Interlayers based junctions

In addition, it is important to remind that in many type of junctions the molecules are not even in physical contact with one of the electrodes, and therefore an additional, unknown, resistive contribution is measured. For instance (1) in STM-based junctions the STM tip and the molecules are separated by a gap, (2) in Hg based LAJs the top electrode is covered by alkane monolayers (Fig. 5a, b), (3) in E-Galn-based junction the electrode carries always a film of oxide (Fig. 5c) and (4) in the interlayer-based junctions (Ds) there is a film between the molecules and the top electrode (Fig. 1). 

Recently, Melosh has obtained electrically stable LAJs as large as 9 mm2 by atomic deposition of a nanometer-thick passivating layer of aluminium oxide on top of self-assembled organic monolayers with hydrophilic terminal groups [158,159]. Obviously, interlayers based junctions limit electrical measurements only to organic SAMs less conductive than the protecting layer. 

Fig. 7 Current densities J vs applied bias measured in a polymer-interlayer based LAJs for 1,8-octanedithiol, 1,10-decanedithiol, 1,12-dodecanedithiol and 1,14-tetradecanedithiol. Inset-. InJ as a Junction of the molecular length measured at 0.1 V, 0.3 V and 0.5 V bias. (Reprinted with permission from [80])...

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