Post-Growth Annealing Effects of In0.5Ga0.5As Quantum Dots Grown by Heterogeneous Droplet Epitaxy

Post-growth rapid thermal annealing modifies the structural and the optical properties of the In$_{0.5}$Ga$_{0.5}$As quantum dots grown on GaAs substrates by using heterogeneous droplet epitaxy. It is found that at annealing temperatures up to 750 $^\circ$C, a significant decrease in the intersublevel ($E_{01}=E_{1} - E_{0}$) from 55 to 23.7 meV occurs together with about a 62-meV blueshift. Also, we observe a decrease in the activation energy of about 200 meV. These results are explained by interdiffusion of In-Ga atoms at the interface between the QD and the GaAs barrier, which changes the composition of the QDs. KCI Citation Count: 5