Abstract
Dye-sensitized solar cells (DSCs) are molecular photovoltaics that operate efficiently in direct solar and ambient light by employing dye-impregnated mesoscopic TiO2 films with a redox electrolyte or hole conductor. Here, we report on an advanced DSC architecture, which achieves efficiencies of 13.1% under air mass 1.5 global, 100 mW cm(-2) solar radiation, and power conversion efficiency of 32% under a standard Osram 930 Warm White fluorescent tube light at 1,000 lux intensity. The cell substantially benefits from the direct contact of the dye-impregnated TiO2 film with the poly(3,4-ethylenedioxythiophene) (PEDOT) counter electrode acting as a hole collector. This reduces the diffusion path of redox mediator to merely the mesoporous TiO2 film attenuating the Warburg resistance, which thereby boosts the photovoltaic performance. This architecture will not only accelerate the practical exploitation of DSCs, but also foster new types of light-harvesting devices using mesoscopic TiO2 and PEDOT as electron and hole collection layers, respectively.