Abstract
We study photoluminescence and triplet-triplet exciton annihilation in a neat film of a fac-tris(2-phenylpyridyl)iridium(III) -cored dendrimer and in its blend with a -bis(-carbazolyl)biphenyl host for the temperature range of . The nearest neighbor hopping rate of triplet excitons is found to increase by a factor of 2 with temperature between 150 and and is temperature independent at lower temperature. The intermolecular quenching rate follows the Arrhenius law with an activation energy of , which can be explained by stronger dipole-dipole interactions with the donor molecule in the higher triplet substate. The results indicate that energy disorder has no significant effect on triplet transport and quenching in these materials.
- Received 28 June 2007
DOI:https://doi.org/10.1103/PhysRevB.77.085211
©2008 American Physical Society