Exciton scattering in heterostructures with (In,Ga)As/GaAs quantum wells

Abstract

Reflectance spectroscopy is used to study exciton scattering caused by phonons, nonradiative excitons, and free carriers in a heterostructure with a wide (In,Ga)As/GaAs quantum well. Nonradiative excitons and free carriers are created via additional monochromatic illumination by a tunable laser. Constants of exciton–acoustic phonon and exciton–LO phonon scattering are determined from the temperature variations in the nonradiative broadening of exciton resonances. The excitation spectra of nonradiative broadening reveal sharp resonances associated with exciton–exciton scattering and a smooth background caused by exciton–free carrier scattering.