A seminar entitled Fabrication and characterization  silicon nano wires  heterojunction for Photonic Devices hold at the College of Science, Department of physics.  The presenter( Hanaa Hashim inaya) aim the study is to Structural, morphological and optical properties of prepared SiNWs are investigated silicon nanowire  arrays are prepared by metal-assisted chemical etching (MACE) method using an Ag as a catalyst and different etching time and  application forthe  solar cells , photosensor heterojunction and using SiNWs as working electrode in the Photoelectrochemical