Temperature Dependent Photoluminescence from InAs/GaAs Quantum Dots Grown by Molecular Beam Epitaxy

Abstract

We have reported structural and optical properties of self-assembled InAs/GaAs quantum dot (QD) grown by molecular beam epitaxy with different arsenic to indium flux ratios (V/III ratios). By increasing the V/III ratio from 9 to 160, average diameter and height of the InAs QDs decreased, but areal density of them increased. The InAs QDs grown under V/III ratio of 30 had a highest-aspect-ratio of 0.134 among them grown with other conditions. Optical property of the InAs QD was investigated by the temperature-dependent photoluminescence (PL) and integrated PL. From the temperature dependence PL measurements of InAs QDs, the activation energies of E-a1 and E-a2 for the InAs QDs were obtained 48 +/- 3 meV and 229 +/- 23 meV, respectively. It was considered that the values of E-a1 and E-a2 are corresponded to the energy difference between ground-state and first excited state, and the energy difference between ground-state and wetting layer, respectively.