Intracenter transitions of iron-group ions in II-VI semiconductor matrices

A review is made of studies of intracenter optical transitions in 3d shells of iron-group divalent (magnetic) ions. Attention is focused on the emission spectra of Mn2+ ions in CdTe, ZnS, and ZnSe crystals. An analysis is made of the structure of intracenter absorption and luminescence and of the effect that the elemental matrix composition, magnetic-ion concentration, temperature, hydrostatic pressure, and structural phase transitions exert on the intracenter transitions. The mutual influence of two electronic excitation relaxation mechanisms, interband and intracenter, is considered. The specific features of the intracenter emission of magnetic ions embedded in two-dimensional systems and nanocrystals associated with a variation in sp-d exchange interaction and other factors are discussed. Data on the decay kinetics over the intracenter luminescence band profile are presented as a function of temperature, magnetic ion concentration, and excitation conditions. The saturation of the luminescence and the variation of its kinetic properties under strong optical excitation, which are caused by excitation migration and the cooperative effect, as well as the manifestation of a nonlinearity in intracenter absorption, are studied. (C) 2002 MAIK "Nauka/Interperiodica".