Kim Se-Yun
Department of Advanced Materials Science and Engineering, Kyungnam University, Changwon-si 51767, Republic of Korea.
Materials (Basel). 2025 Jun 17;18(12):2858. doi: 10.3390/ma18122858.
In this study, we investigated the formation mechanism of organo-metal halide perovskite nanostructures through a two-step process categorized as dissolution-recrystallization. It is proposed that the initial formation of nanostructures is governed by the generation of seed grains, whereas the Ostwald ripening model explains only the subsequent growth stage of these structures. We suggest that newly generated grains-formed adjacent to pre-positioned grains-experience compressive stress arising from volume expansion during the phase transition from PbI to the MAPbI perovskite phase. Owing to their unstable state, these grains may serve as effective seeds for the nucleation and growth of nanostructures. Depending on the dipping time, diverse morphologies such as nanorods, plates, and cuboids were observed. The morphology, including the aspect ratio and growth direction of these nanostructures, appears to be strongly influenced by the residual compressive stress within the seed grains. These findings suggest that the shape and aspect ratio of perovskite nanostructures can be tailored by carefully regulating nucleation, dissolution, and growth dynamics during the two-step process.
在本研究中，我们通过一个被归类为溶解-重结晶的两步过程，研究了有机金属卤化物钙钛矿纳米结构的形成机制。有人提出，纳米结构的初始形成受籽晶生成的控制，而奥斯特瓦尔德熟化模型仅解释了这些结构的后续生长阶段。我们认为，在从PbI到MAPbI钙钛矿相的相变过程中，与预先定位的晶粒相邻形成的新生成晶粒会经历由体积膨胀引起的压应力。由于其不稳定状态，这些晶粒可能作为纳米结构成核和生长的有效籽晶。根据浸渍时间的不同，观察到了纳米棒、薄片和长方体等多种形态。这些纳米结构的形态，包括纵横比和生长方向，似乎受到籽晶内残余压应力的强烈影响。这些发现表明，通过在两步过程中仔细调节成核、溶解和生长动力学，可以定制钙钛矿纳米结构的形状和纵横比。
