OLED displays use organic materials that emit light when electricity is applied. OLEDs enable emissive, bright, thin, flexible and efficient displays. OLEDs are set to replace LCDs in all display applications - from small displays to large TV sets.
UDC OLED material performance, 2012
One of the main problems of OLED displays is the limited lifetime of the OLED materials. In past years we have seen great advances in this area, and today OLED materials are quite long lasting - with material lifetime reaching million hours or more.
Blue OLED lifetime
A blue OLED emitter is the most unstable emitter, and blue OLEDs (required to create a full-color display) suffer from short lifetimes. This is especially true for the efficient phosphorescent blue emitter - and today there's still no commercial efficient blue emitter.
The OLED industry is seeking several routes to develop an efficient blue. PHOLED pioneer Universal Display is developing a blue PHOLED, but has yet to find a commercial-ready material. Other promising route is TADF emitter technology.
The latest OLED lifetime news:
Professor Homas Teets from the University of Houston has been awarded a $589,000 National Science Foundation (NSF) CAREER Award to explore new synthetic strategies for producing photoactive organometallic compounds.
Specifically, Teets will use the award in three research areas - efficient and long-lasting blue OLEd emitters, near-infrared (NIR) emitting compounds and photocatalysts for organic synthesis capable of light-induced electron transfer. The grant will also fund educational projects aimed at children from kindergarten through high school.
In early March we conducted a 10 day trip to Seoul, to attend the OLED Korea 2019 conference (and visit some local display companies).
Visiting Seoul is a great chance to witness some beautiful OLED installations - LG Display has been deploying its OLED lighting and display solutions across town in businesses and tourist attractions. Retail stores of course were showing the latest smartphones by Samsung and LG - all of which adopt high end flexible AMOLED displays.
At the OLED Korea conference, both Merck and Sumitomo detailed their latest OLED inkjet material performance.
The first day of the OLED Korea 2019 conference is almost over - with some interesting lectures and talks by leading OLED companies and professionals. Here are some of the things under discussion today (highlights only):
- Some believe there will be a real market for >$2,000 foldable OLED devices, and some call for cost reductions before real adoption could take place
- LG Display is optimistic regarding the future of OLED TVs
- Samsung will not commit yet to its QD-OLED technology
- Both Cynora and Kyulux are rapidly progressing towards a long lasting TADF/HF blue - but it seems there's still work to be done
- Idemitsu Kosan is increasing its fluorescent OLED emitter efficiency
- Universal Display's RGBB architecture is back on the table - and the company now highlights the architecture's low blue light emission. UDC seems more optimistic then ever regarding blue PHOLED commercialization
- Equipment maker's focus is shifting to China as Korean OLED makers will not increase capacity in the near future
HDTVTest posted an interesting interview with Cadmium-Free QD developer Nanosys CEO and president Jason Hartlove. In this long interview Jason discusses the company's technology and recent achievements.
Jason reveals that the company is working on emissive Quantum Dots displays - and he expects to have a full-color monitor-size QLED display prototype ready by the end of 2019. Jason says that they hope to show these display prototypes in private demos at CES 2020.
In March 2018 OLEDWorks launched its first flexible OLED panels, branded as BendOLEDs. The company now announced that the panels are now commercially available - and rebranded as LumiCurve Wave, which is the first panel in OLEDWorks LumiCurve product family.
The LumiCurve Wave is produced on Corning's 0.1mm thin Willow Glass flexible glass substrate. OLEDWorks says that the Wave panels are extremely thin and light and deliver the superb light quality and excellent color rendering that is uniquely achievable with OLED.
An interview with Cynora's CMO Dr. Andreas Haldi - talking about TADF, lifetime, color points and more
German TADF developer Cynora presented its latest blue TADF material in May 2018 - with a CIEy of 0.14, EQE of 20% and a lifetime of 20 hours LT97 at 700 nits. Cynora expects to have blue material in the mass production by 2020.
Cynora's Chief Marketing Offer, Dr. Andreas Haldi was kind enough to answer a few questions we had regarding TADF emitters, the differences between next-generation emitter technologies, lifetime, color points and more.
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.
IGNIS developed a new driver chip to enhance OLED compensation process using individual pixel sensing
IGNIS Innovation announced that in collaboration with its partners, the company developed a driver chip that incorporates the ability to sense individual pixels on the panel. This new ability integrates into IGNIS' overall external compensation process and can improve the perofrmance and lifetime of AMOLED displays.
IGNIS says that this new IC is already being used on medium sized panels designed for IT and automobile applications.
Samsung researchers study the degradation of blue PHOLED materials, offer new design strategies for longer lasting blue emitters
Researchers from Samsung Electronics and the Ewha Womans University in Korea collaborated in a new study of the degradation in blue phosphorescence OLED materials. This study demonstrate the importance of controlling exciton-induced electron transfer, and more importantly provides strategies for the design of longer-lasting blue PHOLED materials.
The researchers say that the study reveals the charge-neutral generation of polaron pairs (radical ion pairs) by electron transfer from the dopant to host excitons. According to the study, device lifetime correlates linearly with the rate constant for the annihilation of the radical ion pair.