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 micro-crystalline CuI films exhibiting copper and iodine terminated grains are used.

"Selecting Phthalocyanine Polymorphs Using Local Chemical Termination Variations in Copper Iodide" A. J. Ramadan, I. Hancox, S. Huband, C. C. Parkins, S. A. F. Bon, M.Walker, S. Fearn, C. F. McConville, T. S. Jones, and L. A. Rochford http://pubs.acs.org/doi/abs/10.1021/acs.jpcc.6b00354