Inorganic Framework Composition Engineering for Scalable Fabrication of Perovskite/Silicon Tandem Solar Cells
Haowen Luo, Xuntian Zheng, Wenchi Kong, Zhou Liu, Hongjiang Li, Jin Wen, Rui Xia, Hongfei Sun, Pu Wu, Yurui Wang, Yi Mo, Xin Luo, Zilong Huang, Jiajia Hong, Zijing Chu, Xueling Zhang, Guangtao Yang, Yifeng Chen, Zhiqiang Feng, Jifan Gao, Hairen Tan
Abstract
The conformal and scalable growth of perovskite film on industrially textured silicon with a hybrid evaporation-solution method contributes to sufficient light utilization and large-scale commercialization of monolithic perovskite/silicon tandem solar cells. However, the efficacy of this approach is hindered by the incomplete reaction during the transition from spin-coating to blade-coating techniques, notably involving the buried sublimation-PbI 2 . Herein, we demonstrate a triple-source coevaporation (PbI 2, PbCl 2, and CsBr) method combined with the framework-heat-treatment (FHT) strategy. Such inorganic framework composition engineering generates a quasi-two-dimensional layered structure, CsPb 2 X 5, which enlarges the inorganic interlayer spacing and facilitates the penetration of organic salt solution. Consequently, a high-quality perovskite film with fully converted PbI 2 has been achieved. This advance translates into one of the best tandem solar cells that has a stabilized efficiency of 28.3% (1.05 cm 2 ). Impressively, the encapsulated device retains 94% of its initial performance after operating for more than 1200 h under 1-sun illumination in ambient air.