A new iodide layered double perovskite (C3H9NI)4AgBiI8 (IPAB) has been developed based on a short-chain spacer cation, which is the first homologous compound in iodide double perovskites that adopt the Ruddlesden-Popper structure type. Importantly, IPAB is a promising environmentally friendly alternative to the recently rapidly progressing lead halide semiconductors owing to its narrow direct-bandgap of 1.87 eV and excellent stability.

中文翻译：

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（C3H9NI）4AgBiI8：一种基于带隙间隔子阳离子的直接带隙层状双钙钛矿，用于光吸收。

基于短链间隔阳离子，开发了一种新的碘化物层状双钙钛矿（C3H9NI）4AgBiI8（IPAB），它是碘化物双钙钛矿中第一个采用Ruddlesden-Popper结构类型的同源化合物。重要的是，由于IPAB的1.87 eV窄的直接带隙和出色的稳定性，它是最近发展迅速的卤化铅半导体的有希望的环保选择。