Bilayer molecular electronics: all-carbon electronic junctions containing molecular bilayers made with "click" chemistry.

Bilayer molecular junctions were fabricated by using the alkyne/azide "click" reaction on a carbon substrate, followed by deposition of a carbon top contact in a crossbar configuration. The click reaction on an alkyne layer formed by diazonium reduction permitted incorporation of a range of molecules into the resulting bilayer, including alkane, aromatic, and redox-active molecules, with high yield (>90%) and good reproducibility. Detailed characterization of the current-voltage behavior of bilayer molecular junctions indicated that charge transport is consistent with tunneling, but that the effective barrier does not strongly vary with molecular structure for the series of molecules studied.