Development of the high efficiency solution processed fluorescent organic light-emitting device

141107_단국대 이준엽 교수

Korean researchers have developed the highly efficient florescent organic light-emitting device which enables to enhance the efficiency more than three times and is receiving much attention as the next generation display.

This research by the Prof. Jun Yeob Lee, the Ph.D. candidate/researcher Yong Joo Cho (the 1st author) and the Prof. Kyoung Soo Yook from the Department of Polymer Science and Engineering at Dankook University was supported by the Mid-career Researcher Program funded by the Ministry of Science, ICT and Future Planning and the National Research Foundation of Korea as well as the General Researcher Program funded by the Minister of Education and the National Research Foundation of Korea, and the research results were published on the Advanced Materials which is the international journal covering  materials science on the 15th October. (Paper Title: High Efficiency in a Solution-Processed Thermally Activated Delayed-Fluorescence Device Using a Delayed-Fluorescence Emitting Material with Improved Solubility)

Using the solution processing, it is expected to ease and simplify the process of producing the organic light-emitting device as the large area compared to the existing vacuum deposition plating.

However the problem is that when a device is produced through the solution processing using the existing fluorescent emitting material, the efficiency (external quantum efficiency) is only 5%. This is much less than the 20% which is the efficiency when produced by the vacuum deposition plating process.

The research team developed the high efficiency fluorescent organic light-emitting device, improved three times more than the previous fluorescent device for the solution processing. Compared to the existing structure, a solubility was increased by introducing the alkyl group as a substituent. Furthermore, the Donor-Acceptor Structure was employed to realize high efficiency by inducing delayed fluorescence phenomenon.

It is anticipated to advance the commercialization of a large scale organic light-emitting device for the enlargement of a future display.

The decrease of efficiency issue was resolved by making the surface film coating of a device smooth through the development of a new fluorescent light-emitting material which is soluble in organic solvents.

And introducing the strong Donor – Acceptor structure, it was possible to improve the efficiency as drawing delayed fluorescence phenomenon. The Donor – Acceptor structure refers to a monomer composed of an entity that donates electrons to another compound and that accepts electrons transferred from another compound.

Professor Lee revealed that “The following research will be continued to commercialize the solution processed fluorescent organic light-emitting device by developing a new material to improve not only the efficiency but also the lifespan of a device and a device structure appropriate for a solution processing.”

reporter@olednet.co.kr

Life of OLED lighting panel, to reach LED

The life of OLED lighting panel is improving equal to the level of LED (more than 50,000 hours).

According to the NIKKEI report, Kaneka developed the OLED lighting panel with a lifetime of 50,000 hours. The panel is 8×8 cm in size and 1 mm thick, and samples are shipped to some lighting companies. Applying enhanced Blue material, the color change due to thermalization has dropped under 40% and the price is about the same.

KANEKA is producing OLED lighting panel with an annual capacity of about 20,000 panels. In the Lighting fair 2013, the company exhibited OLED lighting panels of 50x50mm and 80x80mm sizes in diverse colors of white, yellow, red, green, and blue which are currently sold at about 4,000 yen for the 50x50mm panel and 6,000 yen for the 80x80mm panel.

The OLED lighting panel with the longest lifetime on sale is LG Chem.’s 100x100mm panel with 80lm/W and 50,000 hours.

The UBI Research issued “2014 OLED lighting Report” prospecting the OLED lighting panel market to be open actively from 2015 and reach about US $ 4,700 million by 2020.

 

<Kaneka announced OLED lighting at Lighting fair 2013>

 

reporter@olednet.co.kr

OLED for Smart Watch!

140912_Smart Watch는 OLED다

As Apple announces the Apple watch on the 9th (local time), the battle of a smart watch began for electronic companies including Samsung, LG, Apple, Sony, Motorola, and even ASUS. With the Samsung’s smart watch the Galaxy Gear, most of the products are released in the form similar to a square type display electric watch. In particular, when it comes to customer’s willingness to purchase a smart watch, the design is a critical element for it requires features for both electric device and fashion item at the same time.

 

Reflecting the comments that the design is rather crude, Samsung and LG adopted a new smart watch design. The Galaxy Gear of Samsung expanded the panel in 2-inch, acquiring visibility and adjusted to appropriately fit on a wrist. LG presented G Watch R with the round shape different from previous square types. The most recently unveiled Apple watch took the design of existing square form but highlighted a sense of softness as the surface curves toward the edges.

 

These all three products employed the flexible OLED which is thin and bendable, and enables different designs more than the glass type LCD as the cutting process is easily modifiable. Furthermore, the display qualities like the color resolution and power efficiency issues were already verified from the success of the Galaxy series which were equipped with the AMOLED panel.

 

The fact that Samsung, LG, and Apple chose to use the flexible OLED must be noted. From this detail, it is expected that there might be another trend in the OLED market as smart watches – though it is only three products for now- take the flexible OLED when the sales of AMOLED panel for mobiles are decreasing at present.

 

reporter@olednet.co.kr

[SID 2014] Latecomers catching up aggressively

AMOLED latecomers; BOE, AUO and Tianma are rapidly catching up the AMOLED development of Samsung Display (SDC) and LG Display (LGD) at SID 2014.

BOE expressed possibility of investing in TV following mobiles by displaying 55” FHD AMOLED panel. In terms of technology readiness level, it is incompatibly lower than panels of LGD and SDC though, it is considerably fast that it was developed in six months and produced in a pilot line in Hefei.

AUO showed that its AMOLED technology had reached at certain level by unveiling 5.7” WQHD (513ppi) ultra-high resolution AMOLED panel. More attention drew towards AUO’s panel because its production method is RGB+FMM as SDC uses and the high resolution is realized with real RGB strip type rather pentile. AUO also expressed its will on AMOLED business by showing 5” HD flexible AMOLED panel and 1.6” AMOLED panel for a smart watch.

Tianma also unveiled 5.5” HD AMOLED panel. Its performance lags behind the current AMOLED panel, but it ai    ms to supply middle-end and low-end panel targeting mass-production of 5.5” FHD AMOLED through continuous R&D.

Challenges of Chinese and Taiwanese makers become serious in the AMOLED market, where Korean makers, SDC and LGD, are dominant, and the latecomers are about to invest in the sector. Thus, it is expected that the AMOLED industry will constantly grow.

<BOE’s55ich FHD OLED panel>

 <AUO’s 5.7inch FHD AMOLED panel>

<AUO’s 5inch HD flexible AMOLED panel>

<Tianma’s 5.5inch HD AMOLED panel>