Does Involving Additional Linker Always Increase the Efficiency of an Organic Dye for p-Type Dye-Sensitized Solar Cells?

A series of different simple and fused conjugated structures as additional spacers for dyes with triphenylamine and cyanoacrylic acid as the donor and acceptor units have been designed and investigated with density functional theory/time-dependent density functional theory studies to understand the consequence on the efficiency for p-type dye-sensitized solar cells (p-DSSCs). According to the calculated charge-transfer properties, light-harvesting efficiencies and driving forces, such as hole injection, dye regeneration, and charge-recombination; benzene and complex fused-ring spacers lead to an effective increase in the efficiencies of such dyes. Our analysis thus provides an assistance in designing more efficient p-type photosensitizers, which contributes to the tandem DSSCs.