Abstract
The electronic structure and thermoelectric properties of strained (biaxially and uniaxially) Sr0.95Pr0.05TiO3 and SrTi0.95Nb0.05O3 are investigated in the temperature range from 300 K to 1200 K. Substitutions of Pr at the Sr site and Nb at the Ti site generate n-type doping and thus improve the thermoelectric performance as compared to pristine SrTiO3. Further enhancement is achieved by the application of strain, for example, of the Seebeck coefficient by 21% for Sr0. 95Pr0. 05TiO3 and 10% for SrTi0. 95Nb0. 05O3 at room temperature in the case of 5% biaxial strain. At 1200 K, we predict figures of merit of 0.58 and 0.55 for 2.5% biaxially strained Sr0. 95Pr0. 05TiO3 and SrTi0. 95Nb0. 05O3, respectively, which are the highest values reported for rare earth doped SrTiO3. (C) 2013 AIP Publishing LLC.