The Synergistic Effect of Phosphonic and Carboxyl Acid Groups for Efficient and Stable Perovskite Solar Cells

• Published in: Materials Vol. 16; no. 23; p. 7306
• Main Authors: Du, Kaihuai, Wang, Aili, Li, Yue, Xu, Yibo, Li, Lvzhou, Yuan, Ningyi, Ding, Jianning
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 24.11.2023
• Subjects: anchoring; Aqueous solutions; Carboxylic acids; Carrier transport; charge transfer; Charge transport; Commercialization; Control equipment; Defects; Efficiency; Electron transport; Energy levels; Functional groups; Glycine; interface passivation; large area; Nanocrystals; Perovskite; Perovskites; Phosphonic acids; Photovoltaic cells; self-assembled small molecule; Self-assembly; Solar cells; Synergistic effect; Tin dioxide; China; Shanghai China; interface passivation; large area; self-assembled small molecule; anchoring; charge transfer
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16237306

Reducing the interfacial defects between the perovskite/electron transport layer (ETL) is the key point to improving the efficient and stable performance of perovskite solar cells (PSCs). In this study, two self-assembled molecules ((aminomethyl)phosphonic acid and glycine) with different functional groups (phosphonic acid (-H PO ) and carboxylic acid (-COOH)) were mixed to form the buried bottom interface of PSCs. The synergistic effect of -H PO with its higher anchoring ability and -COOH with its fast carrier transport improved the performance of PSCs. Additionally, the SnO modified by mixed self-assembly molecules (M-SAM) showed a more appropriate energy level alignment, favoring charge transport and minimizing energy loss. In addition, the amine group (-NH ) on the two small molecules effectively interacted with uncoordinated Pb in perovskite and improved the quality of the perovskite films. Consequently, the (FAPbI ) (MAPbBr ) PSCs with M-SAM reached a PCE of 24.69% (0.08 cm ) and the perovskite modules achieved a champion efficiency of 18.57% (12.25 cm aperture area). Meanwhile, it still maintained more than 91% of its initial PCE after being placed in nitrogen atmosphere at 25 °C for 1500 h, which is better than that of the single-SAM and control devices. Further reference is provided for the future commercialization of perovskite with efficient and stable characteristics.