The electrical characteristics of Ni/n-GaSb Schottky diode

The junction characteristics of the Ni/n-GaSb Schottky diode were discussed on the basis of temperature-dependent current–voltage (I-V-T) measurements. The barrier height and ideality factor assuming thermionic emission (TE) theory shows strong temperature dependence. The Schottky barrier increases from 0.28 to 0.48 eV as the measured temperature increases from 173 to 373 K, while the ideality decreases from 1.82 to 1.15. The series resistance also increases as the measured temperature decreases due to the decrease of carrier concentration. The barrier height is plotted against q/2kT to obtain evidence of the Gaussian distribution of the barrier heights and because of barrier height inhomogeneities. From this plot, the mean barrier height and standard deviation at zero bias for as-deposited Ni/n-GaSb diode were 0.66 eV and 0.107 V, respectively. Furthermore, from a modified Richardson plot, ln(Js/T2)−(q2σS02/2k2T2) versus 1000/T, the activation energy and the Richardson constant values obtained were 0.66 eV and 6.21 A-K−2cm−2, respectively.