The amount of sunlight that hits the Earth every 40 minutes is enough to meet global energy demands for an entire year. The trick, of course, is harnessing it and converting it into useful electricity. A new study has revealed that tweaking graphene allows it to generate two electrons for every photon of light it receives. This could double the amount of electricity currently converted in photovoltaic devices. Marco Grioni from École Polytechnique Fédérale de Lausanne (EPFL) in Switzerland is one of the senior authors on the paper, which was published in Nano Letters.
Graphene is a monolayer of carbon atoms arranged in a honeycomb pattern. It is incredibly light, flexible, exponentially stronger than steel, and capable of conducting electricity even better than copper. In order to make it useful in photovoltaic devices, the researchers needed to have a better idea of graphene’s mechanism for converting light into electricity. This process takes only a femto-second (10-15 sec), which is too quick to easily study.