MIT researchers have enlisted tiny viruses to help assemble solar cells and make significant improvements in their power-conversion efficiency.
Graduate students Xiangnan Dang and Hyunjung Yi — working with Angela Belcher, the W. M. Keck Professor of Energy, and several other researchers — found that a genetically engineered version of a virus called M13, which normally infects bacteria, can be used to control the arrangement of the nanotubes on a surface, keeping the tubes separate so they can’t short out the circuits, and keeping the tubes apart so they don’t clump.
The system the researchers tested used a type of solar cell known as dye-sensitized solar cells, a lightweight and inexpensive type where the active layer is composed of titanium dioxide, rather than the silicon used in conventional solar cells.
In their tests, adding the virus-built structures enhanced the power conversion efficiency to 10.6 percent from 8 percent — almost a one-third improvement.
This dramatic improvement takes place even though the viruses and the nanotubes make up only 0.1 percent by weight of the finished cell.
“A little biology goes a long way,” Belcher said.
The study was recently published online in the journal Nature.