Recently, enormous efforts have been made to develop the efficient, lead (Pb) free and stable perovskite solar cells (PSCs). In this regards, various strategies were applied and the optoelectronic properties of various Pb free perovskites such as (CH₃NH₃)₃Sb₂I₉, (CH₃NH₃)₃Bi₂I₉, Cs₃Sb₂I₉, Cs₃Bi₂I₉, CH₃NH₃SnI₃ and CH₃NH₃GeI₃ etc have been investigated. However, the photovoltaic performance of the developed PSCs was still low and presence of organic moieties in common hole‐transport materials (HTMs) shows poor stability against moisture and heat. Herein, we have investigated the optoelectronic properties of all inorganic Pb free perovskites (Cs₃Sb₂I₉=1 and Cs₃Bi₂I₉=2) and employed novel strategies (dissolution‐recrystallization) to prepare the efficient Pb free PSCs. The band gaps of the 1 and 2 were found to be 2.2 eV and 2.0 eV, respectively. The developed PSCs with 1 and 2 exhibited the power conversion efficiency of 0.68% and 1.087%, respectively.

中文翻译：

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高效能的高效钙钛矿太阳能电池用无机无铅钙钛矿吸光剂。

最近，为开发高效，无铅且稳定的钙钛矿太阳能电池（PSC）付出了巨大的努力。在这方面，应用了各种策略，并且各种无铅钙钛矿例如（CH ₃ NH ₃）₃ Sb ₂ I ₉，（CH ₃ NH ₃）₃ Bi ₂ I ₉，Cs ₃ Sb ₂ I ₉， Cs ₃ Bi ₂ I ₉，CH ₃ NH ₃ SnI ₃和CH ₃ NH₃ GeI ₃等已被研究。但是，已开发的PSC的光伏性能仍然很低，普通的空穴传输材料（HTM）中存在有机部分，显示出对湿气和热的稳定性差。在这里，我们研究了所有无机无铅钙钛矿（Cs ₃ Sb ₂ I ₉ = 1和Cs ₃ Bi ₂ I ₉ = 2）的光电性能，并采用了新颖的策略（溶解-重结晶）来制备有效的无铅PSC。发现1和2的带隙分别为2.2eV和2.0eV。已开发的具有1和2的PSC的功率转换效率分别为0.68％和1.087％。