Efficient near-infrared emission of π-extended cyclometalated iridium complexes based on pyrene in solution-processed polymer light-emitting diode
Abstract
A novel iridium complex grafting hole-transporting triphenylamine (TPA) unit onto cyclometalated ligand, namely t-BuPyrPyTPA)2Ir(acac), was successfully synthesized and characterized. The photophysical, electrochemical and DFT/TD-DFT calculation, as well as electroluminescence properties of this iridium complex were fully investigated. Meanwhile, the PLEDs employing (t-BuPyrPyTPA)2Ir(acac) as dopant presented stable NIR emission peaked at 697 nm and a shoulder at 764 nm with a highest external quantum efficiency (EQE) of 0.56% at 4 wt% dopant concentration. These results demonstrate that expanding the conjugation length of the ligand is an effective way to achieve NIR emission.
- Publication:
-
Chemical Physics Letters
- Pub Date:
- May 2018
- DOI:
- 10.1016/j.cplett.2018.03.046
- Bibcode:
- 2018CPL...699...99L
- Keywords:
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- Near-infrared emission;
- Iridium (III) complex;
- Pyrene;
- Electroluminescence;
- Polymer light-emitting diodes