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New results from polymer OLED developers Cambridge Display Technology (CDT) and Sumation (a 50:50 joint venture between CDT and Sumitomo Chemical Co. Ltd) show dramatic improvement in lifetime for P-OLED devices. The latest figures show improvements of 5 times, 11 times, 6 times, and 5 times for red, green, blue and white materials, respectively, compared with lifetimes reported at the end of 2005.
In the case of blue, lifetime has been increased by 2.5 times in the short time since the last announcement in November 2006.
Data results from spin-coated devices using a common cathode and solution processable materials developed in 2006 demonstrate that lifetimes (the time taken for the display/pixel to fall to half its initial stated luminance) of 24,000, 35,000, 10,000, and 5200 hours for red, green, blue, and white, respectively, have been achieved from an initial luminance of 1000 candelas per square meter (cd/sq.m).
This is equivalent to over 150,000, 198,000, 62,000, and 27,000 hours from an operating brightness of 400 cd/sq.m for these materials (acceleration factors to convert lifetime from one brightness to another have been determined for red, green and blue materials using various initial luminances between 6000 and 800 cd/sq.m and found to be equal to 2, 1.9, and 2 for red, green and blue, respectively). |
