Magnetooptics of (Zn,Cd,Mn)Te/ZnTe heterostructures with a small discontinuity in the valence band potential

Magnetooptics in (Zn,Cd,Mn)Te/ZnTe semimagnetic heterostructures with quantum wells has been thoroughly studied. For the Mn-containing quantum wells, an ordinary giant spin splitting effect is observed: the complete circular polarization in magnetic fields B> 0.5 T, a great increase in the intensity associated with the suppression of Auger recombination in the Mn ions, and a strong red shift of the σ⁺ polarized component are observed. On the contrary, the behavior of structures with nonmagnetic quantum wells and distant semimagnetic ZnMnTe layers is opposite. This unusual behavior is attributed to a high sensitivity of the exciton bond energy to the variation of the valence band potential in the structures with a small band discontinuity; this is confirmed by the computations and allows us to estimate the band chemical discontinuity as −80 ± 20 meV in the ZnTe/CdTe system close to the photoemission data (T. M. Due, Phys. Rev. Lett. 58, 1127 (1987)).