Graphene's solar cell potential revealed by photon absorption

The discovery - made by researchers at the Institute of Photonic Science (ICFO), in collaboration with Massachusetts Institute of Technology, Max Planck Institute for Polymer Research, and Graphenea S.L. Donostia-San Sebastian - demonstrates that graphene is able to convert a single photon that it absorbs into multiple electrons that could drive electric current.

The discovery makes graphene an important alternative material for light detection and harvesting technologies, which are currently based on conventional semiconductors like silicon.

‘In most materials, one absorbed photon generates one electron, but in the case of graphene, we have seen that one absorbed photon is able to produce many excited electrons, and therefore generate larger electrical signals’ said Frank Koppens, group leader at ICFO.

This feature is claimed to make graphene an ideal building block for any device that relies on converting light into electricity. In particular, it enables efficient light detectors and potentially solar cells that can harvest light energy from the full solar spectrum with lower loss.