Very Slow Cooling Dynamics of Photoexcited Carriers in Graphene Observed by Optical-Pump Terahertz-Probe Spectroscopy

Abstract

Using optical-pump terahertz-probe spectroscopy, we study the relaxation dynamics of photoexcited carriers in graphene at different temperatures. We find that at lower temperatures the tail of the relaxation transients as measured by the differential probe transmission becomes slower, extending beyond several hundred picoseconds at temperatures below 50K. We interpret the observed relaxation transients as resulting from the cooling of the photoexcited carriers via phonon emission. The slow cooling of the photoexcited carriers at low temperatures is attributed to the bulk of the electron and hole energy distributions moving close enough to the Dirac point such that both intraband and interband scattering of carriers via optical phonon emission becomes inefficient for removing heat from the carriers. Our model, which includes intraband carrier scattering and interband carrier recombination and generation, agrees very well with the experimental observations.

6 pages and 6 figures

References in corpus (8)

• Controlling electron-phonon interactions in graphene at ultra high carrier densities
• Measurement of the Optical Absorption Spectra of Epitaxial Graphene from Terahertz to Visible
• Ultrafast Photoluminescence from Graphene
• Optical Phonons in Carbon Nanotubes: Kohn Anomalies, Peierls Distortions and Dynamic Effects
• Carrier Recombination and Generation Rates for Intravalley and Intervalley Phonon Scattering in Graphene
• Electron-Hole Generation and Recombination Rates for Coulomb Scattering in Graphene
• Temperature dependence of the anharmonic decay of optical phonons in carbon nanotubes and graphite
• Broadband electromagnetic response and ultrafast dynamics of few-layer epitaxial graphene

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