Heterojunction Interface Anomalous High‐Energy Level Insertion Modulating Carrier Dynamics in High‐Efficiency Antimony Selenide Thin‐Film Solar Cells
Bangzhi Shen, Tingyu Zhang, Junjie Dong, Jinling Zhang, Boning Dong, Han Zhang, Sai Jiang, Ding Gu, LvZhou Li, Shuai Zhang, Jianhua Qiu, Huafei Guo, Ningyi Yuan, Jianning Ding
Abstract
Abstract 1D antimony selenide (Sb 2 Se 3 ) films are commonly used as absorber layers in high‐efficiency thin‐film solar cells due to their excellent optoelectronic properties. However, the performance of Sb 2 Se 3 solar cells is severely limited by serious carrier recombination. Exploring effective carrier recombination and transport regulation is crucial to enhancing the performance of Sb 2 Se 3 solar cells. In this work, unlike previously reported conventional gradient band structures, a high‐energy‐level ultrathin amorphous tin oxide layer (SnO 2 ) deposited by atomic layer deposition is used as an interfacial layer inserted at the cadmium sulfide (CdS)/Sb 2 Se 3 heterojunction. Unlike previously reported interfacial layers, the SnO 2 interface layer does not exhibit significant ion diffusion at the heterojunction interface. Notably, the results indicate that the interfacial SnO 2 layer can promote the [ hk 1] orientation, thereby enhancing orientation‐induced carrier transport. Furthermore, the interfacial SnO 2 layer can significantly reduce both interfacial and bulk defects, improve interfacial carrier extraction, and decrease carrier recombination. This leads to improved carrier transport and collection. Ultimately, a high‐efficiency Sb 2 Se 3 solar cell with an efficiency of 9.73% is achieved based on enhanced [ hk 1] orientation, increased carrier lifetime, and optimized band alignment. This work can also provide crucial theoretical and technical support for the sustainable development of thin‐film solar cells.