Durable All Inorganic Perovskite Tandem Photovoltaics

Abstract Inorganic perovskite tandem solar cells (IPTSCs) are promising candidates to break the efficiency bottleneck and address the stability issue. However, challenges remain in fabricating 2-terminal (2T) IPTSCs due to the inferior film formation and deep trap states induced by tin cations. Herein, a green ligand evolution (GLE) strategy with p-toluenesulfonyl hydrazide is employed to regulate film formation and eliminate deep traps in inorganic narrow bandgap perovskite, enabling the successful development of 2T IPTSCs. Accordingly, the 1.31 eV CsPb0.4Sn0.6I3:GLE device delivers a record efficiency of 17.41%. Combined with the 1.92 eV CsPbI2Br top-cell, 2T-IPTSCs exhibit a champion efficiency of 22.57% (certified 21.92%). Additionally, IPTSCs are engineered to deliver remarkable operation durability under maximum power point tracking, maintaining 80% of the initial efficiency at 65 ℃ for 1510 h and 85℃ for 800 h, respectively.