Scientists Study Quantum Dot Blinking

U.S. physicists trying to determine the origins of quantum dot blinking have created a method of characterizing the phenomenon at faster time scales.

Researchers at the U.S. Department of Energy’s Argonne National Laboratory, the University of Chicago and the California Institute of Technology said nanocrystals of semiconductor material — known as quantum dots — have great promise as light-emitting materials.

The wavelength, or color, of quantum dot lights can be very widely tuned simply by changing the size of the nanoparticles. If a single dot is observed under a microscope, it can be seen to randomly switch between bright and dark states. But the causes of the blinking remain the subject of intense study.

The new methods developed by Matt Pelton of Argonne’s Center for Nanoscale Materials and colleagues has revealed a previously unobserved change in the blinking behavior on time scales less than a few microseconds.

Scientists said the finding might provide new insight into the mechanism of quantum-dot blinking and should help in the development of methods to control and suppress blinking.

Detailed results of the complex study appear in the Proceedings of the National Academy of Sciences.