University of Massachusetts Amherst scientists have developed a breakthrough technique for creating water-soluble nano-modules and controlling molecular assembly of nanoparticles over multiple length scales.
The new method should reduce the time nanotech manufacturing firms spend in trial-and-error searches for materials to make electronic devices such as solar cells, organic transistors, and organic light-emitting diodes.
“The old way can take years,” says materials chemist Paul Lahti, co-director with Thomas Russell of UMass Amherst’s Energy Frontiers Research Center (EFRC), supported by the U.S. Department of Energy.
“Another of our main objectives is to make something that can be scaled up from nano- to mesoscale, and our method does that. It is also much more ecologically friendly because we use water instead of dangerous solvents in the process.
“In our recent paper, we worked on glass, but we want to translate to flexible materials and produce roll-to-roll manufactured materials with water,” said chemist Dhandapani Venkataraman, lead investigator. “We expect to actually get much greater efficiency.” He suggests that reaching 5 percent power conversion efficiency would justify the investment for making small, flexible solar panels to power devices such as smart phones.
If the average smart phone uses 5 watts of power and all 307 million United States users switched from batteries to flexible solar, it could save more than 1500 megawatts per year, Venkataraman estimates. “That’s nearly the output of a nuclear power station,” he says, “and it’s more dramatic when you consider that coal-fired power plants generate 1 megawatt and release 2,250 lbs. of carbon dioxide. So if a fraction of the 6.6 billion mobile phone users globally changed to solar, it would reduce our carbon footprint a lot.”
Doctoral student and first author Tim Gehan says that organic solar cells made in this way can be semi-transparent, as well, “so you could replace tinted windows in a skyscraper and have them all producing electricity during the day when it’s needed. And processing is much cheaper and cleaner with our cells than in traditional methods.”