Infrared absorption by excitons due to photoionization and intraband lattice scattering

Abstract

A quantum mechanical theory is developed for infrared absorption by excitons due to photoionization and intraband lattice scattering. The theory involves the interaction of the excitons with the acoustic and optical phonons. The Maxwellian and Bose‐Einstein distribution functions and the possible locations of the simple exciton band extremum are taken into account. The effect of the exciton photoionization is observable at the threshold frequency at comparatively low exciton concentrations.