BAND ALIGNMENT IN ZNSE ZN1-X-YCDXMNYSE QUANTUM-WELL STRUCTURES/

We present a magneto-optical study of ZnSe/Zn1-x-yCdxMnySe quantum-wel l structures' in which a suitable choice of the Cd composition leads t o a system that is type I at zero magnetic field. When a magnetic fiel d is applied perpendicular to the layers of the structure, the band ed ges split in such a way as to make the upper sigma(-)(+1/2, +3/2) exci ton transition type II, while the ground state sigma(+) (-1/2,-3/2) ex citon component remains type I at all field values. This alignment red uces the probability for carrier relaxation from the higher-energy exc iton component and opens the possibility of hole-spin population inver sion via optical pumping.