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

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. (author)