Large Seebeck coefficients and thermoelectric power factor of La-doped SrTiO3 thin films

Abstract

Seebeck coefficients and conductivity of La-doped SrTiO3 thin films grown by molecular beam epitaxy were measured as a function of carrier concentration. At low carrier concentrations, thin films show very high Seebeck coefficients (up to 980 μV K−1). The maximum thermoelectric power factor was 39 μWcm−1 K−2 at a carrier concentration of 7×1020 cm−3. La-delta-doped superlattices were also characterized and exhibited Seebeck coefficients of ∼500 μV K−1. The results are discussed in the context of reports of enhanced Seebeck coefficients in delta-doped SrTiO3 superlattices.