Making Solar Cells Greener

A dye-sensitized solar cell that uses a protein-producing bacteria and synthesized dye to generate energy from sunlight could provide greener solar cells that are friendlier to the environment and living organisms, according to a Kansas State University graduate student’s research.

Ayomi Perera, a doctoral student, is working under chemistry professor Stefan Bossmann to improve dye-sensitized solar cells. By creating a less toxic dye and combining it with a type of bacteria, Perera has created solar cells that are a greener alternative energy solution to fossil fuels.

“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 the technology more green.”

Ayomi Perera, doctoral student in chemistry, was recently named one of Kansas State University’s winners at the ninth annual Capitol Graduate Research Summit. She was awarded a $500 scholarship for her research on how to make alternative energy a little greener. Here she explains her research.

To make the solar cells greener and more efficient, Perera used the bacteria Mycobacterium smegmatis. A mycobacterium is a type of pathogen that can cause diseases such as tuberculosis, but the species Perera utilized in the study is 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 purifying the protein, she combines it with a synthesized dye that is less toxic than traditional dyes. The protein-dye mixture is coated onto individual solar cells and 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.”

The new dye-sensitized solar cells do not currently improve on the technology’s ability to convert sunlight into electrical current, but they are the first of their kind and could help low-cost solar cells become a more viable option for alternative energy applications.

“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,” she said. “But we have noticed that it’s working, and that means that the protein is not decomposed in the light and electric generating conditions. Because of that, we believe that we’ve actually made the first protein-incorporated solar cell.”

Perera was one of two Kansas State University graduate students named a winner at the ninth annual Capitol Graduate Research Summit in Topeka. She received a $500 scholarship from KansasBio and will present her work at the organization’s board of director’s meeting in May.

For more information, visit: www.k-state.edu