Hybridization of SnO2 and an In-Situ-Oxidized
Ti3C2Tx MXene Electron
Transport Bilayer for High-Performance Planar Perovskite Solar Cells

Yang, Lin; Wang, Baoning; Dall’Agnese, Chunxiang; Dall’Agnese, Yohan; Chen, Gang; Jena, Ajay Kumar; Wang, Xiao-Feng; Miyasaka, Tsutomu

doi:10.1021/acssuschemeng.1c05245.s001

Hybridization of SnO₂ and an In-Situ-Oxidized Ti₃C₂T_x MXene Electron Transport Bilayer for High-Performance Planar Perovskite Solar Cells

journal contribution

posted on 2021-09-27, 05:03 authored by Lin Yang, Baoning Wang, Chunxiang Dall’Agnese, Yohan Dall’Agnese, Gang Chen, Ajay Kumar Jena, Xiao-Feng Wang, Tsutomu Miyasaka

Tuning the electrical conductivity of two-dimensional (2D) MXenes by modifying the termination groups and controlled oxidation offers great potential for photovoltaic applications. Here, in-situ-oxidized Ti₃C₂T_x (O–Ti₃C₂T_x) MXene was introduced to form a nanoscale heterojunction with SnO₂ that was applied as an electron transport layer (ETL) in a MAPbI₃ perovskite solar cell (PSC). Taking advantage of the transition from metallicity to semiconductivity during the oxidation process of Ti₃C₂T_x, the properties of Ti₃C₂T_x could be tuned to have its energy levels well matched with the perovskite. Besides, the insertion of O–Ti₃C₂T_x improved the electron mobility of the SnO₂ ETL. Hence, the O–Ti₃C₂T_x/SnO₂ heterojunction offered better electron extraction and reduced recombination between the ETL and the perovskite, thus rendering an increase of the power conversion efficiency (PCE) from 17.68% to 20.09% and enhancement of stability in air.