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Nat Nanotechnol. 2011 Jan;6(1):33-8. doi: 10.1038/nnano.2010.240. Epub 2010 Dec 12.

Vibrational and electronic heating in nanoscale junctions.

Author information

1
Department of Physics and Astronomy, Rice University, 6100 Main Street, Houston, Texas 77005, USA.

Abstract

Understanding and controlling the flow of heat is a major challenge in nanoelectronics. When a junction is driven out of equilibrium by light or the flow of electric charge, the vibrational and electronic degrees of freedom are, in general, no longer described by a single temperature. Moreover, characterizing the steady-state vibrational and electronic distributions in situ is extremely challenging. Here, we show that surface-enhanced Raman emission may be used to determine the effective temperatures for both the vibrational modes and the electrons in the current in a biased metallic nanoscale junction decorated with molecules. Molecular vibrations show mode-specific pumping by both optical excitation and d.c. current, with effective temperatures exceeding several hundred kelvin. Anti-Stokes electronic Raman emission indicates that the effective electronic temperature at bias voltages of a few hundred millivolts can reach values up to three times the values measured when there is no current. The precise effective temperatures are model-dependent, but the trends as a function of bias conditions are robust, and allow direct comparisons with theories of nanoscale heating.

PMID:
21151112
DOI:
10.1038/nnano.2010.240
[Indexed for MEDLINE]

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