Electrophoretic Deposition of NiCo2S4 Thin Film As a Catalytic Material for Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSCs) have become one of the most promising photovoltaic devices due to their low cost, simple fabrication, and relatively high powerconversion efficiency.To reduce the cost of DSCs, it is necessary to find out high-efficiency and low-cost alternatives to replace the conventional noble Pt counter electrode (CE). Among inorganic compounds, transition metal sulfides, such as CoS, NiS,MoS₂ and WS₂, have attracted extensive attention dueto their excellent electrocatalytic activity for I₃⁻ reduction.

In this study, NiCo₂S₄ was firstly synthesized via a facile solvothermal method and then subjected to electrophoresis onto a fluorinated tin oxide (FTO) glass substrate. The resultant NiCo₂S₄ CE demonstrated both high transmittance (>75%) at visible wavelengths and improved electrocatalytic activity, while the DSC based on the transparent CE still achieved an impassive cell efficiency of 6.14%.Moreover, the NiCo₂S₄ films deposited by the facile electrophoretic deposition has the following benefits,including low temperature, high depositionrate, controllable thickness, great uniformity, scalable production, and without using any organic binders.Therefore, the DSC assembled withthe transparent NiCo₂S₄ CE could be a promising candidate as Pt-free CE for DSCs application.