Thermally stable Ir/n-ZnO Schottky diodes

Temperature-dependent characteristics of ZnO Schottky diodes with Iridium (Ir) contact electrodes were investigated. Using Norde model, it was found that the effectively Schottky barrier heights of Ir on n-ZnO were around 0.837, 0.829, 0.801, 0.750 and 0.719 eV when measured at 25, 30, 50, 100 and 150 °C, respectively. Using Cheung’s method, it was found that Schottky barrier heights between Ir and the n-ZnO were 0.824, 0.823, 0.789, 0.743 and 0.740 eV when measured at 25, 30, 50, 100 and 150 °C, respectively. The large Schottky barrier heights suggest that Ir is a potentially useful material for ZnO-based ultraviolet Schottky barrier photodetectors and metal–semiconductor-metal photodetectors.