Current Status and Future Prospects of Kesterite Cu2ZnSn(S,Se)4 (CZTSSe) Thin Film Solar Cells Prepared via Electrochemical Deposition

Abstract The fabrication of kesterite Cu 2 ZnSn(S,Se) 4 (CZTSSe) thin‐film solar cells using the electrochemical deposition (ED), which is valued for its industrial feasibility, offers a cost‐effective and environmentally friendly approach to the carbon‐free and clean energy production. However, the reported power conversion efficiency of approximately 10 % for electrodeposited CZTSSe thin‐film solar cells is lower compared to the alternative methods like sputtering and spin‐coating, which is mainly attributed to the phase inhomogeneity and the rough morphology generated during the ED process. Ensuring the microscopic and macroscopic uniformity of the electrodeposited films is crucial for the improvement of the film quality and the device performances. In this review, strategies to address these challenges including the intrinsic film control such as the deposition mode, pH, concentration of metal ions, and complexing agents, as well as the extrinsic approaches such as doping, substitution of metal elements, and the introduction of interfacial layers. In addition, the prospects for the electrochemically deposited CZTSSe solar cells were presented, focusing on the promising applications in tandem, flexible, and solar water‐splitting devices. Finally, this review will provide technical insights into the ED process for preparing CZTSSe solar cells, outlining a perspective for the future development of highly efficient CZTSSe thin film solar cells.