Structure, morphology, and growth dynamics of perfluoro-pentacene thin films

We report high structural order in thin films of the organic semiconductor perfluoro-pentacene (PFP), which is a candidate material for n-type applications, deposited by vacuum sublimation on oxidized silicon wafers. Bragg reflections up to high order in both specular and grazing incidence geometries and a mosaicity of less than 0.01° demonstrate the well defined structure. The thin film entirely consists of crystallites with a structure close to the bulk phase without any contamination with a second phase. Real-time X-ray measurements show that PFP grows in a Stranski–Krastanov growth mode with the first monolayer wetting the substrate before 3d-growth sets in during growth of the second monolayer. Implications for its use are discussed.