Metal Chalcogenides (MxEy; E = S, Se, and Te) as Counter Electrodes for Dye–Sensitized Solar Cells: An Overview and Guidelines

Abstract

The dye‐sensitized solar cell (DSSC), a third‐generation photovoltaic technology, has gained considerable attention since the achievement of around 7% efficiency in 1991. To reduce the cost of the commonly used platinum (Pt) counter electrode (CE), different materials with good electrocatalytic activities have been applied as CEs for DSSCs. Recently, transition metal chalcogenides, such as metal sulfides, metal selenides, and metal tellurides, have been investigated because of their low cost, unique electrocatalytic performance, and electronic structure similar to Pt. However, more efforts remain to be made on the mechanism and application of these metal chalcogenides as CEs for DSSCs. Herein, an overview and guidelines are given on recent advances in binary and multinary metal chalcogenides used as CEs in DSSCs. The synthesis techniques and the effect of morphology optimization and stoichiometric ratios are briefly described. The development of composites made of metal chalcogenides combined with highly electrocatalytic materials, especially carbon‐based materials, is also briefly discussed. Some suggestions and methods to improve the power conversion efficiencies (PCEs) of DSSCs designed with metal chalcogenides as CEs are also provided.