Electrical transport characteristics of Au/n-GaN Schottky diodes

The current-voltage measurements were performed in the temperature range (80-300 K) on Au/ n-GaN Schottky barrier type diodes. The Schottky diode shows non-ideal I(VG) behaviour with ideality factors n equals to 1.18 and 1.81 at 300 K and 80 K, respectively, and are thought to have a metal-interface layer-semiconductor configuration. Under forward bias and for T ≥ 200 K, the electrical current transport was controlled by the thermionic emission (TE) process. However, for T ≤ 200 K, The current was controlled by the thermionic field emission (TFE). The characteristic energy E00 = 3.48 meV was obtained from the I(VG, T) measurements and agreed very well with the value of E00 = 3.62 meV calculated theoretically. The zero-bias barrier height ϕB0 determined from the I(VG) measurements was 0.84 eV at 300 K and decreases to 0.49 eV at 80 K.