Controlling Surface Energetics of Silicon by Intermolecular Interactions between Parallel Self-Assembled Molecular Dipoles

We show that the electrical properties of Si surfaces can be controlled systematically by the extent of intermolecular interactions between molecular dipoles that self-assemble in parallel on the Si surfaces. We draw this conclusion on the basis of experiments with self-assembled hexyltrichlorosilane molecules on SiO x /Si surfaces, with different degrees of Si−O−Si intermolecular bonds. Our results indicate that systematic control of intermolecular interactions of organic molecules on a semiconductor surface provides an important additional molecular handle, in addition to varying the individual molecule’s dipole, for controlling the surface energetics of semiconductor surfaces and, by extension, of semiconductor- and metal-containing interfaces, thus significantly enhancing the molecular control of electronic surfaces and interfaces.