Site-selective molecular organization in organic heterostructures

The microscopic process which take place during the growth of phtalocyanines (F16CuPc), an organic heterostructures based on fluorinated copper, onto the pentacene, was obtained by combining in situ X-ray diffraction and atomic force microscopy (AFM). It was observed that s-structur grows on top of the pentacene terraces, while the l-structure develops along the pentacene step edges. It was also observed that the growth of the phtalocyanines s-structure gives rise to a characteristics increase of the (001) and (002) reflections. The different energetic and electronic environment at the step edges, for phtalocyanines molecules at pentacene step, favors the orientation of the phthalocyanines with its molecular plane parallel to the surface. Because the steps of the underlying pentacene catalyze the growth of the F16CuPc l-structure, it can be used for controlling the morphology and structure of organic films by the use of vicinal organic templates.