Single electron transistor using a molecularly linked gold colloidal particle chain

By applying a dithiol (1,6-hexanedithiol) treatment, it was observed that a submonolayer of gold colloidal particles deposited by using an aminosilane adhesion agent [i.e., 3-(2-aminoethylamino) propyltrimethoxysilane] transform themselves into chains consisting of a few gold colloidal particles. In those chains, gold colloidal particles are believed to be linked by alkane chains derived from the dithiol molecules. The particle chain was formed on a ${\mathrm{SiO}}_{\mathrm{2}}$ substrate with source, drain, and gate metal electrodes defined by electron beam lithography. It was observed that the gold particle chain bridged a gap between the source and drain forming a single electron transistor with a multi-tunnel junction in the particle chain. The electron conduction through the chain exhibited a clear Coulomb staircase and the periodic conductance oscillation as a function of gate voltage. These measurement results corresponded closely to the results of a simulation based on the orthodox theory.