We study electrical transport in strongly coupled, molecularly linked, gold nanoparticle (NP) films whose bulk dc conductances are governed by percolation phenomena. Films with fewer NPs exhibit current suppression below a threshold voltage, likely due to single-electron charging of NP clusters. In some cases, the thresholds are very large (∼1 V) and suppression persists to room temperature. The thresholds tend to decrease with increasing amounts of NPs in the film, and eventually, metal-like conductance is observed down to at least 10 K. The observed trend toward metal-like conductance, despite the presence of film disorder, is enabled by strong inter-NP coupling and increasing film connectivity. The latter is an inherent property of molecularly linked NP films due to both robust chemical inter-NP linkages provided by alkane dithiol linker molecules, coupled with the ability to grow chains of connected NPs to arbitrary lengths through cyclical Au/dithol treatments. In the case of small thresholds, our data is well described by a high-temperature approximation of “orthodox” theory for a linear array of tunnel junctions.

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