Enhancing the optical properties of InAs quantum dots by an InAlAsSb overgrown layer

Abstract

The optical properties of InAs quantum dots (QDs) with a GaAs, an InAlAs, or an InAlAsSb overgrown layer are studied. For the InAs QDs with an InAlAsSb overgrown layer, their room temperature photoluminescence intensity is enhanced by as much as 4.5-fold compared to that of the QDs with an InAlAs one while maintaining similar narrow linewidth (26meV) and large ground-to first excited-state separation (103meV). The increase in radiative efficiency of the InAs∕InAlAsSb heterostructure is attributed to its better material quality due to the surfactant nature of Sb adatoms.