Biexciton binding energy and exciton–LO-phonon scattering in ZnSe quantum wires

The dependence of the biexciton binding energy and of the exciton–LO-phonon scattering rate on the wire width is investigated in wet-etched ZnSe quantum wires by temperature-dependent transient four-wave mixing. We observe an increase of the biexciton binding energy with decreasing wire width, reaching an enhancement of about 30% in the smallest wire structure. In addition, we find a decrease of the exciton–LO-phonon scattering rate with decreasing wire size, which is discussed with consideration of the reduced polarity of the exciton wave function and the modified density of final states in narrow wire structures.