Optical Properties I

Abstract

The fundamental energy gaps of most semiconductors span the energy range from zero to about 6 eV. Photons of sufficient energy can excite electrons from the filled valence bands to the empty conduction bands. As a result, the optical spectra of semiconductors provide a rich source of information on their electronic properties. In many semiconductors, photons can also interact with lattice vibrations and with electrons localized on defects, thus making optical techniques also useful for studying these excitations. Their optical properties are the basis of many important applications of semiconductors, such as lasers, light emitting diodes, and photodetectors.