Structural and optical properties of InAs/In0.52Al0.48As self-assembled quantum wires on InP(0Â 0Â 1)

Six-stacked InAs/In0.52Al0.48As self-assembled quantum wires (QWRs) on InP(0 0 1) by molecular-beam epitaxy (MBE) have been studied by high-resolution transmission electron microscopy (HRTEM) and polarized PL measurements. We obtained the chemical lattice fringe (CLF) image of InAs self-assembled QWRs embedded in the In0.52Al0.48As matrix by the interference between the (0 0 2)-diffracted beam and the transmitted beam in the image plane of the objective lens. The results show that the InAs QWRs were bounded by (1¯1¯3), (0 0 1) and (1 1 4) facets. Both the size and strain distribution in QWRs were determined. It was found that with the growth of successive periods, the height and height fluctuation of InAs QWRs decreased from the bottom period to the upper one. Some suggestions are put forward for further improving the uniformity of the stacked InAs QWRs.