Single electron charging effects in gold nanoclusters on alkanedithiol layers with different molecular lengths

Homogeneous gold nanoclusters grown on Au(1 1 1) substrate covered with hexanedithiol, octanedithiol and decanedithiol layers were studied by tunneling and photoelectron spectroscopies at room temperature. The charging energy e2/2C, where C is the capacitance between a cluster and Au(1 1 1) substrate determined from Coulomb blockade in tunneling spectroscopy, well describes the Au 4f core-level binding energy shifts observed in X-ray photoelectron spectroscopy. The charging energy depends on the amount of Au deposition, which governs the apparent height of clusters in small standard deviations, but not significantly on the length of molecules, which determines the thickness of the layer. The deviations of the cluster size affect that of the capacitance C and the line width of Au 4f spectra.