Molecular junctions made of tungsten-polyoxometalate self-assembled monolayers: Towards polyoxometalate-based molecular electronics devices

Journal article, 2011

In this work, the electrical conduction of planar Au junctions electrically bridged by a polyoxometalate-based self-assembled monolayer, aimed to be used in hybrid silicon/molecular memory devices, is discussed. Tunnelling assisted by the presence of polyoxometalate anions is recognised as the main conduction mechanism for these devices. Fluctuations and hysteresis that are profoundly observed in the current-voltage characteristics for the smallest junctions suggest that the anions number is the more crucial factor in the devices behaviour. Quantitative analysis of the obtained characteristics based on Simmons's model reveals an increase in the tunnelling barrier height as the electrode distance increases from 20 to 200 nm. (C) 2011 Elsevier B.V. All rights reserved.