Wang Shiwei, Wang Yixuan, Wei Qi, Wang Junling
School of Chemical Engineering, Advanced Research Institute of Materials Science, Changchun University of Technology Changchun 130012 China
Hainan Vocational University of Science and Technology Haikou 571126 China.
RSC Adv. 2022 Sep 29;12(43):27775-27780. doi: 10.1039/d2ra04919h. eCollection 2022 Sep 28.
Organic-inorganic hybrid perovskites have attracted much attention for opto-electronic applications due to their low trap density, strong light absorption, and superior charge transport performance. Generally, the high efficiency of perovskite electro-optical thin films depends on their high-quality perovskite single crystals. In this work, the external illumination is applied on the perovskite single crystals growing in solution. It was shown that larger size CHNHPbI single crystals can be obtained under illumination conditions. In addition, CHNHPbI films are prepared by a one-step spin coating process under illumination, the crystal size and film quality of which have been obviously improved due to the effect of illumination in the film forming process. The efficiency of the average cells based on CHNHPbI films increased from 15.2% for the normal conditions to 17.7% for the illumination one, which is consistent with the light enhanced growth of CHNHPbI single crystals in their solution. The "photo-inhibition nucleation" mechanism is proposed to explain the light-induced enhancement of perovskite crystal growth.
有机-无机杂化钙钛矿因其低陷阱密度、强光吸收和优异的电荷传输性能而在光电子应用中备受关注。一般来说，钙钛矿电光薄膜的高效率取决于其高质量的钙钛矿单晶。在这项工作中，对溶液中生长的钙钛矿单晶施加外部光照。结果表明，在光照条件下可以获得更大尺寸的CHNHPbI单晶。此外，通过一步旋涂工艺在光照下制备CHNHPbI薄膜，由于成膜过程中光照的作用，其晶体尺寸和薄膜质量得到了明显改善。基于CHNHPbI薄膜的平均电池效率从正常条件下的15.2%提高到光照条件下的17.7%，这与CHNHPbI单晶在其溶液中的光增强生长一致。提出了“光抑制成核”机制来解释光诱导的钙钛矿晶体生长增强。
