Abstract

In polar materials such as GaAs:Si shallow-donor transitions become strongly coupled to LO phonons when the transition energy approaches the LO-phonon energy. This resonant polaron effect manifests itself around the LO-phonon energy (296 cm⁻¹) as an avoided crossing of the electronic-transition energy versus magnetic field.^1,2 However, in the region between the TO and LO phonons, the Reststrahlen band, photoconductivity measurements are extremely difficult because of the very small penetration depth of light in this region.² In addition, the strongly varying dielectric function of the GaAs around the TO/LO-phonon frequencies gives rise to artifacts in the weak photoconductivity spectra.²

© 1995 Optical Society of America