Japanese Researchers Double Green Phosphorescent OLED Efficiency

A research group from the Kanazawa
Institute of Technology in Japan succeeded in making an green phospor-based OLED achieving a very high
light-emitting efficiency of 210lm/W (56.9% more efficient than existing OLEDs).

The OLED is a bottom-emission type on a 0.7mm-thick glass plate. 

The material for the device's light-emitting layer is a host material called "CBP" added with an iridium complex, "Ir(ppy)3." Its light emission peak lies in the range of wavelengths between 500 and 550nm, which corresponds to green color.

When emitting light at a luminance of 10cd/m2, it has a
light-emitting efficiency of 210lm/W and a light-extraction efficiency
of 56.9%. On the other hand, when emitting light without the
high-refractive glass plate, its light-emitting efficiency is only
94.3lm/W. This means the glass plate boosted the light-extraction
efficiency by 2.3 times.

Posted: Apr 03,2009 by Ron Mertens