Tuning the Coulomb charging energy in cross-linked nanoparticle films

Abstract

We have systematically tuned the Coulomb charging energy in cross-linked gold nanoparticle films by varying both the nanoparticle size and the length of the cross-linker molecules. We show that at low temperatures $(T\ensuremath{\lesssim}100\phantom{\rule{0.3em}{0ex}}\mathrm{K})$, the observed conduction behavior can be closely described with a classical percolation model for interacting metal particles embedded in an effective dielectric medium. The ease and precision with which one can control the geometrical parameters make these cross-linked nanoparticle systems attractive as model systems for the study of electronic conduction in granular materials.