Analysis of temperature dependent I – V measurements on Pd/ZnO Schottky barrier diodes and the determination of the Richardson constant

Temperature dependent current–voltage ( I – V ) and Hall measurements were performed on Pd/ZnO Schottky barrier diodes in the range 20–300 K. The apparent Richardson constant was found to be 8.60 × 10 - 9 A K - 2 cm - 2 in the 60–160 K temperature range, and mean barrier height of 0.50 eV in the 180–300 K temperature range. After barrier height inhomogeneities correction, the Richardson constant and the mean barrier height were obtained as 167 A K - 2 cm - 2 and 0.61 eV in the temperature range 80–180 K, respectively. A defect level with energy at 0.12 eV below the conduction band was observed using the saturation current plot and ( 0.11 ± 0.01 ) eV using deep level transient spectroscopy measurements.