Replacing \(Ag ^{TS} SCH_2-R\) with \(Ag^{TS}O_2C-R\) in EGaIn-Based Tunneling Junctions Does Not Significantly Change Rates of Charge Transport

Abstract

This paper compares rates of charge transport by tunneling across junctions with the structures \(Ag^{TS}X(CH_2)_{2n}CH_3 //Ga_2O_3 /EGaIn \space\) (n=1–8 and \(X= -SCH_2-\) and \(O_2C-\)); 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 (\(\beta\), Å\(^{−1}\)) and the injection current (\(J_0\), A cm\(^{−2}\)) of the junctions comprising SAMs of n-alkanethiolates and n-alkanoates. Replacing \(Ag^{TS}SCH_2-R\) with \(Ag^{TS}O_2C-R\) (R=alkyl chains) had no significant influence on \(J_0\) (ca. \(3\times10^3 A cm^{−2}\)) or \(\beta\) (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 \(\beta\) for aliphatic (0.79 Å\(^{−1}\)) and aromatic (0.60 Å\(^{−1}\)) SAMs differed significantly.