Abstract
We have investigated the carrier dynamics in As/InP quantum wells with various well widths as a function of temperature and carrier density using time-resolved photoluminescence spectroscopy. At low temperatures (T<50 K), we find pure excitonic recombination. At elevated temperatures, two radiative recombination paths are present, and the proportion of free-carrier recombination to excitonic recombination increases as the temperature is raised. We observe a nonlinear increase of the radiative lifetime caused by thermal ionization of excitons. Exciton binding energies in the range between 9 and 15 meV and majority carrier concentrations of about 1.2× are deduced from the ratio between the high and low injection lifetimes. The exciton binding energy increases with decreasing well thicknesses, in good agreement with theoretical predictions.
- Received 24 August 1992
DOI:https://doi.org/10.1103/PhysRevB.47.1671
©1993 American Physical Society