24.20%‐Efficiency MA‐Free Perovskite Solar Cells Enabled by Siloxane Derivative Interface Engineering
Yuwei Duan, Kun He, Lu Yang, Jie Xu, Wenjing Zhao, Zhike Liu
Abstract
Abstract Suppressing defects at the interface between the TiO 2 electron transport layer (ETL) and perovskite film is critical for high efficiency and stable perovskite solar cells (PSCs). Herein, a siloxane derivative diethylphosphatoethylsilicic acid (PSiOH) is developed to modify the interface of TiO 2 ETL/FA 0.83 Cs 0.17 PbI 3 perovskite. Comprehensive characteristics reveal that silicon hydroxyl (SiOH) in PSiOH can reduce surface defects, improve the electrical properties and optimize the energy band structure of TiO 2 by forming a SiOTi bond, while the phosphate bond (PO) in PSiOH can passivate Pb‐related defects on the perovskite bottom surface. Consequently, PSiOH‐modified PSCs yield a remarkable power conversation efficiency of 24.20% and improved air, thermal, or illumination stabilities. This study provides insight into passivation defects at the buried interface for efficient and stable PSCs.