Molecular orientation of cadmium hexadecafluorophthalocyanine films influenced by annealing and electrochemistry

This work shows that it was possible to obtain thin films with a high degree of organization, without using sophisticated equipment. Hexadecafluorophthalocyanine was synthetized and thin films were prepared by means of casting technique. The molecular organization of the films was investigated, using annealing and electrochemistry experiments. Solution and films were investigated by UV-VIS spectroscopy displaying B and Q bands (322 and 624 nm, respectively, in solution) and Q band at 633 nm in the film. After annealing or electrochemistry measurements, this band changes to 640 nm, indicating some J aggregates formation. FTIR spectra show that the molecules have a preferred face-on orientation on the substrates, which enhanced after annealing. X-ray results showed, after electrochemistry treatment, that all molecules are in a face-on orientation, which may be important for applications where high molecular orientation is required. After the application of an electrical potential in the films, crystallites could be evidenced by AFM analyses.