Efficient up-conversion of triplet excitons into a singlet state and its application for organic light emitting diodes
Abstract
A material possessing a very small energy gap between its singlet and triplet excited states, ΔE1-3, which allows efficient up-conversion of triplet excitons into a singlet state and leads to efficient thermally activated delayed fluorescence (TADF), is reported. The compound, 2-biphenyl-4,6-bis(12-phenylindolo[2,3-a] carbazole-11-yl)-1,3,5-triazine, breaks the restriction of a large energy gap, with a ΔE1-3 of just 0.11 eV, while maintaining a high fluorescent radiative decay rate (kr∼107). The intense TADF provides a pathway for highly efficient electroluminescence.
- Publication:
-
Applied Physics Letters
- Pub Date:
- February 2011
- DOI:
- 10.1063/1.3558906
- Bibcode:
- 2011ApPhL..98h3302E
- Keywords:
-
- electroluminescence;
- energy gap;
- excitons;
- fluorescence;
- organic light emitting diodes;
- 85.60.Jb;
- 78.60.Fi;
- 71.35.-y;
- Light-emitting devices;
- Electroluminescence;
- Excitons and related phenomena