Highly efficient luminescence from space-confined charge-transfer emitters
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Highly efficient light emission has been realized from organic complexes by strategically positioning and orientating the electron donors and acceptors.
Organic light-emitting diodes (OLEDs) are attractive for flat-panel displays and ecofriendly lighting sources. Excited-state complexes known as exciplexes emit light when electrons are exchanged between an electron donor and an electron acceptor. They are promising for use in OLEDs but suffer from low efficiencies because difficulties in aligning the component molecules in the optimum directions.
Now, a team led by researchers at Soochow University in China has come up with a strategy for overcoming this limitation of exciplexes. It involves using rigid linker molecules to optimize the spacing and orientations of the donors and acceptors.
OLEDs based on these exciplexes had substantially higher light output than those with less rigid linkers.
This design strategy could be applied to other combinations of donors and acceptors, the researchers say.
- Nature Materials (2020) Advanced online publication. doi: 10.1038/s41563-020-0710-z