Identifying a “Raoult’s Law” Relationship To Modulate the Stoichiometry of Hybrid Perovskite Films by Amino-Deliquescence/Efflorescence in Mixed Amine Vapors
Identifying a “Raoult’s Law” Relationship To Modulate the Stoichiometry of Hybrid Perovskite Films by Amino-Deliquescence/Efflorescence in Mixed Amine Vapors
复制标题
确定“拉乌尔定律”关系，通过混合胺蒸气中的氨基潮解/风化来调节混合钙钛矿薄膜的化学计量
DOI：
10.1021/acs.jpcc.3c01900
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Cahoon, James F.
中科院分区：
文献类型：
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作者：
Serafin, Lorenzo Y.;Meyers, Jonathan K.;Bryan, Alicia C.;Broun, Katherine G.;Cahoon, James F.
杂化钙钛矿(HPS)是一类很有前途的光电子学半导体材料，其中的有机成分为调制物理性质提供了难得的机会。控制含有一种以上有机组分─的薄膜的组成，例如含有两种有机氨的准二维Ruddlesden-Popper杂化钙钛矿(RPHPS)─，对于合理设计目标性质是很重要的。在这里，我们报告了RPHP薄膜与胺蒸气之间的基本相互作用，以了解基于蒸气的方法调节薄膜成分的可能性。在高于临界压力的甲胺和正丁胺混合蒸气中，我们发现RPHP薄膜在高度放热的溶液驱动下，通过氨基潮解而自发液化。在降低胺压的情况下，薄膜通过氨基风化重新结晶，但其组成与原始薄膜相比发生了显著变化。对光吸收和X射线衍射数据的分析表明，薄膜中甲基铵和正丁基铵的比例与蒸汽中相应的胺比例近似线性相关，关系类似于Raoult定律。结果表明，氨基液态是一种独特的相，可以通过与蒸气交换来控制胺的浓度，氨基开花后生成具有化学计量比的RPHP薄膜和取决于气相环境的晶相。本文对RPHP气/固相互作用的基本理解可以打开更先进的基于蒸汽的方法来设计HP膜的结构和性能的大门。
Hybrid perovskites (HPs) are a promising class of semiconductor materials for optoelectronic applications, and the organic components within them offer a singular opportunity to modulate physical properties. Control over the composition of films with more than one organic component─such as the class ofquasi-two-dimensional Ruddlesden–Popper hybrid perovskites (RPHPs) containing two organic ammoniums─is important for the rational design of targeted properties. Here, we report the fundamental interactions between RPHP films and amine vapors to understand the potential for vapor-based methods to modulate film composition. In a vapor mixture of methylamine andn-butylamine above a critical pressure, we found that RPHP films spontaneously liquefy by amino-deliquescence, driven by a highly exothermic heat of solution. Upon decreasing the amine pressure, the films recrystallized by amino-efflorescence but with a composition dramatically altered compared to the original film. Analysis of optical absorption and X-ray diffraction data demonstrates that the ratio of methylammonium andn-butylammonium in the films depends approximately linearly on the corresponding amine ratios in the vapor, following a relationship analogous to Raoult’s law. The results demonstrate that an amino-deliquesced liquid state is a unique phase in which amine concentrations can be controlled via exchange with the vapor, yielding RPHP films after amino-efflorescence with a stoichiometry and crystal phase that depends upon the vapor environment. The fundamental understanding of RPHP vapor/solid interactions developed herein could open the door to more advanced vapor-based methods to engineer the structure and properties of HP films.