Part I Perfect crystal semiconductors: 1a - energy band theory - pseudopotential method empirical, self-consistent, quasi-particle; LCAO method; k.p method spin-orbit splitting effect; alloy semiconductors; stress effect; temperature effect. 1b - Optical properties - absorption and exciton effect; photo luminescence and photo luminescence excitation; modulation spectroscopy; Raman scattering and polaritons. Part 2 Non-perfect crystal semiconductors: 2a - defects in semiconductors - effective mass shallow impurity states; deep defect states, cluster method, super cell method and Green's function methods; emission and capture and transcient experiments; electron spin resonance methods; electron lattice interation and lattice relaxation effects; negative U centers multi-phonon non-radiative transition; DX center and EL2 defects. 2b - Semiconductor surfaces - two dimensional periodicity and surface reconstruction; surface states; photo-electron spectroscopy; LEED, STM and other experimental methods. 2c - Heterojunctions, quantum wells and superlattices, quantum wires and quantum dots, quantum hall effects, new phenomena and new devices due to quantum confinement effects.