Au/Mn5Ge3/n-Ge(111) Schottky barrier characteristics from I-V-T and C-V-T data

I-V and C-V measurements performed on Au/Mn5Ge3/n-Ge structures, prepared for spintronic applications, are presented and analysed over a wide range of temperatures (50 K–300 K) with the goal of elucidating the prevailing conduction mechanism(s). The effects of image force lowering and recombination in the depletion region on the measured current are shown to be of little significance and cannot acceptably explain the drawbacks that arise when a pure thermionic emission model is used in analyzing the temperature dependence of the obtained electrical characteristics. Considering, however, the eventual contribution of thermally assisted tunneling to the current generating mechanism could explain the departure from pure thermionic emission. Thermionic field emission seems indeed to explain better our I-V data and the temperature dependence of related parameters. Also, the C-V measurements reveal a nonuniform carrier distribution with manifest peaks in the doping profile, possibly signifying the existence of charge accumulation and trap centers.