Selecting phthalocyanine polymorphs using local chemical termination variations in copper iodide

Copper(I) iodide (CuI) thin films are employed as a structural templating layer for the growth of metal-free phthalocyanine (H2Pc) thin films. Structural polymorphs are observed in X-ray diffraction patterns when microcrystalline CuI films exhibiting copper and iodine terminated grains are used. Each polymorph is nucleated from a single termination, and distinctive crystallite morphologies are observed for each.