The Molecular Arrangements of Alkanethiol Self-Assembled Monolayers on Au(111) Studied by Scanning Tunneling Microscopy

Abstract
Structures of self-assembled monolayers (SAMs) of alkanethiol molecules were studied by scanning tunneling microscopy (STM) in ultrahigh vacuum (UHV). Molecularly resolved STM images of alkanethiol SAMs were obtained under a high-resistance tunneling condition. The observed images show that the monolayers consist of the (√3×√3)R30° lattice structure, c(4×2) superlattice and the stripe structures which have a unit cell of p×√3. We observed a new molecular arrangement in the c(4×2) superlattice. The details of the stripe structures are also described.