ATOMIC SCALE INVESTIGATION OF MOLECULAR SELF-ASSEMBLY AND SINGLE MOLECULE MANIPULATION ON SURFACES

Abstract

In this thesis, low-temperature scanning tunneling microscope has been used as a tool for real-space imaging, electronic structure characterization as well as single-molecule manipulation within self-assembled monolayers on graphite. We first present a investigation of two-dimensional crystallization of C60:pentacene binary system on Ag(111). After that, single-dipole molecule switching within single-component vanadyl phthalocyanine (VOPc) monolayer is investigated. VOPc molecules can be switched between O-up and O-down configurations and the spatially resolved scanning tunneling spectroscopy measurements allow the identification of the electronic structures of VOPc with different dipole orientation. Finally, the reversible single-dipole switching is extended to binary molecular networks formed by chloroaluminium phthalocyanine (ClAlPc) and perfluoropentacene (PFP), which allows for tunning of the dipole density and enhancing the structure stability. As corroborated by density functional theory calculations, we propose that the switching is achieved by ¿shuttling¿ the Cl atom between two sides of the ClAlPc molecular plane.