Influence of Sr doping on BaTiO3 properties: A combined DFT and experimental approach

Barium titanate (BaTiO₃) has been extensively used as a compound due to its potential for optoelectronics and electronic applications. The density functional theory (DFT) calculations as well as chemically prepared thin films were used to investigate the effect of the alkaline earth metal Sr on the electronic, thermoelectric, structural, morphological, and optical properties of the BaTiO₃ host matrix. It was found in band structure analysis that the bandgap nature changed from indirect to direct bandgap upon incorporation of the Sr atom into the BaTiO₃ host lattice. Thermoelectric characteristics showed notable changes in response to temperature and doping. The investigation demonstrated that optimized electrical conductivity, reduced thermal conductivity, and an enhanced Seebeck coefficient were achieved with a precise (5.55 %) Sr content. XRD analysis revealed the cubic phase of the prepared thin films. Morphological investigation showed the evolution of grain with the increase in dopant contents. The theoretical and experimentally measured optical characteristics also revealed that Sr doping improved the material’s refractive index, conductivity, and absorption coefficient in the visible and ultraviolet energy ranges. Significant enhancements in electronic, thermoelectric, and optical properties suggest that doped BaTiO₃ could be considered a potential applicant for optoelectronic as well as thermoelectric applications.