TADF, 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 TADF technology. 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 HF) 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:
WiseChip Semiconductor, based in Taiwan, is one of the world's leading PMOLED maker (in fact in 2015 Wisechip said it's the world's second largest). Wisechip is developing next-generation PMOLED displays, including flexible panels, transparent panels and Hyperfluorescence/TADF PMOLEDs.
WiseChip recently announced its first, and the world’s first, Hyperfluorescence display, using TADF materials provided by Kyulux. Can you tell some more about this display and its properties?
This 2.70” 128x64 product is adopted mostly in industrial products. The size matters in such market but the main problem was to increase the brightness due to the limited efficiency of the fluorescence emitters. The Hyperfluorescence technology helps to settle the problem and can reach up 2.5 times brighter. It performs much better readability so users do not have to stand right in front of the device. This feature adds to the value of the end product.
TADF emitter developer Kyulux announced that it has shipped the first batch of its yellow TADF emitter to Taiwan's Wisechip to be used it the world's first TADF / Hyperfluorescence display, the 2.7" PMOLED announced in October 2019 - which means that the display will likely start to ship soon.
Wisechip's first HF PMOLED is a 2.7" 128x64 monochrome yellow display, that reaches a brightness of 220 nits - 2.5 times brighter than Wisechip's fluorescent yellow PMOLED. The lifetime of this display is 50,000 hours. Wisechip says this display is aimed for the medical, industrial and electronic products markets, and in the future it will launch TADF/HF PMOLEDs for the wearable and consumer electronics markets as well.
Canon announced that the company is looking into entering the OLED materials market. The company says its Fukui Canon Materials subsidiary will take the lead on this project, together with Canon's own R&D team.
Canon did not disclose what kind of OLED materials will be produced, but Canon has some TADF patents and it could look into TADF emitters.
OLED material developer Cynora recently announced its first commercial product, the cyBlueBooster fluorescent blue emitter that is 15% more efficient that current fluorescent blue emitters on the market.
This was a very interesting announcement, and Cynora's CEO Adam Kablanian was kind enough to answer a few questions we had to help understand the new material and Cynora's current business and latest technology.
OLED material developer Cynora announced its first commercial product, a fluorescent blue emitter that is based on an "advanced molecular design" that is 15% more efficient that current fluorescent blue emitters on the market. Cynora brands its new material as cyBlueBooster, and it says it is currently available for commercialization in several shades of blue.
This could be very exciting news - while the whole industry is looking for next-generation emitters using TADF or PHOLED technologies, Cynora could have found an easier path to reduce power consumption by 15%. OF course a TADF or PHOLED emitter will achieve a reduction of 75% in power consumption compared to currently-used fluorescent emitters.
TADF, 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 at around 2012, originally at Kyushu University in Japan and today many academic groups and several commercial companies are developing TADF materials.
The main reason companies are interested in TADF emission is that it could lead to an efficient and long-lasting blue OLED emitter - something that hasn't been yet achieved by other means (mainly - UDC's Phosphorescent OLED emitter technology). In recent years companies initiated commercial development of red, green and yellow TADF emitters as these can offer a lower cost alternative to UDC's PHOLEDs materials.
Idemitsu Kosan and Toray developed a red TADF/HF device that is the world's most efficient OLED emitter
Idemitsu Kosan and Toray Industries announced that the companies have jointly developed a red OLED device that is the world's most efficient emitter at 46 cd/A. The device uses a TADF emitter combined with red fluorescent materials (which likely means this is a HyperFluorescence device).
Idemitsu and Toray has been collaborating on OLED material development since 2017. This new device uses Idemitsu's TADF material combined with Toray's new red fluorescent material. The two companies say that this new material provides the same results as currently used red phosphorescent devices, and the plan is now to "drive forward to secure adoption of their materials" in mobile and TV applications.
A new company has recently been launched in Poland, to commercialize a new family of TADF OLED compounds. Noctiluca, which takes its name from a bio-luminescent marine creature, was established a few months ago with aims to be the world's first company to produce a commercial-ready blue TADF emitter.
Noctiluca's story begins with an innovative organic DSSC solar cell platform that was developed at Synthex, an organic chemistry development platform company based in Toruń, Poland. A few years ago the researchers turned their attention to light emitting materials (which are quite similar to the light harvesting materials used in solar panels) and intensive research culminated in a promising family of new TADF compounds - which was then spun-off as Noctiluca,
Wisechip announced that it launched the world's first Hyperfluorescence OLED display - a 2.7" monochrome yellow 128x64 PMOLED. The brightness of this display reaches 220 nits - which is 2.5 times the brightness of Wisechip's fluorescent yellow PMOLED. The lifetime of this display is 50,000 hours.
Hyperfluorescence OLED emitters represent the 4th-generation of OLED emitter systems. HF is an actually a system that combines fluorescence emitters (1st-gen) with TADF (3rd-gen) hosts - to achieve a high efficiency , long lifetimes and narrow-spectrum emission.
Researchers from the Max Planck Institute for Polymer Research (MPI-P) have developed an efficient OLED device that is comprised of a single organic material layer - replacing the normal stack of 5-7 layers in modern OLED devices.
The researchers managed to create this OLED device by using a TADF material (CzDBA, diboron based TADF) and by using a newly developed charge injection strategy. The OLED device features a low operating voltage (2.9V at 10,000 cd/m2, an EQE of 19% (at 500 cd/m2) and a lifetime of 1,880 hours at 50% (for 1,000 cd/m2). The color of the device is greenish-yellow.