Electronic Glue Promises Less Expensive Semiconductors

Figure 1: A vial of nanocrystals in solution. These nanocrystals serve as “electronic glue” for semiconductor-based technologies. Courtesy of Dan Dry

Semiconductors have served as choice 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. But that is expensive and can make large-scale applications such as rooftop solar-energy collectors prohibitive.

Figure 2: Working with nanocrystals under the environmentally controlled conditions of a glovebox permits researchers to perform chemical procedures not possible under room conditions. Courtesy of Dan Dry

For those uses, engineers see great potential in semiconductor nanocrystals, 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. But a problem remains: The crystals are unable to efficiently transfer their electric charges to one another due to surface ligands — bulky, insulating organic molecules that cap nanocrystals.

Figure 3: A nanocrystal sample is extracted using a pipette. Courtesy of Dan Dry

The electronic glue developed in Dmitri Talapin’s laboratory at the University of Chicago solves the ligand problem. The team describes in the journal Science how substituting the insulating organic molecules with novel inorganic molecules dramatically increases the electronic coupling between nanocrystals. The University of Chicago licensed the underlying technology for thermoelectric applications to Evident Technologies in February.

http://news.uchicago.edu/news.php?asset_id=1631 

June 11, 2009