A review of the development of graphene-incorporated dye-sensitized solar cells

To utilize abundant solar energy, dye-sensitized solar cells (DSSCs) have attracted researchers’ attention due to many reasons, such as low production costs, easy fabrication methods, low toxicity of the materials, and relatively high-power conversion efficiencies. The use of expensive metal-dye complexes, the lack of long-term stability due to the use of liquid electrolytes, and the use of rare and expensive Pt as the CE are the major drawbacks preventing the large-scale production of DSSCs. However, recent studies showed alternative materials can be used to enhance the DSSC performance. The unique properties of graphene make it an ideal additive to improve the functions of all three components of DSSCs. Graphene’s high optical transmittance and electron mobility are suitable to improve transparent conducting substrates and nanostructured wide bandgap semiconductor layers of the photoelectrode. Graphene quantum dots have a wide absorption spectrum and thus can be used as photosensitizers. High catalytic activity, high electrical conductivity, high corrosion resistance, and a larger specific surface area make graphene and its composites suitable for making CEs. In addition, graphene has been used to improve composite electrolytes intended for DSSCs. Considering all these facts, this article reviews the recent developments and applications of graphene-based materials in photoelectrodes, electrolytes and CEs and the possible uses of graphene to improve DSSCs.