Non-radiative energy transfer between impurity ions in crystals: configuration mixing

Abstract

In this work, the non-radiative energy transfer mechanism between a pair of distinct dopant ions in a monocrystalline matrix is reviewed, the transfer mechanism is contemplated as a result of the configuration mixing of the energy levels of the subsystem donor-acceptor couple. When this resonance is considerable, a strong mixing takes place between two of the wave functions of the involved ions, and this mixing results in an increased value of the probability of non-radiative energy transfer. On the other hand, Dexter's classical theory for non-radiative energy transfer can be applied as a limiting case when the energy resonance is neglected. The rate of non-radiative energy transfer has been calculated for various systems where this process has been observed, finding that, for specific energy levels of the subsystem pair the calculated non-radiative excitation transfer is in close agreement with the experimentally determined rate. (C) 1999 Elsevier Science B.V. All rights reserved.