CCMP Seminar Series: Dr. Andrew Danos

Despite dominating current research in organic light-emitting diodes [1], thermally activated delayed fluorescence (TADF) emitters are themselves far from commercially mature. Specific material limitations and host requirements present formidable and ongoing challenges for blue emission, necessary for both lighting and display applications. [2] Recently, the development of TADF-Hyperfluorescence approaches has yielded significant advances [3], but commercially viable high-triplet host materials remain elusive.

In this talk, I will outline how a parallel class of TADF emissive materials—exciplexes formed from mixtures of separate donor and acceptor materials—may offer an alternative way forward. Exciplex emitters are widely overlooked because their intrinsic performance has not kept pace with covalently bonded emitters [4], but when deployed instead as a host, this is compensated for by their fast exciton conversion and balanced charge transport. The discovery of sub-bandgap absorption bands in exciplex mixtures also indicates their very nature is misunderstood, as is their potential to support highly efficient and durable optoelectronic devices.

[1]10.1021/acs.chemrev.3c00755

[2]10.1021/acsami.1c09189

[3]10.1038/s41566-024-01395-1

[4]10.1021/acs.jpclett.8b03646