[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.

[IMID 2018] Samsung Display, The key material that will connect the smart world and the individual in the future is the display

At IMID 2018 held in BEXCO, Busan, Korea on August 29, Kwak Jin-Oh, vice president of Samsung Display, delivered a keynote speech on the theme of ‘The Infinite Evolution with Display’. He emphasized “Display will be the key material to link to the smart world and the creation of a new world and environment will be accelerated.”

Comparing the evolution of living things with the evolution of displays, Kwak pointed out the direction of the next-generation displays such as ‘size diversity from small to large size, adaption in design inclusive of full screen and flexible, and convergence with other technologies’.

In terms of size diversity, Kwak said, “High-resolution displays that can feel realism in small and medium-sized area, and displays that can be immersed like a big screen in a movie theater in large area, are required.”

The design adaptation then was referred to design autonomy as one of the values of next-generation displays. He further emphasized the value of rollable and stretchable displays as well as foldable displays in small and medium sized displays.

Kwak said that Samsung is developing rollable displays as well as foldable displays that are currently attracting great interest. Unlike foldable display, rollable display requires consideration of the stress on the front of the panel. He commented “Because there are many things to consider such as the time when it is rolled up, and the number of times it is rolled and unrolled, the company is conducting research to solve them.”

He also introduced a stretchable display that can implement patterns freely, and explained that it is developing various structures using RGB pixel unit and stretchable unit to implement displays that have high reliability with low stress.

Mentioning about biotechnology at the convergence area, he pointed out that new fusion technologies need to be considered such as measurement of oxygen saturation by transmitting light to hemoglobin or changes in the wake up mode and sleep mode of the display depending on the melatonin change.

Finally, Kwak concluded that display is evolving to create a new society and environment, emphasizing that display is the key material to link between the individual and the smart world in the forthcoming 5G era.

[IMID 2018] LG Display, showcased 2-stack RGB OLED for automobile OLED with improved life span.

At IMID 2018 held in BEXCO, Busan on August 29, Kim Kwan-Soo, research fellow of LG Display presented about a new OLED technology for automotive displays.

Kim said that RGB OLEDs applied to mobile devices and WRGB OLEDs applied to TVs do not satisfy customers’ needs in terms of life span. To solve this issue, he introduced 2 stack RGB OLED in which RGB OLED has the same tandem structure as WRGB.

Because 2 stack RGB OLED can be thick due to adding a layer of CCL (charge generation layer) to the multi-layer structure, HTL is made thinner than before and the charge balance of the emitting layer is optimized.

As a result, the 2-stack RGB OLED shows 1.5 ~ 2 times higher emitting efficiency than the 1-stack RGB OLED. Its lifetime is increased by 4 times on T80 basis.

However, the 2-stack structure has a disadvantage in that it has higher power consumption than the general structure. Thus, it is necessary to make efforts to solve this disadvantage.

[IMID 2018] LG Display and Samsung Display exhibited a large number of large, and small & medium sized OLED applications.

LG Display and Samsung Display introduced a number of applications using OLED at IMID 2018 held in BEXCO, Busan, drawing attention from many visitors. In particular, LG Display displayed its strategies mostly for large OLED applications such as 77-inch transparent OLED and 55-inch video wall OLED, while Samsung Display introduced the small and medium sized OLED applications mainly for automotive and virtual reality devices.

First, the panel thickness of the 77 inch transparent flexible OLED introduced by LG Display is 400 μm, the bending radius is 80 mm, and the luminance is 200 nit based on full white.

LG Display explained that it would improve the required transmittance and durability. Also, it commented that the goal is to reduce bezel to 0.5 mm at its display of 4 FHD OLEDs with 3.8 mm bezel.

In addition, LG Display presented a 1200ppi 4.3-inch WRGB OLED for virtual reality devices. One official explained that WRGB OLED, which represents the resolution by etching the color filter, would be advantageous for higher resolution than RGB using the deposition method.

Meanwhile, Samsung Display exhibited a number of automotive OLEDs, including unbreakable OLED for 6.22 inch steering wheel, 1000R curved OLED for passenger monitor, transparent OLED for HUD, S-curved OLED for CIO and rollable OLED. The concerned official expects the OLED to be widely applied to inside automobiles because it has excellent design autonomy, compared to LCD.

He added “Although there are many things to be improved, such as brightness and reliability, it is continuously improving the required performance through the feedback from European customers”.

Furthermore, Samsung Display showcased light field display and 2,000ppi resolution RGB OLED for virtual reality devices.

[IMID 2018] OLEDON, developed ‘curved plane source FMM deposition technology’ for 2250ppi AMOLED for the first time in the world

OLEDON is a company which develops plane source deposition technology for high resolution AMOLED manufacturing. Hwang Chang-Hoon, CEO of  OLEDON announced in IMID 2018 that it developed ‘curved plane source FMM deposition technology’ that can be adopted to 2250ppi AMOLED pixels, for the first time in the world.

Conventional linear source FMM deposition technology has a shadow distance of 3um. The available production range is 570ppi AMOLED resolution. On the other hand, the plane source deposition technology already demonstrated in OLEDON can achieve a resolution of 800 to 1200 ppi of AMOLED with a shadow distance of 0.8 to 1.5 μm. Meanwhile, the newly developed ‘curved plane source FMM deposition technology’ is an upgraded technology of the plane source deposition technology which can realize the maximum resolution of AMOLED to 2250ppi with a shadow distance of 0.18 ~ 0.6μm.

The principle is that light is gathered through a concave mirror, a curved surface is applied to the conventional flat plane source, and the light emitting material does not spread, but is precisely deposited at a desired position, thereby reducing the shadow distance.

If this technology is commercialized, it is expected that it can be widely applied not only to mobile devices but also to virtual reality devices.

JOLED raised 47 billion yen to spur solution process OLED business for automobiles.

JOLED, the world’s first to successfully commercialize solution process OLED products, announced that it had raised a total of 47 billion yen as a third-party capital increase.

According to JOLED, Denso will invest 30 billion yen, Toyota Tsusho 10 billion yen, Sumitomo chemical 5 billion yen and SCREEN Finetech Solutions 2 billion yen. JOLED is known to cooperate with Denso to develop automotive displays and Sumitomo chemical to develop OLED materials for solution process.

In particular, Denso has been mainly using TFT-LCD for automotive displays, but it is expected to lead the development for applying lightweight and easy-to-shape OLED to automobile interior through this investment.

It is expected that this funding will accelerate the establishment of production system for the mass-production of JOLED’s solution process OLED. JOLED announced on July 1 that it would set up a “JOLED Nomi Office” in Nomi-city, Ishikawa, and aim to operate in 2020.

Major production products are medium-sized (10 to 32-inch) solution process OLEDs that will be used for cars or high-end monitors. Also, Toshiaki Arai, chief technologist of JOLED announced that they would target the middle-sized OLED market with solution process OLED, at the 2018 OLED Korea conference hosted by UBI Research in March.