Over 10% Efficient Sb <sub>2</sub> (S,Se) <sub>3</sub> Solar Cells Enabled by CsI‐Doping Strategy
Lei Zhang, Jianzha Zheng, Cong Liu, Yifei Xie, Hanyu Lu, Qinrong Luo, Yulong Liu, Huidong Yang, Kai Shen, Yaohua Mai
Abstract
Abstract Antimony selenosulfide (Sb 2 (S,Se) 3 ) is an emerging quasi‐1D photovoltaic semiconductor with exceptional photoelectric properties. The low‐symmetry chain structure contains complex defects and makes it difficult to improve electrical properties via doping method. This article reports a doping strategy to enhance the efficiency of Sb 2 (S,Se) 3 solar cells by using alkali halide (CsI) as the hydrothermal reaction precursor. It is found that the Cs and I ions are effectively doped and atomically coordinate with Sb ions and S/Se ions. The CsI‐doping Sb 2 (S,Se) 3 absorbers exhibit enhanced grain morphologies and reduced trap densities. The consequential CsI‐doping Sb 2 (S,Se) 3 based solar cells demonstrate favorable band alignment, suppressed carrier recombination, and improved device performance. An efficiency as high as 10.05% under standard AM1.5 illumination irradiance is achieved. This precursor‐based alkali halide doping strategy provides a useful guidance for high‐efficiency antimony selenosulfide solar cells.