New research paves the way for more efficient and stable blue OLED displays

New research by scientists at Durham University reveals an unexpected path to brighter, more efficient and more stable blue organic light-emitting diodes (OLEDs).

The results, published in the journal Natural photonics could help enable the next generation of energy-efficient display technologies.

OLED displays, used in most modern smartphones and televisions, rely on the emission of light from specialized organic molecules.

Obtaining a stable and efficient blue emission suitable for screens remains a major challenge.

Now, researchers at Durham University have developed a new design strategy using ‘hyperfluorescent’ OLEDs, in which energy is transferred from a ‘sensitizer’ molecule to a separate ’emitter’ molecule.

Surprisingly, the team found that sensitizer molecules previously thought to be poor emitters worked remarkably well in hyperfluorescent OLEDs.

“We discovered a ‘dead spot’ where materials overlooked by conventional thinking can become very effective when used as sensitizers in hyperfluorescence OLEDs,” said Kleitos Stavrou of Durham University, lead author of the study.

In particular, the ACRSA molecule was found to triple the efficiency of OLEDs when used as a sensitizer in hyperfluorescence OLEDs.

The researchers attribute this to ACRSA’s rigid molecular structure and its long-lived excited states.

Even more strikingly, using a greenish sensitizer, such as ACRSA, deep blue light emission can be achieved by transferring energy from the ACRSA to a blue terminal emitter.

“This approach reduces exciton energy compared to direct blue emission in devices, enabling more stable and longer-lasting blue OLEDs,” said study lead author Professor Andrew Monkman from the Department in physics from the University of Durham.

Overall, the strategy provides a new molecular design paradigm for stable and highly efficient screens.

“Our results reveal uncharted territory for hyperfluorescent OLEDs that could significantly expand the choice of materials for the next generation of displays that will also consume up to 30% less electricity,” Professor Monkman said.

The researchers then plan to develop more hyperfluorescent OLEDs, with industrial partners, for commercial applications.