Tip-Height-Controlled Removal of Alkanethiol Self-Assembled Monolayer on Au(111) Surface

Abstract

Using a scanning tunneling microscope (STM), we demonstrated the tip-height-controlled removal of self-assembled monolayers (SAMs) on an Au(111) surface in air. The monolayer films were selectively removed by the mechanical tip contact while scanning. By controlling tunneling current at a constant sample bias voltage, the appropriate tip height was investigated for the removal of different alkanethiol SAMs: octanethiol, decanethiol and dodecanethiol. The tip height for the removal of alkanethiol SAMs was dependent on the film thickness. This result indicated that selective molecular removal of SAMs on the Au(111) surface could be accomplished by controlling the tip height.