Improving Performance of Dye-Sensitized Solar Cell by Multi-Emission Effect of Phosphors.

Generally, the N-719 dye, used in dye-sensitized solar cells (DSSCs), only absorbs visible light in the wavelength range from 400 to 700 nm. Consequently, most of the ultraviolet and infrared rays from the sun are not utilized by this dye. However, ultraviolet and infrared rays can be converted to visible light by upconversion luminescence. Such visible light can then be reabsorbed by the dye, allowing for a larger range of solar irradiation to be utilized in DSSCs. Phosphor (ZnGa2O4, Y2O3:Er(3+)), acting as a luminescence medium, was added to the TiO2 electrode of DSSCs, and owing to the effect of upconversion, it increased their photocurrent density and efficiency. Phosphor (ZnGa2O4, Y2O3:Er(3+)) co-doped TiO2 electrode cells showed better performance than phosphor-free cells. In fact, the highest efficiency observed for a DSSC containing five phosphor layers was 7.03% with a short-circuit current density (Jsc) of 15.62 mA/cm2, an open circuit voltage (Voc) of 0.661 V, and a fill factor (FF) of 68.17%.