification. While two-dimensional perovskite protective layers can isolate water and oxygen corrosion and the reaction between metals and halide ions to some extent, the two-dimensional structure undergoes a phase transition with the perovskite, forming a two-dimensional-three-dimensional hybrid structure, which adversely affects the long-term stability of perovskite solar cells. One-dimensional structures, due to their poor conductivity and loose packing, hinder interfacial charge transport in the one-dimensional-three-dimensional hybrid perovskite structure, affecting device efficiency, although they can improve the stability of the thin film and the device. Therefore, this paper proposes a novel method for passivating perovskite thin film grain boundaries to improve the efficiency and stability of perovskite solar cells while influencing interfacial charge transport.

[0004] In patent CN115117250A, the invention modifies the perovskite layer with alkylbenzimidazole to form a one-dimensional structural layer on the perovskite surface, improving the stability of the thin film and device. However, alkyl chains are detrimental to charge transport, resulting in poor conductivity and loose stacking of the formed one-dimensional structural layer. This hinders interfacial charge transport in the one-dimensional-three-dimensional hybrid perovskite structure, affecting device efficiency. Therefore, there is an urgent need to develop a simple and easy-to-implement in-situ bulk phase-grain boundary passivation method for perovskite thin films to improve device efficiency and stability. Summary of the Invention

[0005] The purpose of this invention is to provide a method for preparing an aromatic hydrocarbon-based benzodiazole one-dimensional structure-perovskite composite thin film and a solar cell, so as to solve the problems mentioned in the background art.

[0006] The technical solution adopted in this invention is: The first aspect of the present invention provides a solar cell, comprising, from bottom to top: a transparent conductive glass substrate, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a metal electrode; wherein the perovskite light-absorbing layer is an aromatic hydrocarbon benzodiazole one-dimensional structure-perovskite composite thin film.

[0007] Furthermore, the general formula of the one-dimensional structure of the aromatic hydrocarbon benzodiazole is MBX. n Where M is an aromatic hydrocarbon benzodiazole and B is Pb 2+ Sn 2+ One or more of the following, where X is one or more of the halide ions.

[0008] Furthermore, the aromatic hydrocarbon benzodiazole is an aromatic hydrocarbon halide, wherein the aromatic hydrocarbon group includes phenyl, benzyl, phenethyl, naphthyl, anthraceneyl, and phenanthrene.

[0009] Furthermore, the perovskite precursor is an AX and BX2 type compound, wherein A is CH3NH3. + HC(=NH)NH2 + Cs + 、Rb + K + One or more of them, where B is Pb 2+ Sn 2+ One or more of the following, where X is one or more of the halide ions.

[0010] Furthermore, the precursor of the AX-type compound is one or more of CH3NH3Br, HC(=NH)NH3I, and CsI; the precursor of the BX2-type compound is one or more of PbI2 and SnI2.

[0011] The second aspect of this invention provides a method for preparing an aromatic hydrocarbon-benzodiazole one-dimensional structure-perovskite composite film, wherein a perovskite layer is passivated by bulk doping: aromatic hydrocarbon-benzodiazole is mixed and dissolved in a perovskite precursor solution to prepare an aromatic hydrocarbon-benzodiazole-modified perovskite precursor solution; the aromatic hydrocarbon-benzodiazole-modified perovskite precursor solution is coated on an electron transport layer; and after heat treatment, a perovskite light-absorbing layer is obtained.

[0012] Furthermore, the solvent of the perovskite precursor solution is one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, γ-butyrolactone, and 2-mercaptoethanol.

[0013] Furthermore, the concentration of the aromatic hydrocarbon benzodiazole molecule in the solvent is 0.5-5 mg / mL.

[0014] Furthermore, the stirring temperature of the solution when the aromatic hydrocarbon benzodiazole is mixed and dissolved is 30-100℃, and the stirring time is 0.5-50 h.

[0015] A third aspect of the present invention provides a method for preparing a solar cell, comprising: Aromatic hydrocarbon benzodiazoles were mixed and dissolved in a perovskite precursor solution to prepare a perovskite precursor solution modified with aromatic hydrocarbon benzodiazoles. Pre-treated substrate consisting of conductive glass / electron transport layer: The prepared perovskite precursor solution containing aromatic hydrocarbon benzodiazole was coated onto the substrate and then annealed to obtain an aromatic hydrocarbon benzodiazole one-dimensional structure-perovskite composite thin film light-absorbing layer. A hole transport layer is formed on the surface of the light-absorbing layer; A back electrode layer is formed on the surface of the hole transport layer.

[0016] The beneficial effects of this invention are: 1. The present invention introduces aromatic hydrocarbon benzodiazole into the perovskite precursor solution, which can react with residual metal halides to form a one-dimensional passivation structure in situ at the grain boundaries of the perovskite film, thereby repairing grain boundary defects.

[0017] 2. The one-dimensional structure based on aromatic hydrocarbon benzodiazole derivatives prepared in this invention has multiple π-π conjugated systems (benzene ring-benzene ring; benzodiazole-benzodiazole), which can accelerate charge extraction and transport at grain boundaries / interfaces, thereby improving the photoelectric conversion efficiency of the device.

[0018] 3. The aromatic hydrocarbon-based benzodiazole one-dimensional structure-perovskite composite thin film light-absorbing layer prepared by this invention has good stability and will not continue to react with the three-dimensional perovskite light-absorbing layer structure to form a mixed-dimensional structure. This invention ensures that the device structure has a longer-term stability. At the same time, it can block ion migration at grain boundaries and improve the operational stability of the device.

[0019] 4. The solar cells based on the one-dimensional structure of aromatic hydrocarbon benzodiazole-perovskite composite thin film prepared by this invention have high efficiency, good stability, and good repeatability. The photoelectric conversion efficiency increases from the basic 19.74% to 23.20%, and the stability exceeds 1000 hours. This greatly improves the photoelectric conversion efficiency and stability of perovskite solar cells prepared by the low-temperature solution method and has extremely high application prospects. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the solar cell structure of the aromatic hydrocarbon benzodiazole one-dimensional structure-perovskite composite thin film of the present invention. Figure 2 The crystal structure (a) and XRD pattern (b) of the one-dimensional passivation layer based on phenyl-benzodiazole of this invention are shown.

[0021] Figure 3 The current-voltage curve of the solar cell with a phenylbenzodiazole one-dimensional structure-perovskite composite film added at a concentration of 0.5 mg / mL in Example 1 is shown. Figure 4 The current-voltage curve of the solar cell with a one-dimensional structure-perovskite composite film of naphthylbenzodiazole at a concentration of 0.2 mg / mL is shown in Example 2. Figure 5 The current-voltage curve of the solar cell with an anthraxylbenzodiazole one-dimensional structure-perovskite composite film added at a concentration of 0.4 mg / mL in Example 3 is shown. Figure 6 The current-voltage curve of the solar cell with a one-dimensional perovskite composite film of phenanthrenebenzodiazole at a concentration of 0.5 mg / mL is shown in Example 4. Figure 7 The current-voltage curve of the perovskite solar cell without the addition of aromatic hydrocarbon benzodiazole is shown in Comparative Example 1. Figure 8 The current-voltage curves of the perovskite solar cell with a one-dimensional interface modified by phenylbenzodiazole at a concentration of 0.5 mg / mL, as shown in Comparative Example 2. Figure 9 The current-voltage curve of the solar cell with a one-dimensional structure-perovskite composite film of 0.5 mg / mL n-octylbenzodiazole added to Comparative Example 3 is shown. Figure 10 SEM image of the one-dimensional perovskite composite film with phenylbenzodiazole added at a concentration of 0.5 mg / mL in Example 1; Figure 11 SEM image of the phenylbenzodiazole-free one-dimensional perovskite composite film prepared in Comparative Example 1.

[0022] Explanation of reference numerals in the attached figures: 1. Metal electrode; 2. Hole transport layer; 3. Benzodiazole one-dimensional structure-perovskite composite thin film layer; 4. Electron transport layer; 5. Transparent conductive glass substrate. Detailed Implementation

[0023] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0024] It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are only for illustrative purposes and to aid those skilled in the art in understanding and reading the content disclosed herein. They are not intended to limit the implementation conditions of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to the size, without affecting the effects and objectives achieved by the invention, should fall within the scope of the technical content disclosed in this invention. The technical solution of this invention is further described in conjunction with specific embodiments, but it should be understood that the scope of protection of this invention is not limited to the specific embodiments. Any substitutions or combinations of solvents, antisolvents, changes in perovskite composition, and the 1D introduction amount and time of phenylbenzodiazole made without departing from the spirit and principle of this invention should be considered equivalent substitution methods and are all included within the scope of protection of this invention.

[0025] To address the issue that alkyl chains are not conducive to charge transport, resulting in poor conductivity and loose stacking of the formed one-dimensional structural layer, which hinders interfacial charge transport in the one-dimensional-three-dimensional hybrid perovskite structure and affects device efficiency.

[0026] This invention proposes to utilize the reaction of aromatic hydrocarbon benzodiazole derivatives with residual metal halides in the perovskite precursor solution to form a one-dimensional passivation structure in situ at the grain boundaries and surface of the perovskite film. Due to the presence of aromatic hydrocarbon groups in this passivation structure, π-π stacking can be formed, accelerating charge extraction and transport at grain boundaries / interfaces, thereby improving the photoelectric conversion efficiency of the device. Simultaneously, the presence of aromatic hydrocarbon groups in the structure results in a rich π-conjugated hydrophobic structure within the one-dimensional passivation structure, effectively enhancing the stability of the device. The perovskite solar cell prepared by this invention exhibits advantages such as high photoelectric conversion efficiency and good stability. The highest efficiency can reach over 23.20%, and the stability is over 1000 hours, demonstrating extremely high practical application value.

[0027] Specifically, this invention provides a solar cell with an aromatic hydrocarbon-based benzodiazole one-dimensional structure-perovskite composite thin film, such as... Figure 1 As shown, from bottom to top, it includes: a transparent conductive glass substrate 1, an electron transport layer 2, an aromatic hydrocarbon benzodiazole one-dimensional structure-perovskite composite thin film 3, a hole transport layer 4, and a metal electrode 5. The perovskite layer 3 is formed in situ at the grain boundaries of the perovskite thin film by adding aromatic hydrocarbon benzodiazole.

[0028] The perovskite layer is passivated using a bulk doping method (in-situ passivation with additives): Aromatic hydrocarbon benzodiazole is dissolved in a perovskite precursor solution to prepare a perovskite precursor solution modified with aromatic hydrocarbon benzodiazole. The perovskite precursor solution modified with aromatic hydrocarbon benzodiazole is spin-coated onto an electron transport layer. After heat treatment, the perovskite layer is prepared to obtain a light-absorbing layer with an aromatic hydrocarbon benzodiazole one-dimensional structure-perovskite composite film.

[0029] The perovskite precursors are AX and BX2 type compounds, where A is CH3NH3. + HC(=NH)NH2 + Cs + 、Rb + K + One or more of them, where B is Pb 2+ Sn 2+ One or more of the following, where X is one or more of a halide ion. The precursor of AX-type compounds is preferably one or more of CH3NH3Br, HC(=NH)NH3I, and CsI, and the precursor of BX2-type compounds is preferably one or more of PbI2 and SnI2.

[0030] The solvent for the perovskite precursor solution is one or more of N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylpyrrolidone (NMP), γ-butyrolactone (GBL), 2-mercaptoethanol (2-Me), etc., preferably DMF or DMSO.

[0031] In some embodiments, the concentration of the aromatic hydrocarbon benzodiazole molecule in the organic solvent is 0.05-5 mg / mL, for example, it can be 0.05 mg / mL, 0.2 mg / mL, 0.4 mg / mL, 0.5 mg / mL, 1 mg / mL, 5 mg / mL, etc.

[0032] The general formula for the one-dimensional structure of aromatic hydrocarbon benzodiazole is MBX. n Where M is an aromatic hydrocarbon benzodiazole and B is Pb 2+ Sn 2+ One or more of the following, where X is one or more of the halide ions.

[0033] In some embodiments, the aromatic hydrocarbon benzodiazole is an aromatic hydrocarbon halide and is selected from at least one of phenyl, benzyl, phenethyl, naphthyl, anthraceneyl, phenanthrene, etc.

[0034] The present invention also provides a method for preparing a solar cell comprising the above-mentioned aromatic hydrocarbon benzodiazole one-dimensional structure-perovskite composite thin film, comprising the following steps: S1: Prepare a perovskite light-absorbing layer precursor solution by dissolving aromatic hydrocarbon benzodiazole mixture in the perovskite precursor solution to prepare a perovskite precursor solution modified with aromatic hydrocarbon benzodiazole. S2: Substrate composed of pretreated conductive glass / electron transport layer: S3: The precursor solution prepared in S1 is coated onto the substrate and then annealed to obtain an aromatic hydrocarbon benzodiazole one-dimensional structure-perovskite composite thin film light-absorbing layer. S4: A hole transport layer is formed on the surface of the light-absorbing layer; S5: A back electrode layer is formed on the surface of the hole transport layer.

[0035] In some embodiments, the stirring temperature for dissolving the aromatic hydrocarbon benzodiazole mixture in the perovskite precursor solution is 30-100°C, for example, 30°C, 40°C, 55°C, 70°C, 100°C, etc.; the stirring time is 0.5-50 h, for example, 0.5 h, 1 h, 2 h, 5 h, 10 h, 50 h, etc.

[0036] In some embodiments, the precursor solution of the aromatic hydrocarbon-based benzodiazole one-dimensional structure-perovskite composite thin film light-absorbing layer can be coated onto the electron transport layer of the substrate by at least one of spin coating, blade coating, dip coating, slot coating, and spray coating methods. The thickness of the aromatic hydrocarbon-based benzodiazole one-dimensional structure-perovskite composite light-absorbing layer is 100-1000 nm. The spin coating speed is 2000-8000 rpm, and the spin coating time is 20-100 s; the blade coating speed is 5-500 mm / s. -1 The annealing process involves heating at 50-200℃ for 5-30 minutes.

[0037] In some embodiments, the transparent conductive glass substrate is one of fluorine-doped tin dioxide, indium tin oxide, or a flexible substrate.

[0038] In some embodiments, the electron transport layer is an n-type inorganic semiconductor or an n-type organic semiconductor, including but not limited to at least one of the following: PCBM, TiO2, mesoporous TiO2, SnO2, ZnO or ZnO-ZnS, preferably TiO2, and the thickness of the electron transport layer is 10-200 nm, preferably 30-100 nm.

[0039] In some embodiments, the hole transport layer is a p-type inorganic or p-type organic semiconductor, and the material of the hole transport layer is one of 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene, poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine], poly(3-hexylthiophene-2,5-diyl), polyethylenedioxythiophene-poly(styrene sulfonate), and cuprous thiocyanate, preferably 2,2',7,7'-tetratetra[N,N-di(4-methoxyphenyl)amino]-9,9'-spirodifluorene (Spiro-OMeTAD), and the thickness of the hole transport layer is 20-200 nm, preferably 100-200 nm.

[0040] In some embodiments, the back electrode layer is a metal electrode or a carbon-based electrode, wherein the metal electrode is one of gold, silver, or aluminum, and the thickness of the metal electrode is 60-120 nm, preferably 80 nm.

[0041] The invention will now be described in detail through the following embodiments and comparative examples.

[0042] Example 1 S1: Preparation of perovskite light-absorbing layer precursor solution: Weigh appropriate amounts of CsI, MABr, MACl, PbI2, FAI and phenylbenzodiazole according to the required volume of perovskite precursor, add them to a DMF / DMSO mixed solvent with a volume ratio of 4:1, heat at 55 ℃ and stir for 2 h to completely dissolve them, thus preparing a perovskite precursor solution modified with phenylbenzodiazole. The amount of phenylbenzodiazole added is 0.5 mg / mL. Filter through an organic filter head to obtain the perovskite precursor solution containing phenylbenzodiazole. S2: The FTO glass was ultrasonically cleaned in glass cleaner, ultrapure water, acetone and anhydrous ethanol for 20 min in sequence, and then dried with nitrogen. The dried glass was then cleaned in a UV ozone cleaner for 15 min to remove organic matter from the glass surface and enhance the hydrophilicity of the surface. S3: TiO2 was selected as the electron transport layer for the perovskite solar cell: 850 μL of titanium tetrachloride solution was slowly and evenly added dropwise to 40 mL of ultrapure water containing frozen ice. The solution was then allowed to melt slowly. After the ice had completely melted, the solution was poured into a petri dish containing a glass substrate and placed in an oven for hydrothermal reaction at 75 °C for 50 min. After the hydrothermal reaction, the petri dish was removed from the oven, the glass substrate was rinsed with ultrapure water, and then transferred to a muffle furnace and kept at 150 °C for 30 min to dry the surface moisture. Finally, it was transferred to a glove box. S4: 25 μL of the perovskite precursor was dropped onto the FTO substrate covered with the electron transport layer TiO2, and spin-coated at 4000 rpm for 30 s. In the remaining 10 s, 200 μL of the antisolvent ethyl acetate was dropped, and then transferred to a hot stage at 130 ℃ for annealing for 10 min to prepare a perovskite film with a uniform and smooth surface and a thickness of 600 nm. S5: Take 25 μL of chlorobenzene solution of hole transport layer material Spiro-OMeTAD and drop it onto the 1D modified perovskite film of phenylbenzodiazole. Spin-coat at 4000 rpm for 30 s to prepare a hole transport layer with a smooth surface and a thickness of 150 nm. Then transfer it to a drying oven and oxidize it in air for 48 h. S6: A vapor-deposited layer with an area of ​​0.05 cm² 2 An Ag electrode with a thickness of 80 nm was used to obtain a 1D modified perovskite solar cell with phenylbenzodiazole.

[0043] The highest photoelectric conversion efficiency of this battery was tested to be 22.76%. Figure 3 As shown; Example 2

[0044] S1: Preparation of perovskite light-absorbing layer precursor solution: Weigh appropriate amounts of CsI, MABr, MACl, PbI2, FAI and naphthylbenzodiazole according to the required volume of perovskite precursor, add them to a DMF / DMSO mixed solvent with a volume ratio of 4:1, heat at 55 ℃ and stir for 2 h to completely dissolve them, thus preparing a perovskite precursor solution modified with naphthylbenzodiazole. The amount of naphthylbenzodiazole added is 0.2 mg / mL. Filter through an organic filter head to obtain the perovskite precursor solution containing naphthylbenzodiazole. S2: The FTO glass was ultrasonically cleaned in glass cleaner, ultrapure water, acetone and anhydrous ethanol for 20 min in sequence, and then dried with nitrogen. The dried glass was then cleaned in a UV ozone cleaner for 15 min to remove organic matter from the glass surface and enhance the hydrophilicity of the surface. S3: TiO2 was selected as the electron transport layer for the perovskite solar cell: 850 μL of titanium tetrachloride solution was slowly and evenly added dropwise to 40 mL of ultrapure water containing frozen ice. The solution was then allowed to melt slowly. After the ice had completely melted, the solution was poured into a petri dish containing a glass substrate and placed in an oven for hydrothermal reaction at 75 °C for 50 min. After the hydrothermal reaction, the petri dish was removed from the oven, the glass substrate was rinsed with ultrapure water, and then transferred to a muffle furnace and kept at 150 °C for 30 min to dry the surface moisture. Finally, it was transferred to a glove box. S4: 25 μL of the perovskite precursor was dropped onto the FTO substrate covered with the electron transport layer TiO2, and spin-coated at 4000 rpm for 30 s. In the remaining 10 s, 200 μL of the antisolvent ethyl acetate was dropped, and then transferred to a hot stage at 130 ℃ for annealing for 10 min to prepare a perovskite film with a uniform and smooth surface and a thickness of 600 nm. S5: Take 25 μL of chlorobenzene solution of hole transport layer material Spiro-OMeTAD and drop it onto the 1D modified perovskite film of naphthylbenzodiazole. Spin-coat at 4000 rpm for 30 s to prepare a hole transport layer with a smooth surface and a thickness of 150 nm. Then transfer it to a drying oven and oxidize it in air for 48 h. S6: A vapor-deposited layer with an area of ​​0.05 cm² 2 An Ag electrode with a thickness of 80 nm was used to obtain a 1D-modified perovskite solar cell with naphthylbenzodiazole.

[0045] The highest photoelectric conversion efficiency of this battery was tested to be 23.20%. Figure 4 As shown; Example 3

[0046] S1: Preparation of perovskite light-absorbing layer precursor solution: Weigh appropriate amounts of CsI, MABr, MACl, PbI2, FAI and anthraxylbenzodiazole according to the required volume of perovskite precursor, add them to a DMF / DMSO mixed solvent with a volume ratio of 4:1, heat at 55 ℃ and stir for 2 h to completely dissolve them, thus preparing a perovskite precursor solution modified with anthraxylbenzodiazole. The amount of anthraxylbenzodiazole added is 0.4 mg / mL. Filter through an organic filter head to obtain the perovskite precursor solution containing anthraxylbenzodiazole. S2: The FTO glass was ultrasonically cleaned in glass cleaner, ultrapure water, acetone and anhydrous ethanol for 20 min in sequence, and then dried with nitrogen. The dried glass was then cleaned in a UV ozone cleaner for 15 min to remove organic matter from the glass surface and enhance the hydrophilicity of the surface. S3: TiO2 was selected as the electron transport layer for the perovskite solar cell: 850 μL of titanium tetrachloride solution was slowly and evenly added dropwise to 40 mL of ultrapure water containing frozen ice. The solution was then allowed to melt slowly. After the ice had completely melted, the solution was poured into a petri dish containing a glass substrate and placed in an oven for hydrothermal reaction at 75 °C for 50 min. After the hydrothermal reaction, the petri dish was removed from the oven, the glass substrate was rinsed with ultrapure water, and then transferred to a muffle furnace and kept at 150 °C for 30 min to dry the surface moisture. Finally, it was transferred to a glove box. S4: 25 μL of the perovskite precursor was dropped onto the FTO substrate covered with the electron transport layer TiO2, and spin-coated at 4000 rpm for 30 s. In the remaining 10 s, 200 μL of the antisolvent ethyl acetate was dropped, and then transferred to a hot stage at 130 ℃ for annealing for 10 min to prepare a perovskite film with a uniform and smooth surface and a thickness of 600 nm. S5: Take 25 μL of chlorobenzene solution of hole transport layer material Spiro-OMeTAD and drop it onto the 1D modified perovskite film of anthracene benzodiazole. Spin-coat at 4000 rpm for 30 s to prepare a hole transport layer with a smooth surface and a thickness of 150 nm. Then transfer it to a drying oven and oxidize it in air for 48 h. S6: A vapor-deposited layer with an area of ​​0.05 cm² 2 An Ag electrode with a thickness of 80 nm was used to obtain a 1D modified perovskite solar cell with anthraxylbenzodiazole.

[0047] The highest photoelectric conversion efficiency of this battery was tested to be 23.14%. Figure 5 As shown; Example 4

[0048] S1: Preparation of perovskite light-absorbing layer precursor solution: Weigh appropriate amounts of CsI, MABr, MACl, PbI2, FAI and phenanthrenebenzodiazole according to the required volume of perovskite precursor, add them to a DMF / DMSO mixed solvent with a volume ratio of 4:1, heat at 55 ℃ and stir for 2 h to completely dissolve them, thus preparing a perovskite precursor solution modified with phenanthrenebenzodiazole. The amount of phenanthrenebenzodiazole added is 0.5 mg / mL. Filter through an organic filter head to obtain the perovskite precursor solution containing phenanthrenebenzodiazole. S2: The FTO glass was ultrasonically cleaned in glass cleaner, ultrapure water, acetone and anhydrous ethanol for 20 min in sequence, and then dried with nitrogen. The dried glass was then cleaned in a UV ozone cleaner for 15 min to remove organic matter from the glass surface and enhance the hydrophilicity of the surface. S3: TiO2 was selected as the electron transport layer for the perovskite solar cell: 850 μL of titanium tetrachloride solution was slowly and evenly added dropwise to 40 mL of ultrapure water containing frozen ice. The solution was then allowed to melt slowly. After the ice had completely melted, the solution was poured into a petri dish containing a glass substrate and placed in an oven for hydrothermal reaction at 75 °C for 50 min. After the hydrothermal reaction, the petri dish was removed from the oven, the glass substrate was rinsed with ultrapure water, and then transferred to a muffle furnace and kept at 150 °C for 30 min to dry the surface moisture. Finally, it was transferred to a glove box. S4: 25 μL of the perovskite precursor was dropped onto the FTO substrate covered with the electron transport layer TiO2, and spin-coated at 4000 rpm for 30 s. In the remaining 10 s, 200 μL of the antisolvent ethyl acetate was dropped, and then transferred to a hot stage at 130 ℃ for annealing for 10 min to prepare a perovskite film with a uniform and smooth surface and a thickness of 600 nm. S5: Take 25 μL of chlorobenzene solution of hole transport layer material Spiro-OMeTAD and drop it onto the 1D modified perovskite film of phenanthrenebenzodiazole. Spin-coat at 4000 rpm for 30 s to prepare a hole transport layer with a smooth surface and a thickness of 150 nm. Then transfer it to a drying oven and oxidize it in air for 48 h. S6: A vapor-deposited layer with an area of ​​0.05 cm² 2 An Ag electrode with a thickness of 80 nm was used to obtain a 1D modified perovskite solar cell with phenanthrenebenzodiazole.

[0049] The highest photoelectric conversion efficiency of this battery was tested to be 22.79%. Figure 6 As shown; Comparative Example 1 S1: Preparation of perovskite light-absorbing layer precursor solution: Weigh appropriate amounts of CsI, MABr, MACl, PbI2, and FAI according to the required volume of perovskite precursor, add DMF / DMSO mixed solvent with a volume ratio of 4:1, heat at 55 ℃ and stir for 2 h to completely dissolve it, then filter with an organic filter head to obtain the perovskite precursor solution. S2: The FTO glass was ultrasonically cleaned in glass cleaner, ultrapure water, acetone and anhydrous ethanol for 20 min in sequence, and then dried with nitrogen. The dried glass was then cleaned in a UV ozone cleaner for 15 min to remove organic matter from the glass surface and enhance the hydrophilicity of the surface. S3: TiO2 was selected as the electron transport layer for the perovskite solar cell: 850 μL of titanium tetrachloride solution was slowly and evenly added dropwise to 40 mL of ultrapure water containing frozen ice. The solution was then allowed to melt slowly. After the ice had completely melted, the solution was poured into a petri dish containing a glass substrate and placed in an oven for hydrothermal reaction at 75 °C for 50 min. After the hydrothermal reaction, the petri dish was removed from the oven, the glass substrate was rinsed with ultrapure water, and then transferred to a muffle furnace and kept at 150 °C for 30 min to dry the surface moisture. Finally, it was transferred to a glove box. S4: 25 μL of the perovskite precursor was dropped onto the FTO substrate covered with the electron transport layer TiO2, and spin-coated at 4000 rpm for 30 s. In the remaining 10 s, 200 μL of the antisolvent ethyl acetate was dropped, and then transferred to a hot stage at 130 °C for annealing for 10 min to prepare a perovskite film with a uniform and smooth surface and a thickness of 600 nm. S5: Take 25 μL of chlorobenzene solution of hole transport layer material Spiro-OMeTAD, drop it onto the perovskite film, spin coat it at 4000 rmp for 30 s to prepare a hole transport layer with a smooth surface and a thickness of 150 nm, and then transfer it to a drying oven to oxidize in air for 48 h. S6: A vapor-deposited layer with an area of ​​0.05 cm² 2 An Ag electrode with a thickness of 80 nm is used to obtain an unmodified perovskite solar cell.

[0050] The highest photoelectric conversion efficiency of this battery was tested to be 19.74%. Figure 7 As shown; Comparative Example 2 S1: Preparation of perovskite light-absorbing layer precursor solution: Weigh appropriate amounts of CsI, MABr, MACl, PbI2, and FAI according to the required volume of perovskite precursor, add DMF / DMSO mixed solvent with a volume ratio of 4:1, heat at 55 ℃ and stir for 2 h to completely dissolve it, then filter with an organic filter head to obtain the perovskite precursor solution. S2: The FTO glass was ultrasonically cleaned in glass cleaner, ultrapure water, acetone and anhydrous ethanol for 20 min in sequence, and then dried with nitrogen. The dried glass was then cleaned in a UV ozone cleaner for 15 min to remove organic matter from the glass surface and enhance the hydrophilicity of the surface. S3: TiO2 was selected as the electron transport layer for the perovskite solar cell: 850 μL of titanium tetrachloride solution was slowly and evenly added dropwise to 40 mL of ultrapure water containing frozen ice. The solution was then allowed to melt slowly. After the ice had completely melted, the solution was poured into a petri dish containing a glass substrate and placed in an oven for hydrothermal reaction at 75 °C for 50 min. After the hydrothermal reaction, the petri dish was removed from the oven, the glass substrate was rinsed with ultrapure water, and then transferred to a muffle furnace and kept at 150 °C for 30 min to dry the surface moisture. Finally, it was transferred to a glove box. S4: 25 μL of the perovskite precursor was dropped onto the FTO substrate covered with the electron transport layer TiO2, and spin-coated at 4000 rpm for 30 s. In the remaining 10 s, 200 μL of the antisolvent ethyl acetate was dropped, and then transferred to a hot stage at 130 ℃ for annealing for 10 min to prepare a perovskite film with a uniform and smooth surface and a thickness of 600 nm. S5: Preparation of 1D of phenylbenzodiazole: First, benzodiazole, K2CO3 and CH3CN are mixed and stirred. Then, aromatic hydrocarbon halides are added dropwise to obtain a mixed solution. The solution is stirred, extracted and dried to obtain 1D of phenylbenzodiazole. S6: Take an appropriate amount of phenylbenzodiazole 1D prepared in S5 and dissolve it in isopropanol to obtain a phenylbenzodiazole 1D solution with a concentration of 0.5 mg / mL. Spin-coat the solution onto the perovskite light-absorbing layer at a speed of 4000 rpm for 30 s. After the spin-coating is completed, heat it at 100℃ for 5 min and then anneal it to obtain a one-dimensional modified layer.

[0051] S7: Take 25 μL of chlorobenzene solution of hole transport layer material Spiro-OMeTAD, drop it onto the perovskite film, spin coat it at 4000 rmp for 30 s to prepare a hole transport layer with a smooth surface and a thickness of 150 nm, and then transfer it to a drying oven to oxidize in air for 48 h. S8: A vapor-deposited layer with an area of ​​0.05 cm² 2 An Ag electrode with a thickness of 80 nm was used to obtain a 1D interface-modified perovskite solar cell with phenylbenzodiazole.

[0052] The highest photoelectric conversion efficiency of this battery was tested to be 21.71%. Figure 8 As shown; Comparative Example 3 S1: Preparation of perovskite light-absorbing layer precursor solution: Weigh appropriate amounts of CsI, MABr, MACl, PbI2, FAI and n-octylbenzodiazole according to the required volume of perovskite precursor, add them to a DMF / DMSO mixed solvent with a volume ratio of 4:1, heat at 55 ℃ and stir for 2 h to completely dissolve them, thus preparing a perovskite precursor solution modified with n-octylbenzodiazole. The amount of n-octylbenzodiazole added is 0.5 mg / mL. Filter through an organic filter head to obtain the perovskite precursor solution containing n-octylbenzodiazole. S2: The FTO glass was ultrasonically cleaned in glass cleaner, ultrapure water, acetone and anhydrous ethanol for 20 min in sequence, and then dried with nitrogen. The dried glass was then cleaned in a UV ozone cleaner for 15 min to remove organic matter from the glass surface and enhance the hydrophilicity of the surface. S3: TiO2 was selected as the electron transport layer for the perovskite solar cell: 850 μL of titanium tetrachloride solution was slowly and evenly added dropwise to 40 mL of ultrapure water containing frozen ice. The solution was then allowed to melt slowly. After the ice had completely melted, the solution was poured into a petri dish containing a glass substrate and placed in an oven for hydrothermal reaction at 75 °C for 50 min. After the hydrothermal reaction, the petri dish was removed from the oven, the glass substrate was rinsed with ultrapure water, and then transferred to a muffle furnace and kept at 150 °C for 30 min to dry the surface moisture. Finally, it was transferred to a glove box. S4: 25 μL of the perovskite precursor was dropped onto the FTO substrate covered with the electron transport layer TiO2, and spin-coated at 4000 rpm for 30 s. In the remaining 10 s, 200 μL of the antisolvent ethyl acetate was dropped, and then transferred to a hot stage at 130 ℃ for annealing for 10 min to prepare a perovskite film with a uniform and smooth surface and a thickness of 600 nm. S5: Take 25 μL of chlorobenzene solution of hole transport layer material Spiro-OMeTAD and drop it onto the 1D modified perovskite film of n-octylbenzodiazole. Spin-coat at 4000 rpm for 30 s to prepare a hole transport layer with a smooth surface and a thickness of 150 nm. Then transfer it to a drying oven and oxidize it in air for 48 h. S6: A vapor-deposited layer with an area of ​​0.05 cm² 2 An Ag electrode with a thickness of 80 nm was used to obtain a 1D modified perovskite solar cell with n-octylbenzodiazole.

[0053] The highest photoelectric conversion efficiency of this battery was tested to be 20.68%. Figure 9 As shown.

[0054] By comparing the photoelectric conversion efficiency of the batteries obtained from the above examples and comparative examples, it can be seen that the photoelectric conversion efficiency of comparative examples 1-3 is significantly lower than that of examples 1-4. This indicates that the perovskite solar cells prepared using the aromatic hydrocarbon benzodiazole one-dimensional structure-perovskite composite thin film proposed in this invention in examples 1-4 have significantly improved photoelectric conversion efficiency compared to unmodified perovskite solar cells. Figure 10 The SEM image of the perovskite film modified with aromatic hydrocarbon benzodiazole proposed in this invention shows a one-dimensional structure at the perovskite grain boundaries. The presence of this one-dimensional structure can passivate excess PbI2 at the grain boundaries, reduce the influence of water and oxygen on the perovskite film, and improve its stability. Figure 11 The image shows an unmodified perovskite film with obvious PbI2 at the grain boundaries. The presence of PbI2 accelerates the decomposition of the perovskite film and is detrimental to its stability.

[0055] This invention describes preferred embodiments and their effects. However, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to include both the preferred embodiments and all changes and modifications falling within the scope of this invention.

[0056] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A solar cell, characterized in that, From bottom to top, it includes: a transparent conductive glass substrate, an electron transport layer, a perovskite light-absorbing layer, a hole transport layer, and a metal electrode; wherein, the perovskite light-absorbing layer is an aromatic hydrocarbon benzodiazole one-dimensional structure-perovskite composite film.

2. The solar cell according to claim 1, characterized in that, The general formula of the one-dimensional structure of the aromatic hydrocarbon benzodiazole is MBX. n Where M is an aromatic hydrocarbon benzodiazole and B is Pb 2+ Sn 2+ One or more of the following, where X is one or more of the halide ions.

3. The solar cell according to claim 1, characterized in that, The aromatic hydrocarbon benzodiazole is an aromatic hydrocarbon halide, wherein the aromatic hydrocarbon group includes phenyl, benzyl, phenethyl, naphthyl, anthraceneyl, and phenanthrene.

4. A method for preparing an aromatic hydrocarbon-based benzodiazole one-dimensional structure-perovskite composite thin film, characterized in that, The perovskite layer is passivated by bulk doping: Aromatic hydrocarbon benzodiazole is mixed and dissolved in a perovskite precursor solution to prepare a perovskite precursor solution modified with aromatic hydrocarbon benzodiazole. The perovskite precursor solution modified with aromatic hydrocarbon benzodiazole is coated on an electron transport layer and then heat-treated to obtain a perovskite light-absorbing layer.

5. The preparation method according to claim 4, characterized in that, The perovskite precursor is an AX and BX2 type compound, where A is CH3NH3. + HC(=NH)NH2 + Cs + 、Rb + K + One or more of them, where B is Pb 2+ Sn 2+ One or more of the following, where X is one or more of the halide ions.

6. The preparation method according to claim 5, characterized in that, The precursors of AX-type compounds are one or more of CH3NH3Br, HC(=NH)NH3I, and CsI; the precursors of BX2-type compounds are one or more of PbI2 and SnI2.

7. The preparation method according to claim 4, characterized in that, The solvent for the perovskite precursor solution is one or more of N,N-dimethylformamide, dimethyl sulfoxide, N-methylpyrrolidone, γ-butyrolactone, and 2-mercaptoethanol.

8. The preparation method according to claim 7, characterized in that, The concentration of the aromatic hydrocarbon benzodiazole molecule in the solvent is 0.5-5 mg / mL.

9. The preparation method according to claim 7, characterized in that, The solution temperature for mixing and dissolving the aromatic hydrocarbon benzodiazole is 30-100℃, and the stirring time is 0.5-50 h.

10. A method for preparing a solar cell, characterized in that, include: Aromatic hydrocarbon benzodiazoles were mixed and dissolved in a perovskite precursor solution to prepare a perovskite precursor solution modified with aromatic hydrocarbon benzodiazoles. Pre-treated substrate consisting of conductive glass / electron transport layer: The prepared perovskite precursor solution containing aromatic hydrocarbon benzodiazole was coated onto the substrate and then annealed to obtain an aromatic hydrocarbon benzodiazole one-dimensional structure-perovskite composite thin film light-absorbing layer. A hole transport layer is formed on the surface of the light-absorbing layer; A back electrode layer is formed on the surface of the hole transport layer.

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