Temperature effects on intrachain recombination of bipolarons in conjugated polymers

The temperature influence over the intrachain recombination dynamics between oppositely charged bipolarons has been theoretically investigated using a version of the Su–Schrieffer–Heeger model. The results shown that, below of a critical temperature regime, these charge carriers can recombine into a biexciton. This excited state is a light emissive specie that can emit one photon and turn into an exciton state. This specie can thereafter decay to the ground state by other photon emission. This knowledge can enlighten the understanding needed to improve the internal quantum efficiency of electroluminescence in Polymer Light Emitting Diodes.