Localized states in wide-gap oxide glasses

Localized states manifest themselves by light absorption at the optical gap of a glass and by luminescence excited there with Stoke's shift. They are created by the minority structural motifs of one or many structural modifications in which a material can exist, and which can provide electronic states absorption at the optical gap. Their wavefunctions overlapping determine the luminescence intensity dependence on the temperature [I(T)on the order of magnitude exp(- T/T0)] and power law (t-1) of luminescence decay kinetics, which include intra-center processes due to triplet-singlet transitions and recombination processes due to a tunnel and overbarrier transitions, as well as a fast component of luminescence decay (some ns) due to singlet-singlet transitions.