论文标题
温度，压力和湿度对FAPBI $ _3 $的各种多晶型物的稳定性和过渡动力学的影响
Influence of Temperature, Pressure and Humidity on the Stabilities and Transitions Kinetics of the Various Polymorphs of FAPbI$_3$
论文作者
论文摘要
Fapbi $ _ {3} $的各种聚合物之间的相变（FAPI，FA = formamidinium ch（NH $ _ {2} $）$ _ {2}^+$）由Anelastric，eLastric，电视和X射线差异测量$ $ $ _ {2}^+$）研究，从$ $ $ fape）上播放了$ flode $ f fapy $δ2H。在施用低至0.2〜GPA后，样品变成橙色，从部分转化到其他六边形多晶型物4H和6H方面已解释。根据有关混合动力和无机perovskites abx abx $ _ {3} $具有大阳离子的稳定性的稳定性，讨论了这种现象。值得注意的是，房间和较高温度的FAPI的行为就像是钙钛矿的$ t $，而室温却低于室温，它的行为就像是小$ t $的钙钛矿。少量的插入水增强了多晶型物之间转化的动力学。因此，似乎值得尝试改善合成过程中原子扩散和结晶，因此，通过受控的少量水，应在实现足够均匀且平滑的微观结构后应彻底去除，从而最终的光伏性能。
The phase transitions between the various polymorphs of FAPbI$_{3}$ (FAPI, FA = formamidinium CH(NH$_{2}$)$_{2}^+$) are studied by anelastic, dielectric and X--ray diffraction measurements on samples pressed from $δ-$FAPI (2H phase) yellow powder. The samples become orange after application of as little as 0.2~GPa, which has been explained in terms of partial transformations to the other hexagonal polymorphs 4H and 6H. The phenomenon is discussed in the light of what is known about the stability of the various polymorphs of hybrid and inorganic perovskites ABX$_{3}$ with large A cations and hence large tolerance factor $t$. Remarkably, FAPI at room and higher temperature behaves like a perovskite with large $t$, while just below room temperature it behaves like a perovskite with small $t$. The kinetics of the transformations between the polymorphs is enhanced by small amounts of intercalated water. It seems therefore worthy to try improving the atomic diffusion and crystallization during synthesis, and hence the final photovoltaic performance, through controlled small amounts of water that should be thoroughly removed after a sufficiently homogeneous and smooth microstructure is achieved.
