Morphological control of GaAs quantum dots grown by droplet epitaxy using a thin AlGaAs capping layer

We demonstrate the control of GaAs quantum dots morphology by using a thin AlGaAs capping layer. The AlGaAs layer uniformly covers the GaAs quantum dots and provides protections against thermally induced deformation up to 580 degrees C, which allows improved dot quality. In addition, annealing of AlGaAs-capped quantum dots at 640 degrees C flattens the top of the dots, leading to the formation of height-controlled quantum dots and their narrow inhomogeneous width of 28 meV. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3493262]