Giant magneto-photoelectric effect in suspended graphene
Sonntag, J. and Kurzmann, A. and Geller, M. and Queisser, F. and Lorke, A. and Schützhold, R.
NEW JOURNAL OF PHYSICS
Volume: 19 Pages:
We study the optical response of a suspended, monolayer graphene field-effect transistor structure in magnetic fields of up to 9 T (quantum Hall regime). With an illumination power of only 3 μW, we measure a photocurrent of up to 400 nA (without an applied bias) corresponding to a photo-responsivity of 0.13 A W-1, which we believe to be one of the highest values ever measured in single-layer graphene. We discuss possible mechanisms for generating this strong photo-response (17 electron-hole pairs per 100 incident photons). Based on our experimental findings, we believe that the most likely scenario is a ballistic two-stage process including carrier multiplication via Auger-type inelastic Coulomb scattering at the graphene edge. © 2017 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.