Photo-induced liquid crystal alignment with discotic films

Photo-induced liquid crystal alignment using cross-linked discotic compound s was demonstrated. These discotic compounds exhibit good solubility in com mon organic solvents, 60 degreesC processing temperature and excellent ther mal stability. A linearly polarized long wave ultraviolet light (lambda = 3 50 nm) was used to initiate the cross-linking process which, in turn, induc es liquid crystal alignment on the discotic film surface. The polarity of d iscotic compounds plays an important role in affecting the pretilt angle of the liquid crystal alignment. A pretilt angle of 1 +/- 0.4 degrees was obt ained using single exposure at oblique angle. Potential application of this new photo-alignment film for low temperature poly-silicon thin-film-transi stor liquid crystal display is foreseeable.