Crystal Structures and Reciprocal Lattice, Free-electron model ?? electron gas, Fermi-Dirac distribution, Fermi surface, Band theory of solids ?? Bloch Theorem , Brillouin zone, Kronig Penney model, Band gap and Bragg reflection, effective mass, holes, Conductivity of metals Semiconductors ?? Intrinsic and extrinsic semiconductors, carrier concentration, electrical conductivity and mobility, Hall effect, direct and indirect band gap. Dielectric and optical properties ?? absorption and optical properties of semiconductors, Dielectric constant, polarizability, sources of polarizaility- dipolar, ionic, electronic. Complex dielectric constant, dielectric losses,