双硫腙后处理诱导的钙钛矿膜二次结晶和钝化

有机-无机杂化钙钛矿较低的缺陷形成能和表面的悬挂键会导致其薄膜中产生铅缺陷。这些深能级缺陷会直接引起载流子的非辐射复合,导致有机-无机杂化钙钛矿光伏器件的界面接触和载流子传输效率变差,最终降低了器件的综合性能。采用双硫腙作为钙钛矿薄膜表面的二次结晶诱导剂和铅缺陷钝化剂,通过对钙钛矿膜进行后处理的方法实现对钙钛矿薄膜的形貌调控和缺陷钝化。进一步的研究结果表明,双硫腙通过与铅离子配位的方式有效地钝化了铅缺陷,并诱导了表面钙钛矿晶体的二次结晶,改善了薄膜质量,进而提高了器件的综合性能。

Secondary Crystallization and Passivation of Perovskite Film Induced by Dithizone Post-treatment

The low defect formation energy and surface dangling bonds of organic-inorganic hybrid perovskite can cause the formation of Pb defects in the film. Pb defects belong to the deep level defects, which can reduce the device performances by acting as the charge trap sites to accelerate the non-radiative recombination of carriers, and resulting in poor interface contact and carrier transmission performance. Therefore, passivating the Pb defects in perovskite film is necessary. In this study, dithizone was used as the secondary crystallization inducer and Pb defect passivator of the organic-inorganic hybrid perovskite film. After post-treating the perovskite film with dithizone, the size of the perovskite grains and the film morphology were regulated. Further research results show that dithizone can passivate the Pb defects effectively by coordinating with lead ions, induce secondary crystallization of perovskite crystals, improve the quality of the film, and thus enhancing the device efficiency and stability.