First-principles analysis of Sr-doped BaTiO3 perovskites’ structural, optical, and thermoelectric properties

The influence of strontium (Sr) incorporation on the crystal structure of barium titanate (BaTiO 3 ) has been extensively studied using density functional theory (DFT) calculations with the WIEN2k package and the GGA-PBE method, resulting in significant improvements in its optical and transport properties. Sr substitution effectively narrows the band gap while simultaneously improving the dielectric function, electrical conductivity, optical absorption, and refractive index over the UV–visible spectrum. These changes demonstrate the significant potential of Sr-doped BaTiO 3 for cutting-edge optoelectronic and solar cell applications. Transport property studies reveal a typical behavior of degenerate semiconductors. High thermoelectric efficiency is supported by enhanced Seebeck coefficients for the doped structures and figures of merit (ZT), which increase from 0.24 for BaTiO 3 to 0.40 and 0.38 for Ba 0.875 Sr 0.125 TiO 3 and Ba 0.75 Sr 0.25 TiO 3 , respectively. Additionally, the materials exhibit low thermal conductivity, favorable for thermoelectric energy conversion. These findings provide valuable insights into carrier transport mechanisms and material optimization. Further experimental validation and thermal stability studies are essential to confirm the suitability of Sr-doped BaTiO 3 for practical devices in energy, optoelectronics and thermoelectric applications.