Effects of Post-growth Thermal Annealing on MBE-grown InAlGaAs/GaAs Quantum Dots

Quaternary InAlGaAs/GaAs quantum dots (QDs) were grown to achieve emission at <1 μm and the effects of post-growth thermal annealing on the optical and morphological properties were experimentally investigated. A QD density as high as > 5 × 10 ¹⁰ cm ⁻² and FWHM of 77 meV at 20 K are achieved for the as-grown QD ensemble. After the rapid thermal annealing (RTA) treatment, remarkable improvements in the optical properties of the QDs are observed as the integrated photoluminescence (PL) intensity improves by a factor of 2 and the FWHM reduces to 29 meV.