Structure and Reactivity within Ultrathin Molecular Films

摘要

A new technique based on the nonlinear optical phenomenon - second harmonic generation - has been developed for probing the structure of nano- to micrometer thickness thin films made of small and medium size organic molecules. It was found that the magnitude of the inter-molecular interaction plays a critical role in determining the growth mechanism, structure, crystallization kinetics, and phase transitions of the thin molecular films. The nonlinear optical technique can even allow the determination of the orientation and alignment of the molecules at the interface between the thin film and the substrate. Order of the molecules in the interfacial layer affects the crystallization mechanism in the thin film.