Scientists are always looking for ways to increase the efficiency of renewable energy, and now researchers at the Massachusetts Institute of Technology are utilizing viruses to enhance the efficiency of solar cells at the microscopic level. In an article in the journal Nature Nanotechnology, the scientists revealed that viruses could be used to organize carbon nanotubes in dye-sensitized solar cells, reaping efficiency gains of a full third.
Carbon nanotubes come in two types – semiconductors (which control the flow of an electric current) or metals (which act like wires, allowing current to flow easily). The semiconducting variety enhances the performance of solar cells, but the metallic ones do not. The team wanted to find a way to make all the nanotubes the same type, so they turned to viruses.
Graduate students Xiangnan Dang and Hyunjung Yi worked with Angela Belcher, the W. M. Keck Professor of Energy, and found that a genetically engineered version of a virus called M13, could be used to control the arrangement of the nanotubes on a surface. It kept them seperate, so the tubes didn’t clump, preventing them from shorting out the circuits.
The system was tested on dye-sensitized solar cells, a lightweight and inexpensive type of solar cell, and it was found the virus-built structures enhanced the power conversion efficiency to 10.6 percent from 8 percent — almost an entire third improvement.
“A little biology goes a long way,” Belcher says. With further work, the researchers think they can ramp up the efficiency even further and they only add 0.1% to the weight.