A seminar entitled Preparation and Characterization of CdS and PbS Chalcogenides Compounds and CdS/PbS photodiode hold at the College of Science, Department of Physics. The presenter Alaa Hasan Abdul-Hussein demonstrates the most important objectives of study Preparation of thin films of CdS and PbS nanostructures using chemical bath deposition method and studying the effect of temperature, deposition substrates and number of deposition layers on their structural, surface and optical properties, and using them by fabrication Al-CdS photoconductor detector and n-CdS/p-PbS photodiode.