Development of Phosphorescent White OLED
with Extremely High Power Efficiency and Long Lifetime
Tomoyuki Nakayama, Kunimasa Hiyama, Keiichi Furukawa, and Hirofumi Ohtani
Konica Minolta Technology Center, Inc., Display Technology R&D Laboratories,
7. Summary and Conclusion Remarks
We developed the all phosphorescent white OLED device which has power efficiency of 64lm/W, Lifetime of 10000 hours at initial luminance of 1000cd/m2 with a light out-coupling technique. EQE of 20% and low drive voltage that is near 3.5V was realized. Realization of the performance was due to development of organic materials, such as blue phosphorescent and electron transport materials, and progress of organic layer structure design technology.
As shown in Fig.7, performance of the OLED developed surpasses electric bulbs and is reaching a domain of fluorescent lamps. Although further detailed examination will be needed in future, a good characteristic about durability, such as storage stability, which is important in practical use was obtained so far.
For future, further improvement of Lifetime will be necessary while improving power efficiency. If a device of longer Lifetime is realized, the foot of the application spreads out greatly.
We hope that the development discussed in this paper opens up a course to practical use of OLED as lighting sources for illumination use, backlights and others.