Synergistic Effects of Interfacial Energy Level Regulation and Stress Relaxation via a Buried Interface for Highly Efficient Perovskite Solar Cells
Jianfei Fu1, Jiajia Zhang1, Taoyi Zhang2, Ligang Yuan3, Zelong Zhang1, Zhixuan Jiang1, Zhezhi Huang1, Tiao Wu1, Keyou Yan3, Longgui Zhang2, Ailian Wang2, Wenxi Ji2*（计文希）, Yi Zhou1*（周祎）, and Bo Song1*（宋波）
1 Laboratory of Advanced Optoelectronic Materials, Suzhou Key Laboratory of Novel Semiconductor Materials and Devices, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China
2 Sinopec (Beijing) Research Institute of Chemical Industry Co., Ltd, Beijing 100013, China;
3 School of Environment and Energy, State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510006, China
ACS Nano 2023, 17, 2802--2812
An electron-transport layer with appropriate energy alignment and enhanced charge transfer is critical for perovskite solar cells (PSCs). In addition, interface stress and lattice distortion are inevitable during the crystallization process of perovskite. Herein, IT-4F is introduced into PSCs at the buried SnO2 and perovskite interface, which assists in releasing the residual stress in the perovskite layer. Meanwhile, the work function of SnO2/IT-4F is lower than that of SnO2, which facilitates charge transfer from perovskite to ETL and consequently leads to a significant improvement in the power conversion efficiency (PCE) to 23.73%. The VOC obtained is as high as 1.17 V, corresponding to a low voltage deficit of 0.38 V for a 1.55 eV bandgap. Consequently, the device based on IT-4F maintains 94% of the initial PCE over 2700 h when stored in N2 and retains 87% of the initial PCE after operation for 1000 h.