Temperature dependence of reverse bias capacitance-voltage characteristics of Sn/p-GaTe Schottky diodes

A Schottky barrier diode on unintentionally doped p-type GaTe grown by the directional freezing method was obtained and characterized by the capacitance-voltage technique as a function of temperature (100-300 K). Using vacuum evaporated Sn as the Schottky barrier contact and In for the ohmic contact, high-quality diodes were produced. The discrepancy between Schottky barrier heights (BHs) obtained from current-voltage-temperature and capacitance-voltage-temperature measurements is explained by the introduction of a spatial distribution of BHs due to barrier height inhomogeneities that prevail at the metal/GaTe interface. The deviations of apparent BHs were investigated by considering the microstructure of the metal/GaTe interface. It was found that the dispersion of this distribution across the contact area grew increasingly larger at lower temperatures and was responsible for the increasing difference between apparent BHs obtained from the two techniques.