High quality InAs quantum dots grown on patterned Si with a GaAs buffer layer.

Ordered and dense InAs quantum dots grown on patterned Si(100) with a thin GaAs buffer layer have been investigated by transmission electron microscopy and electron energy loss spectroscopy. {111} faceted InAs quantum dots with good crystallinity were observed on top of the underlying GaAs buffer layer. It was revealed that the GaAs buffer layer and the lateral expansion of InAs have played key roles in releasing the misfit strain between InAs and Si and suppressing the formation of lattice defects in InAs quantum dots. These results suggest a possible pathway for the strain relaxation in the formation of quantum dots.