MAGNETOOPTICAL STUDY OF DONOR-ACCEPTOR PAIR TRANSITIONS IN CDTE/(CD.MN)TE-MQW STRUCTURES

In strained CdTe (Cd,Mn)Te - MQW structures, grown by MBE on InSb substrates, donor-acceptor pair (DAP) transitions in the CdTe wells are studied by luminescence and excitation spectroscopy in magnetic fields up to 5T. For comparison, free and bound excitons are investigated in the same samples. By using the measured 1h-hh exciton energy splitting, a valence/conduction band offset ratio of 1.7 ± 0.2 was determined by Kronig-Penney model calculations. With decreasing well width an increasing confinement-induced peak shift of the DAP lines was found, being smaller than for free excitons. No peak shift but a strong asymmetric broadening of the DAP lines was observed with increasing magnetic fields. The results can be explained on the basis of a model, which takes into account the strong localization of the acceptor-bound hole together with the effects of bound magnetic polarons. © 1991.