Preparation of a Phosphor/TiO2 nanoparticle composite layer for applications in dye-sensitized solar cells

The conversion luminescence of a phosphor from the ultraviolet region to the visible region can enhance the light harvesting in dye-sensitized solar cells (DSSCs), because many dyes can only absorb visible light. To explore the influence of phosphor additives on the conversion efficiency of DSSC, we introduce the nanocrystalline YAG:Eu phosphors into TiO2 photoelectrodes. The photoluminescence measurement showed that a broad solar spectrum including the ultraviolet region could be reabsorbed by the dye N-719 via conversion luminescence due to the phosphor. With the introduction of the phosphor, both the photocurrent and the photovoltage of the DSSC could be improved due to the enhanced light harvesting and the elevated energy levels of the oxides. With the optimal concentration of phosphor doping in the electrode, the cells light-to-electricity conversion efficiency could be improved by a factor of 1.14 compared to that for a cell without phosphor doping.