High-Efficiency Dye-Sensitized Solar Cells Based on Kesterite CuZnSnSe Inlaid on a Flexible Carbon Fabric Composite Counter Electrode.

Composite counter electrodes have been shown to be a practical and effective strategy in dye-sensitized solar cell (DSSC) application. In this work, we designed and prepared a single-crystal CuZnSnSe (CZTSe) plate structure on flexible carbon fabric as a DSSC cathode, which combines the best of the two worlds, namely, the superior catalytic activity and hierarchical microstructure of kesterite CZTSe and the high conductivity and expanded framework of carbon fabric. The composite counter electrode presented a power conversion efficiency of 8.45% and a long-term bending reservation. The remarkable device property is due to the high catalytic activity, good adherence to conductive matrix grains, effective electron migration, and quick iodide species diffusion of the novel cathode. Our results suggest that the CZTSe@carbon fabric composite could be a high-efficiency Pt-free cathode in DSSCs.