The Electrical and Thermal Transport Properties of La-Doped SrTiO(3) with Sc(2)O(3) Composite

Donor-doped strontium titanate (SrTiO(3)) is one of the most promising n-type oxide thermoelectric materials. Routine doping of La at Sr site can change the charge scattering mechanism, and meanwhile can significantly increase the power factor in the temperature range of 423–773 K. In addition, the introduction of Sc partially substitutes Sr, thus further increasing the electron concentration and optimizing the electrical transport properties. Moreover, the excess Sc in the form of Sc(2)O(3) composite suppresses multifrequency phonon transport, leading to low thermal conductivity of κ = 3.78 W·m(−1)·K(−1) at 773 K for sample Sr(0.88)La(0.06)Sc(0.06)TiO(3) with the highest doping content. Thus, the thermoelectric performance of SrTiO(3) can be significantly enhanced by synergistic optimization of electrical transport and thermal transport properties via cation doping and composite engineering.