  We describe a strategy for conversion of optical power into DC electrical
power using resonant absorption in plasmonic nanostructures. A thermodynamic
analysis of the underlying mechanism motivates our description of the
phenomenon, which we term the plasmoelectric effect. Power conversion results
from the dependence of optically generated heat on shifts of the plasmon
resonance frequency that occur with changes of electron density. We model an
all-metal device constructed from 10 nm radius silver spheres and predict a
characteristic conversion efficiency of 14.3% under 1 kW m-2 intensity,
single-frequency radiation. We discuss strategies for enhanced efficiency,
broadband power conversion, and further applications of this new class of
optoelectronic device.
