Surface morphology studies of phthalocyanine thin films: mechanism of the alpha->beta_1 phase transition

摘要

Free base phthalocyanine films have been grown on glass substrates by organic molecular beam deposition. In situ post-growth annealing of the samples leads to the alpha->beta_1 transformation. Different transition states have been identified and their morphological properties studied by atomic force and optical microscopy. The transition occurs via a discrete number of nucleations and is preceded by an elongation of the α crystallites. The beta_1 crystallites grow but are confined to domains of similar orientation. Increased thickness produces larger domains and better orientation, while only partial transformation occurs below 94 nm.