| 초록 |
In this work, we designed and synthesized two Ir(III) complexes named as tBuCN-FIroz and tBuCN-FIrim containing the chromophoric ancillary ligands 2-(4,5-dihydrooxazol-2-yl)phenol (oz) and 2-(1-ethyl-4,5-dihydro-1H-imidazol-2-yl)phenol (im), respectively, and a highly functionalized phenyl pyridine derivative, 3-(4-(tert-butyl)pyridin-2-yl)-2,6-difluorobenzonitrile, as C^N ligand. Introduction of oxazoline/imidazoline heterocycle into the ancillary ligand has enriched the MLCT nature of the emitting excited state, and the substituents on C^N ligand (fluoro & cyano) have an effect of enhancing intersystem crossings (ISC). As a result, tBuCN-FIroz and tBuCN-FIrim exhibited high PLQYs of about 90±3% with bright sky-blue light emission at 480 nm and bluish-green light at 495 nm, respectively. In particular, the PhOLEDs fabricated in dry process showed maximum EQEs of 21.9% for tBuCN-FIroz and 19.7% for tBuCN-FIrim, respectively. |
