  We study the impact of optical field-enhancement effects on the
optoelectronic properties of metal nanoparticle arrays. Applying a focused ion
beam lithography in combination with an electron beam deposition technique we
can pattern electrical contacts in a way to give rise to an electromagnetic
field-enhancement. A further field-enhancement is achieved by the plasmon
resonance of the particles. Both effects are directly observed in the
photoconductance of the arrays.
