Abstract
Large variations in quantum dot concentrations were obtained with simultaneous growths on vicinal GaAs [001] substrates with different surface step densities. It was found that decreasing dot-dot separation blueshifts all levels, narrows intersublevel transition energies, shortens luminescence decay times for excited states, and increases inhomogeneous photoluminescence broadening. These changes in optical properties are attributed to a progressive strain deformation of the confining potentials and to the increasing effects of positional disorder in denser dot ensembles.
- Received 22 April 1999
DOI:https://doi.org/10.1103/PhysRevB.60.R8517
©1999 American Physical Society