Separating triplet exciton diffusion from triplet-triplet annihilation by the introduction of a mediator.

ABSTRACT: Triplet-triplet annihilation photon upconversion (TTA-UC) combines the energy of two photons to provide one of higher energy that can be used to drive photochemical or photophysical processes. TTA-UC proceeds at high efficiencies in dilute solution, but in solid state the efficiency drastically reduces. This is because exciton diffusion, compared to molecular diffusion in solid annihilator films, suffers concentration induced quenching, undermining efficient emission. Here, we provide a method to decouple the triplet exciton diffusion and the annihilation processes using an exciton transporting mediator as host. At low exciton densities emission occurs from the annihilator, while at higher exciton intensities TTA and emission from the mediator is observed. The low concentration of the anni

SUBMITTER: Carrod AJ 

PROVIDER: S-EPMC11639907 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature