The rate of charge tunneling through self-assembled monolayers is insensitive to many functional group substitutions.

This paper characterizes the rates of charge transport by tunneling across a series of molecules—arrayed in self-assembled monolayers—containing a common head group and body (HS(CH)CONH(CH)-) and structurally varied tail groups (-R). These molecules are assembled in junctions of the structure Ag/SAM//GaO/EGaIn. Over a range of common aliphatic, aromatic, and heteroaromatic organic tail groups, changing the structure of R does not significantly influence the rate of tunneling.