Wang Hanyu, Yang Lang, Lv Weifeng, Gan Maoqi, Zhang Zheng, Lv Zhijiang, Liu Xingchong, Li Haimin
School of New Energy and Materials, Southwest Petroleum University, Chengdu 610500, China.
ACS Appl Mater Interfaces. 2025 Apr 2;17(13):19754-19761. doi: 10.1021/acsami.5c01012. Epub 2025 Mar 19.
Although perovskite solar cells (PSCs) are advancing rapidly, a series of issues including interfacial nonradiative recombination losses continue to constrain their photovoltaic performance. Herein, a multifunctional fluorinated pseudohalide ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIMTFSI) is introduced at the buried interface to passivate the interfacial defect and consolidate the perovskite ABX structure effectively. The results reveal that the fluorine and sulfonyl groups on EMIMTFSI can passivate the oxygen vacancy defects in the SnO layer, thereby enhancing the interfacial contact and effectively suppressing the nonradiative charge recombination. In addition, EMIMTFSI facilitates the oriented growth of perovskite along the (110) plane and promotes the enlargement of perovskite grains. Furthermore, the anionic TFSI and cationic EMIM ions stabilize the perovskite ABX structure by filling X-vacancy defects in the perovskite crystals and by coordinating them with uncoordinated Pb defects. Hence, the W EMIMTFSI device exhibits a significant increase in power conversion efficiency from 20.74% to 22.73% and obtains an excellent long-term stability. This study presents a possible innovative way to achieve a highly efficient and stabilizing PSC by EMIMTFSI multifunctional modifications at buried interfaces.
