On the studies of capacitance-voltage-temperature and deep level characteristics of an Au/p-GaTe Schottky diode

Abstract

This paper deals with the capacitive properties of an unintentionally doped Au/p-GaTe/In Schottky junction. The capacitance-voltage (C-V) measurements are realized at 120–300 K temperature range and also, the deep level characteristics at bulk of p-GaTe are investigated by thermally stimulated capacitance measurement technique (TSC). The C-V measurements yield the C−2 − Vr curves with fairly high correlation at high temperatures. However, the anomaly decreasing of the capacitance values with the temperature is attributed to the ionization of the deep levels which are electrically active at closely 100–270 K temperature ranges. In addition, due to the effect on the measured capacitance curves of the series resistance, the true capacitance characteristics are obtained. The values of barrier height are calculated to be 0.639 eV at 300 K and 1.556 eV at 140 K and it does not follow to the variation of forbidden energy band gap of p-GaTe. In addition, it is seen that the barrier height values from true capacitance curves are the more resolute from the barrier heights of measured capacitance curves. Moreover, the rapid increasing of the barrier height values at low temperatures is only attributed to the effect of the deep levels.