Forget silicon — the next major light-absorbing material in solar cells could be carbon. Chemists at Indiana University Bloomington have figured out how to effectively create big sheets of carbon that collect light — a discovery that could lead to cheap, non-toxic solar cells.
Carbon used in the chemists’ solar cells appears in the form of graphene (similar to graphite found in pencil lead), which can absorb a wide range of light frequencies. In the past, scientists have found large sheets of graphene to be too unwieldy to work with. That’s because larger sheets become sticky and often attach to other sheets. But the IU researchers figured out how to make ultra-stable non-sticky graphene sheets by “attaching a semi-rigid, semi-flexible, three-dimensional sidegroup to the sides of the graphene.”
Now that the IU chemists have managed to collect energy using carbon, they have to figure out how to turn it into electricity. Eventually, the discovery could lead to carbon becoming an important light-absorbing material for the solar industry — potentially as an alternative to expensive silicon and ruthenium, which is as rare as platinum.
Lead photo of a graphene sheet by the Condensed Matter Physics Group