LOCALIZATION-INDUCED BLUESHIFT IN QUANTUM WIRES - DIRECT EVIDENCE FROM MAGNETOPHOTOLUMINESCENCE MEASUREMENTS

For In0.53Ga0.47As/InP quantum wires fabricated from quantum well mate rial by dry etching and epitaxial regrowth, a blueshift with decreasin g wire width is found, where the blueshift is larger than expected by lateral quantization. in magnetophotoluminescence, the quantum well cl early displays a feature that is due to carrier transport between grow th islands of different well widths. This feature cannot be observed f or small wire structures, which means that the carrier transport is su ppressed in these structures. Hence, magnetophotoluminescence measurem ents give new direct evidence for the fact that the excitons are more acid more localized in states of higher energy as the wire width is de creased, which explains the blueshift in the optical spectra. (C) 1996 American Institute of Physics.