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

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 mu V K-1). The maximum thermoelectric power factor was 39 mu Wcm(-1) K-2 at a carrier concentration of 7 x 10(20) cm(-3). La-delta-doped superlattices were also characterized and exhibited Seebeck coefficients of similar to 500 mu V K-1. The results are discussed in the context of reports of enhanced Seebeck coefficients in delta-doped SrTiO3 superlattices. (C) 2010 American Institute of Physics. [doi:10.1063/1.3471398]