Transient Photocurrent Responses of Sr_1‐xCe_xTiO₃ Perovskites Under Visible Light Illumination for Photovoltaic Applications

The objective of this study was to synthesize strontium titanate (Sr_1-xCe_xTiO₃) doped with Ce³⁺ by solid state method. Its crystalline structure is Sr_1-xCe_xTiO₃, and its bandgap ranges from ~3.3 to ~2.7 eV. In the photoluminescence of samples excited at 288 nm, the maximum emission of blue light was observed at 380 and 390 nm. Photocatalytic results show that dye molecules have a high absorbance, whereas their surface area is large. According to a line sweep voltammetric plot (LSV), illumination increases the current density by 0.4 μA cm^-2 compared with dark conditions. It was demonstrated that the material changed from n-type to p-type under doping. Chronoamperometry spectra were obtained for sample Sr_1-xCe_xTiO₃ (x = 0, 0.005, 0.01, 0.03, 0.05) when an electrical voltage of 0.8 V was applied versus NHE. The plots indicate an increase in the current density under "light ON" conditions and a decrease under "light OFF" conditions. As Ce³⁺ concentration increases, the photocurrent increases until about 3 mol%, after which it decreases abruptly.