The Many Faces of Mixed Ion Perovskites: Unraveling and Understanding the Crystallization Process
The Many Faces of Mixed Ion Perovskites: Unraveling and Understanding the Crystallization Process
复制标题
DOI：
10.1021/acsenergylett.7b00981
复制
发表时间：
2017-12-01
影响因子：
22
通讯作者：
Nazeeruddin, Mohammad Khaja
中科院分区：
文献类型：
--
作者：
Gratia, Paul;Zimmermann, Iwan;Nazeeruddin, Mohammad Khaja
了解有机-无机卤化物钙钛矿的结晶过程对于制备可再生、高效的钙钛矿太阳能电池具有重要意义。我们首次报道了混合离子钙钛矿结晶过程中普遍存在的六方多型(6H和4H)的发现和相互作用，即(FAPbI(3))(X)(MAPbBr3)(1-x)。这些多型体是首次报道的六方卤化铅基钙钛矿，它们协调了钙钛矿结晶序列，表现为2H(三角洲相)-4H-6H-3R(3C)，在极端条件下常见于无机过渡金属氧化物钙钛矿。我们发现，在晶格中掺入~gt；3%Cs+离子所产生的化学压力成功地抑制了这些环境敏感多型体的形成，阐明了广泛报道的含Cs+混合离子钙钛矿的器件稳定性和重现性得到改善的原因。
Understanding the crystallization process of organic-inorganic halide perovskites is of paramount importance for fabrication of reproducible and efficient perovskite solar cells. We report for the first time on the discovery and interplay of ubiquitous hexagonal polytypes (6H and 4H) during the crystallization process of mixed ion perovskite, namely (FAPbI(3))(x)(MAPbBr(3))(1-x). These polytypes, the first reported 31) hexagonal lead-halide-based perovskites, orchestrate a perovskite crystallization sequence revealed as 2H (delta phase)-4H-6H-3R(3C), commonly found among inorganic transition metal oxide perovskites under extreme conditions. We show that the chemical pressure arising from the incorporation of >3% Cs+ cations into the lattice successfully inhibits the formation of these environmentally sensitive polytypes, elucidating the origin of the widely reported improved device stability and reproducibility of Cs+-containing mixed ion perovskites.