TYPE-II INTERFACE EXCITON IN ZNSE (ZN,MN)SE HETEROSTRUCTURES/

Two emission bands are observed in the photoluminescence spectrum of Z nSe/(Zn,Mn)Se heterostructures. These bands emerge in a magnetic field and are associated with interface excitons formed as a result of a ma gnetic-field-induced type-I-type-II transition of the band alignment. Time-resolved measurements yield lifelines in the ns range signifying a relatively large spatial separation of electrons and holes and hence low optical oscillator strength. These features are confirmed by a th eoretical analysis of the interface exciton state revealing a reduced importance of the electron-hole Coulomb interaction in comparison with type-II excitons in quantum wells.