Researchers from Durham University have uncovered a scientific ‘blind spot’ and shown that a molecule previously thought to be a poor emitter of light may actually be optimum for boosting efficiency and stability in next-generation blue organic light-emitting diode (OLED) displays.
The discovery, published in the journal Nature Photonics, reveals that the molecule called ACRSA, which was deemed a subpar light emitter, could help to triple the efficiency of blue OLEDs, enabling advances in energy-saving displays.
The team found that ACRSA could increase device efficiency from 10% to more than 28% when used as a sensitiser in ‘hyperfluorescent’ OLEDs. ACRSA, the greenish sensitiser, was found to enable blue emission through a green-to-blue approach where the ACRSA molecule transfers its energy to a blue terminal emitter. This results in reduced exciton energy compared to direct blue emitters.
Professor Andrew Monkman of Durham University’s Physics Department and senior author of the study said: “This approach reduces exciton energy compared to direct blue emission in devices, allowing more stable, longer-lasting blue OLEDs. Our findings reveal an unexplored territory for hyperfluorescent OLEDs that could greatly expand material choices for the next generation of displays."
The discovery is particularly beneficial given OLED technology is present in most modern smartphones and televisions, and how finding efficient and stable blue OLED emission has been an ongoing challenge.
It is hoped the strategy could offer a new practical blueprint for OLED efficiency, and that it may also open up new possibilities for fundamental research.
