Tuning the electron transport mechanism in metal nanoparticles arrays by the manipulation of the electronic coupling and structural disorder

Nanostructured artificial atom solids by C49-phase TiSi2 nanoparticles embedded in Si polycrystalline matrices were fabricated by a self-assembling methodology, based on the annealing of Si/Ti multilayers. We demonstrate that the annealing process of the multilayers is a suitable methodology to tune the electronic transport mechanism, since by an appropriate choice of the annealing parameters (temperature and time) it is possible to tailor the mean nanoparticle size, the surface-to-surface distance and their dispersion. As a consequence, the array charging energy, the array structural disorder and the electronic coupling between the nanoparticles can be tailored and the transport properties can be varied from insulating to metallic regimes. This behavior is shown to be consistent with the Mott-Hubbard model for the description of the electronic structure in artificial atom solids.