Improvement of the Thermoelectric Properties of the Perovskite SrTiO3 by Cr-Doping

In recent years, among different thermoelectric materials, SrTiO3 have been receiving great attention due to their greater capacity and conversion between electrical energy and heat energy. The thermoelectric properties of the SrTiO3 can be improved by substitutional doping on different sites (A-site and B-site) in the lattice. In this study, the improvement of the thermoelectric performance of the perovskite SrTiO3 by Cr-doping has been investigated. The doped SrTiO3 with Cr was synthesized by the conventional solid-state reaction method. The electronic transport properties including Seebeck coefficient, electrical conductivity, and thermal transport properties in a moderate temperature regime from 300 to 900K have been investigated. The large absolute value of the Seebeck coefficient with low thermal conductivity was achieved by Cr-doping. The electrical conductivity was quite low but increased with increasing doping level up to x=0.002mol, and; hence, the power factor increased with increasing doping level up to x=0.002mol. The maximum ZT value was observed for SrTi0.998Cr0.002O3 at 773K by the combination of a high value of the Seebeck coefficient and low thermal conductivity.