Single-crystalline thin-film growth via solution-mediated polymorphic transformation of octahexyl-substituted phthalocyanine and its optical anisotropy

摘要

The fabrication of a single-crystalline thin film of non-peripheral octahexyl-phthalocyanine (C6PcH(2)) was realized by performing a tetrahydrofuran (THF) vapor treatment on a the spin-coated film. The solution-mediated polymorphic transformation of C6PcH(2) was promoted in the THF vapor, and a single-crystalline thin film with alpha-phase crystal grew in the thin film when setting an appropriate temperature. The thin film exhibited optical anisotropy, such as a high dichroic ratio, and the color of the transmitted light varied from green to transparent depending on the polarization direction. The molecular packing structure on the substrate was determined by X-ray diffraction and polarized absorption measurements.