Formation of Confined C60Islands within Octanethiol Self-Assembled Monolayers on Au(111)

Abstract

Confined C60 islands have been grown within octanethiol self-assembled monolayers (SAMs) on the Au(111) surface. The structure of the C60 islands is investigated by use of scanning tunneling microscopy (STM), and a single ordered phase of the close-packed C60 islands with a (2√3 × 2√3)R30° structure is found. In the vicinity of the close-packed C60 island there are loosely packed C60 molecules which are mixed with the thiolate species. Floating C60 on top of the SAM, in the form of either compact islands or individual molecules, is not found at room temperature and above. The diffusion of C60 molecules is strongly controlled by the structure of the SAM, and the (√3 × √3)R30° phase of the SAM is not permissible to diffusing C60 molecules.