Polycomponent Electrocatalysts for I-Mediated Dye-Sensitized Solar Cells

Dye-sensitized solar cells (DSSCs) are promising photovoltaic devices with reasonably high power conversion efficiencies and significantly lower costs compared to other solar cell types (e.g. silicon/thin film solar cells). A typical DSSC device consists of a mesoporous TiO₂ film sensitized with a dye as the photoanode, an electrolyte with the iodide/triiodide redox couple, and a Pt film as the counter electrode (CE). Recently, a large variety of inexpensive materials have been developed as alternatives to conventional Pt counter electrodes. Among these, polycomponent counter electrodes composed of inorganic compounds (e.g. Cu₂ZnSnS₄, CuInS₂ and NiCo₂S₄) have attracted more interest due to their comparable electrocatalytic activity and abundance. This chapter will summarize recently reported polycomponent materials for use in DSSCs. Emphasis will be placed on the role of these new materials and how they translate into enhanced performance in DSSCs.