EXCITATION TRANSFER IN DONOR-ACCEPTOR PAIR LUMINESCENCE

In the analysis of spectral and time dependencies of donor-acceptor pair (DAP) spectra, it has usually been assumed that the primary factors are the distribution of pair separations together with the dependence of the decay and of the emitted energies on these separations. We have measured the time decay of the DAP luminescence in ZnSe as a function of excitation wavelength and show that, instead, excitation transfer via localized states cannot be neglected. We also point out that such transfer appears very reasonable, based on transfer versus luminescence decay rates.