Abstract
Carrier cooling is investigated by means of time-resolved photoluminescence spectroscopy in an undoped As/As/InP heterostructure and in undoped and modulation-doped As/As multiple-quantum-well structures. The cooling dynamics of electrons and holes is analyzed by a theoretical model based on Fermi-Dirac statistics and taking into account polar-optical scattering and acoustic-deformation-potential scattering as energy-loss and Auger processes as heating mechanisms. The energy loss of holes by polar-optical scattering is close to theoretical expectations in the low-excitation regime, but is reduced by 2 orders of magnitude for high-excitation densities. This reduction is attributed to a hot phonon effect. For electrons the polar-optical energy-loss rate is strongly reduced even at low excitation densities as compared to theoretical expectations. We assume that screening of the Coulomb interaction between carriers and lattice might play a role beside the hot phonon overpopulation to explain this phenomenon.
- Received 3 October 1988
DOI:https://doi.org/10.1103/PhysRevB.39.5234
©1989 American Physical Society