Small Organic Molecules In The Au (111) Surface Interaction Force And The Assembly Of The Scanning Tunneling Microscopy Study

With the advent of the scanning tunneling microscope (STM), for the first time it has been possible to explore the atomic-realm of surfaces in real space. With the help of STM, we can not only resolve the surface or surface-adsorbed nanostructure in atomic scale, but also carry out in situ spectroscopic studies. Moreover, manipulation of single atoms, molecules and clusters has become possible. STM has been widely utilized in physical science, chemistry, material science and biology in recent decades. In this thesis, we studied interaction and self-assembly of organic molecules on the Au (111) surface by taking advantage of UHV-LT-STM.In Chapter 1, we briefly introduce the fundamental principle and method of STM in both experimental and theoretical aspects. We also reviewed the recent progress in surface and surface-adsorbed nanostructures study with STM as well as the STM techniques employed. Then, we introduce the background, significance, status quo and content of our work.In Chapter 2, we studied the adsorption behavior of two different metal phthalocyanine (MPc) on Au(111). Combination with theory calculation, we found that it was the competition between Coulomb repulsion among localized charges built up at the molecule-surface interface by charge redistribution occurring upon chemisorption and molecule-surface interaction which lead the adsorption behavior.In Chapter 3, we investigated the chiral self-assembly structure of CoOEP molecules on Au(111). We found the structure was stable and did not change with the number of molecules, but it disappeared when the molecular coverage was too high. Proved by dI/dV map, the molecular did not change during the assembly progress.