In this work, ZnMgO/Si Heterojunction Photodetector was fabricated by deposited a Zinc doped Magnesium Oxide (ZnMgO) Nanostructure (prepared via laser ablation in the water) on silicon (Si) substrate using the drop-casting method. X-ray diffraction XRD and scanning electron microscopy SEM were used to obtain properties of the prepared nanostructure material. X-ray diffraction results showed that ZnMgO Nanoparticles have a hexagonal structure at 2Θ = 34:31° and 34.76°. The scanning electron microscopy image displays a flower-like hierarchical structure with a full array of about 2µm. The current-voltage (I-V) characteristics of ZnMgO/Si Heterostructure Photodetector possess a good rectifying property with suitable an ideality factor which changes from 2.63 to 1.241 as Mg doping increases and in addition to the high spectral responsivity with the low dark current
