TADF OLED emitters, or Thermally Activated Delayed Fluorescence, is a relatively new class of OLED emitter materials that promise efficient and long-lifetime performance without any heavy metals. TADF research started in earnest in 2012, and the first TADF emitters reached commercial status at the end of 2019.
There are currently three main challenges with OLED emitters that TADF aims to solve - an efficient and long-lasting blue color emitter, low cost alternatives current red and green emitters and the development of soluble OLEDs that can be deposited using low cost ink-jet printing or other "wet" methods.
TADF is being developed by several companies. Japan-based Kyulux was established to commercialize Prof. Adachi's HyperFluoresence technology, which combines two emitter systems, TADF and Fluorescence. Germany-based Cynora is focusing on a blue TADF emitter. Both companies are working hard to achieve commercial-ready materials. While a blue TADF (or HyperFluoresence) emitter is not here yet, in late 2019 Kyulux and Wisechip brought to market the first OLED with a yellow HF emitter.
Idemitsu Kosan also considers TADF as one of the key OLED technologies and intends to focus on TADF in the future. In late 2019 Idemitsu together with Toray announced the world's most efficient red OLED emitter - based on Idemitsu's TADF/HF material. UDC has been recently awarded a patent on TADF materials, although the company says that TADF is not in its focus.
The latest TADF news:
According to reports, Samsung Display acquired OLED material developer Cynora, for about $300 million. Samsung acquires just the IP and technology, and Cynora terminated its entire workforce a couple of weeks ago. Samsung is already an investor in Cynora, and so is LGD.
Cynora has been low on cash (its last financing round was in 2019), according to reports, and did not manage to find new investors, and so the company opted to be sold to Samsung. The reported sum seems to be rather high for an emergency exit, and some later reports quotes much lower sums, perhaps even around $30 million or so.
Researchers from the Polish Academy of Sciences (PAS) and from the Silesian University of Technology have developed new OLED emitter materials based on aromatic electron-donating and -accepting moieties bridged by an antiaromatic seven-membered ring.
The researchers say that the new design of its N-doped PAHs is very flexible, and their properties are very responsive to the choice of the electron-accepting group. The researchers can thus can tune the emission mechanism between TADF emission and room temperature phosphorescence (RTP) emission, which gives high degree of control over the emission profile.
Kyulux explains how narrow-spectrum Hyperfluorescence emission is more efficient than PHOLED emission
Second-generation OLED phosphorescence emission features an internal quantum efficiency of almost 100% - which would normally mean you cannot get more efficient than that.
As Kyulux explains in a recent post, though, phosphorescent suffers from a wide emission spectrum. In order to achieve a good color gamut (for which as narrow-spectrum emission as possible is best) display makers have to filter out the "tail" of the emission. This results in reduced brightness and efficiency.
Kyulux says it is on track to commercialize green Hyperfluorescence materials in 2023, red and blue in 2024
Kyulux gave a very upbeat presentation at SID Displayweek, during which it updated on its latest material specification and its commercialization plans.
Kyulux managed to increase the lifetime of its Hyperfluorescence emitter systems (which features an IQE of 100% and a narrow emission spectrum) quite dramatically in the past year – its green material now offers a lifetime of 59,000 hours (LT95@1000 nits, top emission), while the red material is at 20,000 hours. The blue material has also increase from280 hours to 450 hours in the past year.
UK-based SolOLED secured 200,000 GBP (almost $250,000 USD) in new funding from Scottish Enterprise to commercialize its novel OLED TADF emitter materials. SolOLED is launching a collaborative research project with CENSIS to commercialize the materials.
SolOLED was established in 2021 in the UK, to develop a family of novel solution-based TADF OLED emitter, based on technology that originated from the University of St. Andrews.
Poland-based TADF developer Noctiluca went public at the Polish NewConnect stock exchange last week. The company now trades under the NCL ticker.
Noctiluca did not raise any funds in this IPO, as it has no need for more funds at this stage, but this move will enable some stock holders to realize their funds and other to join as stakeholders in the company.
Poland is aiming to become a major innovation and high-tech hub, and the country is already enjoying a growing industry, focusing on IT, bio-technology, robotics and nanotechnology.
Poland has a strong material science and development expertise, and in recent years we have been seeing OLED and display-related ventures out of Poland. It seems Poland is poised to become an interesting location to watch for future innovation in the OLED industry.
Ergis Group noDiffusion OLED encapsulation film
One such company is the Poland-based Ergis Group, a leader in plastic processing active in markets such as food packaging, industrial, automotive, medical and more. In 2020, Ergis launched its first product for the optoelectronic applications (such as the display market and photovoltaics) - the Ergis noDiffusion films for flexible OLED panels (both displays and lighting) and OPVs. Ergis is using a unique ALD-based technology that enables it to offer high performance films on low cost PET films.
In recent years, we have seen accelerated OLED materials development, aided by software tools based on machine learning and Artificial Intelligence. This is an excellent development which contributes to the continued improvement in OLED efficiency, brightness and lifetime.
Kyulux's Kyumatic AI material discover system
The promise of these new technologies is the ability to screen millions of possible molecules and systems quickly and efficiently. Materials scientists can then take the most promising candidates and perform real synthesis and experiments to confirm the operation in actual OLED devices.
Notion Systems is a leading supplier of industrial ink jet printing systems. The n.jet inkjet platform from Notion Systems is used to produce printed circuit boards, OLED & QLED displays, sensors and high-quality 3D parts.
We present the following interview with the Company's CEO and founder, Dr. Michael Doran.
Q: Hello Michael. Can you detail notion systems' offering for the OLED industry? We understand you offer R&D and production systems, for both RBG printing and TFE printing.
Notion Systems offers a system platform called n.jet display series that prints functional layers at various steps of display production and for a range of display technologies. These include rigid, flexible, OLED, QLED and micro displays. The platform meets the most stringent requirements for process environment and process stability.
Hyperfluoresence emitter system developer Kyulux announced that its green material is getting close to commercialization. The company is now working closely with OLED makers, preparing for early adoption.
Kyulux says that its green emitter has not only met the required performance of OLED panel makers, in terms of efficiency, lifetime and driving voltage - but has actually surpassed the performance of green phosphorescent emitters in top emission devices. The green HF device achieves higher current efficiency, longer lifetime and offers a narrow emission spectrum and can thus enable better chromaticity.