Relaxation dynamics of Mn2+ intraion excitation in Cd0.5Mn0.5Te:: Dependence on the optical pumping level

A study is reported of the Mn2+ intracenter 3d luminescence in a dilute Cd0.5Mn0.5Te magnetic semiconductor at pulsed excitations of up to 3.5 MW/cm(2). At high excitation levels and at a temperature of 77 K, the kinetics varies strongly over the emission band profile. The luminescence decay curve can be resolved into a fast and a delayed component, which correspond to the excitation of extended and localized states in the manganese ion system. The fast relaxation of the extended states is largely determined by the up-conversion. As the temperature is lowered, the contribution of the fast component at the center of the emission band and in its low-energy wing decreases because of the weakening role of the extended states lying above the mobility edge. (C) 2001 MAIK "Nauka/Interperiodica".