Perovskite solar cell containing ferroelectric two-dimensional perovskite material and method of making the same

Abstract

The application relates to the field of solar cells, in particular to a perovskite solar cell and a preparation method thereof, which comprises the following steps: after the conductive substrate is treated, a SAM solution is spin-coated on the conductive substrate, annealing treatment is conducted, and a SAM hole transport layer is obtained; a two-dimensional perovskite precursor solution is spin-coated on the SAM hole transport layer, annealing treatment is conducted, and a two-dimensional perovskite layer is obtained; wherein the two-dimensional perovskite layer has ferroelectricity; a three-dimensional perovskite precursor solution is spin-coated on the two-dimensional perovskite layer, annealing treatment is conducted, and a three-dimensional perovskite light absorption layer is obtained; a PCBM solution is spin-coated on the three-dimensional perovskite light absorption layer, annealing treatment is conducted, and a PCBM electron transport layer is obtained; a BCP solution is spin-coated on the PCBM electron transport layer, annealing treatment is conducted, and a BCP electron modification layer is obtained; an electrode layer is additionally arranged on the BCP electron modification layer, and a perovskite solar cell is obtained. The perovskite solar cell prepared by the application has higher photoelectric conversion efficiency and stability.

Description

Technical Field

[0001] This invention relates to the field of perovskite solar cell technology, and more specifically, to a perovskite solar cell containing ferroelectric two-dimensional perovskite material and its preparation method. Background Technology

[0002] Solar energy is one of the most abundant renewable energy sources on Earth, and solar cell technology, which can directly convert sunlight into electricity, provides a green approach to solving environmental and climate problems. Among these, perovskite solar cells (PSCs) have developed rapidly and are widely recognized as a new generation of photovoltaic devices. Since their initial report in 2009, the photoelectric conversion efficiency (PCE) of perovskite solar cells has rapidly increased from 3.8% to 25.7%, making it the fastest-growing solar cell technology to date. Furthermore, the lightweight, flexible, simple fabrication process, low-temperature processing, and large-area printing capabilities of perovskite solar cells make them ideal for manufacturing flexible devices. Compared to rigid solar cells, flexible solar cells are lightweight, bendable, and easy to transport and install. Therefore, they can be applied to wearable power generation devices, large-area integrated photovoltaic devices, and have the potential for high-altitude installation. With the development of rigid devices, the PCE of flexible perovskite solar cells has also reached 23.84%.

[0003] However, despite the significant efficiency improvements in flexible perovskite solar cells in a short period, their commercial development remains hampered by insufficient stability. Due to factors such as the poor ductility of perovskite solar cell electrode materials, the brittleness of polycrystalline perovskite films, and the mismatch in thermal expansion coefficients between material layers, device performance is easily degraded under external forces such as bending, stretching, and folding, severely impacting cell efficiency and long-term operational stability. Furthermore, environmental factors such as oxygen, light, heat, and humidity also negatively affect the long-term stability of perovskite solar cells. Two-dimensional perovskites, formed by introducing insulating long-chain organic functional groups into three-dimensional perovskites, possess a typical layered structure and exhibit superior stability compared to three-dimensional perovskite materials. However, the large organic spacer cations in two-dimensional perovskites hinder carrier transport, resulting in lower photoelectric conversion efficiency. Ensuring high stability and high photoelectric conversion efficiency in perovskite solar cells has become a current research hotspot. Summary of the Invention

[0004] The technical problem solved by this invention is how to ensure that perovskite solar cells have high stability and high photoelectric conversion efficiency.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a perovskite solar cell containing ferroelectric two-dimensional perovskite material includes the following steps:

[0007] Step S1: After cleaning and drying the conductive substrate and treating it with air plasma, spin-coating the SAM solution onto the conductive substrate and performing the first annealing treatment to obtain the SAM hole transport layer.

[0008] Step S2: Spin-coat the two-dimensional perovskite precursor solution onto the SAM hole transport layer and perform a second annealing treatment to obtain a two-dimensional perovskite layer; wherein, the two-dimensional perovskite layer has ferroelectric properties;

[0009] Step S3: Spin-coat a three-dimensional perovskite precursor solution onto the two-dimensional perovskite layer and perform a third annealing treatment to obtain a three-dimensional perovskite light-absorbing layer.

[0010] Step S4: Spin-coat PCBM solution onto the three-dimensional perovskite light-absorbing layer and perform a fourth annealing treatment to obtain a PCBM electron transport layer; spin-coat BCP solution onto the PCBM electron transport layer and perform a fifth annealing treatment to obtain a BCP electron modification layer.

[0011] Step S5: Add an electrode layer to the BCP electronic modification layer to obtain a perovskite solar cell.

[0012] Preferably, in step S2, the material of the two-dimensional perovskite layer is (MBA)2PbI4.

[0013] Preferably, in step S2, the method for preparing the two-dimensional perovskite precursor solution includes: dissolving 1-phenylethylamine iodine and PbI2 in a molar ratio of 2:1 in a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide to obtain the two-dimensional perovskite precursor solution.

[0014] Preferably, in step S2, the temperature of the second annealing treatment is 70-100℃ and the time is 1-5 min.

[0015] Preferably, in step S3, the molecular structural formula of the material of the three-dimensional perovskite light-absorbing layer is FA. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 3.

[0016] Preferably, in step S3, the method for preparing the three-dimensional perovskite precursor solution includes: dissolving FAI, PbBr2, PbI2 and CsBr in a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide to obtain the three-dimensional perovskite precursor solution.

[0017] Preferably, in step S3, the temperature of the third annealing treatment is 100-150℃ and the time is 10-40 min.

[0018] Preferably, in step S1, the material of the SAM hole transport layer is [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid.

[0019] Preferably, in step S1, the conductive substrate is a flexible substrate.

[0020] The present invention also provides a perovskite solar cell containing ferroelectric two-dimensional perovskite material, which is prepared by the method described above for preparing a perovskite solar cell containing ferroelectric two-dimensional perovskite material.

[0021] Compared with existing technologies, the perovskite solar cell prepared in this invention uses a three-dimensional perovskite material with high photoelectric conversion efficiency as the perovskite light-absorbing layer. A ferroelectric two-dimensional perovskite layer is disposed between the self-assembled monolayer (SAM) hole transport layer and the three-dimensional perovskite light-absorbing layer. This ferroelectric two-dimensional perovskite layer improves the stability of the perovskite solar cell and enhances the built-in electric field (BEF) due to its ferroelectricity, thereby increasing the exciton dissociation efficiency, effectively suppressing non-radiative recombination losses, and overcoming the defect of large organic spacer cations hindering carrier transport in the two-dimensional perovskite material, further improving the photoelectric conversion efficiency. Furthermore, spin-coating the two-dimensional perovskite layer onto the SAM hole transport layer allows the two-dimensional perovskite to act as a seed crystal, optimizing the crystallization process of the three-dimensional perovskite, forming a more uniformly distributed three-dimensional perovskite film, and releasing residual tensile stress in the film. Therefore, this perovskite solar cell also exhibits higher photoelectric conversion efficiency and stability. Attached Figure Description

[0022] Figure 1 This is a flowchart illustrating the fabrication of perovskite solar cells in an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the structure of a perovskite solar cell in an embodiment of the present invention;

[0024] Figure 3 The structural formula is 1-phenylethylamine iodine (MBAI);

[0025] Figure 4 This is the IV curve of the perovskite solar cell prepared in Example 1 under dark conditions;

[0026] Figure 5 This is a PV curve of the perovskite solar cell prepared in Example 1 under dark conditions;

[0027] Figure 6 This is a comparison of the IV curves of the perovskite solar cells prepared in Example 1 and the comparative example under illumination conditions.

[0028] Figure 7 This is a comparison diagram of the bending stability of the perovskite solar cells prepared in Example 1 and the comparative example. Detailed Implementation

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0030] It should be noted that, unless otherwise specified, the features in the embodiments of this invention can be combined with each other. The terms "comprising," "including," "containing," and "having" are non-limiting, meaning that other steps and other components that do not affect the results can be added. The above terms cover the terms "composed of" and "substantially composed of." Unless otherwise specified, the materials, equipment, and reagents are commercially available.

[0031] Additionally, it's important to clarify that the terms one-dimensional, two-dimensional, and three-dimensional perovskite refer to the dimensionality of the perovskite structure. One-dimensional perovskite (1D perovskite) refers to perovskite crystals arranged in a straight line. Its structure is similar to a fiber. Two-dimensional perovskite (2D perovskite) refers to perovskite crystals arranged in a plane. Its structure is similar to a thin sheet. Three-dimensional perovskite (3D perovskite) refers to perovskite crystals arranged in three-dimensional space.

[0032] like Figure 1 As shown, this embodiment of the invention provides a method for preparing a perovskite solar cell containing ferroelectric two-dimensional perovskite material, comprising the following steps:

[0033] Step S1: After cleaning and drying the conductive substrate and treating it with air plasma, spin-coating the SAM solution onto the conductive substrate and performing the first annealing treatment to obtain the SAM hole transport layer.

[0034] Step S2: Spin-coat the two-dimensional perovskite precursor solution onto the SAM hole transport layer and perform a second annealing treatment to obtain a two-dimensional perovskite layer; wherein, the two-dimensional perovskite layer has ferroelectric properties;

[0035] Step S3: Spin-coat a three-dimensional perovskite precursor solution onto the two-dimensional perovskite layer and perform a third annealing treatment to obtain a three-dimensional perovskite light-absorbing layer.

[0036] Step S4: Spin-coat PCBM solution onto the three-dimensional perovskite light-absorbing layer and perform a fourth annealing treatment to obtain a PCBM electron transport layer; spin-coat BCP solution onto the PCBM electron transport layer and perform a fifth annealing treatment to obtain a BCP electron modification layer.

[0037] Step S5: Add an electrode layer to the BCP electronic modification layer to obtain a perovskite solar cell.

[0038] The structure of this perovskite solar cell is as follows: Figure 2 As shown, from Figure 2 As can be seen, the perovskite solar cell is an inverted perovskite solar cell structure. Considering that the inorganic metal oxide carrier transport layer in a formal perovskite solar cell structure almost always requires high-temperature fabrication, and flexible plastic substrates are difficult to withstand high-temperature annealing, the inverted perovskite solar cell structure is better suited for flexible perovskite solar cells. Compared to rigid perovskite solar cells, flexible perovskite solar cells have advantages such as light weight, flexibility, and ease of transportation and installation. Therefore, they can be applied to wearable power generation devices, large-area integrated photovoltaic devices, and have the potential for high-altitude installation.

[0039] Compared with existing technologies, the perovskite solar cell prepared in this embodiment of the invention uses a three-dimensional perovskite material with high photoelectric conversion efficiency as the perovskite light-absorbing layer. A ferroelectric two-dimensional perovskite layer is disposed between the SAM hole transport layer and the three-dimensional perovskite light-absorbing layer. This ferroelectric two-dimensional perovskite layer improves the stability of the perovskite solar cell and enhances the built-in electric field of the cell due to its ferroelectricity, thereby increasing the exciton dissociation efficiency, effectively suppressing non-radiative recombination losses, and overcoming the defect of large organic spacer cations in the two-dimensional perovskite material hindering carrier transport, further improving the photoelectric conversion efficiency of the cell. Furthermore, spin-coating the two-dimensional perovskite layer onto the SAM hole transport layer allows the two-dimensional perovskite to act as a seed crystal to optimize the crystallization process of the three-dimensional perovskite, forming a three-dimensional perovskite film with a more uniform grain distribution and releasing residual tensile stress in the film. Therefore, this perovskite solar cell also exhibits higher photoelectric conversion efficiency and stability.

[0040] In embodiments of the present invention, in step S1, the conductive substrate can be selected from PEN, PET, and ITO. Exemplarily, the specific steps of cleaning, drying, and treating the conductive substrate with air plasma include: sequentially washing the etched conductive substrate with detergent, deionized water, acetone, and isopropanol for 30 minutes. The cleaned conductive substrate is then dried with N2 gas and treated with air-plasma for 5-10 minutes. In step S1, spin-coating a SAM solution onto the conductive substrate and performing a first annealing treatment to obtain a SAM hole transport layer includes: spin-coating a SAM ethanol solution onto the conductive substrate in an N2 atmosphere, and then annealing at 80-120°C for 5-15 minutes to obtain the SAM hole transport layer; wherein the spin-coating speed is 2000-5000 rpm, the time is 15-40 s, and the material of the SAM hole transport layer is [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz).

[0041] In an embodiment of the present invention, in step S2, the material of the two-dimensional perovskite layer is (MBA)₂PbI₄. (MBA)₂PbI₄ is a two-dimensional perovskite material that also possesses ferroelectric properties. The ferroelectric (MBA)₂PbI₄ layer can, on the one hand, improve the stability of perovskite solar cells; on the other hand, due to the ferroelectricity of the two-dimensional perovskite layer, the built-in electric field of the cell is enhanced, improving the exciton dissociation efficiency, effectively suppressing non-radiative recombination losses, overcoming the defect of large organic spacer cations hindering carrier transport in two-dimensional perovskite materials, and further improving the photoelectric conversion efficiency of the cell.

[0042] In an embodiment of the present invention, step S2 involves spin-coating a two-dimensional perovskite precursor solution onto the SAM hole transport layer and performing a second annealing treatment to obtain a two-dimensional perovskite layer. This includes: dissolving 1-phenylethylamine iodide (MBAI) and PbI2 in a molar ratio of 2:1 in a mixed solvent composed of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4:1 to obtain a (MBA)2PbI4 precursor solution; spin-coating the (MBA)2PbI4 precursor solution onto the SAM hole transport layer and annealing it at 70-100°C for 1-5 min to obtain the (MBA)2PbI4 layer, i.e., the two-dimensional perovskite layer. The spin-coating speed is 4000-6000 rpm, and the time is 20-40 s. In this embodiment of the present invention, setting the molar ratio of 1-phenylethylamine iodide (MBAI) to PbI2 to 2:1 ensures the formation rate of (MBA)2PbI4. The structural formula of 1-phenylethylamine iodine (MBAI) is as follows: Figure 3 As shown.

[0043] In an embodiment of the present invention, in step S3, the molecular structural formula of the material of the three-dimensional perovskite light-absorbing layer is FA. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 3.

[0044] In an embodiment of the present invention, in step S3, a three-dimensional perovskite precursor solution is spin-coated onto the two-dimensional perovskite layer, followed by a third annealing treatment to obtain a three-dimensional perovskite light-absorbing layer. This includes dissolving 301 mg formamidinium hydroiodate (FAI), 91.8 mg PbBr2, 806.8 mg PbI2, and 53.2 mg CsBr in a mixed solvent composed of 1050 μl DMF and 150 μl DMSO to obtain FAI. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3. Precursor solution, i.e., three-dimensional perovskite precursor solution; FA 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3. The precursor solution was spin-coated onto a two-dimensional perovskite layer and annealed at 100-150℃ for 10-40 min to obtain FA. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3 The light-absorbing layer is the three-dimensional perovskite light-absorbing layer; wherein, the spin coating speed is 3000-5000 rpm, the time is 20-40s, and the diethyl ether anti-solvent is added dropwise at 10-20s.

[0045] In an embodiment of the present invention, a PCBM solution is spin-coated onto the three-dimensional perovskite light-absorbing layer, followed by a fourth annealing treatment to obtain a PCBM electron transport layer; a BCP solution is spin-coated onto the PCBM electron transport layer, followed by a fifth annealing treatment to obtain a 2,9-dimethyl-4,7-biphenyl-1,10-o-diazaphenanthroline (BCP) electron-modified layer. This process includes: spin-coating a 20 mg / ml PCBM chlorobenzene solution onto the three-dimensional perovskite light-absorbing layer and annealing at 60-100°C for 1-5 min to obtain the PCBM electron transport layer, wherein the spin-coating speed is 1500-3000 rpm and the time is 20-40 s; and spin-coating a 0.5 mg / ml BCP isopropanol solution onto the PCBM electron transport layer and annealing at 80-100°C for 1-5 min to obtain the BCP electron-modified layer, wherein the spin-coating speed is 2000-5000 rpm and the time is 20-40 s.

[0046] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0047] Example 1

[0048] 1.1 The etched PEN substrate was washed sequentially with detergent, deionized water, acetone and isopropanol for 30 min; the cleaned PEN substrate was dried with N2 gas and treated with air-plasma for 10 min; in N2 atmosphere, an ethanol solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz) was spin-coated onto the PEN substrate, and then annealed at 120℃ for 5 min to obtain the SAM hole transport layer.

[0049] 1.2. Dissolve 1-phenylethylamine iodide (MBAI) and PbI2 in a molar ratio of 2:1 in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4:1 to obtain a (MBA)2PbI4 precursor solution. Spin-coat the (MBA)2PbI4 precursor solution onto the SAM hole transport layer and anneal at 100°C for 1 min to obtain the (MBA)2PbI4 layer, i.e., the two-dimensional perovskite layer. The spin-coating speed is 6000 rpm and the time is 20 s.

[0050] 1.3. Dissolve 301 mg FAI, 91.8 mg PbBr2, 806.8 mg PbI2, and 53.2 mg CsBr in a mixed solvent of 1050 μl DMF and 150 μl DMSO to obtain FA. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3. Precursor solution, i.e., three-dimensional perovskite precursor solution; FA 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3 The precursor solution was spin-coated onto a two-dimensional perovskite layer and annealed at 150°C for 10 min to obtain FA. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3 The light-absorbing layer is a three-dimensional perovskite light-absorbing layer; wherein, the spin coating speed is 5000 rpm, the time is 20s, and diethyl ether anti-solvent is added at 10s.

[0051] 1.4 A 20 mg / ml PCBM chlorobenzene solution was spin-coated onto the three-dimensional perovskite light-absorbing layer and annealed at 100 °C for 1 min to obtain the PCBM electron transport layer. The spin-coating speed was 3000 rpm and the time was 20 s. A 0.5 mg / ml BCP isopropanol solution was spin-coated onto the PCBM electron transport layer and annealed at 100 °C for 1 min to obtain the BCP electron-modified layer. The spin-coating speed was 5000 rpm and the time was 20 s.

[0052] 1.5. An Ag electrode is deposited on the BCP electronic modification layer to obtain a perovskite solar cell.

[0053] Example 2

[0054] 2.1 The etched PET substrate was washed sequentially with detergent, deionized water, acetone and isopropanol for 30 min; the cleaned PET substrate was dried with N2 gas and treated with air-plasma for 5 min; in N2 atmosphere, an ethanol solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz) was spin-coated onto the PET substrate, and then annealed at 80°C for 15 min to obtain the SAM hole transport layer.

[0055] 2.2. Dissolve 1-phenylethylamine iodide (MBAI) and PbI2 in a molar ratio of 2:1 in a mixed solvent of N,N-dimethylformamide (DMF) and dimethyl sulfoxide (DMSO) in a volume ratio of 4:1 to obtain a (MBA)2PbI4 precursor solution. Spin-coat the (MBA)2PbI4 precursor solution onto the SAM hole transport layer and anneal at 70°C for 5 min to obtain the (MBA)2PbI4 layer, i.e., the two-dimensional perovskite layer. The spin-coating speed is 4000 rpm and the time is 40 s.

[0056] 2.3. Dissolve 301 mg FAI, 91.8 mg PbBr2, 806.8 mg PbI2, and 53.2 mg CsBr in a mixed solvent of 1050 μl DMF and 150 μl DMSO to obtain FA. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3. Precursor solution, i.e., three-dimensional perovskite precursor solution; FA 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3 The precursor solution was spin-coated onto a two-dimensional perovskite layer and annealed at 100°C for 40 min to obtain FA. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125)3 The light-absorbing layer is a three-dimensional perovskite light-absorbing layer; wherein, the spin coating speed is 3000 rpm and the time is 40 s, and diethyl ether anti-solvent is added at 20 s.

[0057] 2.4 A 20 mg / ml PCBM chlorobenzene solution was spin-coated onto the three-dimensional perovskite light-absorbing layer and annealed at 60 °C for 5 min to obtain the PCBM electron transport layer. The spin-coating speed was 1500 rpm and the time was 40 s. A 0.5 mg / ml BCP isopropanol solution was spin-coated onto the PCBM electron transport layer and annealed at 80 °C for 5 min to obtain the BCP electron-modified layer. The spin-coating speed was 2000 rpm and the time was 40 s.

[0058] 2.5. An Ag electrode is deposited on the BCP electronic modification layer to obtain a perovskite solar cell.

[0059] Comparative Example

[0060] 3.1 The etched PEN substrate was washed sequentially with detergent, deionized water, acetone and isopropanol for 30 min; the cleaned PEN substrate was dried with N2 gas and treated with air-plasma for 10 min; in N2 atmosphere, an ethanol solution of [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid (MeO-2PACz) was spin-coated onto the PEN substrate, and then annealed at 120℃ for 5 min to obtain the SAM hole transport layer.

[0061] 3.2. Dissolve 301 mg FAI, 91.8 mg PbBr2, 806.8 mg PbI2, and 53.2 mg CsBr in a mixed solvent of 1050 μl DMF and 150 μl DMSO to obtain FA. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3. Precursor solution, i.e., three-dimensional perovskite precursor solution; FA 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3. The precursor solution was spin-coated onto the SAM hole transport layer and annealed at 150°C for 10 min to obtain FA. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 )3 The light-absorbing layer is a three-dimensional perovskite light-absorbing layer; wherein, the spin coating speed is 5000 rpm, the time is 20s, and diethyl ether anti-solvent is added at 10s.

[0062] 3.3 A 20 mg / ml PCBM chlorobenzene solution was spin-coated onto the three-dimensional perovskite light-absorbing layer and annealed at 100 °C for 1 min to obtain the PCBM electron transport layer. The spin-coating speed was 3000 rpm and the time was 20 s. A 0.5 mg / ml BCP isopropanol solution was spin-coated onto the PCBM electron transport layer and annealed at 100 °C for 1 min to obtain the BCP electron-modified layer. The spin-coating speed was 5000 rpm and the time was 20 s.

[0063] 3.4. An Ag electrode is deposited on the BCP electronic modification layer to obtain a perovskite solar cell.

[0064] Experimental Example

[0065] The perovskite solar cell prepared in Example 1 was subjected to IV testing in a dark environment. The test results are as follows: Figure 4 As shown, by Figure 4 It can be observed that the IV curve of the perovskite solar cell exhibits two opposite peaks at ±4V under positive and negative electric fields, corresponding to the ferroelectric switching voltages, indicating that the polarization switching of the two-dimensional perovskite changes the resistance of the perovskite solar cell. After applying opposite voltages, the thin film is in a stable state with two opposite polarization directions. This confirms the ferroelectricity of (MBA)₂PbI₄₂D perovskite. Through the analysis of… Figure 4 The integral of the current over time can be obtained Figure 5 The polarization-voltage (PV) hysteresis loop is shown. It should be noted that... Figure 5 The vertical axis, Polarization, represents the polarization intensity.

[0066] IV curve tests (under illumination) and bending stability tests were conducted on the perovskite solar cells prepared in Example 1 and Comparative Example 1. Figure 6 This is a comparison chart of the IV curves of the perovskite solar cells prepared in Example 1 and the comparative example. Figure 6 As can be seen, the perovskite solar cell prepared in Example 1 has improved open-circuit voltage and short-circuit current compared to the perovskite solar cell prepared in the comparative example, exhibiting higher photoelectric conversion efficiency. Figure 7 This is a comparison diagram of the bending stability of the perovskite solar cells prepared in Example 1 and the comparative example. Figure 7 It can be seen that the perovskite solar cell prepared in Example 1 exhibits better stability, maintaining 85% of its initial efficiency after 1000 bending cycles. Compared to the perovskite solar cell prepared in the comparative example, its stability is significantly improved. It should be noted that... Figure 6 and Figure 7 The "withMBAI" corresponds to Example 1, and the "control" series corresponds to the proportional model. Figure 7The horizontal axis represents the number of bending cycles, and the vertical axis represents the normalized photoelectric conversion efficiency (PCE).

[0067] Furthermore, it should be noted that although the present invention has been disclosed as described above, the scope of protection of the present invention is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for preparing a perovskite solar cell containing ferroelectric two-dimensional perovskite material, characterized in that, Includes the following steps: Step S1: After cleaning and drying the conductive substrate and treating it with air plasma, spin-coating the SAM solution onto the conductive substrate and performing the first annealing treatment to obtain the SAM hole transport layer. Step S2: Spin-coat the two-dimensional perovskite precursor solution onto the SAM hole transport layer and perform a second annealing treatment to obtain a two-dimensional perovskite layer; wherein, the two-dimensional perovskite layer has ferroelectric properties and the material of the two-dimensional perovskite layer is (MBA)2PbI4. Step S3: Spin-coat a three-dimensional perovskite precursor solution onto the two-dimensional perovskite layer, and perform a third annealing treatment to obtain a three-dimensional perovskite light-absorbing layer; the molecular structural formula of the material of the three-dimensional perovskite light-absorbing layer is FA. 0.875 Cs 0.125 Pb(I 0.875 Br 0.125 3; Step S4: Spin-coat PCBM solution onto the three-dimensional perovskite light-absorbing layer and perform a fourth annealing treatment to obtain a PCBM electron transport layer; spin-coat BCP solution onto the PCBM electron transport layer and perform a fifth annealing treatment to obtain a BCP electron modification layer. Step S5: Add an electrode layer to the BCP electronic modification layer to obtain a perovskite solar cell.

2. The method for preparing a perovskite solar cell containing ferroelectric two-dimensional perovskite material according to claim 1, characterized in that, In step S2, the preparation method of the two-dimensional perovskite precursor solution includes: dissolving 1-phenylethylamine iodine and PbI2 in a molar ratio of 2:1 in a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide to obtain the two-dimensional perovskite precursor solution.

3. The method for preparing a perovskite solar cell containing ferroelectric two-dimensional perovskite material according to claim 2, characterized in that, In step S2, the temperature of the second annealing treatment is 70-100℃, and the time is 1-5 minutes.

4. The method for preparing a perovskite solar cell containing ferroelectric two-dimensional perovskite material according to claim 1, characterized in that, In step S3, the method for preparing the three-dimensional perovskite precursor solution includes: dissolving FAI, PbBr2, PbI2 and CsBr in a mixed solvent composed of N,N-dimethylformamide and dimethyl sulfoxide to obtain the three-dimensional perovskite precursor solution.

5. The method for preparing a perovskite solar cell containing ferroelectric two-dimensional perovskite material according to claim 1, characterized in that, In step S3, the temperature of the third annealing treatment is 100-150℃, and the time is 10-40 minutes.

6. The method for preparing a perovskite solar cell containing ferroelectric two-dimensional perovskite material according to claim 1, characterized in that, In step S1, the material of the SAM hole transport layer is [2-(3,6-dimethoxy-9H-carbazole-9-yl)ethyl]phosphonic acid.

7. The method for preparing a perovskite solar cell containing ferroelectric two-dimensional perovskite material according to claim 1, characterized in that, In step S1, the conductive substrate is a flexible substrate.

8. A perovskite solar cell containing ferroelectric two-dimensional perovskite material, characterized in that, The perovskite solar cell is prepared using the method described in any one of claims 1-7 for preparing a ferroelectric two-dimensional perovskite solar cell.

Images