Optical spectroscopy of GaAs–AlGaAs v-groove quantum wires

An optical and magneto-optical study of GaAs-AlGaAs v-groove quantum wires is reported. Electroluminescence (EL) spectra, recorded as a function of current for wires grown within a p-i-n structure, show clear evidence for one-dimensional subband filling effects and recombination from excited subbands. Magneto-EL measurements, for fields applied along the three orthogonal spatial directions, demonstrate the anisotropy of the subband wavefunctions, with the anisotropy increasing with increasing subband index. With increasing carrier density the diamagnetic shift of the ground state emission increases, consistent with a transition from excitonic to free carrier behaviour. Photoluminescence measurements with a spatial resolution of similar to 1 mu m enable the study of single quantum wires, allowing the observation of exciton localisation by wire width fluctuations. (C) 1998 Elsevier Science B.V. All rights reserved.