Topological analysis of Au particles inAu/SiO2 nanocomposite films designed for molecular conduction measurement through Voronoidiagram

Abstract

Monolayered Au/SiO2 nanocomposite films with a high Au particle number density and insulating property wereprepared by radio frequency magnetron co-sputtering to develop a new substrate formolecular conduction measurement. The topologies of Au nanoparticles distributed in theSiO2 matrix were statistically evaluated by morphology observation using a field emissionscanning electron microscope (FE-SEM) and the Voronoi diagram of a circle set byregarding the Au nanoparticles as a circle generator. The mean Au particle size andthe interparticle distance between neighbours increased with deposition time.However, the fraction of the neighbouring Au nanoparticle combinations havinginterparticle distance shorter than a certain length increased as the deposition timeincreased. The results also demonstrated that many conducting paths several tens ofnanometres long can be created by attaching conductive molecules 2.4 nm long betweenthe Au nanoparticle combinations. Thus this suggests that the nanocompositesubstrate can provide a facile way to measure conducting properties of molecules.