The impact of laser energy on the photoresponsive characteristics of CdO/Si visible light photodetector

Abstract In this article, cadmium oxide (CdO) was deposited using pulsed laser deposition approach on porous silicon (Si) wafer for visible light photodetector application, through which a series of devices were proposed as a function of the deposition energy. The microstructural as well as optical characteristics of the prepared film/s were demonstrated, respectively, using x-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and ultraviolet visible light spectroscopy (UV-Vis) analysis. In details, the UV-Vis analysis revealed the occurrence of optical band gaps within the range of 2.38 -2.42 eV, while an average nanoparticle diameter was found to be 45 nm using FE-SEM technique. This in turn demonstrated a sound relation with the photoresponsive behavior of the attained photodetectors. A photoresponsivity and specific detectivity of 1.9 μA/mW and 1.21×10^9 Jones were attained using 700 mJ laser energy. In the meanwhile, the estimated response/recover time of the addressed laser energy was found to be 300 sec. and 340 sec., respectively. The photo-responsive characteristics of the fabricated devices were found to be in positive linear correlation with the applied laser energy.