The preferred facet orientation of GaAs pyramids for high-quality InAs and InxGa1−xAs quantum dot growth

The energetically favorable facet orientation of GaAs pyramids for InAs quantum dot (QD) growth was studied in terms of a crystallographic matching perspective. The predicted apparent interface is (5.6 1 1)GaAs, which agrees well with the best substrate (5 1 1)GaAs in previous experimental observations. This allows close-packed planes, (1 1 1)InAs and (1¯11)GaAs, with their edges meeting at the interface. The dependence of preferred facet orientation on the indium ratio of InxGa1−xAs QDs is also studied, which provides a new way to fabricate high-quality InxGa1−xAs QDs.