OLED developer Novaled has reported white OLEDs for lighting applications with an efficiency of 35 lm/W and a lifetime of 100,000 hours at a brightness of 1000 cd/m2.
Based on its proprietary PIN OLED technology and materials, Novaled's device exhibits CIE colour coordinates of x,y = 0,43/0,44 (which is yellowish white) with a colour rendering index CRI of 90.
The OLED features a stacked setup with blue fluorescent and red/green phosphorescent emitter materials (hybrid approach). For the stacking layer and transport layer, Novaled proprietary materials have been used. The OLED device is equipped with a standard outcoupling enhancement film.
The measurement was carried out in an integrating sphere taking into account only the full forward emission with substrate edges and backside covered, thus corresponding to a real-life application. At a higher brightness level of 4,000 cd/m2, the efficiency was 31 lm/W, with no significant changes in colour and CRI value.
“With this achievement Novaled proves once more the advantages of its technology and associated materials for an OLED device combining high performance and long lifetime”, says Jan Birnstock, Novaled VP Technology Transfer. “We are working on enhanced outcoupling solutions and large area devices. When associated with a proper phosphorescent blue, we are confident of reaching 100 lm/W combined with a long lifetime in the near future.”