Thermally activated delayed fluorescence emitters with intramolecular proton transfer for high luminance solution-processed organic light-emitting diodes
Abstract
We report an organic emitter containing a β-triketone electron acceptor core and phenoxazine as the electron donors ( TPXZBM ) for solution-processed organic light-emitting diodes (OLEDs). The resulting molecule is very unusual because it shows both thermally activated delayed fluorescence (TADF) and intramolecular proton transfer. We compare its performance with the previously reported diketone analogue PXZPDO . Solution-processed OLEDs of PXZPDO and TPXZBM show maximum external quantum efficiencies of 20.1% and 12.7%, respectively. The results obtained for the solution-processed PXZPDO -based device are as good as the previously reported evaporated device. At a very high luminance of 10,000 cd/m2 the efficiency of the OLEDs was 10.6% for PXZPDO and 4.7% for TPXZBM , demonstrating relatively low efficiency roll-off for TADF materials. The low efficiency roll-off was rationalized on the basis of the short delayed lifetimes of 1.35 μs for PXZPDO and 1.44 μs for TPXZBM . Our results suggest that intramolecular proton transfer may be useful for the design of OLED materials with low efficiency roll-off.
Citation
Gupta , A , Li , W , Ruseckas , A , Lian , C , Carpenter-Warren , C L , Cordes , D B , Slawin , A M Z , Jacquemin , D , Samuel , I D W & Zysman-Colman , E 2021 , ' Thermally activated delayed fluorescence emitters with intramolecular proton transfer for high luminance solution-processed organic light-emitting diodes ' , ACS Applied Materials & Interfaces , vol. Articles ASAP . https://doi.org/10.1021/acsami.1c02248
Publication
ACS Applied Materials & Interfaces
Status
Peer reviewed
ISSN
1944-8244Type
Journal article
Description
AKG is grateful to the Royal Society for Newton International Fellowship NF171163. We acknowledge support from the Engineering and Physical Sciences Research Council of the UK (grants EP/P010482/1 and EP/L017008/1). We thank the EPSRC UK National Mass Spectrometry Facility at Swansea University for analytical services. We thank Umicore for providing palladium (II) acetate.Collections
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