iEnergy: Over 25% Record-High Efficiency! Flexible Perovskite Solar Cells
Release Date:
2024-04-09 15:57
Source:
The team led by Yi Chenyi from the Department of Electrical Engineering at Tsinghua University has developed a chemical bath deposition method for preparing tin dioxide (SnO₂) that is compatible with flexible substrates. 2 ) The electron transport layer process achieved 25.09% ( Certification efficiency is 24.90%. the world’s highest efficiency record for flexible perovskite solar cells.
Flexible perovskite solar cells (FPSCs) have attracted considerable attention due to their unique advantages, including being lightweight and thin, exhibiting a high power-to-mass ratio, and being capable of bending and conforming to various shapes. However, both the fabrication and operational processes of FPSCs are susceptible to external forces and mechanical deformation, and flexible substrates commonly used, such as PET, often struggle to withstand temperatures exceeding 150°C for extended periods. o At temperatures above C, it is difficult to deposit conductive films such as FTO that require high-temperature post-treatment on its surface, so only materials like ITO can be used. However, ITO is easily corroded by strong acids under low-pH conditions, making it challenging to employ conventional SnCl 2 High-quality SnO₂ was prepared on this flexible substrate using a chemical water bath method with the addition of hydrochloric acid (with a minimum pH of approximately 1). 2 Electronic transport layer films. Consequently, the efficiency of flexible perovskite solar cells remains significantly lower than that of rigid devices.
Structural diagram of the flexible device and its physical sample, along with the efficiency test curve of the flexible perovskite solar cell prepared via chemical bath deposition.
To address these issues, the team led by Yi Chenyi at Tsinghua University has developed a high-quality SnO. 2 A new fabrication process for the electron transport layer. By using SnSO 4 Replace the conventional SnCl 2 As a tin source, SnO can be controllably grown and synthesized under constant pH conditions without the addition of strong acids. 2 a thin film, thereby making it suitable for acid-sensitive flexible ITO substrates. A uniformly coated, dense SnO₂ layer was obtained under mild and controllable growth conditions. 2 A thin film was fabricated, and FPSCs with a power conversion efficiency (PCE) of 25.09% (certified at 24.90%) were realized using this film, representing the highest reported PCE to date for flexible perovskite solar cells.
Advances in the highest efficiency of flexible perovskite solar cells and the use of SnCl 2 and SnSO 4 Preparation of SnO on a Flexible Substrate 2 Differences in the membrane.
Cross-sectional SEM images and performance test results of flexible perovskite solar cells
Based on SnSO 4 The FPSCs exhibit excellent durability, retaining more than 90% of their initial power conversion efficiency after 10,000 bending cycles; tests indicate that the SnSO-based 4 (With SnCl 2 Compared with the SnO prepared) 2 Perovskite solar cells with an electron-transport layer exhibit improved thermal stability. This can be attributed to the tin sulfate–based SnO 2 on SO 4 2- With Pb 2+ The strong interfacial interaction can reduce interface defects and enhance the thermal stability of perovskite devices. In addition, the new process involving SnO 2 The controllable growth not only ensures excellent reproducibility of the chemical bath process but also enables the bath to be reused, thereby reducing raw material consumption and minimizing the environmental impact of the process.
Relevant research findings have been published under the title “Through SnO” 2 “Controllable Growth Enables 25% Efficiency Flexible Perovskite Solar Cells” (25%-Efficiency Flexible Perovskite Solar Cells Via Controllable Growth of SnO 2 ) titled, was published on March 22 in the Journal of Power and Energy (English Edition) ( iEnergy ).
Ren Ningyu, a postdoctoral researcher in the Department of Electrical Engineering at Tsinghua University, along with Ph.D. students Tan Liguo and Li Minghao from the class of 2021, are the co-first authors of the paper, while Yi Chenyi is the corresponding author.
