Localization‐induced blueshift in quantum wires: Direct evidence from magnetophotoluminescence measurements

For In0.53Ga0.47As/InP quantum wires fabricated from quantum well material by dry etching and epitaxial regrowth, a blueshift with decreasing wire width is found, where the blueshift is larger than expected by lateral quantization. In magnetophotoluminescence, the quantum well clearly displays a feature that is due to carrier transport between growth islands of different well widths. This feature cannot be observed for small wire structures, which means that the carrier transport is suppressed in these structures. Hence, magnetophotoluminescence measurements give new direct evidence for the fact that the excitons are more and more localized in states of higher energy as the wire width is decreased, which explains the blueshift in the optical spectra.