Doping-induced changes in the physical properties of In2O3:Sn films

Abstract

Here we report studies carried out on heavily tin-doped and undoped indium oxide films. Structural, electronic transport and compositional properties of the sprayed films deposited with different doping levels of tin (0-110 at.% in solution), were investigated. X-ray diffraction, room-temperature Hall effect measurements, conductivity measurements at low temperatures and x-ray photoelectron spectroscopy were used for these studies. The films were polycrystalline and the preferred growth showed systematic changes with dopant incorporation from (400) to (222). The carrier mobility was very sensitive to these changes in orientation of preferred growth as well as the grain size. The high carrier concentration ( approximately 1020 cm-3) implied that the films belong to the class of degenerate semiconductors. Such a high carrier concentration was a result of increased non-stoichiometry and increased dopant incorporation. The conductivity measurements at low temperatures show that with increased Sn incorporation, electronic transport is governed by ionized impurity scattering and acoustic lattice scattering.