The $I-V$ characteristics of single-layer Au nanocluster films are found to depend on the size of the Au core of the nanoclusters with the threshold voltage rising as the cluster size decreases. The thresholds are also found to depend linearly on array length and temperature up to 300 K. At the higher temperatures, the thresholds are observed to go negative, which may be interpreted as an effect of transport over a barrier. These findings, interpreted using numerical simulation, provide strong evidence that the system is governed by Coulomb blockade and that disorder, though clearly present, plays only a secondary role.

• Received 11 September 2000

DOI:https://doi.org/10.1103/PhysRevB.64.033408