Highly twisted α-diketone-based thermally activated delayed fluorescence emitters and their use in organic light-emitting diodes

We have designed a highly twisted small TADF emitter PXZ-α-DK based on an a-diketone (α-DK) as a strong acceptor and phenoxazine (PXZ) as a strong donor to obtain red-shifted emission in comparison to the equivalent a-diketone linked to 9,9-dimethyl-9,10-dihydroacridine (DMAC). The PXZ-α-DK shows emission at 586 nm and DMAC-α-DK shows emission at 548 nm in 1,3-bis(N-carbazolyl)benzene (mCP) host at 1.5 wt% doping of the emitter, with short-delayed lifetimes of 6.9 μs for PXZ-α-DK and 7.6 μs for DMAC-α-DK. OLEDs fabricated using these emitters show green electroluminescence at 555 nm for DMAC-α-DK, with a maximum external quantum efficiency, EQEmax, of 6.3%, and orange electroluminescence at 585 nm for PXZ-α-DK, with an EQEmax of 0.8%. We corroborate the optoelectronic properties of these emitters with DFT calculations.

Citation

Gupta , A K , Matulaitis , T , Cordes , D B , Slawin , A M Z , Samuel , I D W & Zysman-Colman , E 2021 , ' Highly twisted α-diketone-based thermally activated delayed fluorescence emitters and their use in organic light-emitting diodes ' , Canadian Journal of Chemistry , vol. Early View . https://doi.org/10.1139/cjc-2021-0208

Publication

Canadian Journal of Chemistry

Status

Peer reviewed

DOI

https://doi.org/10.1139/cjc-2021-0208

ISSN

0008-4042

Type

Journal article

Rights

Copyright © 2021 The Author(s). This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1139/cjc-2021-0208

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 are also grateful for financial support from the University of St Andrews Restarting Research and Restarting Interdisciplinary Research Funding Schemes (SARRF and SARIRF) which are funded through the Scottish Funding Council grant reference SFC/AN/08/020.

Collections

University of St Andrews Research

URI

http://hdl.handle.net/10023/24060