Fission of singlet excitons into triplet-exciton pairs in molecular crystals

Abstract
A kinetic model of singlet-exciton fission into pairs of triplet excitons in aromatic hydrocarbon crystals is presented. The model is based on Suna's hopping model for triplet-exciton fusion. The assumptions made in this description of fission and the relationship between fusion and fission are analyzed in detail. According to this theoretical model, the magnetic field modulation of anthracene hot singlet fission is the reverse of the modulation of triplet fusion. Accurate observations of fission, however, have shown there are some consistent differences, and these differences are discussed in terms of the fission process.