Biexciton creation and recombination in a GaAs quantum well

The conditions required for the generation of biexcitons in quantum wells are discussed, and a model line shape for biexciton recombination is fitted to observed biexciton photoluminescence spectra. It is shown that the biexciton density at a given optical injection rate is much enhanced by resonant generation at either the light-hole or the heavy-hole exciton. Unlike the case of silicon, the biexciton density is found not to vary as the square of the exciton density and this is attributed in part to the short lifetime of the excitons and biexcitons.