Quadruple-Cation Wide-Bandgap Mixed-Halide Tin Perovskite Solar Cells

High Resolution Image Download MS PowerPoint Slide Tin-based perovskite solar cells (TPSCs) are a promising alternative to the traditional lead-based PSCs for lead-free photovoltaic applications. To further promote the performance and stability, a tandem type of TPSC is an attractive direction to pursue. To serve as a low-bandgap TPSC with the bandgap ( E g ) of around 1.4 eV, searching for a high-bandgap TPSC with an E g in the range 1.8–2.0 eV is an important task to build a lead-free tandem TPSC. Herein, we report the first quadruple-cation wide-bandgap TPSC with the perovskite structure of FA 0.55 MA 0.25 Cs 0.1 PMA 0.1 SnBr 2 I (FA, formamidinium; MA, methylammonium; PMA, phenylmethylammonium) and an E g of 1.93 eV to give the efficiency of power conversion of 6.2%. We found that PMA plays a key role in passivating the grain surface of perovskites and the interface between the perovskite and the hole-transport layer to give high performance and great stability for a wide-bandgap TPSC with a quadruple-cation configuration.