New nanocrystals don't 'blink'

ROCHESTER, N.Y., May 12 (UPI) -- U.S. scientists say they have created a nanocrystal that constantly emits light.

For more than a decade, scientists have been frustrated in attempts to create continuously emitting light sources from individual molecules because of an optical quirk called "blinking." But now researchers from the University of Rochester and the Eastman Kodak Co. say they've solved the problem by determining the basic physics behind the phenomenon and creating the new nanocrystal.

The scientists said their achievement might open the door to dramatically less expensive and more versatile lasers, brighter LED lighting and biological markers that track how a drug interacts with a cell at a level never before possible.

"A nanocrystal that has just absorbed the energy from a photon has two choices to rid itself of the excess energy -- emission of light or of heat," University of Rochester Associate Professor Todd Krauss, lead author of the study, said. "If the nanocrystal emits that energy as heat, you've essentially lost that energy."

Krauss worked with engineers at Kodak and researchers at the Naval Research Laboratory and Cornell University to discover the new, non-blinking nanocrystals.

The research that included Keith Kahen, senior principal scientist of Kodak; Alexander Efros of the Naval Research Laboratory, researchers Megan Hahn, Xiaoyong Wang and Alexander Efros is reported in the May 7 online issue of the journal Nature.