Resonant time-integrated and time-resolved photoluminescence in ZnSe-based heterostructures

We study non-radiative processes in two kinds of II–VI wide band gap heterostructures: ZnSe/(Zn,Mn)Se and (Zn,Cd)Se/ZnSe by means of resonant time-integrated and time-resolved photoluminescence. In the ZnSe/(Zn,Mn)Se heterostructure, we evidence the existence of an unusual relaxation channel between two excitons, which have different natures and which are localized in adjacent layers. This relaxation process is made easier by the temperature and inhibited by the magnetic field. In the (Zn,Cd)Se/ZnSe heterostructure, we deduce, from the temperature variation of the photoluminescence decay time of the photoluminescence, that the main non-radiative mechanism, responsible for the quenching of the photoluminescence intensity with increasing temperature, is the heavy holes thermal escape out of the well in the 100–200 K temperature range.