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Tungstate-mediated In-situ Passivation of Grain Boundary Grooves in Perovskite Solar Cells |
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| Authors: | Rundong Fan Qizhen Song Zijian Huang Yue Ma Mengqi Xiao Xudan Huang Huachao Zai Jiaqian Kang Haipeng Xie Yongli Gao Lina Wang Yu Zhang Lan Wang Feng Wang Xiao Zhang Wentao Zhou Nengxu Li Xueyun Wang Yang Bai Guilin Liu Qi Chen Lifen Wang Huanping Zhou |
| Institution: | 1. School of Materials Science and Engineering, Peking University Beijing 100871 (P. R. China) Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, BIC-ESAT, Beijing, 100871 P. R. China
These authors contributed equally to this work.;2. Department of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081 P. R. China These authors contributed equally to this work.;3. School of Materials Science and Engineering, Peking University Beijing 100871 (P. R. China) Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials, Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, BIC-ESAT, Beijing, 100871 P. R. China;4. Department of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081 P. R. China;5. Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, 100081 P. R. China;6. Institute of Super-Microstructure and Ultrafast Process in Advance Materials, School of physic and Electronics, Central South University Changsha, Hunan, 410012 P. R. China;7. Department of Physics and Astronomy, University of Rochester, Rochester, NY 14627 USA;8. School of Science, Jiangnan University, Wuxi, 214122 P. R. China |
| Abstract: | Possessed with advantageous optoelectronic properties, perovskites have boosted the rapid development of solution-processed solar cells. The performance of perovskite solar cells (PSCs) is significantly weakened by the carrier loss at grain boundary grooves (GBGs); however, it receives limited attention and there lacks effective approach to solve this issue. Herein, for the first time, we constructed the tungstate/perovskite heterointerface via a “two step” in situ reaction approach that provides effective defect passivation and ensures efficient carrier dynamics at the GBGs. The exposed perovskite at grain boundaries is converted to wide-band-gap PbWO4 via an in-situ reaction between Pb2+ and tungstate ions, which passivate defects due to the strong ionic bonding. Moreover, recombination loss is further suppressed via the heterointerface energetics modification based on an additional transformation from PbWO4 to CaWO4. PSCs based on this groove modification strategy showed good universality in both normal and inverted structure, with an improved efficiency of 23.25 % in the n-i-p device and 23.33 % in the p-i-n device. Stable power output of the modified device could maintain 91.7 % after around 1100 h, and the device efficiency could retain 92.5 % after aging in air for around 2110 h, and 93.1 % after aging at 85 °C in N2 for 972 h. |
| Keywords: | Grain-Boundary Grooves Passivation Perovskite Solar Cells Stability Tungstate |