Forming single molecular junctions between indium tin oxide electrodes

We have demonstrated that indium tin oxide (ITO) can be used as contact electrodes to form molecular junctions via ITO-carboxylic acid bonds. We measured the conductance of n -alkane terminated with dicarboxylic acids using conducting atomic force microscope break junction. The conductance decreases exponentially with molecular length with a decay constant of ∼0.80 Å-1, which is similar to that of Au-carboxylic acid junctions. However, the contact conductance of ITO-carboxylic acid is smaller than that of Au-carboxylic acid, reflecting different electronic couplings between the linker group and electrodes. From the average breakdown force and stretching length, we estimated the binding energy of ITO-carboxylic acid.