Adsorption of Pentacene on the 2–Fold Surface of the Icosahedral Ag–In–Yb Quasicrystal

The adsorption of pentacene molecules on the 2–fold surface of the icosahedral (i)–Ag–In–Yb quasicrystal (QC) has been studied using scanning tunnelling microscopy (STM). The STM images show that the molecules are arranged in rows, and aligned predominantly along the high–symmetry 5–fold and 2–fold axes of the surface. The row separation perpendicular to the 5–fold symmetry axes is either short S = 0.79 ± 0.03 nm or long L = 1.24 ± 0.02 nm. The ratio between them is close to the golden mean (τ = 1.618…) and creates segments of the Fibonacci sequence. Fourier transform of the scanning tunnelling microscopy (STM) images reveal 2–fold, quasicrystalline, long–range order. A comparison of the STM features with the model structure of the substrate shows that Pn molecules adsorb at Yb sites.