Electron-Electron Interactions in Sb-Doped SnO2 Thin Films

Abstract

Electrical conductivity and Hall-effect measurements on undoped and Sb-doped SnO2 thin films prepared by the sol-gel technique were carried out as a function of temperature (55 K to 300 K). Structural characterizations of the films were performed by atomic force microscopy (AFM) and x-ray diffraction (XRD). A doping-induced metal-insulator transition (MIT) was observed. On the metallic side of the transition, the experimental data were interpreted in terms of electron-electron interactions (EEI). The existence of EEI was confirmed by excellent agreement between theoretical and experimental data. The experimental data on the insulator side of the transition were analyzed in terms of variable-range hopping (VRH) conduction. A complete set of parameters describing the properties of the localized electrons, including hopping energy, hopping distance, and the value of the density of states at the Fermi level, was determined.