CAPTURE AND RECOMBINATION OF ACCEPTOR-BOUND EXCITONS IN THE TRANSITION REGION FROM A 2-DIMENSIONAL TO A QUASI-3-DIMENSIONAL GAAS ALGAAS SYSTEM/

The capture and recombination processes for acceptor bound excitons (B Es) have been studied for GaAs/AlGaAs multiple quantum well structures , by varying the barrier thickness for a constant 100 angstrom well wi dth. The observed decay time for the acceptor BE increases rapidly wit h decreasing barrier width, and is determined by the relative confinem ent of the electron and hole wave functions. The capture rate of free excitons to the BE state of the neutral acceptor increases by about a factor 7 from a two-dimensional to a three-dimensionlike system.