BINDING OF BIEXCITONS IN GAAS ALXGA1-XAS SUPERLATTICES/

Properties of the heavy-hole excitons and biexcitons in GaAs/Al0.3Ga0. 7As superlattices are studied using linear and nonlinear optical techn iques. In superlattices with miniband halfwidths less than the exciton binding energy, the biexciton binding energy is found to be the same as in the noninteracting multiple quantum wells of the same width. Whe n the miniband halfwidth exceeds the exciton binding energy, the biexc iton binding energy decreases abruptly to the bulk value.