In:
Advanced Science, Wiley, Vol. 9, No. 25 ( 2022-09)
Abstract:
Four isomeric, homoleptic iridium(III) metal complexes bearing 5‐(trifluoromethyl)imidazo[4,5‐b]pyridin‐2‐ylidene and 6‐(trifluoromethyl)imidazo[4,5‐b] pyridin‐2‐ylidene‐based cyclometalating chelates are successfully synthesized. The meridional isomers can be converted to facial isomers through acid induced isomerization. The m ‐isomers display a relatively broadened and red‐shifted emission, while f ‐isomers exhibit narrowed blue emission band, together with higher photoluminescent quantum yields and reduced radiative lifetime relative to the mer ‐counterparts. Maximum external quantum efficiencies of 13.5% and 22.8% are achieved for the electrophosphorescent devices based on f ‐tpb1 and m ‐tpb1 as dopant emitter together with CIE coordinates of (0.15, 0.23) and (0.22, 0.45), respectively. By using f‐ tpb1 as the sensitizing phosphor and t ‐DABNA as thermally activated delayed fluorescence (TADF) terminal emitter, hyperluminescent OLEDs are successfully fabricated, giving high efficiency of 29.6%, full width at half maximum (FWHM) of 30 nm, and CIE coordinates of (0.13, 0.11), confirming the efficient Förster resonance energy transfer (FRET) process.
Type of Medium:
Online Resource
ISSN:
2198-3844
,
2198-3844
DOI:
10.1002/advs.202201150
Language:
English
Publisher:
Wiley
Publication Date:
2022
detail.hit.zdb_id:
2808093-2