Controlling templating effects at the organic/inorganic interface using (111) oriented copper iodide

Abstract

Structural templating of organic semiconductors affords control of out-of-plane film structure and molecular orientation with respect to solid surfaces. Herein we use a prototypical copper iodide (CuI)/planar phthalocyanine system to produce detailed surface and crystal structure information using atomic force microscopy (AFM) and X-ray diffraction (XRD). The out-of-plane structure of the CuI layer was characterised and identified as the (111) plane of single crystal CuI. The dependance of surface morphology and grain size in the CuI (111) templating layer upon substrate temperature was demonstrated. The formation of a thin film of iron phthalocyanine (FePc) on this model layer was characterised at multiple points during growth, changes in the surface morphology were observed, and the crystal structure of the final film was used to infer the molecular orientation therein. These changes were elucidated using the re-determined single crystal structure of FePc which is also presented.