Multi‐Level Passivation of MAPbI3 Perovskite for Efficient and Stable Photovoltaics. (31st December 2021)

• Record Type: Journal Article
• Authors: Wei, Ning; Chen, Yuetian; Wang, Xingtao; Miao, Yanfeng; Qin, Zhixiao; Liu, Xiaomin; Wei, Hao; Zhao, Yixin
• Is Part Of: Advanced functional materials. Volume 32:Number 16(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2021-12-31
• Subjects: ionic liquids -- multi‐level distribution -- one‐dimension -- perovskite solar cells -- stability; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adfm.202108944
• Languages: English
• ISSNs: 1616-301X

Abstract

Abstract: The photovoltaic performance and long‐term stability of perovskite solar cells (PSCs) are greatly affected by trap states. Herein, a functional ionic liquid of 1‐ethyl‐3‐methylimidazolium trifluoroacetate (EMIMTFA) is introduced, in which the 1‐ethyl‐3‐methylimidazolium cations (EMIM + ) can interact with PbI2 to form a stable one‐dimensional (1D) perovskite of EMIMPbI3, and the trifluoroacetic acid anions (TFA − ) can passivate the interface between the electron transfer layer and the perovskite layer. Unlike, the widely studied low dimensional perovskite capping layers or quasi‐2D configuration, the EMIM + cations not only distribute on the top surface and inside the bulk phase, but also accumulate at the buried interface of 3D perovskite film, achieving a multi‐level distribution. The different defect states are successfully passivated by this distribution mode, leading to a significant decrease of non‐radiative recombination. As a result, the methyammonium lead iodide‐based PSCs with the EMIMTFA additive show an enhanced photovoltaic performance with a champion power conversion efficiency up to 22.14% and improved long‐term stability. This work demonstrates that the formation of multilevel low‐dimensional structure is a new strategy for the preparation of efficient and stable PSCs. Abstract : EMIM + interacts with PbI2 to form a 1D perovskite of EMIMPbI3 and exhibits an overall multi‐level distribution, achieving effective defect passivation and improved photovoltaic performance for MAPbI3 ‐based perovskite solar cells with an EMIMTFA additive. This work provides a novel strategy for using ionic liquids to improve the performance of perovskite photovoltaic devices.