Affiliation:
1. Department of Applied Physics The Hong Kong Polytechnic University Hung Hom Kowloon Hong Kong SAR 999077 P. R. China
2. State Key Laboratory of Solidification Processing Center for Nano Energy Materials School of Materials Science and Engineering Northwestern Polytechnical University Xi'an 710072 P. R. China
Abstract
Abstract[4‐(3,6‐dimethyl‐9H‐carbazol‐9yl)butyl]phosphonic acid (Me‐4PACz) self‐assembled molecules (SAM) are an effective method to solve the problem of the buried interface of NiOx in inverted perovskite solar cells (PSCs). However, the Me‐4PACz end group (carbazole core) cannot forcefully passivate defects at the bottom of the perovskite film. Here, a Co‐SAM strategy is employed to modify the buried interface of PSCs. Me‐4PACz is doped with phosphorylcholine chloride (PC) to form a Co‐SAM to improve the monolayer coverage and reduce leakage current. The phosphate group and chloride ions (Cl−) in PC can inhibit NiOx surface defects. Meantime, the quaternary ammonium ions and Cl− in PC can fill organic cations and halogen vacancies in the perovskite film to enable defects passivation. Moreover, Co‐SAM can promote the growth of perovskite crystals, collaboratively solve the problem of buried defects, suppress nonradiative recombination, accelerate carrier transmission, and relieve the residual stress of the perovskite film. Consequently, the Co‐SAM modified devices show power conversion efficiencies as high as 25.09% as well as excellent device stability with 93% initial efficiency after 1000 h of operation under one‐sun illumination. This work demonstrates the novel approach for enhancing the performance and stability of PSCs by modifying Co‐SAM on NiOx.
Funder
National Natural Science Foundation of China
Hong Kong Polytechnic University
Research Grants Council, University Grants Committee
Subject
Mechanical Engineering,Mechanics of Materials,General Materials Science