Replacing Ag(TS)SCH(2)-R with Ag(TS)O(2)C-R in EGaIn-based tunneling junctions does not significantly change rates of charge transport

Angew Chem Int Ed Engl. 2014 Apr 7;53(15):3889-93. doi: 10.1002/anie.201308472. Epub 2014 Mar 5.

Abstract

This paper compares rates of charge transport by tunneling across junctions with the structures Ag(TS) X(CH2 )2n CH3 //Ga2 O3 /EGaIn (n=1-8 and X= SCH2  and O2 C); here Ag(TS) is template-stripped silver, and EGaIn is the eutectic alloy of gallium and indium. Its objective was to compare the tunneling decay coefficient (β, Å(-1) ) and the injection current (J0 , A cm(-2) ) of the junctions comprising SAMs of n-alkanethiolates and n-alkanoates. Replacing Ag(TS) SCH2 -R with Ag(TS) O2 C-R (R=alkyl chains) had no significant influence on J0 (ca. 3×10(3) A cm(-2) ) or β (0.75-0.79 Å(-1) )-an indication that such changes (both structural and electronic) in the Ag(TS) XR interface do not influence the rate of charge transport. A comparison of junctions comprising oligo(phenylene)carboxylates and n-alkanoates showed, as expected, that β for aliphatic (0.79 Å(-1) ) and aromatic (0.60 Å(-1) ) SAMs differed significantly.

Keywords: EGaIn junction; alkanoates; charge transport; molecular electronics; self-assembled monolayer; tunneling.