Heterojunction Annealing Enabling Record Open‐Circuit Voltage in Antimony Triselenide Solar Cells
Rong Tang, Shuo Chen, Zhuanghao Zheng, Zhenghua Su, Jingting Luo, Ping Fan, Xianghua Zhang, Jiang Tang, Guangxing Liang
Abstract
Abstract Despite the fact that antimony triselenide (Sb 2 Se 3 ) thin‐film solar cells have undergone rapid development in recent years, the large open‐circuit voltage ( V OC ) deficit still remains as the biggest bottleneck, as even the world‐record device suffers from a large V OC deficit of 0.59 V. Here, an effective interface engineering approach is reported where the Sb 2 Se 3 /CdS heterojunction (HTJ) is subjected to a post‐annealing treatment using a rapid thermal process. It is found that nonradiative recombination near the Sb 2 Se 3 /CdS HTJ, including interface recombination and space charge region recombination, is greatly suppressed after the HTJ annealing treatment. Ultimately, a substrate Sb 2 Se 3 /CdS thin‐film solar cell with a competitive power conversion efficiency of 8.64% and a record V OC of 0.52 V is successfully fabricated. The device exhibits a much mitigated V OC deficit of 0.49 V, which is lower than that of any other reported efficient antimony chalcogenide solar cell.