Dye-sensitized solar cells composed of photoactive composite photoelectrodes with enhanced solar energy conversion efficiency

Abstract

Phosphor particles were introduced as a luminescent medium to improve the overall efficiency of dye sensitized solar cells (DSSCs). In the preparation process, TiO₂ and phosphor particles were mixed to make photoelectrodes with bilayer (TiO₂/mix), 3-layer (TiO₂/mix/TiO₂) and 4-layer (TiO₂/mix/TiO₂/mix) structures. The cell with the bilayer structure (TiO₂/mix) after treating with TiCl₄ solution showed the highest light-to-electric energy conversion efficiency (8.78%), which was ∼25.8% higher than that of a cell with a pure TiO₂ layer under the same experimental conditions. The improvement in the energy conversion efficiency of DSSCs was attributed to phosphor enhanced incident light-harvesting via up- and down-conversion luminescence processes, resulting in an increase in the photocurrent.