Those characteristics, Aspuru-Guzik said, point toward one of the major possible applications for the cells as a cheap power source for the more than 2 billion people world-wide without access to electricity.
"If you want to install solar cells on a building, you need them to last 20 or 30 years," he said. "But the real market for this technology is someone in the third world to have a cheap and portable source of energy that you can connect to a battery that's a big deal."
To create the database, researchers at Harvard first worked with scientists at Stanford to define a new class of molecules based on 26 basic fragments which could be combined in more than 3 million possible arrangements, explained Johannes Hachmann, a Research Associate in Harvard's Department of Chemistry and Chemical Biology.
To begin the work of characterizing each possibility, they then turned to the World Community Grid, a project founded by IBM, which uses distributed volunteer computing spare computer time donated by thousands of participants around the world to perform this vast number of calculations.
"Of the 3.1 million candidates, we have now characterized about 2.3 million, meaning we have electronic structure data for them," Hachmann said. "We can plug that data into models which predict how well each molecule would work for solar cell applications. Based on those results we rank the potential of each molecule those rankings are part of what we released."
"One has to take our ranking of materials as one would take that of candidate compounds for pharmaceutical applications," Aspuru-Guzik said. "The ranking is not foolproof but rather a guide to interesting families of molecular patters to explore. We look at it in a statistical sense and point out enriched and depleted fragments that are interesting targets for expe
|Contact: Peter Reuell|