Studies on phase transformations of Cu-phthalocyanine thin films

Copper phthalocyanine (CuPc) thin films were obtained by sublimation technique on Siwafer substrates maintained at room temperature. As-deposited CuPc films with less than 0.1µm thickness crystallize primarily in the a-form with a preferential orientation of the crystallites in the (200) direction. The effect of randomizing of the orientation of the CuPc crystallites is observed as the film thickness increases, whereas the preference in appearance of the a-form remains. The changes in phase composition, structure, morphology and surface chemical compostion of as-deposited CuPc thin films due to different heat treatment conditions were investigated by x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS)