Viruses are mostly seen as the bad side of nature, the fallen creation or just that unwanted flu during those sunny days when you were supposed to go play outside. For Angela Belcher viruses are working tools, since she and her MIT colleagues have just found a way to guide some of them so they make solar cells more efficient, by as much as a third.
Carbon nanotubes have been found to improve solar cells’ efficiency, but they tend to clump together when put to use, so their semiconducting abilities are decreased. Belcher and her team (Graduate students Xiangnan Dang and Hyunjung Yi and others mentioned here) used a virus that normally infects bacteria, called M13. They found out that M13 can be genetically engineered to control the arrangement of the carbon nanotubes on a flat surface and keep them apart, so they don’t clump together and ruin the job.
The team performed tests on dye-sensitized (Graetzel) solar cells, which have titanium dioxide as the semiconductor part. These cells have proved themselves cheap to produce, but rather inefficient. Belcher showed that putting nanotubes among the ingredients of such a solar cell can increase its efficiency from 8.6% to 10%, while only weighing 0.1% of the finished cell.
Belcher and her colleagues say that the technology can also be applied to other types of solar cells, like silicon-based ones (which are the most spread), and even to those cutting-edge quantum-dot solar cells. “A little biology goes a long way,” she says.
With a passion for using viruses and generally natural things in good purposes, Angela Belcher’s activity has been described by us several times before.