Improving Photovoltaic Performance of Dye-Sensitized Solar Cell by Effect of Y2O3:Yb3+, Er3+

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 infrared radiation from the sun is not utilized by this dye. However, infrared radiation 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. Yb3+, Er-doped yttrium oxide (Y2O3:Yb3+, Er3+), 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. DSSCs coated with phosphor layers containing Y2O3:Yb3+, Er3+ showed better performance than phosphor-free cells. In fact, the highest efficiency observed for a DSSC containing five phosphor layers was 6.95% with a short-circuit current density (J(sc)) of 15.91 mA/cm(2), an open circuit voltage (V-oc) of 0.67 V, and a fill factor (FF) of 65.05%.