New fluorescent OLEDs more efficient than once believed

Posted by David Gomez

Engineering researchers at the University of Michigan have created a remarkably effective fluorescent blue OLED.

OLED means organic light emitting diode for those who don’t know.

OLEDs are viewed as the next generation of display technology. They are already being used in televisions, cell phones and computers, and they could potentially be used for a vast array of light sources from billboards to indoor and outdoor lighting. Fluorescent OLEDs are usually less efficient at radiating light per unit area than their phosphorescent equivalents.
    
According to the University of Michigan News Service, that may be changing because of new findings by Professor John Kieffer and graduate student Changgua Zhen of the Department of Materials Science and Engineering. They released a research paper in the journal Advanced Functional Materials that destroys earlier records.

It used to be that the limit for the efficiency of fluorescent OLEDs was 5 percent. But now, Kieffer and his coworkers have made fluorescent OLEDs with a near 10 percent efficiency level.

"Our results clearly indicate that fluorescent material have a bright future for highly efficient and stable OLEDs for flat-panel display and lighting applications," Kieffer said.

This was achieved by restructuring a material being used by U-M collaborators in Singapore using computer models.

"With the material, they had some positive results," Kieffer said.

"We took those molecules and started to reconfigure them in a computer model, adding different functional groups in a systematic way. We identified the mechanisms that control the performance of OLEDs, and by applying the fundamental understanding so obtained we improved the materials characteristics. Our research demonstrated the importance of simulation-based predictive design."

The paper is titled: "Achieving Highly Efficient Fluorescent Blue Organic Light-Emitting Diodes Through Optimizing Molecular Structures and Device Configuration". And guess what? It’s behind an extremely overpriced academic journal pay wall.

Information provided by: University of Michigan News Service.