Binding energy of biexcitons in GaAs-AlxGa1-xAs quantum wells

The energy of a biexciton in a GaAs-AlxGa1-xAs quantum well is calculated variationally by use of a two-parameter trial wave function. The calculated binding energy, relative to two well-separated excitons, is greater than that given previously by Kleinman [Phys. Rev. B 28, 871 (1983)]. Our binding energy takes its greatest value when the well width is approximately 10 Angstrom. The ratio of the binding energy of a biexciton to that of an exciton for a range of well thickness (5-300 Angstrom) is found to be from 0.127 to 0.284. which agrees fairly well with previous experimental results. The results of our approach are compared with those of earlier theories. (C) 1998 American Institute of Physics. [S0021-8979(98)00417-4].