Chemists go 'back to the future' to untangle quantum dot mystery

For more than 30 years, researchers have been creating quantum dots—tiny, crystalline, nanoscale semiconductors with remarkable optical and electronic properties.

They've applied them to improve television sets, for example, to greatly enhance color. A host of otherapplicationsare being pursued, involving integrated circuits, solar cells, computing, medical imaging, and inkjet printing, among others.

But quantum dot synthesis has occurred largely by trialanderror, because little has been understood about how the chemicals involved in making quantum dots—some highly toxic—actually interact to form the resulting nanoparticles.

That may be about to change. In a paper in Nature Communications, Todd Krauss, professor and chair of the Department of Chemistry at the University of Rochester, and PhD student Leah Frenette, the lead author, describe the underlying mechanisms involved in the formation of a widely used class of quantum dots that use cadmium and selenium compounds as their molecular precursors.

Ironically, the team discoveredthat, at one point during this process, the safer, more controllable compounds now employed decompose into the same highly toxic compounds that were used in initial quantum dot production 30 years ago.