DFT study of thermoelectric performance of SrTiO3 doped by tantalum

Abstract

This paper deals with enhancement of thermoelectric performance of SrTiO3 - a perovskite-based material by doping Ti-site with Ta. The electronic and the thermoelectric transport properties of doped SrTiO3 were studied using the first principle calculation in full-potential of density functional theory. Spin-orbit coupling including Hubbard U parameter influences were observed in the investigation. Energy band structure and electron density of state were determined for electronic properties. The Seebeck coefficients, thermal conductivity, electrical conductivity as well as thermoelectric efficiency ZT were calculated for thermoelectric properties. The results of our calculations revealed that narrowing the bandgap of the material leads to the increase of thermoelectric efficiency ZT. At spin-orbit coupling with DFT+U method, ZT of 0.18 at 750 K were obtained and this is similar to the experimental data reported.