Triplet-triplet annihilation in a thermally activated delayed fluorescence emitter lightly doped in a host

Akitsugu Niwa, Shota Haseyama, Takashi Kobayashi, Takashi Nagase, Kenichi Goushi, Chihaya Adachi, Hiroyoshi Naito

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Triplet-triplet annihilation (TTA) will change the ratio between fluorescence and phosphorescence in the photoluminescence spectrum of a thermally activated delayed fluorescence emitter at very low temperature. Using the resultant spectral blueshift, this study investigated the nature of TTA in 1,2,3,5-tetrakis(carbazol-9-yl)-4,6-dicyanobenzene (4CzIPN) doped in a host material. The spectral blueshift is not caused by singlet-triplet annihilation and the emitter saturation effect and is less influenced by the emitter aggregates, particularly for the case of a lower doping concentration. Using these features, it is possible to focus on TTA. For 4CzIPN, the spectral blueshift due to TTA is recognized even in samples with the doping concentration as low as 1 wt. %.

Original languageEnglish
Article number083301
JournalApplied Physics Letters
Issue number8
Publication statusPublished - Aug 20 2018


All Science Journal Classification (ASJC) codes

  • Physics and Astronomy (miscellaneous)

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