Delayed fluorescence ODMR as a probe of triplet-triplet fusion probability

Abstract

Absσa ct. A kinetic scheme is presented to rationalize recent observations of delayed f1uores-cence ODMR in isotopically mixed naphth외ene crystals, in which the sign of the sign외 changes from negative to positive as the critical concentration for triplet-triplet σansport among the perprotonated σaps is approached. πIe effects of chop야d optic외 excitation, prolonged microwave pumping, temperature and light intensity are considered. πIe observation of positive DF-ODMR in the high concentration case is used to obtain a lower 파nit for the ratio of the annihilation constant k 2 to the pair dissociation constant k -I'