Controlling the Interface Dynamics at Au Nanoparticle–Oxide Interfaces

With interface sizes rapidly reducing to the nanometer scale, it has become vital to understand how size and structure can affect transport behavior between materials in order to tune the energy barrier for various applications. In this study, the fabrication of Schottky barriers between 20 nm Au nanoparticles and Nb-doped SrTiO₃ substrates is reported. The calculated barrier height and ideality factors are compared for dopant concentrations ranging over three orders of magnitude. The results show that the lowest doped substrates exhibit transport characteristics dominated by thermionic emission while the highest doped substrates are dominated by tunneling and the transition is best described by classical theory with the addition of edge effects to account for nonideal behavior.