Orientation-controlled mesoporous PbI2 scaffold for 22.7% perovskite solar cells

• Published in: Science China materials 2023-04, Vol.66 (4), p.1313-1322
• Main Authors: Huang, Dejun, Liu, Qianyu, Ma, Zhu, Li, Yanlin, Yan, Guangyuan, Hou, Shanyue, Du, Zhuowei, Yang, Junbo, Chen, Yi, Tang, Shufang, Zhou, Hengyu, Xiang, Yan, Zhang, Wenfeng, Huang, Yuelong, Mai, Yaohua
• Format: Article
• Language: English
• Subjects: Carrier lifetime; Chemistry and Materials Science; Chemistry/Food Science; Crystal defects; Crystallization; Energy conversion efficiency; Grain boundaries; Materials Science; Nicotinamide; Perovskites; Photovoltaic cells; Scaffolds; Solar cells
• ISSN: 2095-8226; 2199-4501
• DOI: 10.1007/s40843-022-2289-5

Sequential deposition is a promising tactic for perovskite film fabrication. However, the highly crystalline and compact morphology of PbI 2 film will hinder the quality and reproducibility of perovskite films. Here, nicotinamide (NTM) derivatives were introduced as simple and effective multifunctional ligands into the PbI 2 precursor solution. Orientation-controlled and mesoporous PbI 2 scaffolds formed due to strong chemical interaction and accelerated solvent volatilization. Nanobelt PbI 2 crystals were also generated at the grain boundaries of perovskite films with NTM derivatives, which can passivate the defects and enhance the carrier lifetime. As a result, the perovskite solar cells based on 6-(trifluoromethyl) nicotinamide-modulated films showed an enhanced power conversion efficiency of 22.7%, of which 98.8% was maintained even after 2000 h of aging. Our findings offer a distinctive understanding of regulating the crystallization of PbI 2 films and manipulating excess PbI 2 structure for efficient perovskite solar cells.