BINDING-ENERGIES OF WANNIER EXCITONS IN GAAS-GA1-XALXAS QUANTUM-WELL STRUCTURES (REPRINTED FROM SOLID-STATE COMMUN, VOL 45, PG 831-835, 1983)

Binding energies of Wannier excitons in a quantum well structure consi sting of a single slab of GaAs sandwiched between two semi-infinite sl abs of Ga1-xAlxAs are calculated using a variational approach. Due to reduction in symmetry along the axis of growth of these quantum well s tructures and the presence of band discontinuities at the interfaces, the degeneracy of the valence band of GaAs is removed leading to two e xciton systems, namely, the heavy hole exciton and the light hole exci ton. The variations of the binding energies of these two excitons as a function of the size of the GaAs quantum wells for various values of the heights of the potential barrier are calculated and their behavior is discussed.