OSRAM develops high-performance transparent white OLED
By Emily Clark
December 16, 2007
December 17, 2007 OSRAM Opto Semiconductors has developed a transparent white OLED (organic light-emitting diode) tile that opens up the potential for new applications in furniture and interior design.
The OLED tile has achieved a luminous efficiency of more than 20 lumens per watt (lm/W) at a brightness of 1000 candela square meter (cd/m² - most monitors rate at about 300), with the large-scale prototype lighting up an area of nearly 90 cm². The OLED is transparent whether it is powered on or off (its transparency is currently rated at 55% but as the product is further developed, this value is expected to reach 75%). This means that partitions that are almost invisible by day can provide a pleasant diffused light at night, and as the relative strengths of the beams in the two hemispheres of the tile can be adjusted within a wide range, allowing the surface light source to be configured for light to shine only in the required direction, the technology could bring a new edge to the shape and character of lighting design.
OLEDs are composed of a film of organic compounds that produce electroluminescence when exposed to AC power and unlike LCDs, OLEDs do not require a backlight to function and are more power-efficient as a result. They are expected to bring significant changes to the entire lighting market as this technology becomes more prevalent. Areas of potential application for OLEDs include television screens, computer displays, portable screens, advertising and also as light sources for general space illumination and large-area light-emitting elements.
The technology demonstrated by OSRAM was part of part of the project known as OPAL 2008 a research initiative of the Germany Ministry for Education and Research dedicated to studying organic light emitting diodes for illumination applications.