Electron beam lithography on Langmuir−Blodgett films of alkanethiol-capped gold nanoparticles is shown to be a viable strategy to define nanometer scale structures of such particles. Sub-50 nm wide “nanowires”, the thickness of which is controlled at the single particle level, are created with e-beam doses in the mC/cm2 range. It is shown that the patterns are formed by radiation-induced cross-linking of the alkyl chains and that they can be contacted and studied electrically.

We describe a simple process for preparing sub-3 nm gaps by means of controllable breaking of gold wires lithographed on a SiO 2 /Si substrate at low temperature (4.2 K). We show that the mechanism involved is thermally assisted electromigration. We investigate the effect of the high electric field developed at the final stage of the breaking of the nanowire and observe that the current-voltage characteristics (I -V ) of the resulting electrodes are stable up to ∼5 V. This high-electric-field stability gives access to the well-known Fowler-Nordheim regime (eV > 0 ) in the I -V characteristic, thus allowing an accurate characterization of the gap size. The size of the gap is found to be between 1 and 2 nm. We validate this characterization by fabricating single-electron tunnelling devices based on alkylthiol capped gold nanoparticles.