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arXiv · 1505.01762

Giant magneto-photoelectric effect in suspended graphene

Jens Sonntag·Annika Kurzmann·Martin Geller·Friedemann Queisser·Axel Lorke·Ralf Schützhold
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Abstract

We study the optical response of a suspended graphene field-effect transistor in magnetic fields of up to 9 T (quantum Hall regime). With an illumination power of only 3 {\mu}W, we measure a photocurrent of up to 400 nA, corresponding to a photo-responsivity of 0.14 A/W, which we believe to be the highest value ever measured in single-layer graphene. We estimate that every absorbed photon creates more than 8 electron-hole pairs, which demonstrates highly effective carrier multiplication. As suggested by the dependence of the photocurrent on gate voltage and magnetic field, we propose a ballistic two-stage mechanism where the incident photons create primary charge carriers which then excite secondary charge carriers in the chiral edge states via Auger-type inelastic Coulomb scattering processes at the graphene edge.

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Jens Sonntag, Annika Kurzmann, Martin Geller, Friedemann Queisser, Axel Lorke, Ralf Schützhold. 2015-05-07. Giant magneto-photoelectric effect in suspended graphene. https://arxiv.org/abs/1505.01762

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