Interface modification method of perovskite thin film, perovskite solar cell and preparation method of perovskite solar cell

Abstract

The invention provides an interface modification method of a perovskite thin film, a perovskite solar cell and a preparation method of the perovskite solar cell, and belongs to the technical field of perovskite solar cells. The interface modification method comprises the following steps: S1, dissolving trimesoyl chloride in a solvent to obtain an interface modification material solution; s2, coating a perovskite thin film with the interface modification material solution to obtain an interface modification layer wet film; and S3, carrying out heat treatment on the interface modification layer wet film to obtain the interface modification layer. According to the interface modification method, an interface modification layer with reactivity is introduced between a perovskite thin film and a transmission layer, the interface modification layer can react with formamidine ions on the surface of the perovskite thin film, a polymer network is formed on the surface of the perovskite thin film, corrosion of water, oxygen and an electrode to the perovskite thin film is resisted, and the performance of the perovskite thin film is improved. Therefore, the stability of the perovskite solar cell is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of perovskite solar cells, and particularly relates to an interface modification method for perovskite thin films, a perovskite solar cell, and a preparation method thereof. Background Art

[0002] Due to its high photoelectric conversion performance and low-cost manufacturing process, perovskite solar cells have become a research hotspot in the photovoltaic field in recent years. However, the interface defect problem of the perovskite thin film itself significantly affects the stability and photoelectric conversion efficiency of its optoelectronic devices. There are usually problems of energy level mismatch, grain boundary defects, and interface instability at the interfaces between the perovskite thin film and the electron transport layer and the hole transport layer. These defects will lead to increased carrier recombination and increased interface impedance, thereby reducing the conversion efficiency of perovskite solar cells. In addition, the uncoordinated ions and polar molecules at the above-mentioned interfaces are also easily eroded by water and oxygen in the environment, further accelerating the decay of device performance. Therefore, interface modification technology has become an important research direction for improving the performance of perovskite solar cells.

[0003] Existing research shows that by introducing an interface modification material between the perovskite thin film and the transport layer or chemically passivating the surface of the perovskite thin film, interface defects can be effectively reduced, interface stability can be improved, and carrier transport efficiency can be enhanced. By reasonably designing the interface modification strategy, not only can carrier recombination be inhibited, but also the moisture resistance and oxidation resistance of the device can be enhanced, and the device life can be extended. Therefore, developing a new perovskite interface modification method has important scientific research and practical application values. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems in the related art to some extent. For this purpose, an embodiment of the present invention provides an interface modification method for perovskite thin films, a perovskite solar cell, and a preparation method thereof. The interface modification method introduces an interface modification layer between the perovskite thin film and the transport layer, and the interface modification layer can protect the perovskite thin film, resist the corrosion of water, oxygen, and the electrode to the perovskite thin film, and improve the stability of the perovskite solar cell.

[0005] An embodiment of the present invention provides an interface modification method for perovskite thin films, including the following steps:

[0006] S1. Dissolve trimesoyl chloride in a solvent to obtain an interface modification material solution;

[0007] S2. Coat the interface modification material solution on the perovskite thin film to obtain a wet film of the interface modification layer;

[0008] S3. Heat-treat the wet film of the interface modification layer to obtain an interface modification layer.

[0009] The advantages and technical effects brought by the interface modification method of the embodiments of the present invention are as follows:

[0010] (1) By coating a solution of an interface modification material with trimellitic acid chloride as the active ingredient, an interface modification layer capable of reacting with the components of the perovskite thin film is formed on the surface of the prepared perovskite thin film, and the material of the interface modification layer is trimellitic acid chloride.

[0011] (2) As an interface modification material, trimellitic acid chloride can react with perovskite molecules. Specifically, the formyl chloride groups on the benzene ring in trimellitic acid chloride can undergo a condensation reaction with the amino groups in the formamidinium ions of perovskite. At the same time, since there are three formyl chloride groups on trimellitic acid chloride and two amino groups in the formamidinium ions of perovskite, the multi-site reaction can form a polymer network on the surface of the perovskite thin film, protecting the perovskite thin film and reducing the corrosion of the perovskite thin film by water, oxygen, and the electrodes, thereby effectively improving the stability of the perovskite solar cell.

[0012] In some embodiments, in the solution of the interface modification material, the concentration of trimellitic acid chloride is 0.01 - 2 mg / mL.

[0013] In some embodiments, the solvent is isopropyl alcohol and / or trifluoroethanol.

[0014] In some embodiments, the coating amount of the interface modification material solution is 80 - 150 μL of the interface modification material solution per square centimeter of the perovskite thin film.

[0015] In some embodiments, the coating method of the interface modification material solution is spin coating, dip coating, blade coating, or slot die coating.

[0016] In some embodiments, the holding temperature of the heat treatment is 80 - 120 °C, and the holding time of the heat treatment is 5 - 30 min.

[0017] In addition, the embodiments of the present invention provide a perovskite solar cell, in which an interface modification layer is provided between the perovskite thin film and the electron transport layer, or an interface modification layer is provided between the perovskite thin film and the hole transport layer, and the material of the interface modification layer is trimellitic acid chloride.

[0018] The advantages and technical effects brought by the perovskite solar cell of the embodiments of the present invention are as follows:

[0019] (1) The perovskite solar cell of the embodiments of the present invention introduces an interface modification layer capable of reacting with the components of the perovskite thin film between the perovskite thin film and the transport layer, and the material of the interface modification layer is trimellitic acid chloride.

[0020] (2) As an interfacial modification material, trimellitic acid trichloride can react with perovskite molecules. Specifically, the formyl chloride groups on the benzene ring of trimellitic acid trichloride can undergo a condensation reaction with the amino groups in the formamidinium ions of perovskite. At the same time, since there are three formyl chloride groups on trimellitic acid trichloride and two amino groups in the formamidinium ions of perovskite, the multi-site reaction can form a polymer network on the surface of the perovskite film, protecting the perovskite film and reducing the corrosion of the perovskite film by water, oxygen, and the electrodes, thereby effectively improving the stability of the perovskite solar cell.

[0021] In addition, the embodiment of the present invention also provides a preparation method of a perovskite solar cell. The preparation method uses the following interfacial modification method to prepare the interfacial modification layer, and the interfacial modification method includes the following steps:

[0022] S1. Dissolve trimellitic acid trichloride in a solvent to obtain an interfacial modification material solution;

[0023] S2. Coat the interfacial modification material solution on the perovskite film to obtain a wet film of the interfacial modification layer;

[0024] S3. Heat-treat the wet film of the interfacial modification layer to obtain the interfacial modification layer.

[0025] The advantages and technical effects brought by the preparation method of the perovskite solar cell in the embodiment of the present invention are as follows:

[0026] Since the interfacial modification method of the embodiment of the present invention is used to prepare the interfacial modification layer, an interfacial modification layer made of trimellitic acid trichloride is introduced between the perovskite film and the electron transport layer or the hole transport layer. Therefore, the preparation method of the perovskite solar cell in the embodiment of the present invention can effectively improve the photoelectric conversion efficiency and stability of the battery.

[0027] In some embodiments, in the interfacial modification material solution, the concentration of trimellitic acid trichloride is 0.01 - 2 mg / mL.

[0028] In some embodiments, the coating amount of the interfacial modification material solution is 80 - 150 μL of the interfacial modification material solution per square centimeter of the perovskite film. Description of the Drawings

[0029] Figure 1 is the structural formula of trimellitic acid trichloride.

[0030] Figure 2 is a schematic diagram of the condensation reaction of trimellitic acid trichloride with diamine in the perovskite component.

[0031] Figure 3 is the current-voltage curve of the perovskite solar cells before and after aging in Example 1 and Comparative Example 1. Detailed Embodiments

[0032] Embodiments of the present invention will be described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0033] An embodiment of the present invention provides a method for interfacial modification of a perovskite thin film, comprising the following steps:

[0034] S1. Dissolve trimesoyl chloride (structural formula as Figure 1 shown) in a solvent to obtain an interfacial modification material solution;

[0035] S2. Coat the interfacial modification material solution on the perovskite thin film to obtain a wet film of the interfacial modification layer;

[0036] S3. Heat-treat the wet film of the interfacial modification layer to obtain an interfacial modification layer.

[0037] The interfacial modification method of the embodiment of the present invention forms an interfacial modification layer capable of reacting with the components of the perovskite thin film on the surface of the prepared perovskite thin film by coating an interfacial modification material solution with trimesoyl chloride as the active ingredient. The material of the interfacial modification layer is trimesoyl chloride. As an interfacial modification material, trimesoyl chloride can react with perovskite molecules. Specifically, the formyl chloride groups on the benzene ring of trimesoyl chloride can undergo a condensation reaction with the amino groups in the formamidinium ions of perovskite (as Figure 2 shown). At the same time, since there are three formyl chloride groups on trimesoyl chloride and two amino groups in the formamidinium ions of perovskite, the multi-site reaction can form a polymer network on the surface of the perovskite thin film, protecting the perovskite thin film and reducing the corrosion of the perovskite thin film by water, oxygen and electrodes, thereby effectively improving the stability of the perovskite solar cell.

[0038] In some embodiments, in the interfacial modification material solution, the concentration of trimesoyl chloride is 0.01 - 2 mg / mL, such as 0.01 mg / mL, 0.05 mg / mL, 0.1 mg / mL, 0.5 mg / mL, 1 mg / mL, 2 mg / mL, etc. When the concentration of trimesoyl chloride in the interfacial modification material solution is too low, the thickness of the interfacial modification layer obtained with the same coating amount of the interfacial modification material solution is too small, which is not conducive to improving the photoelectric conversion efficiency and stability of the perovskite solar cell. When the concentration of trimesoyl chloride in the interfacial modification material solution is too high, it is not conducive to the uniform coating of the interfacial modification material solution, and it is also not conducive to improving the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0039] In some embodiments, the solvent is isopropyl alcohol and / or trifluoroethanol. The above-mentioned alcohol solvents have good solubility in trimesoyl chloride, and are more likely to evaporate and be removed during the heat treatment of the wet film of the interfacial modification layer after the coating of the interfacial modification material solution.

[0040] In some embodiments, the coating amount of the interfacial modification material solution is 80 - 150 μL of the interfacial modification material solution per square centimeter of the perovskite film coated. When the coating amount of the interfacial modification material solution is too small, the thickness of the obtained interfacial modification layer is too small, which is not conducive to improving the photoelectric conversion efficiency and stability of the perovskite solar cell. When the coating amount of the interfacial modification material solution is too large, cracks are likely to appear in the perovskite film, which will reduce the photoelectric conversion efficiency and stability of the perovskite solar cell.

[0041] In some embodiments, the coating method of the interfacial modification material solution is spin coating, dip coating, blade coating, slot coating, etc. The above-listed coating methods can uniformly coat the interfacial modification material solution on the surface of the perovskite film.

[0042] In some embodiments, the holding temperature of the heat treatment is 80 - 120 °C, such as 80 °C, 90 °C, 100 °C, 110 °C, 120 °C, etc., and the holding time of the heat treatment is 5 - 30 min, such as 5 min, 10 min, 15 min, 20 min, 25 min, 30 min, etc. When the holding temperature of the heat treatment is too low or the holding time is too short, it is not conducive to quickly removing the solvent in the wet film of the interfacial modification layer to obtain the interfacial modification layer. When the holding temperature of the heat treatment is too high or the holding time is too long, it is not conducive to cost reduction and efficiency improvement.

[0043] In addition, an embodiment of the present invention provides a perovskite solar cell, in which an interfacial modification layer is provided between the perovskite film and the electron transport layer, or an interfacial modification layer is provided between the perovskite film and the hole transport layer, and the material of the interfacial modification layer is trimesoyl chloride.

[0044] The perovskite solar cell of the embodiment of the present invention introduces an interfacial modification layer that can react with the components of the perovskite film between the perovskite film and the transport layer, and the material of the interfacial modification layer is trimesoyl chloride. As an interfacial modification material, trimesoyl chloride can react with perovskite molecules. Specifically, the formyl chloride groups on the benzene ring of trimesoyl chloride can undergo a condensation reaction with the amino group in the formamidinium ion of perovskite. At the same time, since there are three formyl chloride groups on trimesoyl chloride and two amino groups in the formamidinium ion of perovskite, the multi-site reaction can form a polymer network on the surface of the perovskite film to protect the perovskite film and reduce the corrosion of water, oxygen and the electrode on the perovskite film, thereby effectively improving the stability of the perovskite solar cell.

[0045] It should be noted that the structure of a conventional perovskite solar cell is a conductive substrate / electron transport layer / perovskite thin film / hole transport layer / optionally a buffer layer / electrode. Therefore, the structure of the perovskite solar cell prepared by the interface modification method of the embodiments of the present invention is a conductive substrate / electron transport layer / perovskite thin film / interface modification layer / hole transport layer / optionally a buffer layer / electrode, and an interface modification layer is introduced between the perovskite thin film and the hole transport layer. The structure of a reverse perovskite solar cell is a conductive substrate / hole transport layer / perovskite thin film / electron transport layer / optionally a buffer layer / electrode. Therefore, the structure of the perovskite solar cell prepared by the interface modification method of the embodiments of the present invention is a conductive substrate / hole transport layer / perovskite thin film / interface modification layer / electron transport layer / optionally a buffer layer / electrode, and an interface modification layer is introduced between the perovskite thin film and the electron transport layer.

[0046] In addition, the embodiments of the present invention also provide a preparation method of a perovskite solar cell. The preparation method uses the following interface modification method to prepare the interface modification layer. The interface modification method includes the following steps:

[0047] S1. Dissolve trimesoyl chloride in a solvent to obtain an interface modification material solution;

[0048] S2. Coat the interface modification material solution on the perovskite thin film to obtain a wet film of the interface modification layer;

[0049] S3. Heat-treat the wet film of the interface modification layer to obtain the interface modification layer.

[0050] Since the interface modification method of the embodiments of the present invention is used to prepare the interface modification layer, an interface modification layer made of trimesoyl chloride is introduced between the perovskite thin film and the electron transport layer or the hole transport layer. Therefore, the preparation method of the perovskite solar cell of the embodiments of the present invention can effectively improve the photoelectric conversion efficiency and stability of the battery.

[0051] In some embodiments, in the interface modification material solution, the concentration of trimesoyl chloride is 0.01 - 2 mg / mL.

[0052] In some embodiments, the coating amount of the interface modification material solution is 80 - 150 μL of the interface modification material solution per square centimeter of the perovskite thin film.

[0053] The present invention will be described in detail below with reference to the embodiments and the drawings.

[0054] Example 1

[0055] (1) Place (1×1 cm 2)The ITO conductive glass was cleaned, and a nickel oxide thin film with a thickness of 10 nm was magnetron sputtered on the ITO conductive glass as a hole transport layer.

[0056] (2) Lead iodide, lead bromide, formamidinium iodide, and cesium iodide with a molar ratio of 0.85:0.15:0.78:0.22 were dissolved in a mixed solution of DMF and DMSO with a volume ratio of 4:1 and mixed evenly to obtain a perovskite precursor solution. The perovskite precursor solution was spin-coated on the surface of the nickel oxide thin film by a one-step method at a rotation speed of 3000 rpm for 30 s. Anti-solvent ethyl acetate was dropped at the 20th second of spin-coating to obtain a perovskite wet film, and then annealed at 100 °C for 20 min to obtain a perovskite thin film with a thickness of 600 nm.

[0057] (3) Trimellitic acid trichloride was dissolved in isopropanol to obtain an interfacial modification material solution with a concentration of 0.5 mg / mL. Then, according to the dosage of coating 80 μL of the interfacial modification material solution per square centimeter of the perovskite thin film, the interfacial modification material solution was spin-coated on the surface of the perovskite thin film at a rotation speed of 4000 rpm for 30 s to obtain an interfacial modification layer wet film, and then heat-treated at 100 °C for 10 min to obtain an interfacial modification layer.

[0058] (4) The sample prepared above was placed in a vacuum thermal evaporation chamber. When the pressure in the evaporation chamber was lower than 1×10 -5 Pa, evaporation of C 60 started at an evaporation rate of 0.2 nm / s and was deposited on the perovskite thin film to obtain a C 60 layer with a thickness of 30 nm; then, BCP was evaporated at an evaporation rate of 0.1 nm / s and deposited on the C 60 layer to obtain a BCP layer with a thickness of 3 nm; finally, Cu was evaporated at an evaporation rate of 0.5 nm / s and deposited on the BCP layer to obtain a Cu electrode layer with a thickness of 100 nm. Thus, a perovskite solar cell was obtained.

[0059] Example 2

[0060] This example has the same method as Example 1, except that in step (3), the concentration of trimellitic acid trichloride in the interfacial modification material solution is 1 mg / mL.

[0061] Example 3

[0062] This example has the same method as Example 1, except that in step (3), the concentration of trimellitic acid trichloride in the interfacial modification material solution is 2 mg / mL.

[0063] Example 4

[0064] This example has the same method as Example 1, except that in step (3), the solvent used to prepare the interfacial modification material solution is trifluoroethanol.

[0065] Comparative Example 1

[0066] This comparative example is the same as the method of Example 1, except that step (3) is omitted, and the resulting perovskite solar cell lacks an interfacial modification layer.

[0067] Performance Test

[0068] The perovskite solar cells obtained in each of the examples and comparative examples were subjected to photoelectric conversion efficiency tests. The test results are shown in Table 1. Then, they were stored in a glove box for 60 days of aging, and the photoelectric conversion efficiency tests are shown in Table 1. The current-voltage curves of the perovskite solar cells of Example 1 and Comparative Example 1 before and after aging are as Figure 3 shown.

[0069] Table 1. Photoelectric conversion efficiencies of the perovskite solar cells of each example and comparative example

[0070]

[0071] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc. 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 invention. 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. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0072] Although the embodiments of the present invention 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 invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for interface modification of a perovskite film, characterized in that: The following steps are involved: S1. dissolving trimesoyl chloride in a solvent to obtain an interface modification material solution; S2. coating the interface modification material solution on the perovskite film to obtain an interface modification layer wet film; S3. heat-treating the wet film of the interface modification layer to obtain an interface modification layer.

2. The interface modification method according to claim 1, characterized in that: In the interface modification material solution, the concentration of trimesoyl chloride is 0.01-2 mg / mL.

3. The interface modification method according to claim 1 or 2, characterized in that: The solvent is isopropanol and / or trifluoroethanol.

4. The interface modification method according to claim 1 or 2, characterized in that: The coating amount of the interface modification material solution is 80-150 μL of the interface modification material solution per square centimeter of the perovskite film.

5. The interface modification method according to claim 1 or 2, characterized in that: The interface modification material solution is coated by spin coating, dip coating, scraping coating or slit coating.

6. The interface modification method according to claim 1 or 2, characterized in that: The heat treatment is carried out at a holding temperature of 80-120° C. and for a holding time of 5-30 min.

7. A perovskite solar cell, characterized in that: An interface modification layer is arranged between the perovskite film and the electron transport layer, or an interface modification layer is arranged between the perovskite film and the hole transport layer, and the material of the interface modification layer is trimesoyl chloride.

8. The method for preparing a perovskite solar cell according to claim 7, characterized in that: The interface modification layer is prepared by the following interface modification method, which comprises the following steps: S1. dissolving trimesoyl chloride in a solvent to obtain an interface modification material solution; S2. coating the interface modification material solution on the perovskite film to obtain an interface modification layer wet film; S3. heat-treating the wet film of the interface modification layer to obtain the interface modification layer.

9. The preparation method according to claim 8, characterized in that: In the interface modification material solution, the concentration of trimesoyl chloride is 0.01-2 mg / mL.

10. The preparation method according to claim 8, characterized in that: The coating amount of the interface modification material solution is 80-150 μL of the interface modification material solution per square centimeter of the perovskite film.

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