Magnetic field-induced type-I type-IT transition in (ZnMn)Se/(ZnBe)Se spin superlattices

We have performed a magneto-optical study on spin superlattice structures fabricated on the basis of (ZnMn)Se/(ZnBe)Se. The band alignment of a Zno.9 1Mno.0 9 Se/ Zno.972 Beo. 02 8 Se superlattice was found to undergo a type-I to type-Il transition for one of the exciton spin component. This spin superlattice formation manfests itself in an asymmetric Zeeman splitting of a spatially direct exciton resulting from a spin dependent change of the exciton binding energy. A pronounced broadening of the spatially direct exciton in reflectance and photoluminescence excitation spectra was observed when scattering in the (ZnBe)Se barriers becomes possible.