Carrier Transport Enhancement Mechanism in Highly Efficient Antimony Selenide Thin‐Film Solar Cell
Yandi Luo, Guojie Chen, Shuo Chen, Nafees Ahmad, Muhammad Azam, Zhuanghao Zheng, Zhenghua Su, Michel Cathelinaud, Hongli Ma, Zhi‐Gang Chen, Ping Fan, Xianghua Zhang, Guangxing Liang
Abstract
Abstract Exhibiting outstanding optoelectronic properties, antimony selenide (Sb 2 Se 3 ) has attracted considerable interest and has been developed as a light absorber layer for thin‐film solar cells over the decade. However, current state‐of‐the‐art Sb 2 Se 3 devices suffer from unsatisfactory “cliff‐like” band alignment and severe interface recombination loss, which deteriorates device performance. In this study, the heterojunction interface of an Sb 2 Se 3 solar cell is improved by introducing effective aluminum (Al 3+ ) cation into the CdS buffer layer. Then, the energy band alignment of Sb 2 Se 3 /CdS:Al heterojunction is modified from a “cliff‐like” structure to a “spike‐like” structure. Finally, heterojunction interface engineering suppresses recombination losses and strengthens carrier transport, resulting in a high efficiency of 8.41% for the substrate‐structured Sb 2 Se 3 solar cell. This study proposes a facile strategy for interfacial treatment and elucidates the related carrier transport enhancement mechanism, paving a bright avenue to overcome the efficiency bottleneck of Sb 2 Se 3 thin‐film solar cells.