Philips and Novaled set new benchmarks for white OLEDs

June 1, 2006
After achieving 32 lm/W for a white OLED., researchers are now targeting 50 lm/W as the next benchmark.
Royal Philips Electronics and Novaled have announced what they describe as an unsurpassed record combination for efficiency and lifetime of high-brightness white OLEDs.

The joint research effort between Philips Lighting, Philips Research and Novaled has developed a white OLED with an efficacy of 32 lm/W at a brightness of 1000 cd/m2. The device had color coordinates of (0.47, 0.45) and a CRI of 88.

That same device structure simultaneously had a lifetime of more than 20,000 hours, which the companies describe as a major achievement for a future commercialization of the OLED technology for lighting applications.

The efficiency of the device was measured in an integrating sphere using only the forward emission cone of the OLED device without attaching any lens or any other volume-type luminaire. This is the only method to reliably predict power efficiency values for large-area lighting tiles.

"This is an important step forward, as it consistently proves the potential of the OLED technology for lighting applications and shows continuous strong advancements in the technical development," said Dietrich Bertram, manager of the OLED development at Philips Lighting.

Jan Blochwitz-Nimoth, CTO of the Novaled AG added, "This result combines for the first time ultra-high power efficiency and high operational stability and can pave the way to a bright future of OLED lighting. We expect to be able to increase this efficiency to values above 50lm/W in the near future."

The joint research effort is another example of successful collaboration between leading OLED R&D centers in Europe. The result will be used in future developments and ongoing projects as well as the European projectOLLA (Organic LEDs for Lighting Applications), in which both parties are involved.