Soroush is a professor of chemical and biological engineering in the College of Engineering.
Solar panels, like those commonly perched atop house roofs or in sun-drenched fields, quietly harvesting the sun’s radiant energy, are one of the standard-bearers of the green energy movement. But could they be better—more efficient, durable and affordable? That’s what engineers from Drexel and the University of Pennsylvania are trying to find out, with the aid of a little nanotechnology and a lot of mathematical modeling.
A three-year grant from the National Science Foundation has set the team on a track to explore ways to make new photoelectric cells more efficient, durable and affordable. The group is examining “dye-sensitized” solar panels, which capture radiation via photosensitive dye and convert it into electricity. Their goal: to streamline the electron transfer process inside the solar panels to make them more efficient at converting the radiation into electricity.
Dye-sensitized solar panels currently convert about 11 to 12 percent of the sunlight that hits them into electricity. The researchers are pushing to make these panels at least as efficient as their silicon counterparts, which currently convert about twice as much radiation as the dye-sensitized panels.
Despite this relative inefficiency, dye-sensitized panels have many advantages over silicon cells. Among the advantages of dye-sensitized solar cells are low cost, ease of manufacturing and construction from stable and abundant resource materials.
“Our ultimate goal is to design and test a highly efficient dye-sensitized solar cell array through computational optimal design, synthesis and integration,” says Masoud Soroush, the project’s lead principal investigator from Drexel.
Also, the durability of the dye-sensitized panels, combined with their ability to absorb more sunlight per surface area than standard silicon-based solar panels, make them attractive for mainstream use. There is also the potential to make dye-sensitized cells flexible, which would open them to a variety of new applications that are not options for the more rigid silicon panels. Due to the lagging energy conversion rate of dye-sensitized cells, however, they are not as widely used as silicon panels. But with help from the group’s research, this obstacle could soon be surmounted.
The primary strategies put forth by the group involve organizing the erratic movement of radiation-excited, or “photogenerated,” electrons into a more orderly flow and maintaining that flow through the interior of solar cell by refining the material in its electrolyte substrate.
“We are seeking the combination of electrolyte and electrode materials and cell design that provide the highest power conversion efficiency,” Soroush says. “The final design should have minimum losses in electrical conduction within the photoanode and electrolyte of the cell.”