Electronic transport in porphyrin supermolecule-gold nanoparticle assemblies

Temperature-dependent transport of hybrid structures consisting of gold nanoparticle arrays functionalized by conjugated organic molecules [(4'-thiophenyl)ethynyl-terminated meso-to-meso ethyne-bridged (porphinato)zinc(II) complexes] that possess exceptional optical and electronic properties was characterized. Differential conductance analysis distinguished the functional forms of the temperature and voltage dependences for a range of sample particles and molecular attachments. Thermally assisted tunneling describes transport for all cases and the associated mechanistic parameters can be used to determine the relative roles of activation energy, work function, and so forth. These results provide the basis on which to examine plasmon-influenced conduction in hybrid systems.