Observation of a Coulomb staircase in electron transport through a molecularly linked chain of gold colloidal particles

Submonolayer gold colloidal particles were deposited by using aminosilane [3-(2-aminoethylamino)propyltrimethoxysilane] as an adhesion agent on the substrate. It was observed that these submonolayer particles transform themselves into short chains of a few gold colloidal particles after a subsequent dithiol (1,6-hexanedithiol) treatment and an additional gold colloidal particle deposition. These chains bridged a gap that was formed between source and drain metal electrodes defined by electron beam lithography; thus realizing a quasi one dimensional current path between the source and drain. The device exhibited a clear Coulomb staircase at both 4.2 and 77 K.