In situ characterization of functional organic thin films by energy dispersive grazing incidence X-ray diffraction

We are investigating well-ordered highly crystalline thin films made using organic molecular beam deposition (OMBD) since it is important to control the formation mechanism at the initial growth process. Then, we developed a new in situ technique of energy dispersive grazing incidence X-ray diffraction utilized within an ultrahigh vacuum system. This technique (in situ ED-GID) makes it possible to examine the crystal structure, orientation and morphology of organic thin films during deposition without any damage to the film. In the present review, we examined the growth process of thin films of functional organic dyes, fullerene (C60) and p-sexiphenyl (6P) by using this in situ ED-GID. The crystal strucutre and molecular orientation in epitaxially-grown thin films were confirmed during the initial stages of growth. Also, the morphology of C60 thin films was examined during the deposition. As a result, it was confirmed that the decay curves of X-ray fluorescence indicate different island growth in C60 thin films.