Composition dependent metal-semiconductor transition in transparent and conductive La-doped BaSnO3 epitaxial films

Perovskite-structured (LaxBa1-x)SnO3 (x = 0-0.20) (LBSO) films were epitaxially grown on MgO substrates by pulsed laser deposition, and the structural, electrical, and optical properties of the films were investigated. Results show that these films exhibit a high transmittance of more than 90% in the visible region and dopant concentration-dependent metal-semiconductor transition (MST). With increasing La content from 0 to 0.20 in LBSO films, the MST temperatures decrease from 105 to 32 K and then increase again regularly. The semiconducting behaviors at low temperatures of the films with different La doping concentrations were explained by two different conductive models based on weak localization and Anderson localization. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4770299]