A vial of nanocrystals in solution, which serve as “electronic glue” for semiconductor-based technologies. (University of Chicago/Dan Dry)

Researchers at the University of Chicago and Lawrence Berkeley National Laboratory have developed an “electronic glue” that could speed up advances in semiconductor-based technologies, including solar cells and thermoelectric devices that convert sun light and waste heat, respectively, into useful electrical energy.

Semiconductors have served as prime materials for many electronic and optical devices because of their physical properties. Commercial solar cells, computer chips and other semiconductor technologies typically use large semiconductor crystals. These crystals are expensive, and can make large-scale applications like rooftop solar-energy collectors prohibitive.

Engineers see a possible solution to this problem in semiconductor nanocrystals, which are sometimes just a few hundred atoms each. Nanocrystals can be readily mass-produced and used for device manufacturing via inkjet printing and other solution-based processes. Yet the nanocrystals have a problem of their own – an inability to efficiently transfer their electric charges to one another due to surface ligands (bulky, insulating organic molecules that cap the crystals).

The “electronic glue” that was developed in the laboratory of Dmitri Talapin, Assistant Professor of Chemistry at the University of Chicago, solves the ligand problem. The researchers worked with the nanocrystals in the environmentally controlled conditions of a glovebox, permitting them to perform chemical procedures not possible under room conditions. The team substituted the insulating organic molecules with novel inorganic molecules, which dramatically increases the electronic coupling between nanocrystals.

The research was funded by the American Chemical Society Petroleum Research Fund, the Chicago Energy Initiative, the U.S. Department of Energy, and Evident Technologies.

(University of Chicago)