Seeing Is Believing: Scientists Visualize Record Exciton Diffusion Length

Date posted
Funding Agency
(Funded by the U.S. Department of Energy)

Optoelectronics, a technology that gives off, detects, or controls light, is used everywhere in modern electronics and includes light-emitting diodes and solar cells. Within these devices, the movement of excitons (pairs of negative electrons and positive holes) determines how well the device performs. Until now, the distance that excitons could travel in conventional optoelectronic systems was around 30-70 nanometers, and there was no way to directly image how the excitons move. Now, a team of researchers from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the Swiss Federal Institute of Technology Lausanne has designed and made a nanocrystal system in which excitons can move a record distance of 200 nanometers, an order of magnitude larger than what was previously possible.