Ultrafast Photoluminescence from Graphene
arXiv:1006.5769 · doi:10.1103/PhysRevLett.105.127404
Abstract
Since graphene has no band gap, photoluminescence is not expected from relaxed charge carriers. We have, however, observed significant light emission from graphene under excitation by ultrashort (30-fs) laser pulses. Light emission was found to occur across the visible spectral range (1.7 - 3.5 eV), with emitted photon energies exceeding that of the excitation laser (1.5 eV). The emission exhibits a nonlinear dependence on the laser fluence. In two-pulse correlation measurements of the time-domain response, a dominant relaxation time of tens of femtoseconds is observed. A two-temperature model describing the electrons and their interaction with strongly coupled optical phonons can account for the experimental observations.
13 pages, 7 figures, supplemental material included
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Cited by in corpus (7)
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- Observation of suppressed terahertz absorption in photoexcited graphene
- Nitrogen-Functionalized Graphene Nanoflakes (GNFs:N): Tunable Photoluminescence and Electronic Structures
- Evidence for Extraction of Photoexcited Hot Carriers from Graphene