InAs self-assembled nanostructures grown on InP(001)

The 6-period stacked layers of self-assembled InAs quasi-quantum wires(qQWR s) and quantum dots(QDs) embedded into InAlAs on InP(001) substrates have b een prepared by solid molecular beam epitaxy. The structures are characteri zed by atomic force microscopy(AFM) and transmission electron microscopy(TE M). From AFM we have observed for the first time that InAs qQWRs and QDs co exist, and we explained this phenomenon from the view of the energy related to the islands. Cross-sectional TEM shows that InAs qQWRs are vertically a ligned every other layer along the growth direction [001], which disagrees with conventional vertical self-alignment of InAs QDs on GaAs substrate.