BASF and Osram announced that:

• A big step towards energy-saving OLED lighting with efficiency of more than 60 lm/W
• International standard for white color requirements met

BASF and Osram Opto Semiconductors have developed a highly efficient white organic light-emitting diode (OLED): for the first time an OLED not only is able to achieve a light yield of over 60 lumens per watt (lm/W), but also, at the same time, meets the international Energy Star SSL Standard with regard to color requirements. Lighting efficiency on this scale had been achieved previously. Lighting efficiency describes the ratio of luminous flux given off by a lamp to the amount of power consumed; the greater the yield, the less energy is lost. However, up until now the color values of OLEDs have not been within the acceptable band for color coordinates around the Planck curve, as defined by the Energy Star SSL Standard. The color values of the new OLED are within this band – its light retains the white color at different levels of intensity.

The experts at BASF are dealing with the material side of the OLEDs and, within the framework of the OPAL project, are developing the optimum component structures in partnership with Philips and Osram. BASF reached an important milestone in OLED research a few years ago. White light from OLEDs can best be obtained by combining red, green and blue light. For a long time there was no efficient source for deep-blue light. In 2003 BASF researchers laid the foundation for a phosphorescent blue emitter by developing a new class of materials based on an iridium complex. “Our aim is to develop stable blue phosphorescence emitters. Whilst the color coordinates and efficiencies of the new blue OLEDs are already outstanding, the service life still presents many challenges,” explains Dr. Elmar Keßenich, OLED project manager at BASF Future Business GmbH. “If we manage to produce deep-blue stable emitters, that will open up the way for us to make white OLED light tiles with a light yield of more than 100 lm/W.”

BASF