Highly efficient exciton-exciton annihilation in single conjugated polymer chains.

ABSTRACT: The number of excitons that conjugated polymers can support at any one time underpins their optoelectronic performance in light-emitting diodes and as laser gain media, as it sets a natural limit on exciton density. Here we have measured the time-resolved photon statistics of single, isolated chains of polyfluorene to extract the absolute number of independent emitting sites present and its time dependence by studying the intramolecular exciton-exciton annihilation. We find that after 100 ps each chain can only support 1 or 2 independent excitons, and that even at the earliest times this number rises only to 4, suggesting a high degree of electronic coupling between chromophores that facilitates efficient exciton-exciton annihilation. In circumstances where a low density of low-energy site

SUBMITTER: Fairbairn NJ 

PROVIDER: S-EPMC12820388 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature