Low-temperature electrical properties and barrier inhomogeneities in ITO/-Ga₂O₃ Schottky diode

This study reports the electronic properties of the indium tin oxide (ITO)/beta-Ga2O3 Schottky diode through the temperature (50-320 K)-dependent current density-voltage, capacitance-voltage, and admittance spectroscopy experiments. The room-temperature turn-on voltage of the ITO/beta-Ga2O3 diode was observed to be 0.83 V, and it exhibited a slow increase with decreasing temperature. The ITO/beta-Ga2O3 diode's ideality factor (n) varied from 3.92 to 1.05, and the zero-bias Schottky barrier height (phi(bo)) varied from 0.31 to 1.28 eV. The temperature-dependent n and phi(bo) indicate the spatial inhomogeneities of the potential barrier at the Ga2O3-ITO interface. We exploit the Gaussian distribution model to explain the Schottky barrier inhomogeneities, which could be associated with the defects observed by the admittance spectroscopy method.