-With pictures-
A new research from scientists at Durham University reveals an unexpected pathway towards brighter, more efficient, and more stable blue organic light-emitting diodes (OLEDs).
The findings, published in the journal Nature Photonics could help enable the next generation of energy-saving display technologies.
OLED displays, used in most modern smartphones and TVs, rely on light emission from specialised organic molecules.
Obtaining stable, efficient blue emission suitable for displays remains a key challenge.
Now, Durham University researchers have unlocked a new design strategy using "hyperfluorescent" OLEDs, where energy is transferred from a ‘sensitiser’ molecule to a separate ‘emitter’ molecule.
Surprisingly, the team found that sensitiser molecules previously dismissed as poor emitters actually perform remarkably well in hyperfluorescent OLEDs.
"We discovered a 'blind spot' where materials overlooked by conventional thinking can become highly effective when used as sensitisers in hyperfluorescence OLEDs," said Kleitos Stavrou of Durham University, lead author of the study.
In particular, the molecule ACRSA was found to triple the OLED efficiency when used as a sensitiser in hyperfluorescence OLEDs.
The researchers attribute this to ACRSA's rigid molecular structure and long-lived excited states.
Even more strikingly, using a greenish sensitiser, such as ACRSA, deep blue light emission can be achieved by transferring ACRSA’s energy to a blue terminal emitter.
“This approach reduces exciton energy compared to direct blue emission in devices, allowing more stable, longer-lasting blue OLEDs,” said senior author of the study, Professor Andrew Monkman of Durham University’s Physics Department.
Overall, the strategy provides a new molecular design paradigm for stable and highly efficient displays.
“Our findings reveal an unexplored territory for hyperfluorescent OLEDs that could greatly expand material choices for the next generation of displays, that will also use up to 30% less electricity” said Professor Monkman.
The researchers next plan to further develop hyperfluorescent OLEDs, with industrial partners, towards commercial applications.
ENDS
Media Information
Kleitos Stavrou and Professor Andrew Monkman from Durham University are available for interview and can be contacted on a.p.monkman@durham.ac.uk.
Alternatively, please contact Durham University Communications Office for interview requests on communications.team@durham.ac.uk or +44 (0)191 334 8623.
Graphics
Associated images are available via the following link: https://www.dropbox.com/scl/fo/tideskid6mcmenspikhy0/h?rlkey=ht3v1fnae6twr0gpgv9tf4rui&dl=0
Source Information
‘Key requirements for Ultra-Efficient Sensitisation in Hyperfluorescence OLEDs’, (2024), K Stavrou, L Franca, A Danos and A Monkman, Nature Photonics.
After the embargo lifts, the paper can be accessed via this link: https://doi.org/10.1038/s41566-024-01395-1
For an embargoed copy of the paper please contact Durham University Communications Office on communications.team@durham.ac.uk.
About Durham University
Durham University is a globally outstanding centre of teaching and research based in historic Durham City in the UK.
We are a collegiate university committed to inspiring our people to do outstanding things at Durham and in the world.
We conduct research that improves lives globally and we are ranked as a world top 100 university with an international reputation in research and education (QS World University Rankings 2024).
We are a member of the Russell Group of leading research-intensive UK universities and we are consistently ranked as a top 10 university in national league tables (Times and Sunday Times Good University Guide, Guardian University Guide and The Complete University Guide).
For more information about Durham University visit: www.durham.ac.uk/about/
END OF MEDIA RELEASE – issued by Durham University Communications Office.
Journal
Nature Photonics