Researchers find plants could have long-term solar potential

Cambridge, Mass.: New research from the Massachusetts Institute of Technology (MIT) has found the solution to degrading photovoltaic cells could be harvested in plants, as reported by MIT News.

The sun’s rays can damage materials that are used to harvest electricity. Plants, on the other hand, constantly break down and then reassemble their light-capturing molecules, so that the structures capturing the sun’s energy are always brand new.

MIT Associate Professor of Chemical Engineering Michael Strano and his research team have now imitated that process using a novel set of self-assembling molecules that can turn sunlight into electricity. The molecules can be repeatedly broken down and then reassembled by adding or removing a solution.

“There’s a lot of emphasis on the initial efficiency that scientists measure when they’re making a device, but not a lot on what happens later,” Strano says, noting that many new systems, other than conventional silicon-based photovoltaic cells, face significant degradation.

The individual reactions of these new molecular structures in converting sunlight are about 40 per cent efficient — double that of current leading commercial solar cells. Stranos says it could be closer to 100 per cent, but they are working on increasing the concentration.

“It’s a new way of thinking about photovoltaic technology,” Strano says. “These ideas will find their way into future technologies as engineers think about installing solar panels and ways of deferring maintenance and making materials more fault-tolerant or damage resistant.”

The team used a system of compounds that included carbon nanotubes, the phospholipids, and the proteins that make up the reaction centers, which can spontaneously assemble themselves into a light-harvesting structure that produces an electric current. Their work is outlined in a paper in Nature Chemistry.