Theoretical and Experimental Study of UV Detection Characteristics of Pd/ZnO Nanorod Schottky Diodes

In this work, we report theoretical and experimental study of Pd/ZnO nanorod (NR) Schottky diodes-based ultraviolet photodetector (UV-PD). The ZnO-NRs are deposited on indium tin oxide (ITO) coated glass substrates by using a low-temperature hydrothermal method. The surface morphology of the ZnO-NRs film is characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The SEM image shows vertically grown NRs with uniformity, and XRD shows the preferred (002) orientation of ZnO-NR films. The current-voltage characteristics of Pd/ZnO-NR Schottky diodes are studied under dark and UV light. A voltage bias from -1V to +1V is applied and the ratio of photocurrent to dark current was (similar to 0.17 x 10(2) at V = 0.5V) calculated from the I-V curve. The value of responsivity was found to be 0.111 A/W at lambda = 365 nm and at bias = 0: 50 V. An approximated UV-PD structure has also been numerically simulated using three-dimensional (3D) device simulator from Visual TCAD of Cogenda International. The simulated I-V characteristics have also been plotted under both dark and light conditions. The simulated results are found to be following the nature of experimental results.