Abstract: The nanostructure silicon known as Porous Silicon (PSi) was prepared by the technique of electrochemical etching of crystalline silicon doped boron (p-type) with orientation (100) by using Teflon cell, HF with 40% concentration and Methanol with purity (99.9%) in (1:2) ratio at 9 mA/cm2 current density and 13 min etching time. Ag nanoparticles was prepared by chemical reduction method. The structural, optical and electrical properties was investigated by using X-Ray Diffraction (XRD) Scanning Electron Microscope (SEM) Fourier Transform Infrared Spectroscopy (FTIR) and UV-visible spectrum. The electrical properties of Ag/PSi/c-Si/Al junction was studied by using dark I-V, illuminated I-V, C-V measurement and responsivity. The current study showed improvement in the electrical properties PSi photodetector after embedding AgNPs.