The Indium tin oxide (ITO) interlayer was deposited on the surface of n-Hg3In2Te6 (short for MIT) wafer by means of Pulsed Laser Deposition (PLD) method for improving the Au/n-MIT Schottky contact properties. Through the XPS depth profile analysis, it was found that the In3+ on the surface of MIT changed to In-0 due to the reduction of O-0 during the ITO deposition process. When the ITO interlayer was prepared between Au and MIT, the leakage current and series resistance of Au/n-MIT contact decreased and the Schottky barrier height increased. This phenomenon can be explained that the ITO passivation layer reduced the surface states of MIT wafer and weakened the Fermi level pining, which was caused by that In3+ on the surface of MIT changed into In-0 due to the reduction of O-0 and O2- obtained the electrons from In3+ occupied the Hg2+ vacancies. (C) 2016 Elsevier B.V. All rights reserved.