Enhancement of thermoelectric properties of SrTiO3 by single doping at Sr and Ti site with Ho

Abstract

Electronic and thermoelectric properties of SrTiO3 were studied by doping Sr and Ti sites with Ho at doping rate of 8%. The First principle method based on density functional theory with Hubbard U and BoltzTraP code were used for calculation as implemented in Quantum Espresso. Lattice parameter, density of state and partial density of state, electronic band structure, and charge density were investigated together with thermoelectric properties which was calculated at temperature range of 100 K - 800 K. The calculations show 10% and 19.42% increment in lattice parameter after dopant at Sr and Ti respectively. Likewise the metallic nature of SrTiO3 when doped with Ho at either of the Sr or Ti site were observed on the density of state and electronic band structure. The figure of merit for both compounds were compared with experimental and simulation data of similar doping rate in Pr and similar temperature range. Maximum dimensionless figure of merit 0.345 was observed for SrTi0.92Ho0.08O3 at 650K and Sr0.92Ho0.08TiO3 is 0.386 at 800K while 0.21 at 800K and 0.23 at 670K were reported for Sr0.917Pr0.083TiO3 from simulation and experimental of previous work respectively.