Abstract Formamidinium lead tri-iodide (FAPbI3) perovskite is a promising photovoltaic material due its narrow band gap and superior thermal stability. Herein, ligand-free high quality α-phase FAPbI3 perovskite prepared by a facile hydrothermal method is reported. The phase purity, morphology, size and optical absorption were controlled by different anti-solvents, namely chlorobenzene, diethyl ether and toluene. The FAPbI3 exhibits band gap of 1.39 eV and it is considerably narrower than its polycrystalline counterparts. This solution processed low temperature method revealed that it can be used for preparation of room temperature stable well-crystalline α-FAPbI3 perovskites for photovoltaic and optoelectronic applications.

中文翻译：

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水热法溶剂对甲脒三碘化铅钙钛矿结构和形貌的影响

摘要 甲脒三碘化铅（FAPbI3）钙钛矿因其窄带隙和优异的热稳定性而成为一种很有前途的光伏材料。本文报道了通过简便的水热法制备的无配体的高质量 α 相 FAPbI3 钙钛矿。相纯度、形态、尺寸和光吸收由不同的反溶剂控制，即氯苯、乙醚和甲苯。FAPbI3 的带隙为 1.39 eV，比其多晶对应物窄得多。这种溶液处理的低温方法表明它可用于制备室温稳定的结晶良好的 α-FAPbI3 钙钛矿，用于光伏和光电应用。