Osram transparent OLED offers high efficacy

Dec. 17, 2007
Osram Opto Semiconductors has developed a high-performance, transparent white OLED, that is transparent either when on or off.

Under laboratory conditions the OLED has achieved a luminous efficacy of more than 20 lm/W at a brightness of 1000 cd/m2. This opens up possible applications such as partitions that are almost invisible by day and then provide a pleasant diffused light at night.

The prototype of the transparent white OLED tile with color coordinates 0.396/0.404 (CIE x/y main emissive side) lights up over an area of almost 90 cm2. At present, the transparency of the OLED is 55%. As the product is further developed this value is expected to rise to 75%.

The relative light output from the front and back surfaces of the OLED panel can be adjusted within a wide range. This means that a surface light source installed for example in furniture or on a canopy can be configured so that light shines only in the required direction.

The results were achieved as part of BMBF project OPAL2008 (Germany Ministry for Education and Research, organic light emitting diodes for illumination applications).

Universal Display also recently discussed its results for transparent OLED lighting, funded by the US DOE – see Universal Display reveals transparent white OLEDs for lighting.