Transparent OLED lights up new applications

16 Jan 2008

A transparent OLED prototype is helping Osram Opto Semiconductors to create innovative lighting designs.

Transparent white OLED

Osram Opto Semiconductors has developed a large-area transparent white OLED that achieves a luminous efficacy of over 20 lm/W at a brightness of 1000 cd/m². The company hopes that further improvements to these performance values will open up new applications in the lighting market.

"The production of extremely thin, efficient, transparent and flexible area light sources with excellent quality of light is important," Marion Reichl, public relations manager at Osram Opto Semiconductors, told optics.org. "They could be used as light partitions that are almost invisible by day and then provide a pleasant diffused light at night. They could also be used as mood lighting, canopies of light or integrated into bathroom and kitchen designs."

The transparent OLEDs are still in the R&D stage and increasing performance values significantly is one of Osram's major goals. "The performance is slightly lower compared to other OLED devices but this is the trade-off that you always pay for getting transparency," commented Reichl.

The prototype is transparent either on or off and exhibits a transparence of 55%, which the company hopes to increase to 75%. The OLED has color coordinates of (0.396/0.404) and an active illumination area of 90 cm².

In addition to conventional lighting and emerging LED technology, Osram believes that the market offers room for new applications that are possible only with transparent OLEDs. "Technology always has the greatest success in areas in which its unique selling points have the greatest effect," explained Reichl. "The OLED lighting markets will certainly develop as advances are made in the technology and as costs fall."

Osram could not comment on when the first products would be commercially available, but expects the market launch to be predominantly in the luxury lighting design sector. "The initial volume applications will probably be in the functional design segment in which the principal criteria will be style and quality of light," concluded Reichl.