Dynamics of bound excitons in a ZnSe/(Zn,Mn)Se quantum-well heterostructure

We report on optical experiments performed on a ZnSe/${\mathrm{Zn}}_{0.73}$${\mathrm{Mn}}_{0.27}$Se strained quantum well. The measurements were done by means of resonant time-integrated and time-resolved photoluminescence spectroscopies at temperatures from 1.7 to 100 K. We show that recombination arising from the first excited excitonic state of the heterostructure is present even at low temperature. The quite unusual relaxation channel from this state, namely, a heavy-hole bound interface exciton essentially located in the (Zn,Mn)Se layer, to the fundamental one, a light-hole bound exciton located in the ZnSe layer, is quantitatively studied. In particular, when an external magnetic field is applied, we observe directly the consequences of the giant Zeeman effect occurring in the (Zn,Mn)Se layer on both types of excitons.