Universal in situ oxide-based ABX3-structured seeds for templating halide perovskite growth in All-perovskite tandems
Weiqing Chen, Shun Zhou, Hongsen Cui, Weiwei Meng, Hongling Guan, Guojun Zeng, Yansong Ge, Sengke Cheng, Zhenhua Yu, Dexin Pu, Lishuai Huang, Jin Zhou, Guoyi Chen, Guang Li, Hongyi Fang, Zhiqiu Yu, Hai Zhou, Guojia Fang, Weijun Ke
Abstract
Abstract Precise control over halide perovskite crystallization is pivotal for realizing efficient solar cells. Here, we introduce a strategy utilizing in-situ-formed oxide-based ABX 3 -structured seeds to regulate perovskite crystallization and growth. Introducing potassium stannate into perovskite precursors triggers a spontaneous reaction with lead iodide, producing potassium iodide and lead stannate. Potassium iodide effectively passivates defects, while PbSnO 3 (ABX 3 -structured), exhibiting a 98% lattice match, acts as a template and seed. This approach facilitates pre-nucleation cluster formation, preferential grain orientation, and the elimination of intermediate-phase processes in perovskite films. Incorporating potassium stannate into both the perovskite precursors and the buried hole transport layers enables single-junction 1.25 eV-bandgap Sn-Pb perovskite solar cells to achieve a steady-state efficiency of 23.12% and enhanced stability. Furthermore, all-perovskite tandem devices yield efficiencies of 28.12% (two-terminal) and 28.81% (four-terminal). This versatile templating method also boosts the performance of 1.77 eV and 1.54 eV-bandgap cells, underscoring its broad applicability.