Regulating Energy Band Alignment via Alkaline Metal Fluoride Assisted Solution Post‐Treatment Enabling Sb<sub>2</sub>(S,Se)<sub>3</sub> Solar Cells with 10.7% Efficiency
Yuqi Zhao, Shaoying Wang, Chenhui Jiang, Chuang Li, Peng Xiao, Rongfeng Tang, Junbo Gong, Guilin Chen, Tao Chen, Jianmin Li, Xudong Xiao
Abstract
Abstract Continuously boosting the power conversion efficiency (PCE) and delving deeper into its functionalities are essential problems faced by the very new antimony selenosulfide (Sb 2 (S,Se) 3 ) solar technology. Here, a convenient and effective solution post‐treatment (SPT) technique is used to fabricate high‐performance Sb 2 (S,Se) 3 solar cells, where alkali metal fluorides are applied to improve the quality of Sb 2 (S,Se) 3 films in terms of morphology, crystallinity, and conductivity. In particular, this approach is able to manipulate the S/Se gradient in the films and creates favorable energy alignment which facilitates the carrier transport. As a result, the fill factor and short‐circuit current density of Sb 2 (S,Se) 3 solar cells (Glass/FTO/Zn(O,S)/CdS/Sb 2 (S,Se) 3 /Spiro‐OMeTAD/Au) based on the SPT strategy are significantly enhanced, achieving a champion efficiency of 10.7%. To date, this conversion efficiency value represents the highest efficiency of all Sb‐based solar cells. This study provides an effective post‐treatment strategy for improving the quality of Sb 2 (S,Se) 3 film which sheds new light on the fabrication of high‐efficiency Sb 2 (S,Se) 3 solar cells.