| Literature DB >> 30192504 |
Michael Y Wong1, Simonas Krotkus2, Graeme Copley1, Wenbo Li2, Caroline Murawski2, David Hall1,2, Gordon J Hedley2, Marie Jaricot1, David B Cordes1, Alexandra M Z Slawin1, Yoann Olivier3, David Beljonne3, Luca Muccioli4, Monica Moral5,6, Juan-Carlos Sancho-Garcia6, Malte C Gather2, Ifor D W Samuel2, Eli Zysman-Colman1.
Abstract
A series of four novel deep-blue to sky-blue thermally activated delayed fluorescence (TADF) emitters (2CzdOXDMe, 2CzdOXD4MeOPh, 2CzdOXDPh, and 2CzdOXD4CF3Ph) have been synthesized and characterized. These oxadiazole-based emitters demonstrated bluer emission compared with the reference emitter 2CzPN thanks to the weaker acceptor strength of the oxadiazole moieties. The oxadiazole compounds doped in hosts (mCP and PPT) emitted from 435 to 474 nm with photoluminescence quantum yields ranging from 14-55%. The emitters possess singlet-triplet excited-state energy gaps (Δ EST) between 0.25 and 0.46 eV resulting in delayed components ranging from 4.8 to 25.8 ms. The OLED device with 2CzdOXD4CF3Ph shows a maximum external quantum efficiency of 11.2% with a sky-blue emission at CIE of (0.17, 0.25), while the device with 2CzdOXD4MeOPh shows a maximum external quantum efficiency of 6.6% with a deep-blue emission at CIE of (0.15, 0.11).Entities:
Keywords: DFT calculations; blue emitters; organic light emitting diodes; oxadiazoles; thermally activated delayed fluorescence
Year: 2018 PMID： 30192504 DOI： 10.1021/acsami.8b11136
Source DB: PubMed Journal: ACS Appl Mater Interfaces ISSN： 1944-8244 Impact factor: 9.229