The beginning article of AMOLED and Flexible AMOLED Displays in a six part series. The series is written in collaboration with the Advanced Display Research Center of Kyung-Hee University.
SEOUL,KOREA – The future role of displays will not be limited exclusively to a window displaying information, but will shape our lives. Cell phone displays and electronic books will be rolled up like scrolls and placed into pockets. Personal information on smart phone displays will be shown only to users and not be visible from the periphery. Transparent displays attached to car windows will show drivers map directions, and transparent displays will allow users to view the freshness of food inside refrigerators.
With the fast advancing display technology, these prospects no longer seem to be a distant future. In particular, AMOLED (active-matrix organic light-emitting diode) technology is taking steps towards these dream displays. AMOLED displays are thinner and more energy-efficient than conventional flat screens and embody innovative features that enable a higher contrast radio, more vivid and natural colors, and a wider range of viewing angles. Samsung and LG, Korea based companies, are the two leading companies dominating the global AMOLED market with slight variances in their technologies. LG uses white OLED for full color, and oxide-TFT (thin-film transistor), whereas Samsung uses RGB OLED and LTPS (low-temperature polycrystalline silicon). Both Samsung and LG have successfully developed 55 inch AMOLED displays, although they are not yet mass produced in the market.
The next big thing in the display industry, however, is Flexible AMOLED. It is a technology designed to produce glassless screens which are robust, non-breakable, and flexible. With this enabling innovative design, it can be applied to gadgets such as ergonomic clocks, smartphones, touchable newspapers, and semi-transparent screen. Flexible displays can be applied not only to the IT industry, but also diverse areas including advertising, fashion and interior areas.
This April, Samsung launched its flexible AMOLED display called YOUM. Normal LCD screens are comprised of six layers with two being composed of glass, making them more susceptible to damage. However, Samsung employed a flexible alternative to glass, making the display thinner, lighter and unbreakable. LG also began capital investment for flexible OLED, planning to build 3.5-Gen (730 x 460 mm) flexible OLED line in LG’s Paju plant in Korea. This March, LG began mass producing plastic electronic paper display (EPD) for use in E-books.
Korea generates and leads AMOLED and flexible AMOLED display market
“Investors are now paying keen attention to the Korean display sectors,” said Jin Jang, professor of Kyung Hee University and director of Advanced Display Research Center (ADRC). “Korea is the first country to successfully mass-produce AMOLED displays, although it was not the first one to develop the technology. Several companies in Japan and Taiwan initially spearheaded the business in the early 2000’s, but gave up on mass production. Because of the high associated costs, their business was not profitable. In 2009, Samsung broke into the AMOLED display industry and has been immensely successful.” The company announced its plans to invest 6 trillion won (USD 5 billion) in the AMOLED sector this year.
“In the past, advanced technologies such as semiconductors were started in the U.S. and Japan, and Korea was constantly catching up with them. However, in regards to AMOLED displays, Korea became the country to generate and lead the market, having amassed a 98% market share. Seeing the successes within Korea, Japanese and Taiwanese companies began to invest in AMOLED displays as well,” he said.
“Korea has higher possibilities of success in this industry as large companies have already proven successful in manufacturing them, and the government is making great efforts to support the market.”
The Ministry of Knowledge Economy selected six future technologies industries to invest and foster within a 5 to 7 year span. Among them were transparent flexible displays and their application products: 60 inch transparent and flexible displays together with IT convergence infotainment systems. The industry is expected to generate around USD 70 billion in sales, USD 56 billion in exports, generate 84,000 jobs as well as USD 20 billion in investment by the year 2025. This project will commence this year as a five-year plan.
Recently, China has put forth much effort into fostering the display industry backed by the government. “Despite the rise in China, the market share is still on the rise because Korean companies are ahead of Japanese, Taiwanese and Chinese companies in terms of technical and cost competitiveness. To widen the technology gap, it is time for Korea to focus on developing original technologies and expand into new markets”
Advanced Display Research Center (ADRC) at Kyung Hee University
The Advanced Display Research Center (ADRC) was created in 2001 by Professor Jin Jang and it subsequently led to the establishment of the Department of Information Display at Kyung Hee University. The center is set up to cooperate with Korean companies in display related industries for the development of new materials and devices in TFT-LCD, OLED and FED applications. Performance within the center has so far been outstanding. They developed the world’s first flexible AMOLED. Consecutively, the center also developed the thinnest flexible AMOLED in 2008.
Being the only research center worldwide that is located at a university with such state of the art clean-room facilities; ADRC is capable of making a wide range of devices, including carbon nanotubes (CNTs), TFTs, solar cells, and sensor devices with organic, oxide, and thin-film silicon semiconductors – providing unlimited resources and opportunities for its students. “When you study at ADRC, the sky is the limit!” said Mallory Mativenga, a Ph.D candidate in the department of Information Display and researcher of ADRC. He continued to say, “In addition to sophisticated methods such as sputtering and chemical vapor deposition, the manufacture of oxide and organic semiconductors also includes easy and cheap methods such as solution processing, spin-coating and printing - which are compatible with flexible electronics. Owing to fabrication process optimization, ADRC devices are known for their high performance, high stability and reproducibility, all of which are key properties in understanding intrinsic properties of these semiconductor-based devices.”
One major obstacle in the development of high performance flexible AMOLED displays is the restriction of high temperature processes; high temperatures can ruin flexible substrates such as plastics. In light of this, ADRC recently developed a fabrication technique, which allows the realization of transparent electronics on plastic substrates through high-temperature processes. This technique involves two steps: 1) the electronics are first fabricated at high temperatures on polyimide (PI)/glass carrier substrates; and then 2) detached from the glass and, if necessary, attached to another flexible carrier substrate such as polyethylene terephthalate (PET) for support.
“ADRC is one of the best display research centers in the world,” said Christophe Avis, a Ph.D candidate in the department of Information Display and researcher of ADRC. The French student has studied at the center for five years and recently completed his thesis defense focusing on electronic portions of AMOLED; namely Thin Film Transistors (TFTs). “In partial fulfillment of my graduate studies at Télécom Physique Strasbourg in France, I had the opportunity to take an internship studying OLED for six months at ADRC in 2006. After completing the internship, I was so impressed that I decided to continue my Ph.D in Korea.”
“Studying in the center under Professor Jang was the best opportunity to study AMOLED technology and the related fabrication techniques and processes. ADRC and its director Jang Jin is one of the best and globally renowned leaders in the display field.” The center is also focused on future display technologies. “Conventional TFT uses silicon dioxide as an insulator, but we are trying various types of insulators to reduce power consumption using high-K materials”
He added that, “I believe that everyday life in the future will be replaced with flexible tablets. Displays will be something you don’t have to put in your bag or pockets, but will offer the convenience of a wristwatch.”
International Meeting on Information Display (IMID)
Professor Jang is also a general chair of the 12th International Meeting on Information Display (IMID) (http://www.imid.or.kr/) which will be held at EXCO in Daegu, Korea on August 28~31, 2012. Organized by the Korean Information Display Society (KIDS) and the Society for Information Display (SID), the conference includes a keynote presentation, technical oral presentations, tutorials and poster presentations. Around 2,500 participants, including 500 foreigners from over 20 countries are expected to attend the conference.
Together with SID and International Display Workshops (IDW), IMID is known as the one of the three largest display conferences globally. Covering diverse display technologies including 3D displays, active-matrix devices, display electronics and flexible displays, the conference will invite speakers from many global corporations and academies.
Various distinguished keynote speakers including Cho, Soo-in, CEO of Samsung Mobile Display (SMD) will attend the conference to speak about issues and trends of display industry. Yasuhiro Koike, a professor at Keio University will speak on the status of photonics polymers for Face-to-Face Communication. Henning Sirringhaus, a professor at the University of Cambridge will discuss Low-Temperature, Solution-Processible Organic and Oxide Semiconductors for Flexible Electronics. In terms of other events, tutorials will be held to provide introductory courses for newcomers to information display technologies, and prominent speakers including representatives from Novaled, Holst Centre, Organic Lighting Technologies and Universal Display Corporation will talk during the tutorials in various areas – OLED lighting technology, AMOLED technology, 3D display technology, and flexible display technology.
This year, the meeting will be held in conjunction with other two grand events including International LED & Display EXPO 2012 (LED+2012) and IT Convergence EXPO Korea 2012 (ITCE 2012). LED+2012 is widely regarded as the trade show which contains all LED and display industries in Korea. Visitors can attain useful technical information as well as business opportunities. With 150 companies participating, ITCE 2012 is a competitive trade and consumer IT show in Daegu and Gyeongbuk area, where the IT industry is particularly well developed. For this event, over 30,000 domestic and international buyers will be invited. With a large trade meeting with overseas buyers, international conferences technical seminars, and presentations for new products and technologies, the IT event will be the biggest of its kind in Korea. The big three will cover future technologies and high-tech green industries.