Yan Shao Xin, Han Chang Bao, Huang Jianhua, Chen Yichuan, Zhang Xiaobo, Chen Xiaoqing, Zhang Yongzhe, Yan Hui
Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, China.
College of Petrochemical Engineering, Hunan Petrochemical Vocational Technology College, Hunan 414012, China.
Nanomaterials (Basel). 2021 Feb 12;11(2):473. doi: 10.3390/nano11020473.
Organic-inorganic perovskite single crystals are promising in the field of optoelectronics due to their excellent optoelectronic properties. However, the ion transport of perovskite precursor is poor in confined spaces, which results in difficulty in the preparation of perovskite single-crystal films. Herein, MAPbBr films consisting of square grains were fabricated by the surface-confined process using the organic molecule PEAI (phenethylammonium iodide). Under the effect of oversaturation gradient, PEA is combined with the surface of perovskite grain from top to side, which constrains the lateral growth of grains and induces a downward growth of perovskite, leading to the formation of square grains. With the improvement of concentration PEAI, the perovskite film exhibits a decreased side length of grains (from 0.98 to 12.96 μm) and increased grain number and coverage, as well as crystallinity. The perovskite single crystalline grain films with PEAI showed double photoluminescence (PL) emission peaks due to the existence of iodine-rich perovskite. This work may provide a practical way to fabricate high-quality perovskite films for perovskite photoelectronic devices.
有机-无机钙钛矿单晶由于其优异的光电性能在光电子领域很有前景。然而，钙钛矿前驱体在受限空间中的离子传输较差，这导致钙钛矿单晶膜的制备困难。在此，使用有机分子PEAI（苯乙铵碘化物）通过表面受限工艺制备了由方形晶粒组成的MAPbBr膜。在过饱和梯度的作用下，PEA从顶部到侧面与钙钛矿晶粒表面结合，这限制了晶粒的横向生长并诱导钙钛矿向下生长，从而导致方形晶粒的形成。随着PEAI浓度的提高，钙钛矿膜的晶粒边长减小（从0.98到12.96μm），晶粒数量、覆盖率以及结晶度增加。含有PEAI的钙钛矿单晶粒膜由于富碘钙钛矿的存在而显示出双光致发光（PL）发射峰。这项工作可能为制备用于钙钛矿光电器件的高质量钙钛矿膜提供一种实用方法。
