Damp-Stable Perovskite/Silicon Tandem Solar Cells with Internal Encapsulating Sulfonium-Based Molecules
Haowen Luo, Xinhui Han, Bowen Yang, Wen Ou, Jiajia Suo, Hongfei Sun, Xuntian Zheng, Jiajia Hong, Zijing Chu, Lu Zhao, Shuncheng Yang, Pu Wu, Chenyang Duan, Chenshuaiyu Liu, Manya Li, Ludong Li, Renxing Lin, Wenchi Kong, Hairen Tan
Abstract
Industrially textured perovskite/silicon tandem solar cells are among the most promising candidates for future low-cost photovoltaic deployment. Air-annealing is an inevitable process to fabricate high-quality perovskite films during the hybrid two-step deposition method. However, this process often leads to severe perovskite decomposition on the surface because of moisture exposure and high-temperature. To address this issue, a stabilizing additive─dimethylphenethylsulfonium iodide (DMPESI)─is introduced into the organic salt solution, forming a hydrophobic internal encapsulation layer. As a result, the perovskite surface decomposition is effectively suppressed during the air-annealing process and the resulting perovskite films exhibit significantly enhanced film stability and quality. Consequently, the industrially textured perovskite/silicon tandem solar cells delivered an impressive efficiency of 30.49% (1.21 cm 2 ). Moreover, encapsulated tandem devices retained 84% of their initial efficiency after nearly 1800 h of maximum power point tracking (MPPT) (ISOS-L-1) and 80% after 723 h of damp heat test (ISOS-D-3).