Surface chelation of cesium halide perovskite by dithiocarbamate for efficient and stable solar cells

• Published in: Nature communications Vol. 11; no. 1; p. 4237
• Main Authors: He, Jingjing, Liu, Junxian, Hou, Yu, Wang, Yun, Yang, Shuang, Yang, Hua Gui
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 25.08.2020; Nature Publishing Group; Nature Portfolio
• Subjects: 140/131; 147/135; 639/301/299/946; 639/4077/909/4101; 639/638/675; Bonding strength; Cell surface; Cesium; Cesium halides; Chelation; Defects; Efficiency; Energy conversion efficiency; Engineering; Humanities and Social Sciences; Modulators; multidisciplinary; Open circuit voltage; Optoelectronics; Passivity; Perovskites; Photovoltaic cells; Science; Science (multidisciplinary); Solar cells; Stability; Strategy
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-020-18015-5

Surface engineering has been shown critical for the success of perovskite solar cells by passivating the surface enriched defects and mobile species. The discovery of surface modulators with superior interaction strength to perovskite is of paramount importance since they can retain reliable passivation under various environments. Here, we report a chelation strategy for surface engineering of CsPbI 2 Br perovskite, in which dithiocarbamate molecules can be coordinate to surface Pb sites via strong bidentate chelating bonding. Such chelated CsPbI 2 Br perovskite can realize excellent passivation of surface under-coordinated defects, reaching a champion power conversion efficiency of 17.03% and an open-circuit voltage of 1.37 V of CsPbI 2 Br solar cells. More importantly, our chelation strategy enabled excellent device stability by maintaining 98% of their initial efficiency for over 1400 h in ambient condition. Our findings provide scientific insights on the surface engineering of perovskite that can facilitate the further development and application of perovskite optoelectronics. Surface engineering is a known strategy to optimize the perovskite solar cells but it is usually based on weak bondings, such as Van der Waals, or coorordiating interacterions. Here He et al. report a chelation strategy using strongly adsorbed dithiocarbamate molecules and achieve high efficiency of 17.03% with excellent stability for CsPbI 2 Br based solar cells.