Photon irradiation effects on electrical properties of n-ZnO/p-Si junctions for optoelectronic device

Abstract

Simple high energy laser photon irradiation is a handy tool to tune the functional properties of wide band gap oxide-based devices. Present study reports on the effects of laser photon irradiation on electrical transport behaviour of n -ZnO/ p -Si p-n junctions. The n- type conductivity of ZnO was optimised by doping of stoichiometric amount of Al in ZnO. The n -ZnO/ p -Si junctions were grown on p -Si (100) substrate by pulsed laser deposition. The structural property was analysed by X-ray diffraction. Morphological study was done using atomic force microscopy (AFM) which shows smooth and mono-dispersed surfaces of the p-n junction. The current-voltage ( I-V ) characteristic of the n -ZnO/ p -Si devices have been measured at room temperature in the dark and under illumination. Moreover, the effects of 532 nm visible laser light irradiation on the electric parameter of n -AZO/ p -Si p-n junctions were investigated. The characteristic parameters of the junctions such as barrier height, ideality factor and series resistance were determined from the current-voltage measurement. The results show a promise of ZnO based diode structure for its optoelectronic applications.