Posts

[IMID 2018] Can Blue TADF and Hyperfluorescence meet both efficiency and lifetime?

At IMID 2018 in Busan, BEXCO on August 31, Junji Adachi, CEO of Kyulux disclosed the performance of hyperfluorescence, which adds TADF dopant to the existing fluorescent host and dopant.

The color coordinates of the yellow hyperfluorescence revealed by Junji Adachi are (0.49, 0.50), the FWHM (Full Width at Half Maximum) is 76 nm, the EQE is 15.7% on 1000 nit basis, and the LT50 is 62,000 hours by 1000 nit. And the color coordinates of the green hyperfluorescence are (0.28, 0.65), the FWHM (Full Width at Half Maximum) is 31 nm, the EQE is 20.6% on 1000 nit basis, and the LT50 of 1,000 nit is 48,000 hours.

Junji Adachi also revealed the performance of Blue hyperfluorescence, which is currently under development. The maximum emission wavelength of the blue hyperfluorescence is 470 nm, the EQE at 1000 nit is 22%, and the LT50 at 750 nit is 100 hours. In particular, he predicted that the performance of Blue hyperfluorescence would be further improved in the future, saying that it began to improve rapidly in the first half of 2018.

In the following announcement, Dr. Georgios Liaptsis of CYNORA explained about the deep Blue under development, emphasizing that the wavelength should be 460 nm and the CIEy should be within 0.15. He revealed its performance, adding that CYNORA has been carrying out the necessary research to make the lifetime of deep Blue as long as that of sky Blue even with phenomenon that the life span is getting longer as the Blue goes closer to the sky Blue

Fluorescent blue is currently used for the Blue of all OLED applications. Attention is growing whether Blue TADF or Blue Fluorescence can be commercialized to realize better efficiency and lifetime than existing fluorescent blue.

Next-generation emitting materials, development is under way

At the 4th OLED KOREA CONFERENCE, Kyulux and CYNORA, the leaders in the development of next generation emitting materials, announced the results of research and future development directions.

Junji Adachi, CEO of Kyulux, said, “We are developing Hyperfluorescence in the form of adding a TADF dopant to the existing fluorescent host and dopant.” He also emphasized that the emission FWHM (full width at half maximum) of Hyperfluorescence is about 35% of that of TADF, and the luminance is about twice as high, and this material can solve the drawbacks of TADF (wide FWHM and low luminance) at the same time.

The latest Hyperfluorescence, which Jundi Arachi introduced, has efficiencies of red 28 cd /A, yellow 43 cd/A, green 81 cd / A, and life span is 10,000 hours, 62,000 hours, and 48,000 hours based on LT50 (1000nit) respectively. The color coordinates are red (0.64, 0.36), yellow (0.46, 0.52), and green (0.28, 0.65).

Andreas Haldi, CYNORA’s Chief Marketing Officer of CYNORA, said that the blue TADF emitter developed by CYNORA now has a color coordinate of 0.16, EQE of 24% and 10-hour lifetime (LT97 @ 700nit).

The performance is more than twice as efficient as the blue material currently used in OLEDs, and the color coordinates (0.10) are similar but the lifespan is short. He added that the Blue TADF emitter is scheduled to be developed within 2018 and will be available for mass production in 2019.

He also mentioned that the manufacturing cost is reduced and the power consumption is reduced, thereby minimizing battery consumption if blue TADF emitters with high efficiency are used instead of conventional low-efficiency blue materials. At the same time, it is expected to be able to improve the resolution of OLEDs and be applied to large-scale vacuum processing lines of major panel makers.
According to CYNORA, next step is to develop green TADF emitters (2019) and red emitters (2020) after finishing the development of blue TADF emitters (2018). Thus, it might be completed ‘RGB TADF emitter development’ by 2020.

Material Science to develop blue dopant for OLED … OLED Efficiency ⋅ Lifetime Up↑

A Korean venture company has succeeded in developing blue dopant for Organic Light Emitting Diodes (OLED) that a Japanese company has had its exclusive patent for. The dopant is an element that improves efficiency and life time by mixing with host that actually colors within the OLED.

In the meantime, many domestic material companies have developed OLED host, but it is the first case that a venture company has independently developed dopant on a commercial scale without receiving any support of large corporations.

 

Material Science (CEO Lee Soon-chang), an organic material developer for OLED has developed a technology that can replace Japanese I Company’s patent for blue dopant. Established in 2014, Material Science is supplying HTL( Hole Transporting Layer) and ETL (Electron Transfer Layer) to OLED panel makers.
Half of the 50 employees are R&D personnel. Last year, its sales were 6.6 billion won, and it is expected to exceed 10 billion won this year.

This time, due to the development of blue dopant by Material Science, OLED panel companies have an alternative to supply blue host and dopant besides I Company.

Japanese I Company has been developing blue dopant since 1995. At present, the company has more than 30 patents related to blue dopant (based on Japanese application for a patent), and its major 8 patents are valid until 2034. In particular, it has an exclusive patent for the combination method of blue dopant that includes blue host and pyrene with an anthracene structure (a compound in which three benzene rings are sequentially bonded). For this reason, the panel makers which purchase dopant from I Company must buy its host. If they mix I Company’s blue dopant with another company’s host, it is inevitable to infringe the patent in the case a host material has an anthracene skeleton.

Both Samsung Display and LG Display have been using I Company’s blue dopant and host.

The blue dopant developed by Material Science is designed to make molecules that are completely out of I Company’s compound patent. Conventionally, the method of applying an electron acceptor to a molecule has been used to improve the efficiency and lifetime of OLED and have a blue color.
On the other hand, Material Science introduces electron donor into molecules to improve the efficiency and lifetime while generating dark blue color. This dopant greatly reduces the solvent-dependent color development (solvatochromism) where emission wavelength changes due to the polarity of the surroundings. Therefore, the change of emission wavelength is also greatly reduced.

Jung Jae-ho, a researcher at Material Science said, “We have developed a new structure and a synthesis method, which makes it possible to produce its differentiated dopant.” “Panel companies are now able to utilize various types of blue hosts”. In addition, Material Sciences has been recently developing TADF(Thermally Activated Delayed Fluorescence) that OLED panel makers are struggling to introduce for the longer life of blue-emitting phosphors.

<OLED emitting material market forecast, UBi Research>

According to UBi Research, the OLED organic market is expected to reach $ 3.36 billion by 2021 (about 3.8 trillion won). And blue materials account for 11.5% of total sales.

CYNORA presents record results for high-efficiency blue OLED emitters

CYNORA, a leader in TADF (thermally activated delayed fluorescence) materials for OLEDs, has reached new performance records with its newest blue emitter material. With the current performance, the company is getting close to commercialization of its first product by the end of 2017.

 

Despite urgent requests by the OLED display panel makers for a high-efficiency blue emitter material in the last few years, no material supplier has yet been able to produce such a material. High-efficiency blue emitters are needed to reduce power consumption and increase the display resolution further. At SID 2017, CYNORA presented a blue emitter with a performance that was very close to the requirements of the panel makers. Using TADF technology, the company has achieved 15% EQE at 1000 cd/m² with an emission peak at < 470 nm and a LT97 of > 90 hours (at 700 cd/m²) on a device level.

 

“CYNORA’s latest patent-protected materials show a performance in the range of the customer´s specifications for blue” said Thomas Baumann, CYNORA´s CSO, “This is the best overall performance of a high-efficiency blue emitter so far from what CYNORA has seen. In the finalization of CYNORA’s product development, CYNORA will now focus on moving the emission peak slightly towards 460 nm.”

 

“CYNORA’s progress in the last few months makes us very confident that CYNORA can commercialize CYNORA’s first highly efficient blue emitter by the end of this year, as planned” said Andreas Haldi, CMO at CYNORA. “But CYNORA’s goal is to become a leading OLED material supplier by providing emitters of all display colors. Therefore, CYNORA is planning to follow up on the blue emitter with a green emitter by 2018 and a red emitter by 2019.”

The 4th Generation Emitting Material, Hyperfluorescence

Thermally activated delayed fluorescence(TADF), still under development to complement OLED emitting materials insufficient as both fluorescence and phosphorescent materials, takes time to be commercialized at the present stage. Even Kyulux considered the most advanced company in terms of TADF technology hasn’t yet to commercialized TADF dopant suitable for display.

Adachi, CTO of Kyulux said the unprepared TADF host material is an obstacle to the commercialization of TADF, so the full width at half maximum of emitting peak is too wide to be applied to display. To solve this problem, the 4th generation hyperfluorescence is under development to commercialize the TADF material.

<Kyulux CTO Adachi>

Hyperfluorescence aims at having the effect of a phosphorescent material by adding TADF dopant to existing fluorescence host and dopant.

<Hyperfluorescence Effect>

This effect has a structure that can solve both the full width at half maximum of TADF and the low brightness of fluorescence materials as seen in the above figure, Adachi emphasized.

<Hyperfluorescence vs General fluorescence>

As seen in the above photo, Kyulux’s OLED made of general green fluorescence material and OLED made of hyperfluorescence by adding TADF to this material have a distinct difference on the same substrate.

Kyulux’s goal is to commercialize hyper fluorescence by 2017. Its target is PMOLED.

Meet Prof. Adachi, the initiator of ‘Thermally Activated Delayed Fluorescence’

We visited Adachi’s laboratory at Kyushu university that published the TADF (abbr., Thermally Activated Delayed Fluorescence) thesis firstly to ‘Nature’ in 2010. He looked like a naive graduate student rather than a professor.

<Prof. Adachi , source : OLEDNET>

The reason that Prof. Adachi’s showing a full of enthusiasm for the TADF materials is that he convinces it is the best materials to lower manufacturing costs of OLED panel. Luminescence materials used in present are divided like fluorescence materials as 1st generation, and phosphorescence materials as 2nd generation. Fluorescence materials as 1st generation have a cost-effective and a low-efficiency, whereas phosphorescence materials as 2nd generation have both high-efficiency and also high-costs. This is because it utilizes the rare-earth metal, iridium. TADF as 3rd generation which Prof. Adachi has been driving, is as a structure of 1st generation materials and it has the merit of achieving the efficiency of 2nd generation materials.

TADF materials have special features that are theoretically capable of reaching 100% inter-efficiency and being free to plan molecular. It means that TADF can raise external light-efficiency up to 40%, because it is possible to form oriented materials by rod-shaped molecular planning.

About the question of the timing of commercialization of TADF materials, Prof. Adachi said that it is still insufficient to apply to OLED of Galaxy, while it’ll be possible to utilize it for products with somehow low specification from next year. It is especially expected that green or red dopant may be available. However, he also emphasized that it is essential to increase the electron transfer speed by reducing the band gap of T1 and S1 in order to be the ultimate TADF for use in displays. The electron transfer speed is currently around 1μsec, but if its speed goes up to 10-1 ~ 10-2 μsec, the lifetime would be secured due to reducing molecular degradation. He expressed about that it is necessary to actively attend by manufacturers of luminescence materials, because there are no dedicated host materials that can sufficiently demonstrate the efficiency of TADF dopant due to difficulties in developing TADF materials.

He recently put a thesis, deep blue TADF with a color coordinate of (0.148, 0.098) and external light-efficiency of more than 19.2% at German journal Angewandte.

CYNORA to present its newest OLED device results for TADF blue with EQE up to 24% at the Korea OLED Conference

During the coming OLED Korea Conference, hosted by UBI Research, CYNORA is going to present the newest status of its blue TADF (thermally activated delayed fluorescence) emitters. CYNORA is one of the most active companies in this field with several years of experience in TADF. The company’s focus is on the high-efficiency blue emitter materials, which are currently the biggest limitation for further significant improvement of OLED displays. CYNORA’s blue TADF emitters will enable device makers to produce OLED displays with significantly reduced power consumption and higher display resolution.

<Picture : CYNORA>

An update of the status of TADF emitters at CYNORA will be shown by the CMO, Dr. Andreas Haldi during the Session “Better Materials for Better Performance”. Andreas Haldi will present improved OLED devices with a sky-blue material with an EQE of 24% and with 1000 h lifetime (LT80), both measured at display brightness. The performance of these devices is so far the best result combining efficiency and lifetime that has been reported for the TADF technology with blue emission. Andreas Haldi will also disclose in his presentation some more details relating to the planned commercialization of CYNORA’s blue TADF emitters by end of this year.

<Picture : CYNORA>

UBI Research has recently announced that the OLED emitting material market is increasing sharply and is expected to reach about US$ 980 million in 2017. With Apple starting to use OLED displays in the near future, the demand for high-performance OLED panels will increase significantly. Therefore, the panel makers are currently pushing the adaptation of high-efficiency blue pixels in their panels to gain an edge towards the competition.

CYNORA Achieves a New Milestone in Efficiency and Stability of Blue TADF Emitters for OLEDs

CYNORA, a leader in TADF (thermally activated delayed fluorescence) materials, has developed new material classes that combine both, high efficiency and long lifetime, for blue emission. With these new achievements, the company is on track to reach the performance requested by the OLED industry. The commercialization of CYNORA´s TADF materials is therefore still planned for the end of 2017.

Earlier this year, in May 2016, CYNORA had established two blue emitter systems where one of them showed a high efficiency while the other showed a long lifetime. During the last 6 months CYNORA has made further, significant progress by combining high efficiency and long lifetime in a single blue emitter system. In an OLED device, the new blue material reaches 14% EQE (external quantum efficiency) together with a lifetime of 420h (LT80, at 500 cd/m2, λ < 480 nm). With this performance, CYNORA has now shown that blue TADF emitters can reach OLED display specifications soon.

“Our constant progress on blue TADF emitters was made possible by our growing team of TADF experts and by the close collaboration with CYNORA’s customers” says Thomas Baumann, CSO at CYNORA, “We have developed several classes of high performance TADF materials which we are currently optimizing for market readiness at the end of next year.”

CYNORA’s dopants are fully organic and designed for existing vacuum deposition. The company will adapt the blue TADF emitters for solution processing in a second step. With its blue TADF technology CYNORA will enable device makers to provide OLED displays with significantly increased energy efficiency and higher display resolution.