Investigating the effect of Ca-doping concentration on optical and electronic properties of RaTiO3 for energy applications

The current study utilized DFT (density functional theory) calculations to examine the influence of Ca-doping on the optoelectronic properties of Ra_0.875Ca_0.125TiO₃ (RCT12), Ra_0.75Ca_0.25TiO₃ (RCT25), and Ra_0.625Ca_0.375TiO₃ (RCT37). We utilize the FP-LAPW + lo (full potential linearized augmented plane wave plus local orbital) method in order to solve the Kohn–Sham equations using the generalized gradient approximation (GGA). The GGA model along with Hubbard potential (GGA + U) is utilized to compute fundamental properties of the studied perovskites. The energy bandgap values for RCT12, RCT25, and RCT37 are around 1.96, 1.92 and 1.87 eV, respectively. From the obtained \(\varepsilon_2 (\omega )\) spectra, it is evident that RCT12, RCT25, and RCT37 compounds shows a substantial absorption of incoming photons in the visible and near UV region. The computed values of \(n(\omega )\) for RCT12, RCT25, and RCT37 are 1.79, 1.77 and 1.76, respectively. The aforesaid compounds having \(n(\omega )\) values in the range of 1.0 and 2.0 are regarded as active optical materials. The optoelectronic characteristics of RCT12, RCT25, and RCT37 suggest that they have promising potential for use in energy-related applications like solar cells.