Electrical and optical properties of discotic liquid crystals with various core structures

Electrical and optical properties in discotic liquid crystals having various core structures such as triphenylene, phthalocyanine, metal phthalocyanine and other aromatic moieties have been studied. The electrical conductivity, photoconductivity and carrier mobility are measured as a function of temperature and molecular alignment. The anisotropy of the conductivity and carrier mobility have been confirmed. The molecular alignment characteristics of various discotic liquid crystals have also been investigated by means of a polarizing microscope observation. An excellent uniform molecular alignment, in which the columnar axis aligns perpendicular to the substrates, has been observed in the tetragonal columnar phase of liquid crystal with rare-earth phthalocyanine core.