Enhancement of the binding energy of charged excitons in disordered quantum wires

Negatively and positively charged excitons are identified in the spatially resolved photoluminescence spectra of quantum wires. We demonstrate that charged excitons are weakly localized in disordered quantum wires. As a consequence, the enhancement of the ``binding energy'' of a charged exciton is caused, for a significant part, by the recoil energy transferred to the remaining charged carrier during its radiative recombination. We discover that the Coulomb correlation energy is not the sole origin of the ``binding energy,'' in contrast to charged excitons confined in quantum dots.