Molecular orientation and ordering during initial growth of copper phthalocyanine on Si(111)

Abstract

The molecular orientation and order in the initial growth of copper phthalocyanine on Si(111) was investigated in situ by angular-dependent X-ray absorption spectroscopy. A transition from lying-down to standing-up configuration occurs in less than one monolayer. After the Si surface is passivated by a monolayer of the molecules, only the standing-up structure persists in subsequent growth. The molecular film also exhibits an order - disorder - order transition in the distribution of molecular tilt angle during growth. These transitions are related to the changes of interactions in the system at different stages. © 2007 American Chemical Society.