Molecular multilayers: Structure and templating effects

Powder X-Ray diffraction (XRD) has been used to study multilayered structures grown by organic molecular beam deposition based on the molecular materials PTCDA and metal-free phthalocyanine (H2Pc). Double layers of different polymorphic forms (α β1 and β2) of H2Pc indicate that the structure of the second layer is determined by the properties of the first layer. It is also shown that the first layer completely disrupts the crystallinity of the second layer in heterostructures containing PTCDA and H2Pc. The implication is that a strong templating effect occurs during the growth of multilayer molecular thin film structures. © 2000 Materials Research Society.