A recent paper published in Nature demonstrates that hyperfluorescent OLEDs could significantly reduce the energy required to display the color blue – potentially mitigating, but not solving, screen burn-in.
The study was conducted by researchers from several academic institutions, primarily the University of Cambridge. Poetically titled “Suppression of Dexter transfer by covalent encapsulation for efficient matrix-free narrowband deep blue hyperfluorescent OLEDs,” the paper was published earlier this month.
The research team attempted to find a method for creating OLEDs that could more efficiently emit blue light – one of the three primary colors used to synthesize hues on modern display technology. Individual pixels in a display are composed of three sub-pixels, one for each of red, green, and blue.
Producing blue takes a particularly large amount of energy, and that’s been the case for years. “Essentially, trying to obtain a blue light emitting molecule for OLEDs that satisfies every property that we would like simultaneously (efficiency, stability and color purity) has not been possible after decades of effort,” explained Dr Daniel Congrave, a co-author of the paper.
Instead of trying to find the perfect molecule for emitting blue light, Dr Congrave and his colleagues proposed a dual-molecule hyperfluorescence solution. “Rather than expecting a single type of molecule to achieve all of these things, the idea of hyperfluorescence is to share the work between different molecules that individually do a good job at dealing with the piece of the puzzle that they are allocated,” Congrave explained.
The two primary components of hyperfluorescence – a term coined by scientist Chihaya Adachi and trademarked by display materials specialist Kyulux – are the sensitizer molecule and the terminal emitter molecule. The sensitizer is supposed to efficiently transfer energy into the terminal emitter, which then emits a pure color.
“A really important thing with hyperfluorescence is making sure that the energy actually goes where you want it to, in the right order,” noted Congrave. In the past, a matrix was used to stop energy from being distributed incorrectly – a phenomenon known as “Dexter transfer.” Adding a matrix increases the number of components used to three or more, making production more complicated and thus potentially more expensive.
However, the researchers bypassed the need for a matrix by insulating the terminal emitter with what they termed covalent encapsulation. This allowed for hyperfluorescent OLEDs that exhibited improved efficiency and color purity.
The main objective of the study was to find a commercially viable method that achieves better efficiency – specifically for the blue part of OLEDs. An added bonus may be increased resilience to burn-in, which has caused issues even on the latest iPhone 15 Pro Max.
However, Dr Congrave stressed to us that this isn’t a version of OLED that completely stops burn-in from happening. It’s just a natural consequence of reducing power consumption, which is highest on blue sub-pixels.
Anything detailed in a research paper phase is far from production ready, so don’t expect any OLED monitors or TVs to incorporate this method of hyperfluorescence any time soon. But no doubt Samsung or Sony’s marketing machines will turn this tech – or something very like it – into “HyperBlue” or some other nonsense eventually. ®
