The modification of electrical properties of Au/n-Hg3In2Te6 Schottky contact by the introduction of ITO interlayer

• The roughness of ITO interlayer reduced due to recrystallization with the growth temperature increasing.
• The concentration of In element presented a trend of increasing first and then decreasing from MIT to ITO.
• The leakage current of Au/MIT contact decreased, and the Schottky barrier height increased due to ITO interlayer.

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 In0 due to the reduction of O0 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 In0 due to the reduction of O0 and O2− obtained the electrons from In3+ occupied the Hg2+ vacancies.