Visualization of molecular packing and tilting domains and interface effects in tetracene thin films on H/Si(001) (Phys. Status Solidi B 7/2017)

Abstract

Visualizing molecular crystalline domains and influence of substrate defects are important in understanding the charge transport in organic thin‐film devices. As a prototypical system, vacuum evaporated tetracene films of four molecular layers on hydrogen‐terminated Si(001)‐2 × 1 substrate have been studied by Tersigni et al. (article no. http://doi.wiley.com/10.1002/pssb.201600777). The three microscopic images on the cover page present the same film surface location with atomic force microscopy (AFM), transverse shear microscopy (TSM), and friction force microscopy (FFM), respectively; clearly different structural information contents are revealed. What can be retrieved from these measurements includes two differently oriented in‐plane molecular packing domains due to the substrate lattice symmetry; and two types of subdomain inside each packing domain reflecting molecular tilting orderings and the influence by the substrate atomic steps. TSM evidently shows a sensitivity to probe vertical molecule‐tilt anisotropy for the materials, in addition to its known ability to map the lateral lattice orientations.