Seebeck coefficient of a quantum confined, high-electron-density electron gas in SrTiO3

Abstract

We report on the Seebeck coefficient of quantum confined electron gases in GdTiO3/SrTiO3 heterostructures. These structures contain two-dimensional electron gases with very high sheet-carrier concentrations on the SrTiO3-side of the interface due to intrinsic interface doping. While the sheet carrier concentrations are independent of the thickness of the SrTiO3 layer, the Seebeck coefficient initially increases with SrTiO3 thickness before saturating at a value of similar to 300 mu K/V. A model of the Seebeck coefficient, based on thermally populated, self-consistent, tight binding subbands, captures in a semi-quantitative manner the observed thickness dependence. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4704363]