The contribution of triplet-triplet annihilation to the lifetime and efficiency of fluorescent polymer organic light emitting diodes

King, S.M.; Cass, M.; Pintani, M.; Coward, C.; Dias, F.B.; Monkman, A.P.; Roberts, M.

Abstract

We demonstrate that the fast initial decay of a prototypical fluorescent polymer based organic light emitting diode device is related to the contribution that triplet-triplet annihilation makes to the device efficiency. We show that, during typical operating conditions, approximately 20% of the device efficiency originates from the production of singlet excitons by triplet-triplet annihilation. During prolonged device operation, the triplet excitons are quenched much more easily than the emissive singlets; thus, the contribution to the efficiency from triplet-triplet annihilation is lost during the early stages of the device lifetest. The fast initial decay of the device luminance can be removed by incorporating a triplet quenching additive into the active layer to remove any effect of triplet-triplet annihilation; this yields an increase in the device lifetime of greater than 3x and an even more significant improvement in the initial luminance decay. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3561430]

Citation

King, S., Cass, M., Pintani, M., Coward, C., Dias, F., Monkman, A., & Roberts, M. (2011). The contribution of triplet-triplet annihilation to the lifetime and efficiency of fluorescent polymer organic light emitting diodes. Journal of Applied Physics, 109(7), Article 074502. https://doi.org/10.1063/1.3561430

• Journal Article Type: Article
• Publication Date: Apr 1, 2011
• Deposit Date: Feb 16, 2012
• Publicly Available Date: Sep 26, 2012
• Journal: Journal of Applied Physics
• Print ISSN: 0021-8979
• Electronic ISSN: 1089-7550
• Publisher: American Institute of Physics
• Peer Reviewed: Peer Reviewed
• Volume: 109
• Issue: 7
• Article Number: 074502
• DOI: https://doi.org/10.1063/1.3561430
• Public URL: https://durham-repository.worktribe.com/output/1504626