In 1993, we have developed white-light-emitting OLEDs for the first time. Since then, the performance of white OLEDs has been steadily improved and, today, they are considered to be the light source of the next generation. OLED displays based on white OLEDs have also been developed and large-size displays have been commercialized.  Recently, high quantum efficiencies (QEs) can be obtained by using phosphorescent emitters such as iridium complexes. External QE of 25—30% was achieved for blue, green and red OLEDs, which correspond to the internal QE of nearly 100%. Device lifetime at high luminance levels, which is required for general lighting, has been significantly improved by using the multiphoton structure. By combining the above techniques, OLEDs can be extremely efficient and possess extremely long lifetime, even at high luminance level.  In 2010, Lumiotec Inc. has started small-scale production of white OLED panels in Yamagata, and luminaires using their panels have been commercialized. In this talk, recent progress in white OLED will be discussed.

报告人简介：Junji Kido is a full professor of the Department of Organic Device Engineering at Yamagata University. He received his PhD in polymerchemistry from Polytechnic University, New York, in 1989.Since 2003, Kido has also been the general director of the Research Institute for Organic Electronics founded by the Yamagata prefectural government. His research activities are focused on OLED. He invented a white OLED in 1993 and is working on the development of high performance OLED.