Even alternative energy technologies can sometimes be a little greener, according to a Kansas State University graduate student’s research.
Ayomi Perera, a doctoral student in chemistry, Sri Lanka, is working under Stefan Bossmann, professor of chemistry, to improve dye-sensitized solar cells. The cells are a solar technology that use a dye to help generate energy from sunlight. By creating a less toxic dye and combining it with a bacteria, Perera’s solar cells are friendlier to the environment and living organisms — making an alternative energy solution to fossil fuels even greener.
“Dye-sensitized solar cells, which are solar cells with light-absorbing dye, have been around for more than 20 years, but their highest efficiency has stayed close to 11 percent for some time,” Perera said. “So the thought was that rather than trying to increase the efficiency, let’s try to make to make the technology more green.”
To make the solar cells greener and more efficient, Perera begins with the bacteria Mycobacterium smegmatis. A mycrobacterium is a type of pathogen that can cause diseases such as tuberculosis. Perera is using a species that is completely harmless and can be found in soil and cornflakes. It also produces the protein MspA, which can be used for numerous applications once it has been chemically purified.
After purification, Perera combines the protein with a synthesized dye that is less toxic than traditional dyes. The protein-dye mixture is coated onto individual solar cells — which form large solar panels when assembled — and is then tested with artificial sunlight to measure energy output.
“The idea is that the protein acts as a matrix for electron transfer for this dye that absorbs sunlight,” Perera said. “We want the protein to be able to capture the electron that the dye gives out and then transfer that electron in one direction, thereby generating an electrical current.”
Although the new dye-sensitized solar cells currently do not improve on the technology’s ability to convert sunlight into electrical current, the technology is the first of its kind and could help low-cost solar cells become a more viable option in the alternative energy field.
“This type of research where you have a biodegradable or environmentally friendly component inside a solar cell has not been done before, and the research is still in its early stages right now,” Perera said.