Effect of Immersion Time on the Structure of Octanethiol Self-Assembled Monolayers on Au(lll)at an Elevated Solution Temperature

摘要

The spontaneous adsorption of organic molecules with a reactive headgroup on metal surfaces results in the formation of self-assembled monolayers(SAMs)with well-ordered packing structure and controllable nano-scale thickness.The resulting SAMs have been applied for a variety of technical applications in nanolithography,bio-interfaces,molecular sensors,and molecular electronic devices.1 Alkanethiol SAMs on gold have been thoroughly studied for clarifying the molecular-scale packing structure,molecular orientation,self-assembly phenomena,and structural stability.It was disclosed that alkanethiol SAMs on Au(lll)at saturation coverage are usually composed of well-ordered domains with(√3 × √3)R30° or c(4 × 2)structure,domain boundaries,and many vacancy islands(VIs).High-structural quality of alkanethiol SAMs on Au(111)with large ordered domains and less structural defects can be prepared via a thermal annealing process of pre-covered SAMs or via a high solution temperature.