AMOLED Product Innovations Begin toDifferentiate this Technology from the Pack
by Julie J. Brown
Since Information Display last published a special issue on OLED technology in February 2007, a lot has happened in this exciting new sector of the display industry. Samsung SDI has been expanding the product base of its AMOLED panels, which look wonderful. In addition, Samsung was recognized at the 2008 CES with a Best Buzz Award for its 31-in. AMOLED prototypes. Similarly, Sony impressed with its launch of an 11-in. AMOLED TV, which garnered a 2008 SID/Information Display Display of the Year Award, among its other accolades. Additionally, Chi-Mei Optoelctronics, LG Display, and others have also launched AMOLED products this year.
With all of this innovation in mind, I have been reflecting on the past 10 years in which I have been personally involved in OLED technology. I recall about 8 years ago, an expert in the flat-panel-display industry said to me, "You need to realize that LCDs took (over the) flat (sector) and so OLEDs need to do something different." I believe that OLED technology now has done something different with the new products that are moving into the consumers' hands and countertops. But, of course, I am engrossed in the technology and may be too close to be the best judge. So I have been conducting my own consumer research.
Two weeks ago, I hosted a group of high-school students spending their summer at Princeton University studying science and technology. When I showed them some of the AMOLED products, their response was very telling. I heard words like "wow," it looks so "intense and deep," and "the color is really different." This powerful, direct consumer feedback tells me that OLEDs have done something different – the screen looks better than an LCD to a teen-ager.
The impact of OLED technology, however, is not only the image quality but also the potential for saving power by using phosphorescent OLEDs (PHOLEDs) and addressing the world's great need for "green" products. Once they heard this, it was hard to tell which they were more impressed by: the AMOLED's picture quality or the environmental friendliness. I then asked them to imagine future AMOLED products that could be worn on the wrist or be flexible enough to be rolled up. At this point, I could see that these burgeoning scientists were fascinated by these concepts, which to them seemed more like science fiction than science. But as the articles in this issue of Information Display demonstrate, these innovations are all on the immediate horizon. The articles, from some of the biggest players in the AMOLED sector, provide a snapshot into how work on image quality and new OLED technologies are positioning OLEDs as a completely different, revolutionary FPD technology.
Tetsuo Urabe of Sony describes the company's work in manufacturing AMOLED panels with a vision for increasing display size beyond its first 11-in. AMOLED TV product. In order to achieve manufacturing scale, Sony has had to make critical decisions in panel design in order to achieve a manufacturable high-performance product design. Urabe discusses the technology choices Sony has made for manufacturability today and a prospective direction in the future to achieve ultimate low-power products along with manufacturing scale.
Then switching gears away from AMOLED displays on rigid substrates, we move into the future of flexible OLED displays. A number of companies are now working on the vision for ultra-thin lightweight displays on flexible-substrate systems. For example, 2 years ago, both Samsung SDI and the team of LG Display and Universal Display Corp. reported full-color AMOLED displays built on thin stainless-steel substrates. Now that impressive prototypes have been demonstrated for a number of years, the next challenge is to figure out how to mass-produce such products. A vision for manufacturing flexible AMOLED displays by fashioning AMOLED flexible-display fabrication to fit into existing AMLCD lines is presented in the article from Juhn S. Yoo and his colleagues at LG Display.
Finally, we consider the work ongoing in developing non-Si backplane technology, namely, oxide TFTs. This is an area that has been attracting a great deal of R&D focus. The article by Jae Kyeong Jeong and his colleagues from Samsung SDI poses the question, "Is there any new TFT with the high mobility and excellent uniformity at the same time, which is suitable for the large-sized AMOLED displays?" They then make that case that oxide TFTs could possibly be this technology.
While these articles detail some exciting work in the OLED sector, they truly represent just the tip of the iceberg. This is an exciting time to be working on OLED technology, and I urge you to stay tuned for more exciting developments that are just around the corner. •