Wang Jifei, Luo Shiqiang, Lin Yun, Chen Yifu, Deng Yehao, Li Zhimin, Meng Ke, Chen Gang, Huang Tiantian, Xiao Si, Huang Han, Zhou Conghua, Ding Liming, He Jun, Huang Jinsong, Yuan Yongbo
Hunan Key Laboratory of Super Microstructure and Ultrafast Process, School of Physics and Electronics, Central South University, Changsha, Hunan, 410083, P. R. China.
Department of Applied Physical Sciences, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Nat Commun. 2020 Jan 29;11(1):582. doi: 10.1038/s41467-019-13856-1.
The manipulation of crystal orientation from the thermodynamic equilibrium states is desired in layered hybrid perovskite films to direct charge transport and enhance the perovskite devices performance. Here we report a templated growth mechanism of layered perovskites from 3D-like perovskites which can be a general design rule to align layered perovskites along the out-of-plane direction in films made by both spin-coating and scalable blading process. The method involves suppressing the nucleation of both layered and 3D perovskites inside the perovskite solution using additional ammonium halide salts, which forces the film formation starts from solution surface. The fast drying of solvent at liquid surface leaves 3D-like perovskites which surprisingly templates the growth of layered perovskites, enabled by the periodic corner-sharing octahedra networks on the surface of 3D-like perovskites. This discovery provides deep insights into the nucleation behavior of octahedra-array-based perovskite materials, representing a general strategy to manipulate the orientation of layered perovskites.
在层状杂化钙钛矿薄膜中，人们期望从热力学平衡态操纵晶体取向，以引导电荷传输并提高钙钛矿器件的性能。在此，我们报道了一种从类三维钙钛矿生长层状钙钛矿的模板生长机制，这可以作为一种通用的设计规则，使层状钙钛矿在通过旋涂和可扩展刮涂工艺制备的薄膜中沿面外方向排列。该方法包括使用额外的卤化铵盐抑制钙钛矿溶液中层状和三维钙钛矿的成核，这迫使薄膜从溶液表面开始形成。液体表面溶剂的快速干燥留下类三维钙钛矿，令人惊讶的是，它通过类三维钙钛矿表面上周期性的角共享八面体网络为层状钙钛矿的生长提供模板。这一发现为基于八面体阵列的钙钛矿材料的成核行为提供了深刻见解，代表了一种操纵层状钙钛矿取向的通用策略。
