Bifunctional Compound Induced Dual Back Surface Fields for Efficient Hole Transport Layer‐Free Perovskite Solar Cells
Abstract
Abstract Carbon‐based hole transport layer‐free (C‐HTL‐free) perovskite solar cells (PSCs) are promising for low‐cost and stable photovoltaics, but the HTL absence deteriorates their power conversion efficiency (PCE) due to the lack of back surface field (BSF). In this work, the benefits of forming dual BSFs in improving the PCE of C‐HTL‐free PSCs are first investigated by simulation. Then, trityl tetrakis(pentafluorophenyl)borate (Tr + TPFB − ) is introduced into the C‐HTL‐free PSCs by post‐treatment for the first time, which enables the formation of dual BSFs. TPFB − passivates n‐doping defects in perovskite and leads to the formation of perovskite n‐p homojunction, while Tr + extracts electrons from carbon and lowers its work function, which succeeds realizing dual BSFs. This improves the separation and extraction of photocarriers within the device, which is evidenced by the photoluminescence lifetime imaging of the device cross‐section for the first time. As a result, the average open‐circuit voltage increases significantly by about 70 mV, which largely contributes to the improvement of PCE with a champion value of 20.79% obtained.
Article Details
Authors (14)
Chaoyang Wang
School of Chemistry and Chemical Engineering, Research Institute of Materials Science
Junwei Xiang
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Luoyu Road 1037 Wuhan Hubei 430074 P. R. China
Jiale Liu
Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University
Chuanzhou Han
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Luoyu Road 1037 Wuhan Hubei 430074 P. R. China
Ziwei Zheng
Minghao Xia
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Luoyu Road 1037 Wuhan Hubei 430074 P. R. China
Song Shen
School of Biomedical Sciences and Engineering Guangzhou International Campus South China University of Technology Guangzhou Guangdong P. R. China
Zhaozhen Cui
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Luoyu Road 1037 Wuhan Hubei 430074 P. R. China
Xiaoru Wang
Jiayu Xie
Xiaoyu Li
Anyi Mei
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education Huazhong University of Science and Technology Wuhan Hubei China
Yang Zhou
Hongwei Han
Michael Grätzel Center for Mesoscopic Solar Cells Wuhan National Laboratory for Optoelectronics Key Laboratory of Materials Chemistry for Energy Conversion and Storage of Ministry of Education Huazhong University of Science and Technology Wuhan Hubei China