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A Polymerization-Assisted Grain Growth Strategy for Efficient and Stable Perovskite Solar Cells |
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| Authors: | Yepin Zhao Pengchen Zhu Minhuan Wang Shu Huang Zipeng Zhao Shaun Tan Tae-Hee Han Jin-Wook Lee Tianyi Huang Rui Wang Jingjing Xue Dong Meng Yu Huang Jaime Marian Jia Zhu Yang Yang |
| Affiliation: | 1. Department of Materials Science and Engineering and California Nano Systems Institute, University of California, Los Angeles, CA, 90095 USA;2. Department of Materials Science and Engineering and California Nano Systems Institute, University of California, Los Angeles, CA, 90095 USA National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing, 210093 China;3. Department of Materials Science and Engineering and California Nano Systems Institute, University of California, Los Angeles, CA, 90095 USA Division of Materials Science and Engineering, Hanyang University, Seoul, 04763 Republic of Korea;4. Department of Materials Science and Engineering and California Nano Systems Institute, University of California, Los Angeles, CA, 90095 USA SKKU Advanced Institute of Nanotechnology (SAINT) and Department of Nanoengineering, Sungkyunkwan University, Suwon, 16419 Republic of Korea;5. National Laboratory of Solid State Microstructures, College of Engineering and Applied Sciences, and Jiangsu Key Laboratory of Artificial Functional Materials, Nanjing University, Nanjing, 210093 China |
| Abstract: | Intrinsically, detrimental defects accumulating at the surface and grain boundaries limit both the performance and stability of perovskite solar cells. Small molecules and bulkier polymers with functional groups are utilized to passivate these ionic defects but usually suffer from volatility and precipitation issues, respectively. Here, starting from the addition of small monomers in the PbI2 precursor, a polymerization-assisted grain growth strategy is introduced in the sequential deposition method. With a polymerization process triggered during the PbI2 film annealing, the bulkier polymers formed will be adhered to the grain boundaries, retaining the previously established interactions with PbI2. After perovskite formation, the polymers anchored on the boundaries can effectively passivate undercoordinated lead ions and reduce the defect density. As a result, a champion power conversion efficiency (PCE) of 23.0% is obtained, together with a prolonged lifetime where 85.7% and 91.8% of the initial PCE remain after 504 h continuous illumination and 2208 h shelf storage, respectively. |
| Keywords: | defect passivation dimethyl itaconate intermolecular exchanging grain growth perovskite solar cells polymerization |