"We refer to the edge structures as having a factory roof shape," says Bay. "The tips of the scales protrude and have a tilted slope, like a factory roof." The protrusions repeat approximately every 10 micrometers, with a height of approximately 3 micrometers. "In the beginning we thought smaller nanoscale structures would be most important, but surprisingly in the end we found the structure that was the most effective in improving light extraction was this big-scale structure," says Bay.
Human-made light-emitting devices like LEDs face the same internal reflection problems as fireflies' lanterns and Bay and her colleagues thought a factory roof-shaped coating could make LEDs brighter. In the second Optics Express paper published today, which is included in the Energy Express section of the journal, the researchers describe the method they used to create a jagged overlayer on top of a standard gallium nitride LED. Nicolas Andr, a postdoctoral researcher at the University of Sherbrooke in Canada, deposited a layer of light-sensitive material on top of the LEDs and then exposed sections with a laser to create the triangular factory-roof profile. Since the LEDs were made from a material that slowed light even more than the fireflies' cuticle, the scientists adjusted the dimensions o
|Contact: Angela Stark|
Optical Society of America