Growth of GaxIn1−xAs quantum wire heterostructures by the strain-induced lateral-layer ordering process

Abstract

GaxIn1−xAs quantum wire (QWR) arrays were grown in situ by molecular beam epitaxy. A lateral composition modulation was achieved in the GaxIn1−xAs material system via the strain-induced lateral layer ordering process occurring spontaneously when (GaAs)n/(InAs)n short-period superlattices are grown on (100)-oriented on-axis InP substrates. The resulting quasiperiodic modulation of the GaxIn1−xAs composition, with a periodicity of 300 Å, offers a lateral quantum confinement along the growth plane. The quantum confinement in the growth direction is provided by sandwiching the thin (∼100 Å) laterally ordered GaxIn1−xAs layer between layers of bulk Al0.24Ga0.24In0.52As. The formation of the QWR array is confirmed by cross-sectional transmission electron microscopy and polarized photoluminescence measurements.