Kyulux dramatically improves the performance of its blue HF emitter

Kyulux announced that it has developed a new blue Hyperfluoresence/TADF OLED emitter. Kyulux managed to extend the lifetime of the material and reached 100 hours at LT95 (@ 750 cd/m2) while maintaining a high EQE of 26% - 22% at 1,000 cd/m2. The emission wavelength is 470 nm.

Kyulux says that its blue Hyperfluorescence emitter is the world’s top performing material at the moment. Kyulux now aims to work together with OLED panel makers to improve the systems further by optimizing the device structure and the rest of the OLED stack in pilot production lines.

Source: 
Posted: Jul 19,2018 by Ron Mertens

Comments

That is great news! Finally another player who will work on efficient blue. We definitely need such a material. But 470nm emission maximum for a fluorescent blue is typically a CIE-y coordinate of 0.30-0.35. Is that even still sky blue or is that already green? Definitely not deep blue. I guess that will be the next thing they will have to work on.

 

Great and exciting to finally see progress here after a year without substantial progress!

Would love to see a like-for-like comparison to the data Cynora published earlier this year - lifetime wise Kyulux is more than one order of magnitude better considering the brightness. Even if Ks peak emission really is greener, the rule of thumb is splitting the lifetime in half for every 5 nm of blue shift, which would still indicate that the Japanese tech is conceptually far superior (factor of 3 or more) to the stuff presented by the Germans.

Plus Kyulux is way closer to general commercialization due to their work on green and red PMOLEDs. Incredible how they achieve this even their team is only a third of Cynoras size! Glad to NOT being an investor there right now. 

 

Nice try to belittle this great achievement, but I do not see any reason to be that pessimistic.

I do not know what fluorescent emitter they used, but with a quick Google search you can draw out peer-reviewed data for devices with emission around 470 nm and CIEy of 0.25, like here: 

http://pubs.rsc.org/en/content/articlelanding/2017/tc/c6tc04821h/unauth#!divAbstract

Not saying that Kyulux did 0.25 (although it seems possible), but putting this in a top-emission device with a little microcavity optimization would bring them quite close to the magical CIEy of 0.1 the display makers are craving.  

Realistically, lifetime is way, way harder to achieve than efficiency and color point (which was done in Adachi papers in 2014), so this is awesome news!

Congratulations to Kyulux! Significant progress in the last year. If you would like to see the direct comparison with CYNORA, you will find it in this post from May of last year:

https://www.oled-info.com/cynora-announces-its-latest-blue-tadf-oled-emitter-performance

90h LT97 at 700 nits correspond to 200h LT95 at 700 nits.

Even with microcavity, 470nm is not enough for display. From 470nm to 460nm will be the longest 10 nm for them to travel. UDC spent 20 years to make blue phos emitter work for display and they are still not there. TADF, which also uses triplet, is no different. That said, it is still quite a progress for blue TADF.