updated 04:40 pm EDT, Mon May 11, 2009
Scientists at the University of Rochester working with researchers at Eastman Kodak have created a nanocrystal that constantly emits light instead of regularly wasting energy as heat, as current individual molecules tend to, according to a weekend PhysOrg report. Developing the nanocrystal further could result in brighter LED lights, less expensive lasers and thinner TVs and displays. When the molecule is emitting photons as heat, it goes dark, and is thus said to be blinking.
"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," said Todd Krauss, the primary author of the study and a professor of chemistry at the University of Rochester.
The professor worked with Kodak engineers and researchers at the Naval Research Laboratory and Cornell University to discover the non-blinking nanocrystals. Kieth Kahen, a senior principal scientist at Kodak, along with postdoctorate Megan Hahn in Krauss' lab, synthesized nanocrystals of many different compositions.
The nanocrystal they eventually created did not blink once in four hours of supervision, a feat that's more impressive once one considers they usually occur in miliseconds or minutes. It differs from regular nanocrystals as it has a continuous gradient from a core of cadmium and selenium to a shell of zinc and selenium instead of a well-defined boundary between two semiconductor materials. Thanks to the gradient, the stream of emitted photons is the same as the stream of absorbed photons.
It's also easier to create different colors with the nanocrystal, simply by changing its size rather than using different materials and construction processes. The unnamed nanocrystal technology could one day replace OLED displays, Krauss believes.