Ordering of stacked InAs/GaAs quantum-wires in InAlAs/InGaAs matrix on (100) InP substrates

Abstract

Stacked and wire-like InAs/GaAs nanostructures in InGaAs/InAlAs matrix on InP substrates were grown by molecular beam epitaxy (M BE) and investigated by atomic force microscope (AFM) and transmission electron microscope (TEM). Cross-sectional TEM images showed that the stacked InAs and GaAs quantum-wires in InGaAs matrix were vertically aligned to form a rectangular lattice. In contrast, in InAlAs matrix, the stacked InAs quantum-wires were cross-correlated to form a bcc like lattice. Clear composition modulation was observed in the post-grown matrix material. Based on this result, a kinetic growth model is proposed to explain the stacking behavior of the quantum-wires. (C) 2007 Elsevier B.V. All rights reserved.