The environmental toxicity of Pb in organic-inorganic hybrid perovskite solar cells remains an issue, which has triggered intense research on seeking alternative Pb-free perovskites for solar applications. Halide perovskites based on group-VA cations of Bi3+ and Sb3+ with the same lone-pair ns2 state as Pb2+ are promising candidates. Herein, through a joint experimental and theoretical study, we demonstrate that Cl-incorporated methylammonium Sb halide perovskites (CH3NH3)3Sb2ClXI9-X show promise as efficient solar absorbers for Pb-free perovskite solar cells. Inclusion of methylammonium chloride into the precursor solutions suppresses the formation of the undesired zero-dimensional dimer phase and leads to the successful synthesis of high-quality perovskite films composed of the two-dimensional layered phase favored for photovoltaics. Solar cells based on the as-obtained (CH3NH3)3Sb2ClXI9-X films reach a record-high power conversion efficiency over 2%. This finding offers a new perspective for the development of nontoxic and low-cost Sb-based perovskite solar cells.

中文翻译：

---

含氯诱导锑基无铅钙钛矿太阳能电池层状相的形成

有机-无机杂化钙钛矿太阳能电池中铅的环境毒性仍然是一个问题，这引发了对寻找用于太阳能应用的替代无铅钙钛矿的深入研究。基于具有与 Pb2+ 相同的孤对 ns2 状态的 Bi3+ 和 Sb3+ 的 VA 族阳离子的卤化物钙钛矿是有希望的候选者。在此，通过联合实验和理论研究，我们证明了掺有氯的甲基铵 Sb 卤化物钙钛矿 (CH3NH3)3Sb2ClXI9-X 有望作为无铅钙钛矿太阳能电池的高效太阳能吸收剂。在前体溶液中加入甲基氯化铵可抑制不需要的零维二聚体相的形成，并成功合成由有利于光伏发电的二维层状相组成的高质量钙钛矿薄膜。基于所获得的 (CH3NH3)3Sb2ClXI9-X 薄膜的太阳能电池达到了超过 2% 的创纪录高功率转换效率。这一发现为开发无毒、低成本的 Sb 基钙钛矿太阳能电池提供了新的视角。