CUED Publications database

Ultrafast collinear scattering and carrier multiplication in graphene.

Brida, D and Tomadin, A and Manzoni, C and Kim, YJ and Lombardo, A and Milana, S and Nair, RR and Novoselov, KS and Ferrari, AC and Cerullo, G and Polini, M (2013) Ultrafast collinear scattering and carrier multiplication in graphene. Nat Commun, 4. 1987-.

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Abstract

Graphene is emerging as a viable alternative to conventional optoelectronic, plasmonic and nanophotonic materials. The interaction of light with charge carriers creates an out-of-equilibrium distribution, which relaxes on an ultrafast timescale to a hot Fermi-Dirac distribution, that subsequently cools emitting phonons. Although the slower relaxation mechanisms have been extensively investigated, the initial stages still pose a challenge. Experimentally, they defy the resolution of most pump-probe setups, due to the extremely fast sub-100 fs carrier dynamics. Theoretically, massless Dirac fermions represent a novel many-body problem, fundamentally different from Schrödinger fermions. Here we combine pump-probe spectroscopy with a microscopic theory to investigate electron-electron interactions during the early stages of relaxation. We identify the mechanisms controlling the ultrafast dynamics, in particular the role of collinear scattering. This gives rise to Auger processes, including charge multiplication, which is key in photovoltage generation and photodetectors.

Item Type: Article
Subjects: UNSPECIFIED
Divisions: Div B > Solid State Electronics and Nanoscale Science
Depositing User: Cron Job
Date Deposited: 07 Mar 2014 11:25
Last Modified: 20 Oct 2014 01:08
DOI: 10.1038/ncomms2987