NEC Lighting Ltd has introduced a white OLED device whose luminous efficiency is 156lm/W in its booth at Lighting Fair 2013 from March 3 to 8, 2013, in Tokyo.
 
The device was developed in collaboration with a research group led by Junji Kido, professor at Yamagata University. The luminous efficiency of 156lm/W is the world's highest for a white OLED lighting device.
 
When the light emitting area and brightness of the device are 2 x 2mm and 1,000cd/m2, respectively, its luminous efficiency is 156lm/W. NEC Lighting made a panel by using light-emitting materials developed in the Kido Lab of Yamagata University.
 
Though NEC Lighting did not disclose the details of the materials or the structure of the light-emitting layer, it said that it aimed to beat the efficiency of 142lm/W that Panasonic Corp announced in 2012. Panasonic used a semispherical light-emitting layer for the device having the efficiency, and the new device developed by NEC Lighting seems to use a similar method.
 
This time, NEC Lighting did not exhibit an OLED device having a luminous efficiency of 156lm/W. But it showed a panel that was made by using the same technology and had a brightness of 1,000cd/m2, a luminous efficiency of 75lm/W and a color temperature of 2,800-3,000K.