Connecting the Colloidal Dots

After 15 years of wildly mixed results from colloidal quantum dot light-amplification experiments, many researchers were convinced that some unknown law of physics was stymieing their efforts to drive forward telecommunications technology. Now Patanjali Kambhampati begs to differ.

Kambhampati and his colleagues in the Department of Chemistry have successfully amplified light using this once inconsistent technology. In telecommunications, data is encoded into beams of high-powered coherent light and transmitted through fibre-optic cables—but, because these laser signals diminish over distance, they must be amplified to maintain data integrity. The best available amplification technology is the quantum well, a thin sheet of semi-conductor material that confines electrons to a one-dimensional plane. But, for over 10 years, researchers hoped that colloidal quantum dots, a three-dimensional box for electrons that is a billionth of a meter across, would yield superior results, and at a cheaper cost. In some cases the dots worked, and in many cases they didn’t, and nobody knew why. Until now.