Nanoelectronic circuit elements based on nanoscale metal–molecular networks.

We report a density functional non-equilibrium Green's function study of the electronic transport properties of nanoscale networks composed of Au metal clusters interconnected with thiolated molecules (1,4-benzenedithiol and 1,3,5-benzenetrithiol), connected in linear chains and branched (Y-, diamond-shaped) extended networks. Calculated current–voltage characteristics of the metal–molecular networks exhibited nonlinearities and rectification with negative differential resistance (NDR) peaks that became more pronounced with increasing chain length. A significant overlap of the energetically close delocalized molecular orbitals near the Fermi energy was observed, which likely combine and contribute to electron transport. The transmission spectra of the linear chains and branched networks showed an increase in the number and width of transmission peaks near the Fermi energy, as the structures were extended, indicating enhanced transmission. Peak-to-valley current NDR ratios as large as ~ 500 and rectification ratios of ~ 10 (0.25 V) were shown for linear and branched circuit elements, respectively, illustrating how charge transport through molecular-scale devices could be controlled with precision by modifying the structure and geometry of molecule–nanoparticle networks. These results provide a potential foundation and building block components for exploring and tailoring applications of metallic nanoparticle-molecular networks in various configurations for nanoelectronic devices and circuits, including memory, logic and sensing. [ABSTRACT FROM AUTHOR]