Variable range hopping crossover and magnetotransport in PLD grown Sb doped ZnO thin film

摘要

We report on the variable range hopping (VRH) crossover in the electrical transport of Sb doped ZnO (SZO) thin film. Structural, chemical, electrical and magnetotransport properties were carried out on SZO thin film grown by pulsed laser deposition. X-photoelectron spectroscopy study confirms the presence of both Sb3+(33%) and Sb5+(67%) states. Sb doped ZnO thin film shows n-type behavior which is attributed to the formation of Sb-Zn and/ or Sb-Zn-V-Zn defect complex. Temperature dependent resistivity measurement showed that in a low temperature regime (< 90 K) transport is governed by the 3D-VRH mechanism. A crossover from 3D-VRH to Efros-Shklovoski VRH was observed around 12 K. Negative magnetoresistance (MR) is observed in the entire temperature range (300-5 K), however, there is an upturn in the MR behavior at 5 K suggesting the existence of a positive component. The MR behavior of Sb doped ZnO thin films is explained by the Khosla and Fischer model.