Efficient and stable flexible Sb2Se3 thin film solar cells enabled by an epitaxial CdS buffer layer

Recently, Sb2Se3, an Earth-abundant constituents compound, has emerged as a promising low-cost thin film photovoltaic material. The Sb2Se3 solar cells with a polycrystalline CdS buffer layer suffer from unsatisfactory photoexcitation stability. Herein, we fabricate flexible Sb2Se3 thin film solar cells by utilizing the transferable van der Waals epitaxial CdS on mica as a buffer layer. Compared to the nonepitaxial CdS buffer layer, the epitaxial CdS can significantly reduce the interface defects and interfacial diffusion. With the improved Sb2Se3/CdS interface, we obtained a power conversion efficiency of 7.15%, and the flexible Sb2Se3 solar cell exhibits an excellent stability under the continuous illumination. In addition, after 1000 bending cycles with a 50 degrees bending angle, the flexible device maintained over 90% of the initial efficiency. These encouraging results demonstrate a potential application of Sb2Se3 solar cells in flexible, lightweight, and wearable power supply.

Automated summary

The authors successfully fabricated flexible Sb2Se3 thin film solar cells with epitaxial CdS buffer layer, achieving a high power conversion efficiency and excellent stability. These results demonstrate the potential application of Sb2Se3 solar cells in flexible, lightweight, and wearable power supply.