Light Radiation Annealing Enables Unidirectional Crystallization of Vacuum-Assisted Sn-Pb Perovskite for Efficient Tandem Solar Cells

• Published in: Energy & environmental science 2024
• Main Authors: Ge, Ciyu, Xu, Qi, Liu, Dayu, Ye, Wenjiang, Zhu, Yongxin, Zhang, Peiyan, Yang, Jiakuan, Liang, Guang-xing, Xu, Ling, Zhou, Ying, Song, Haisheng, Chen, Chao, Tang, Jiang
• Format: Article
• Language: English
• ISSN: 1754-5692; 1754-5706
• DOI: 10.1039/D4EE03419H

Vacuum-assisted technology, favored for its low cost, environmental friendliness, and scalability, is widely used in perovskite solar cells and is a preferred choice for commercialized production. However, strong solvent extraction at the interface between the wet film and vacuum causes a thin perovskite film at the top surface and residual solvent at the buried interface, which results in film stratification and buried voids. Consequently, the efficiency of vacuum-assisted Sn-Pb perovskite solar cells remains below 20%. Herein, we propose a light radiation annealing technique with rapid top-down heating to achieve unidirectional nucleation and growth, which effectively suppresses film stratification and buried voids. This approach yields Sn-Pb perovskite films with a more uniform composition and fewer defects. Based on the optimized films, we achieve a record efficiency of 22.31% among all the vacuum-assisted Sn-Pb perovskite solar cells. Moreover, we obtain an impressive efficiency of 27.62% for all-perovskite tandem solar cells.