Short- and Long-Range Order Effects on Resonance Energy Transfer in Crystals and Glasses

摘要

Resonance energy transfer by the Forster-Dexter mechanism in a cubic crystal and in a rigid homogeneous medium is studied. The homogeneous medium is modeled using a hard-sphere fluid (HSF) radial distribution function. This distribution is more realistic than the commonly used uniform distribution with excluded volume (UDEV) function. For the dipole-dipole mechanism, both models yield essentially the same donor luminescence decay, except for small critical radii. For the exchange mechanism, however, the two models differ significantly. In particular, to fit a given experimental decay, the UDEV model requires both a larger effective Bohr radius and a larger rate constant at collisional distance than the HSF model.