Photoelectric properties of the layered raspberry sandwich amorphous ZnCo 2 S 4 @MnCo 2 S 4 /CP composite counter electrode in semiconductor-sensitized solar cells.

Multistage amorphous materials have promising applications in the catalytic performance of dye-sensitized solar cells (DSSCs). Herein, an amorphous sheet-raspberry sandwich-like ZnCo 2 S 4 @MnCo 2 S 4 /CP composite material was rationally designed and developed as a counter electrode (CE) for DSSCs by applying a three-step hydrothermal method. The first development of the amorphous composites as CEs resulted in lower charge transfer resistance at the CE/electrolyte interface and improved the fill factor and short-circuit current density. The excellent catalytic performance is mainly attributed to the large number of unsaturated coordination sites generated by the undirected structure of the lamellar-raspberry intercalated amorphous material, the smooth ion transport interface with a self-built corrosion-resistant layer, coupled with the dual catalytic performance of the Zn, Co, and Mn composites, and the good electrical conductivity of the C substrate. When ZnCo 2 S 4 @MnCo 2 S 4 /CP was used as the CE on a Ti substrate, the photoelectric conversion efficiency was as high as 11.68% ( V oc = 0.821, J sc = 20.14 mA cm -2 , and FF = 0.71) under 100 mW cm -2 light illumination. This paper provides a design idea for amorphous materials in terms of catalytic performance and a method for developing alternatives to Pt electrodes.