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

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 similar to 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.