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arXiv · 0805.4647

Ultrafast Optical-Pump Terahertz-Probe Spectroscopy of the Carrier Relaxation and Recombination Dynamics in Epitaxial Graphene

Paul A. George·Jared Strait·Jahan Dawlaty·Shriram Shivaraman·Mvs Chandrashekhar·Farhan Rana·Michael G. Spencer
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Abstract

The ultrafast relaxation and recombination dynamics of photogenerated electrons and holes in epitaxial graphene are studied using optical-pump Terahertz-probe spectroscopy. The conductivity in graphene at Terahertz frequencies depends on the carrier concentration as well as the carrier distribution in energy. Time-resolved studies of the conductivity can therefore be used to probe the dynamics associated with carrier intraband relaxation and interband recombination. We report the electron-hole recombination times in epitaxial graphene for the first time. Our results show that carrier cooling occurs on sub-picosecond time scales and that interband recombination times are carrier density dependent.

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Paul A. George, Jared Strait, Jahan Dawlaty, Shriram Shivaraman, Mvs Chandrashekhar, Farhan Rana, Michael G. Spencer. 2008-05-30. Ultrafast Optical-Pump Terahertz-Probe Spectroscopy of the Carrier Relaxation and Recombination Dynamics in Epitaxial Graphene. https://doi.org/10.1021/nl8019399

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