BINDING OF QUASI-2-DIMENSIONAL BIEXCITONS

Biexciton binding in GaAs quantum wells has been investigated for a ra nge of well thicknesses (80-160 Angstrom) with spectrally resolved pho toluminescence and transient degenerate four-wave mixing. Both light a nd heavy hole biexcitons are observed. The ratio of the binding energy of the heavy hole biexciton to that of the heavy hole exciton is foun d to be approximate to 0.2, and nearly independent of well width over the investigated range. A new theoretical calculation agrees very well with the experimental ratio. This ratio is larger than predicted by H ayne's rule for three-dimensional biexcitons.