Electrical Characteristics of Ultraviolet Photodetector based on ZnO Nanostructures

ZnO nanostructures were grown on p- type Si substrate by spray pyrolysis technic. A UV light was used as an illuminating source at 365 nm. The current–voltage characteristics of the device under UV illumination showed an enhancement that dark current. The dark current is about 58 μA, and the photocurrent is about 97 μA under a reverse bias voltage of 6 V. The photocurrent characteristic of photodetector is measured under 3 V forward biases and after 18 min it saturated. Continuous measurements indicate the reproducibility and stability of this UV photodetector. The Schottky diode parameters as the barrier height, the ideality factor, and the series resistance as calculated using a method developed by Cheung's method. It was found that ideality factor was greater than unity and barrier height was larger than 0,8 eV.