Phonon-mediated mid-infrared photoresponse of graphene

Michela Badioli; Achim Woessner; Klaas-Jan Tielrooij; Sébastien Nanot; Gabriele Navickaite; Tobias Stauber; F. Javier García de Abajo; Frank H. L. Koppens

doi:10.1021/nl502847v

arXiv · 1601.04531

Phonon-mediated mid-infrared photoresponse of graphene

Michela Badioli·Achim Woessner·Klaas-Jan Tielrooij·Sébastien Nanot·Gabriele Navickaite·Tobias Stauber·F. Javier García de Abajo·Frank H. L. Koppens

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Abstract

The photoresponse of graphene at mid-infrared frequencies is of high technological interest and is governed by fundamentally different underlying physics than the photoresponse at visible frequencies, as the energy of the photons and substrate phonons involved have comparable energies. Here we perform a spectrally resolved study of the graphene photoresponse for mid-infrared light by measuring spatially resolved photocurrent over a broad frequency range (1000-1600 cm$^{-1}$). We unveil the different mechanisms that give rise to photocurrent generation in graphene on a polar substrate. In particular, we find an enhancement of the photoresponse when the light excites bulk or surface phonons of the SiO$_2$ substrate. This work paves the way for the development of graphene-based mid-infrared thermal sensing technology.

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Michela Badioli, Achim Woessner, Klaas-Jan Tielrooij, Sébastien Nanot, Gabriele Navickaite, Tobias Stauber, F. Javier García de Abajo, Frank H. L. Koppens. 2016-01-18. Phonon-mediated mid-infrared photoresponse of graphene. https://doi.org/10.1021/nl502847v

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