Sulfydryl-based perovskite solar cell and preparation method thereof
By adding dimercaptothiadiazole to the perovskite precursor solution, a protective layer is formed by utilizing the interaction between the mercapto group and Pb2+ and its hydrophobicity. This solves the problem of poor stability in perovskite solar cells and achieves long-term stability and Pb2+ leakage prevention in high humidity environments.
Patent Information
- Application Number
- CN202511876374.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-12
- Publication Date
- 2026-03-13
AI Technical Summary
The poor stability of perovskite solar cells is mainly due to Pb2+ leakage, and existing technologies have failed to effectively solve this problem.
A modified perovskite precursor solution was used, and dimercaptothiadiazole was added. By utilizing the strong interaction between the mercapto group and Pb2+ and the hydrophobicity of dimercaptothiadiazole, a protective layer was formed to prevent Pb2+ leakage. Furthermore, the perovskite grains were enlarged through a high-temperature annealing process, which enhanced the stability.
It effectively improves the long-term stability of perovskite solar cells, especially in high humidity environments, extending their lifespan and reducing the risk of Pb2+ leakage.
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Figure CN121665823A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a thiol-based perovskite solar cell and its preparation method, belonging to the field of perovskite solar cell technology. Background Technology
[0002] In 2009, researchers reported the fabrication of the first perovskite solar cell with a conversion efficiency of 3.8% using CH3NH3PbBr3 and CH3NH3PbI3 perovskite sensitized TiO2. After more than a decade of development, the efficiency of perovskite solar cells has now exceeded 27%, even surpassing the efficiency of commercially available polycrystalline silicon solar cells. Moreover, the photoelectric conversion efficiency of perovskite solar cells can be further improved through stacking. However, the stability of perovskite solar cells remains a major obstacle to their commercial application.
[0003] The α-phase (optically active phase) of perovskite readily transforms into the d-phase (non-optically active phase) in the presence of water molecules. This poor humidity stability significantly hinders the commercialization of perovskite. It cannot operate in high humidity environments, and even at low humidity, its effective operating time is far shorter than that of polycrystalline silicon solar cells, which are less demanding in terms of environmental humidity. Furthermore, the Pb content in the perovskite composition... 2+ It is highly toxic, and if it leaks into the environment, it will inevitably have a major negative impact on the environment and users.
[0004] Currently, methods to improve the humidity stability of perovskite solar cells mainly include: improving the perovskite crystal quality to reduce the number of grain boundaries and thus enhance resistance to humidity, or spin-coating a hydrophobic passivation layer onto the perovskite film surface to reduce moisture erosion. However, these strategies rarely consider Pb. 2+ The issue of leakage means that existing technologies still have limitations due to Pb. 2+ The problem of poor stability in perovskite solar cells caused by leakage. Summary of the Invention
[0005] The purpose of this invention is to provide a thiol-based perovskite solar cell and its preparation method, solving the problem of Pb in the prior art. 2+ The problem of poor stability in perovskite solar cells caused by leakage.
[0006] To achieve the above objectives, the present invention employs the following technical solution: In a first aspect, the present invention provides a thiol-based perovskite solar cell, comprising, from bottom to top, a conductive glass, an electron transport layer, a perovskite layer, a hole transport layer, and a back electrode; The perovskite layer is obtained by coating a modified perovskite precursor solution onto the electron transport layer. The modified perovskite precursor solution includes a perovskite precursor solution and a dimercaptothiadiazole.
[0007] Furthermore, the modified perovskite precursor solution is prepared by the following method: Add 0.8~1.2 mg of dimercaptothiadiazole to each 1 ml of the perovskite precursor solution to obtain a modified perovskite precursor solution.
[0008] Furthermore, the chemical formula of the active ingredient in the perovskite precursor solution is ABX3, wherein A is selected from Cs, FA or MA, B is selected from Pb or Sn, and X is selected from I, Br or Cl.
[0009] Furthermore, the hole transport layer is obtained by coating a hole transport precursor solution onto a perovskite layer, and the hole transport precursor solution is prepared by the following method: Lithium bis(trifluoromethanesulfonylimide) and 4-tert-butylpyridine were doped in a solution of 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene.
[0010] Furthermore, the electron transport layer is obtained by spin-coating a TiO2 solution or a SnO2 solution onto a conductive glass.
[0011] Furthermore, the back electrode is a gold electrode, a silver electrode, or a carbon electrode.
[0012] Furthermore, the conductive glass is FTO or ITO.
[0013] In a second aspect, the present invention provides a method for preparing a perovskite solar cell according to any one of the first aspects, comprising: Clean the conductive glass and then treat it with ozone. An electron transport layer is generated by spin-coating TiO2 solution or SnO2 solution onto the upper surface of conductive glass to obtain a first intermediate. The first intermediate is then subjected to high-temperature annealing and ozone treatment. A modified perovskite precursor solution is spin-coated onto the surface of the first intermediate to form a perovskite layer, thus obtaining the second intermediate. The second intermediate is then subjected to high-temperature annealing. A hole transport layer is generated by spin-coating a hole transport precursor solution onto the upper surface of the second intermediate and allowing it to stand for a period of time to obtain the third intermediate. The back electrode is deposited on the surface of the third intermediate to obtain the perovskite solar cell.
[0014] Furthermore, the high-temperature annealing of the first intermediate includes: annealing the first intermediate at 135~165°C for 20~40 minutes; The high-temperature annealing of the second intermediate includes: annealing the second intermediate at 135~165℃ for 5~15 minutes. The settling period is 14 to 34 hours.
[0015] Compared with the prior art, the beneficial effects achieved by the present invention are: This invention provides a thiol-based perovskite solar cell and its preparation method. The method utilizes a dimercaptothiadiazole to modify a perovskite precursor solution. This process leverages the interaction between thiol (-SH) groups and Pb in the perovskite. 2+ The strong interaction between the sulfur atom and the phosphorus group, along with the strong hydrophobicity of the dimercaptothiadiazole, is used to achieve the long-term stability of perovskites. The sulfur atom on the mercapto group has a lone pair of electrons, which can interact with the phosphorus group (Pb). 2+ The empty orbitals on the surface form coordinate bonds, which can effectively prevent potential Pb formation. 2+ Leakage is a concern, and dimercaptothiadiazole organic compounds contain two thiol groups and a thiadiazole ring, resulting in low overall polarity and a compact molecular structure that hinders water molecule interactions, exhibiting strong hydrophobicity. Adding dimercaptothiadiazole to the perovskite precursor solution leads to the interaction of the thiol groups with Pb... 2+ The interaction forces slow down the crystallization process of the precursor to form the perovskite phase, resulting in larger perovskite grains. After spin-coating the perovskite precursor solution, the perovskite gradually crystallizes during annealing, and the dimercaptothiadiazole is repelled to the grain boundaries and surface of the perovskite, acting as a protective layer and effectively improving the long-term stability of perovskite solar cells. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the structure of a perovskite solar cell based on thiol groups provided by the present invention; Figure 2 The structural formula of the dimercaptothiadiazole provided by this invention is as follows: Figure 3 This is a schematic diagram of dimercaptothiadiazole as a protective layer for perovskite thin films provided by the present invention; Figure 4 This is a comparative schematic diagram showing the degradation of perovskite thin films of perovskite solar cells prepared in Example 1 and Comparative Example 1 after 20 days at 25°C and 30% humidity; the left side shows the degradation corresponding to Comparative Example 1, and the right side shows the degradation corresponding to Example 1. Detailed Implementation
[0017] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present invention more clearly, and should not be used to limit the scope of protection of the present invention.
[0018] Example 1
[0019] This embodiment provides a thiol-based perovskite solar cell, which is prepared by the following method: S1. The conductive glass (in this example, FTO, fluorine-doped tin oxide, 2cm*2cm in size) is ultrasonically cleaned sequentially with acetone, isopropanol, and ethanol for 20 minutes. The conductive glass is then subjected to ozone treatment for 30 minutes to enhance surface wettability.
[0020] S2. Spin-coating TiO2 solution onto the surface of conductive glass (or screen printing or spray pyrolysis in other embodiments) to generate an electron transport layer, obtaining a first intermediate. Annealing the first intermediate at 150°C for 30 minutes and then ozone treating the first intermediate for 30 minutes.
[0021] In this embodiment, the TiO2 solution is a TiO2 solution with a mass concentration of 3wt%. The amount of TiO2 solution used during spin coating is 150uL, the spin speed is 3000rpm, and the spin coating time is 30s.
[0022] S3. Spin-coating (or scraping or spraying in other embodiments) the modified perovskite precursor solution onto the upper surface of the first intermediate to form a perovskite layer, thereby obtaining the second intermediate. The second intermediate is then annealed at 150°C for 10 minutes to remove the solvent from the modified perovskite precursor solution.
[0023] In this embodiment, the modified perovskite precursor solution was prepared by the following method: Add 0.8–1.2 mg of dimercaptothiadiazole to each 1 ml of perovskite precursor solution to obtain a modified perovskite precursor solution. The structure of the dimercaptothiadiazole used in this example is as follows: Figure 2 As shown.
[0024] In this embodiment, the perovskite precursor solution is a MAPbI3 solution.
[0025] When spin-coating the modified perovskite precursor solution, the spin-coating speed was 4000 rpm, the spin-coating time was 25 s, and 500 μL of the antisolvent chlorobenzene was continuously added dropwise for 3-4 s after the 5th s after the start of spin-coating.
[0026] S4. A hole transport precursor solution is spin-coated onto the upper surface of the second intermediate to generate a hole transport layer. The mixture is left to stand for 24 hours to ensure that 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene is completely oxidized, thus obtaining the third intermediate.
[0027] In this embodiment, the hole transport precursor solution is prepared by the following method: Lithium bis(trifluoromethanesulfonyl)imide and 4-tert-butylpyridine were doped into a chlorobenzene solution of 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene. The doping method involved uniformly mixing the three raw materials and then adding chlorobenzene solvent. The mass ratio of the 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene solution, lithium bis(trifluoromethanesulfonyl)imide, and 4-tert-butylpyridine (liquid at room temperature) was 72.3 mg:9.1 mg:32.3 mg (35 μL), and the concentration of the 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene solution was 72.3 mg / mL (chlorobenzene solvent).
[0028] S5. A back electrode (gold electrode in this embodiment) with a thickness of 80 nm is deposited on the upper surface of the third intermediate to obtain a perovskite solar cell. The structure of the perovskite solar cell is as follows: Figure 1 As shown.
[0029] Figure 3 This is a schematic diagram of dimercaptothiadiazole as a protective layer for perovskite, with dimercaptothiadiazole distributed around the periphery and perovskite in the center.
[0030] Comparative Example 1 The difference between this comparative example and Example 1 is that the modified perovskite precursor solution is replaced with a perovskite precursor solution, i.e., the perovskite layer does not contain dimercaptothiadiazole.
[0031] To verify the beneficial effects of the present invention, the perovskite solar cells prepared in Example 1 and Comparative Example 1 were subjected to humidity stability tests. Specifically, the two perovskite solar cells were placed in an environment of 25°C and 30% humidity for 20 days. Figure 4 As shown in the degradation data of the perovskite films, the control group (perovskite solar cells prepared in Comparative Example 1) without the addition of dimercaptothiadiazole was completely degraded after 20 days at an average temperature of 25°C and 30% humidity. In contrast, the experimental group with the addition of dimercaptothiadiazole (perovskite solar cells prepared in Example 1) maintained its original optically active α-phase (e.g., ...) after 20 days under the same conditions. Figure 4 (As shown in the figure). This demonstrates that the addition of dimercaptothiadiazole can effectively improve the humidity stability of perovskite films, providing a feasible path for the future commercial application of perovskites.
[0032] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A perovskite solar cell based on thiol groups, characterized in that, It includes, from bottom to top, conductive glass, electron transport layer, perovskite layer, hole transport layer, and back electrode; The perovskite layer is obtained by coating a modified perovskite precursor solution onto the electron transport layer. The modified perovskite precursor solution includes a perovskite precursor solution and a dimercaptothiadiazole.
2. The perovskite solar cell based on thiol groups according to claim 1, characterized in that, The modified perovskite precursor solution was prepared by the following method: Add 0.8~1.2 mg of dimercaptothiadiazole to each 1 ml of the perovskite precursor solution to obtain a modified perovskite precursor solution.
3. The perovskite solar cell based on thiol groups according to claim 1, characterized in that, The chemical formula of the active ingredient in the perovskite precursor solution is ABX3, wherein A is selected from Cs, FA or MA, B is selected from Pb or Sn, and X is selected from I, Br or Cl.
4. The perovskite solar cell based on thiol groups according to claim 1, characterized in that, The hole transport layer is obtained by coating a hole transport precursor solution onto a perovskite layer. The hole transport precursor solution is prepared by the following method: Lithium bis(trifluoromethanesulfonylimide) and 4-tert-butylpyridine were doped in a solution of 2,2',7,7'-tetra(N,N-p-methoxyaniline)-9,9'-spirodifluorene.
5. The perovskite solar cell based on thiol groups according to claim 1, characterized in that, The electron transport layer is obtained by spin-coating a TiO2 solution or a SnO2 solution onto conductive glass.
6. The perovskite solar cell based on thiol groups according to claim 1, characterized in that, The back electrode is a gold electrode, a silver electrode, or a carbon electrode.
7. The perovskite solar cell based on thiol groups according to claim 1, characterized in that, The conductive glass is FTO or ITO.
8. A method for preparing a perovskite solar cell according to any one of claims 1 to 7, characterized in that, include: Clean the conductive glass and then treat it with ozone. An electron transport layer is generated by spin-coating TiO2 solution or SnO2 solution onto the upper surface of conductive glass to obtain a first intermediate. The first intermediate is then subjected to high-temperature annealing and ozone treatment. A modified perovskite precursor solution is spin-coated onto the surface of the first intermediate to form a perovskite layer, thus obtaining the second intermediate. The second intermediate is then subjected to high-temperature annealing. A hole transport layer is generated by spin-coating a hole transport precursor solution onto the upper surface of the second intermediate and allowing it to stand for a period of time to obtain the third intermediate. The back electrode is deposited on the surface of the third intermediate to obtain the perovskite solar cell.
9. The preparation method according to claim 8, characterized in that, The high-temperature annealing of the first intermediate includes: annealing the first intermediate at 135~165℃ for 20~40 minutes. The high-temperature annealing of the second intermediate includes: annealing the second intermediate at 135~165℃ for 5~15 minutes. The settling period is 14 to 34 hours.