Mediating the Local Oxygen-Bridge Interactions of Oxysalt/Perovskite Interface for Defect Passivation of Perovskite Photovoltaics

Nano-Micro Letters

Haiyang Yuan¹  Shuang Yang¹  Hua Gui Yang¹  Ziren Zhou¹  Yu Hou¹  Bing Ge¹  Ze Qing Lin¹  Hui Jun Lian¹ 

[1] Key Laboratory for Ultrafine Materials of Ministry of Education, Shanghai Engineering Research Center of Hierarchical Nanomaterials, School of Materials Science and Engineering, East China University of Science and Technology;

关键词: Solar cell;    Lead halide perovskite;    Passivation;    Oxysalt;    Central atom;   

DOI  :  10.1007/s40820-021-00683-7

来源: DOAJ

【 摘 要 】

Abstract Passivation, as a classical surface treatment technique, has been widely accepted in start-of-the-art perovskite solar cells (PSCs) that can effectively modulate the electronic and chemical property of defective perovskite surface. The discovery of inorganic passivation compounds, such as oxysalts, has largely advanced the efficiency and lifetime of PSCs on account of its favorable electrical property and remarkable inherent stability, but a lack of deep understanding of how its local configuration affects the passivation effectiveness is a huge impediment for future interfacial molecular engineering. Here, we demonstrate the central-atom-dependent-passivation of oxysalt on perovskite surface, in which the central atoms of oxyacid anions dominate the interfacial oxygen-bridge strength. We revealed that the balance of local interactions between the central atoms of oxyacid anions (e.g., N, C, S, P, Si) and the metal cations on perovskite surface (e.g., Pb) generally determines the bond formation at oxysalt/perovskite interface, which can be understood by the bond order conservation principle. Silicate with less electronegative Si central atoms provides strong O-Pb motif and improved passivation effect, delivering a champion efficiency of 17.26% for CsPbI2Br solar cells. Our strategy is also universally effective in improving the device performance of several commonly used perovskite compositions.

【 授权许可】

Unknown