A Multiresonant Thermally Activated Delayed Fluorescent Dendrimer with Intramolecular Energy Transfer: Application for Efficient Host-Free Green Solution-Processed Organic Light-emitting Diodes.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 39780608.
- Also identified by DOI 10.1002/adma.202415289 and PMC identifier 11854867.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The development of narrowband emissive, bright, and stable solution-processed organic light-emitting diodes (SP-OLEDs) remains a challenge. Here, a strategy is presented that merges within a single emitter a TADF sensitizer responsible for exciton harvesting and an MR-TADF motif that provides bright and narrowband emission. This emitter design also shows strong resistance to aggregate formation and aggregation-cause quenching. It is based on a known MR-TADF emitter DtBuCzB with a donor-acceptor TADF moiety consisting of either tert-butylcarbazole donors (tBuCzCO<sub>2</sub>HDCzB) or second-generation carbazole-based donor dendrons (2GtBuCzCO<sub>2</sub>HDCzB) and a benzoate acceptor. The TADF moiety acts as an exciton harvesting antenna and transfers these excitons via Förster resonance energy transfer to the MR-TADF emissive core. The SP-OLEDs with 2GtBuCzCO<sub>2</sub>HDCzB and tBuCzCO<sub>2</sub>HDCzB thus show very high maximum external quantum efficiencies (EQE<sub>max</sub> of 27.9 and 22.0%) and minimal efficiency roll-off out to 5000 cd m<sup>-2</sup>.