Polyfluorene photophysics

The fundamental optical properties and processes that occur in the polyfluorenes are discussed. Details are given on the production of singlet and triplet excitons, their emissive decay channels via fluorescence and phosphorescence and non emissive decay via quenching, together with exciton lifetime and quantum yields of production. The interaction of excitons in these polymers is then discussed at length describing exciton migration dynamics, exciton-exciton annihilation processes and delayed fluorescence and the trapping of excitons at defect sites. Photogenerated charge state production is described along with intra-chain charge transfer states in fluorene co-polymers. Finally, sections describing the optical properties of the beta-phase of polyfluorene are given along with amplified spontaneous emission which occurs at high beta phase exciton populations.