Photoluminescence and electroluminescence of four orange-red and red organic iridium(III) complexes

Publication date: Available online 19 September 2018Source: Journal of Organometallic ChemistryAuthor(s): Ning Su, You-Xuan ZhengAbstractUsing 1-(4-(trifluoromethyl)phenyl)isoquinoline (tfmpiq) and 4-(4-(trifluoromethyl)phenyl) quinazoline (tfmpqz) as the main ligands and pyrazole pyridine derivatives (mepzpy: 2-(3-methyl-1H-pyrazol-5-yl)pyridine, cf3pzpy: 2-(3-(trifluoromethyl)- 1H-pyrazol-5-yl)pyridine) as the ancillary ligands, four iridium(III) complexes (PIQ-Ir1-me, PIQ-Ir2-cf3, PQZ-Ir3-me and PQZ-Ir4-cf3) were synthesized and investigated. Due to the variation of the ligands, these Ir(III) complexes showed different emissions peaking from 602 to 628 nm with the phosphorescence quantum yields of 0.40–0.67. Moreover, applying these Ir(III) complexes as emitters, the organic light-emitting diodes (OLEDs) with the configuration of ITO/HATCN (hexaazatriphenylenehexacabonitrile, 5 nm)/TAPC (bis[4-(N,N-ditolylamino)-phenyl] cyclohexane, 50 nm)/Ir(III) complexes (8 wt%): TCTA (4,4′,4″-tri(9-carbazoyl)triphenylamine, 20 nm)/TmPyPB (1,3,5-tri[(3-pyridyl)-phen-3-yl]benzene, 40 nm)/LiF (1 nm)/Al (100 nm) exhibited good performances. Especially, the device with orange-red PQZ-Ir4-cf3 emitter obtained the best device performances with the maximum current efficiency of 40.04 cd A−1 and the maximum power efficiency of 33.98 lm W−1. For the pure red complex PQZ-Ir4-me with CIE coordinates at (0.64, 0.34) showed the maximum external quantum efficiency of 22....

Source: Journal of Organometallic Chemistry - September 20, 2018 Category: Chemistry Source Type: research