Inspired by the efficiency with which plants convert sunlight into sugar, researchers have fabricated a solar cell that uses photosynthetic proteins to convert light into electricity. Although the prototype device can’t yet rival commercial solar cells made of silicon, it demonstrates a new strategy for making longer-lasting photovoltaic cells.
To make the solar cell, a team of biologists and engineers led by Marc Baldo of the Massachusetts Institute of Technology (MIT) harvested photosynthetic proteins from spinach and the bacterium Rhodobacter sphaeroides and deposited the proteins onto a glass support. Because the proteins naturally reside in an aqueous environment inside a cell membrane, it took some creative chemistry to keep the approximately 2 billion isolated proteins functional on a solid surface.