Perovskite solar cell and preparation method thereof

Abstract

The application discloses a perovskite solar cell and a preparation method thereof. The composition of the perovskite solar cell comprises a glass electrode, an electron transport layer, a sensitized layer, a perovskite film, a hole transport layer and a metal electrode which are sequentially arranged, and the sensitized layer contains stannous ions. The preparation method of the perovskite solar cell comprises the following steps: 1) immersing the glass electrode on which the electron transport layer is deposited into a soluble stannous salt solution for soaking, and then taking out and drying to form the sensitized layer on the electron transport layer; 2) depositing the perovskite material on the sensitized layer to form the perovskite film, and then sequentially depositing the hole transport layer and the metal electrode on the perovskite film to obtain the perovskite solar cell. The perovskite film in the perovskite solar cell has good uniformity and compactness, and the perovskite solar cell has high photoelectric conversion efficiency. The preparation method is simple, and is suitable for large-scale popularization and application.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cell technology, specifically to a perovskite solar cell and its fabrication method. Background Technology

[0002] Perovskite solar cells are a type of solar cell that uses perovskite-type organometal halide semiconductors as light-absorbing materials. Belonging to the third generation of solar cells, they have attracted worldwide attention due to their advantages such as long carrier diffusion length, high photoelectric conversion efficiency, and simple fabrication process. However, the poor uniformity and density of large-area perovskite thin films prepared using existing processes directly affect the photoelectric conversion efficiency of perovskite solar cells, limiting their practical applications.

[0003] Therefore, it is of great significance to develop a perovskite solar cell with good uniformity and density of perovskite thin film and high photoelectric conversion efficiency. Summary of the Invention

[0004] The purpose of this invention is to provide a perovskite solar cell and its preparation method.

[0005] The technical solution adopted in this invention is:

[0006] A perovskite solar cell comprises a glass electrode, an electron transport layer, a sensitization layer, a perovskite thin film, a hole transport layer, and a metal electrode arranged sequentially; the sensitization layer contains tin ions.

[0007] Preferably, the electron transport layer is one of a TiO2 layer or a SnO2 layer.

[0008] Preferably, the perovskite thin film is prepared by the following method:

[0009] 1) Deposit PbI2 solution onto the sensitized layer and anneal at 80℃~100℃ for 5min~15min to form a PbI2 thin film;

[0010] 2) Methylamine iodide (MAI) solution was deposited on a PbI2 film and annealed at 110℃~130℃ for 10min~30min.

[0011] The perovskite thin film is thus obtained.

[0012] Containing tin ions (Sn) 2+ Sn in the sensitization layer 2+ It can react with Pb in PbI2 solution 2+ Forming chemical bonds and affecting Pb 2 +Adsorption can make the PbI2 solution spread more evenly on the sensitized layer, and the uniformity of the PbI2 film is also improved. This can further improve the uniformity and density of the perovskite film on a large-area substrate, and ultimately significantly improve the photoelectric conversion efficiency of the prepared perovskite solar cell.

[0013] Preferably, the hole transport layer is composed of 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)9,9′-spirodifluorene (Spiro-OMeTAD).

[0014] Preferably, the metal electrode is composed of at least one of gold, silver, and copper.

[0015] Preferably, the thickness of the metal electrode is 60 nm to 100 nm.

[0016] A method for fabricating a perovskite solar cell as described above includes the following steps:

[0017] 1) Immerse the glass electrode with the electron transport layer deposited in a soluble stannous salt solution, then remove and dry it to form a sensitized layer on the electron transport layer;

[0018] 2) Perovskite material is deposited on the sensitization layer to form a perovskite thin film, and then a hole transport layer and a metal electrode are deposited sequentially on the perovskite thin film to obtain a perovskite solar cell.

[0019] Preferably, the soluble stannous salt in the soluble stannous salt solution in step 1) is at least one of stannous fluoride, stannous chloride, stannous acetate, stannous sulfate, stannous tartrate, and stannous gluconate.

[0020] Preferably, the solvent in the soluble stannous salt solution in step 1) is at least one of water, ethanol, and isopropanol.

[0021] Preferably, the concentration of the soluble stannous salt solution in step 1) is 9 mg / mL to 15 mg / mL.

[0022] Preferably, the soaking time in step 1) is 3 min to 5 min.

[0023] Preferably, the drying in step 1) is carried out at room temperature (25℃±5℃) for 5 min to 20 min.

[0024] Preferably, the hole transport layer preparation process in step 2) includes the following steps: dispersing the hole transport layer material with a solvent, then spin-coating it onto a perovskite film under nitrogen protection, and allowing it to stand to obtain the hole transport layer.

[0025] The beneficial effects of the present invention are: the perovskite thin film in the perovskite solar cell of the present invention has good uniformity and density, high photoelectric conversion efficiency, and its preparation method is simple, making it suitable for large-scale promotion and application. Attached Figure Description

[0026] Figure 1 This is a flowchart illustrating the fabrication process of the sensitization layer and perovskite thin film in the perovskite solar cell of the embodiment.

[0027] Figure 2 The image shows a SEM image of the perovskite thin film in the perovskite solar cell of the example.

[0028] Figure 3 This is a SEM image of the perovskite thin film in a comparative perovskite solar cell. Detailed Implementation

[0029] The present invention will be further explained and described below with reference to specific embodiments.

[0030] Example:

[0031] A perovskite solar cell is fabricated using the following steps (the fabrication flow chart of the sensitization layer and the perovskite thin film is shown below). Figure 1 As shown):

[0032] 1) The FTO conductive glass was ultrasonically cleaned for 15 minutes each with soapy water, deionized water, anhydrous ethanol and acetone, respectively, and then irradiated with ultraviolet ozone for 30 minutes. TiO2 paste (Dyesol-18NR-T) and anhydrous ethanol were mixed evenly at a mass ratio of 2:7 to prepare TiO2 dispersion. The TiO2 dispersion was then dropped onto the FTO conductive glass, spin-coated at 1500 rpm for 10 seconds, dried at 150℃ for 15 minutes, and sintered at 550℃ for 60 minutes to form an electron transport layer.

[0033] 2) Add 250 mg of SnCl2 powder to 25 mL of ethanol and stir well to make SnCl2 solution. Then put the SnCl2 solution into a glove box filled with nitrogen and let it stand. Then immerse the FTO conductive glass with the electron transport layer deposited in the SnCl2 solution for 5 min. After removing the FTO conductive glass from the SnCl2 solution, let it stand in the glove box for 15 min to form a sensitized layer.

[0034] 3) PbI2 solution was dropped onto the sensitized layer, spin-coated at 3000 rpm for 20 s, and then annealed at 90 °C for 10 min to form a PbI2 film. MAI solution was then dropped onto the PbI2 film, spin-coated at 4000 rpm for 20 s, and then annealed at 110 °C for 10 min to form a perovskite film.

[0035] 4) Dissolve 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)9,9′-spirodifluorene in chlorobenzene, then drop it onto a perovskite film, spin-coat at 4000 rpm for 30 s, and then let it stand in a glove box filled with nitrogen for 24 h to form a hole transport layer.

[0036] 5) Silver is vacuum thermally evaporated onto the hole transport layer to form a silver electrode with a thickness of 80 nm, thus obtaining a perovskite solar cell.

[0037] Comparative example:

[0038] A perovskite solar cell, the preparation method of which includes the following steps:

[0039] 1) The FTO conductive glass was ultrasonically cleaned for 15 minutes each with soapy water, deionized water, anhydrous ethanol and acetone, respectively, and then irradiated with ultraviolet ozone for 30 minutes. TiO2 paste (Dyesol-18NR-T) and anhydrous ethanol were mixed evenly at a mass ratio of 2:7 to prepare TiO2 dispersion. The TiO2 dispersion was then dropped onto the FTO conductive glass, spin-coated at 1500 rpm for 10 seconds, dried at 150℃ for 15 minutes, and sintered at 550℃ for 60 minutes to form an electron transport layer.

[0040] 2) PbI2 solution was dropped onto the electron transport layer, spin-coated at 3000 rpm for 20 s, and then annealed at 90 °C for 10 min to form a PbI2 film. MAI solution was then dropped onto the PbI2 film, spin-coated at 4000 rpm for 20 s, and then annealed at 110 °C for 10 min to form a perovskite film.

[0041] 3) Dissolve 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)9,9′-spirodifluorene in chlorobenzene, then drop it onto a perovskite film, spin-coat at 4000 rpm for 30 seconds, and then let it stand in a glove box filled with nitrogen for 24 hours to form a hole transport layer.

[0042] 4) Silver is vacuum thermally evaporated onto the hole transport layer to form a silver electrode with a thickness of 80 nm, thus obtaining a perovskite solar cell.

[0043] Performance testing:

[0044] Scanning electron microscope (SEM) images of the perovskite thin films in the examples and comparative perovskite solar cells are shown below. Figure 2 and Figure 3 As shown.

[0045] Depend on Figure 2 and Figure 3It can be seen that the perovskite film in the perovskite solar cell of the embodiment has much better uniformity and density than the perovskite film in the comparative perovskite solar cell. This shows that by setting a sensitizing layer containing tin ions in the perovskite solar cell, the uniformity and density of the formed perovskite film can indeed be significantly improved, and ultimately the photoelectric conversion efficiency of the perovskite solar cell can be significantly improved.

[0046] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A method for fabricating a perovskite solar cell, characterized in that, Includes the following steps: 1) The FTO conductive glass was ultrasonically cleaned for 15 min each with soapy water, deionized water, anhydrous ethanol and acetone, respectively, and then irradiated with ultraviolet ozone for 30 min. TiO2 paste and anhydrous ethanol were mixed evenly at a mass ratio of 2:7 to prepare TiO2 dispersion. The TiO2 paste was Dyesol-18NR-T. The TiO2 dispersion was then dropped onto the FTO conductive glass, spin-coated at 1500 rpm for 10 s, dried at 150℃ for 15 min, and sintered at 550℃ for 60 min to form an electron transport layer. 2) Add 250 mg of SnCl2 powder to 25 mL of ethanol and stir well to make SnCl2 solution. Then place the SnCl2 solution in a glove box filled with nitrogen and let it stand. Then immerse the FTO conductive glass with the electron transport layer deposited in the SnCl2 solution for 5 min. After removing the FTO conductive glass from the SnCl2 solution, let it stand in the glove box for 15 min to form a sensitized layer. 3) PbI2 solution was dropped onto the sensitized layer, spin-coated at 3000 rpm for 20 s, and then annealed at 90 °C for 10 min to form a PbI2 film. MAI solution was then dropped onto the PbI2 film, spin-coated at 4000 rpm for 20 s, and then annealed at 110 °C for 10 min to form a perovskite film. 4) Dissolve 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)9,9′-spirodifluorene in chlorobenzene, then drop it onto a perovskite film, spin-coat at 4000 rpm for 30 seconds, and then let it stand in a glove box filled with nitrogen for 24 hours to form a hole transport layer. 5) Silver is vacuum thermally evaporated onto the hole transport layer to form a silver electrode with a thickness of 80 nm, thus obtaining a perovskite solar cell.

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