Macroscopically aligned films of discotic phthalocyanine by zone casting

This work describes a room temperature liquid crystalline phthalocyanine processed by using zone casting. Highly oriented films that were uniform over several square centimeters were obtained on glass support from a mixed solvent (1:1 mixture of toluene and ethylene chloride) solution. A columnar planar alignment of Col(r) in the film layers has been determined by optical polarized microscopy, ultraviolet-visible absorption, atomic force microscopy and x-ray diffraction studies. The films consist of uniaxially oriented ribbon-like structures with molecular columns perpendicular to the solidification direction. The pronounced alignment makes these thin films promising for application in optoelectronic devices.