'Hot' electrons don't mind the gap

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If they’re quick about it, “hot” electrons excited in a plasmonic metal can tunnel their way across a nanoscale gap to a neighboring metal. Rice University scientists said the cool part is what happens in the gap.

A Rice team discovered those electrons can create a photovoltage about a thousand times larger than what is seen if there is no gap. The finding shows it should be possible to create nanoscale photodetectors that convert light into electricity and can be used as sensors or in other sophisticated electronics.

If they’re quick about it, “hot” electrons excited in a plasmonic metal can tunnel their way across a nanoscale gap to a neighboring metal. Rice University scientists said the cool part is what happens in the gap.

A Rice team discovered those electrons can create a photovoltage about a thousand times larger than what is seen if there is no gap. The finding shows it should be possible to create nanoscale photodetectors that convert light into electricity and can be used as sensors or in other sophisticated electronics.

Results from the Rice lab of condensed matter physicist Douglas Natelson appear in the American Chemical Society’s Journal of Physical Chemistry Letters.

Natelson’s lab studies the electronic, magnetic and optical properties of nanoscale structures, often by testing the properties of systems that can only be viewed under a microscope.

See more at Rice University

Image: Rice University scientists discovered that “hot” electrons can create a photovoltage about a thousand times larger than ordinary temperature differences in nanoscale gaps in gold wires. On the left, a laser-heated, bowtie-shaped plasmonic gold nanowire created a small voltage in the wire. On the right, a gold nanowire with a nanogap under the same light source showed a much stronger voltage at the break. Click on the image for a larger version.  (Courtesy of the Natelson Group