3D island growth of 6,13 Pentacenequinone on silicon oxide and gold

We investigated the morphological and structural properties of 6,13 Pentacenequinone thin films (5–50 nm) grown by vacuum thermal evaporation on SiO2 substrates with pre-patterned gold electrodes at room temperature using atomic force microscopy, scanning electron microscopy and X-ray diffraction. The X-ray diffraction always revealed the coexistence of two different crystalline phases, namely the bulk crystal phase and the thin film phase. A comparison of the diffraction data with atomic force microscopy and scanning electron microscopy measurements allowed assigning needle-like (compact) crystallites to the thin film (bulk) phase. The needle-like crystallites started to grow on flat two-dimensional islands lying on an initial wetting layer of Pentacenequinone. This is observed both on the bare silicon oxide substrate and on the polycrystalline gold electrodes.