Although tin-based perovskite has been considered as a kind of potential environmentally-friendly photovoltaic materials, the tin-based perovskite solar cells are limited due to their poor stability and low conversion efficiency mainly tracing to the oxidation from Sn²⁺ to Sn⁴⁺ state in tin-based perovskite films. Herein, a facile reductive approach is developed to suppress the oxidation, in which tiny amount of hydrazine monohydrobromide is doped into FASnI₃-based perovskite precursor solution as a reducing agent. Our results demonstrate that the addition of hydrazine monohydrobromide could reduce the defects and trap states in perovskite by inhibiting formation of tetravalent tin, and increase the open circuit voltage by widening the bandgap of perovskite. As a consequence, the best optimized perovskite solar cell achieves an excellent power conversion efficiency of 7.81%, which represented a 39.5% improvement compared to the best reference device. The optimized devices display stabilized power output near the maximum power point and negligible hysteresis effect.

尽管锡基钙钛矿被认为是一种潜在的环保光伏材料，但是锡基钙钛矿太阳能电池由于其较差的稳定性和低转换效率而受到限制，主要是由于从Sn ²⁺氧化为Sn ⁴⁺锡基钙钛矿薄膜中的状态。本文中，开发了一种抑制氧化的简便还原方法，其中将少量的肼一氢溴化物掺入FASnI _3中。钙钛矿前体溶液作为还原剂。我们的结果表明，肼一氢溴酸盐的加入可以通过抑制四价锡的形成来减少钙钛矿中的缺陷和陷阱态，并通过扩大钙钛矿的带隙来增加开路电压。结果，最佳优化的钙钛矿太阳能电池可实现7.81％的出色功率转换效率，与最佳参考器件相比，可提高39.5％。经过优化的器件在最大功率点附近显示稳定的功率输出，并且磁滞效应可忽略不计。