Improving the Efficiency and Stability of MAPbI3 Perovskite Solar Cells by Dipeptide Molecules

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2024-06, Vol.20 (25), p.e2311400-n/a
• Main Authors: Li, Mingya, Yue, Ziyao, Ye, Zecong, Li, Huixue, Luo, Huanting, Yang, Qing‐Dan, Zhou, Yecheng, Huo, Yanping, Cheng, Yuanhang
• Format: Article
• Language: English
• Subjects: defect passivation; Defects; dipeptide molecules; Efficiency; Energy conversion efficiency; Functional groups; Hydrogen bonds; Hydrophobicity; interface engineering; Lead; Metal halides; perovskite solar cell; Perovskites; Photovoltaic cells; Polypeptides; Solar cells; Stability
• ISSN: 1613-6810; 1613-6829; 1613-6829
• DOI: 10.1002/smll.202311400

Passivating the electronic defects of metal halide perovskite is regarded as an effective way to improve the power conversion efficiency (PCE) of perovskite solar cells (PVSCs). Here, a series of dipeptide molecules with abundant ─C═O, ─O─ and ─NH functional groups as defects passivators for perovskite films are employed. These dipeptide molecules are utilized to treat the surface of prototype methyl ammonium lead iodide (MAPbI3) films and the corresponding PVSCs exhibit enhanced photovoltaic performance and ambient stability, which can be ascribed to: 1) the ─C═O and ─O─ can interact with the undercoordinated Pb2+ ions and the ─NH groups can form hydrogen bonds with the I− ions, passivating the defects in perovskite film and reducing charge recombination in PVSCs; 2) the long alkyl chain of dipeptide molecules increases the hydrophobicity of the perovskite surface and thus enhance the stability of PVSCs. The passivated MAPbI3‐based PVSCs exhibit a champion PCE of 20.3% and retain 60% of the initial PCE after 1000 h. It is believed that the defects passivation engineering using polypeptide moleculars can be applied in other perovskite compositions for high device efficiency and stability. Dipeptide molecules are employed to boost the efficiency and stability of perovskite solar cells. Their abundant ─C═O, ─O─ and ─NH functional groups can effectively passivate the defects in perovskites and their long alkyl chains can help to repel the ingress of moisture into perovskite films.