Observation of many-body effects in the excitonic spectra of semiconductorquantum wires

We report the observation of a blue shift of very sharp luminescence lines in GaAs/AlGaAs quantum wires at increasing excitation density. These sharp lines correspond to recombination of one-dimensional excitons localized in local potential minima due to interface disorder. The evolution of the fine -structured photoluminescence spectra with increasing exciton density is in terpreted in terms of many-body effects which lead to an increase of the ex citon self-energy and to the formation of excitonic complexes. (C) 1998 Els evier Science Ltd. All rights reserved.