Structural and electrical characterization of gold nanoclusters in thin SiO2 films: Realization of a nanoscale tunnel rectifier

Conductive atomic force microscopy has been used to measure the I–V characteristics of nanometric Au clusters embedded in a SiO2 film prepared by sputter deposition and low temperature annealing. Highly local asymmetric rectifier I–V characteristics were evidenced and modelled in terms of electrical transport through an asymmetric double barrier tunnel junction SiO2/Au cluster/SiO2. The threshold voltage depends strongly on the cluster size and barrier thickness according to the model given.