Macroscopically aligned molecular stacking structures in mesogenic phthalocyanine derivative films fabricated by heated spin-coating method

Spin-coated films of a mesogenic phthalocyanine derivative, 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH2), with macroscopic alignment of molecular stacking structure were obtained by processing in liquid-crystal phase of C6PcH2. The column axis direction of the hexagonal columnar structure of C6PcH2 was determined by microscopic observation and polarized optical absorption measurement and was uniform in the millimeter-scale area. Highly ordered molecular stacking structure in the film, which is similar to the single crystal, was clarified by measurement of molecular tilting angle with respect to the column axis. The origin of the macroscopic molecular alignment during film formation was investigated by taking the process-temperature-dependent properties of the films into consideration.