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_0.55MA_0.25Cs_0.1PMA_0.1SnBr₂I (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.

中文翻译：

---

四阳离子宽带隙混合卤化物锡钙钛矿太阳能电池

锡基钙钛矿太阳能电池（TPSC）是无铅光伏应用中传统铅基 PSC 的有前途的替代品。为了进一步提高性能和稳定性，串联型 TPSC 是一个有吸引力的发展方向。为了作为带隙（E _g）约为 1.4 eV 的低带隙 TPSC，寻找E _g在 1.8-2.0 eV 范围内的高带隙 TPSC 是构建无铅串联 TPSC 的一项重要任务。在此，我们报道了第一个四阳离子宽带隙TPSC，其钙钛矿结构为FA _0.55 MA _0.25 Cs _0.1 PMA _0.1 SnBr ₂ I（FA，甲脒；MA，甲基铵；PMA，苯甲基铵），E _g为1.93 eV功率转换效率为 6.2%。我们发现PMA在钝化钙钛矿晶粒表面以及钙钛矿与空穴传输层之间的界面方面发挥着关键作用，从而为具有四重阳离子构型的宽带隙TPSC提供高性能和高稳定性。