DIPOLE-DIPOLE ELECTRONIC-ENERGY TRANSFER - FLUORESCENCE DECAY FUNCTIONS FOR ARBITRARY DISTRIBUTIONS OF DONORS AND ACCEPTORS - SYSTEMS WITH PLANAR GEOMETRY

We derive an expression for direct non-radiative electronic energy tra nsfer which accommodates the possibility of a distribution of donor en vironments. At present we deal with situations in which the sample has a plane of symmetry for the concentration profiles. The relation enab les one to evaluate donor fluorescence decay functions I-D(t) from a k nowledge of donor/acceptor concentration profiles, C-D(z) and C-A(z), along the sample axis z. It reduces to known expressions in the case o f DET in infinite media, and allows simplified asymptotic solutions or facile numerical analysis in systems with more complicated concentrat ion profiles.