Schematic representations of recombination pathways

Excitons are bound “electron-hole” pairs which includes structural relaxation of a single polymer chain (i.e., electron-phonon coupling)

Decay pathways for singlet and triplet decay

Radiative processes, corresponding to absorption or emission of light; Non-radiative processes. a: Fluorescence b: Intersystem crossing (ISC) c: Photoinduced triplet-triplet absorption d: Phosphorescence