MAGNETOOPTICAL STUDY OF ASYMMETRIC CDTE/(CD,MN)TE DOUBLE-QUANTUM-WELL NANOSTRUCTURES

A strained CdTe/(Cd,Mn)Te double-quantum-well nanostructure, grown by MBE on InSb substrate, is studied by CW and ps luminescence, reflection, and excitation spectroscopy in magnetic fields up to 5 T. The two CdTe quantum-wells of the sample have different well widths and are separated by a thin (Cd,Mn)Te barrier. A fast exciton transfer is observed from the higher-energy lh and hh states of the narrow well into the hh state of the broad well. The exciton energies in the wells and barriers and their magnetic-field induced splitting can consistently be explained by model calculations, taking into account the strain known from X-ray diffraction measurements. The decay times of the various luminescence bands are determined.