Influence of linker molecules on charge transport through self-assembled single-nanoparticle devices.

摘要

We investigate electrical characteristics of single-electron electrode/nano-island/electrode devices formed by alkanedithiol assisted self-assembly. Contrary to predictions of the Orthodox model for double tunnel junction devices, we find a significant (∼5 fold) discrepancy in single electron charging energies determined by Coulomb blockade (CB) voltage thresholds in current-voltage measurements vs. those determined by an Arrhenius analysis of conductance in the CB region. The energies do, however, scale with particle sizes, consistent with single electron charging phenomena. We propose that the discrepancy is caused by a multi-barrier junction potential that leads to a voltage divider effect. Temperature and voltage dependent conductance measurements performed outside the blockade region probe the junctions directly and are consistent with this picture. We simulated our data using a suitably modified Orthodox model.