Small Size Limit to Self-Assembled Monolayer Formation on Gold(111)

Abstract

Using molecular dynamics simulations, we show that the minimum diameter of ordered self-assembled monolayer (SAM) structures of alkanethiols on Au(111) is 1.9 nm at room temperature. This presumably sets the ultimate resolution of the SAM patterns created by nanolithography. For SAMs larger than 1.9 nm, the tilt direction of the alkyl chain precesses around the center of the SAM. This precession changes direction on a time scale that increases from picoseconds to nanoseconds as the SAM size varies from 2 to 3 nm.