Energy relaxation due to TO phonon emission in polar semiconductors

Abstract
Electron transitions involving the emission of transverse optical (TO) phonons in polar semiconductors are discussed. Distinction is made in particular between the contributions from the TO modes to the optical deformation potential interaction and the interaction of the TO modes arising via their electromagnetic vector potential. The latter is due solely to the polar nature of the semiconductor. A theory for the emission rate Gamma TO due to the interaction of electrons with the vector potential is described and the calculated rate is compared with the corresponding rate Gamma Def involving the optical deformation potential and with Gamma LO, the emission rate arising from the well known Frohlich mechanism due to the polar longitudinal optical (LO) modes. Typical values are obtained for the case of GaAs in the homogeneous bulk.