Microwave assisted synthesis of ZnO and Pd-ZnO nanospheres for UV photodetector

An ultraviolet photodetector is fabricated with high photoconductive gain, K = 56.3 using ZnO and Palladium doped ZnO Nanospheres (ZnO/Pd-ZnO). The Nanospheres are synthesized using Microwave assisted method. Photoconducting characteristics of the spheres are investigated at 5 V using an UV LED (λ = 395 nm, Optical power = 400 μW). This study define the point defects states especially oxygen vacancy (Vo) and Zinc vacancy (VZn) corroborating to the Photoconducting characteristics using photoluminescence spectra. The achieved best response and recovery associated to high photoconductive gain are 3.9 s and 5.27 s at room temperature. Compared to the conventional photodetectors which uses multi-junction structures and associated lithographic process, here cost effective, single step lithography is highlighted.