Temperature-dependent current-voltage characteristics of Se Schottky contact to n-type Ge

We fabricated Se Schottky contacts to n-type Ge and demonstrated their electrical properties using temperature-dependent current-voltage measurements in the temperature range of 200-300 K. As the temperature decreased, the barrier height decreased and the ideality factor increased. These anomalies could be associated with the barrier height inhomogeneities prevailing at the metal-semiconductor contact. On the assumption of the Gaussian distribution of barrier height, the mean value and standard deviation of barrier height, extracted from the plot of barrier height as a function of q/2kT, were found to be 0.70 and 0.089 eV, respectively. The electric field dependence of the reverse current revealed that the Schottky emission mechanism dominates the current conduction in the reverse bias.