This course will help students to understand the description and classification, intrinsic semiconductors, impurity levels, extrinsic semiconductors mobility, Band structure, Effective mass, Band gap, N-n junctions and schottky diode, barrier layer approximation, I-V and C-V characteristics, Electrical and Optical Properties of Semiconductors, Semiconductor-metal contacts, Ohmic and Schottky contacts Influence of impurities and defects on the properties of these contacts.