Popis: |
We use reflection high energy electron diffraction and grazing incidence X-ray diffraction to study films of the archetype crystalline organic material: 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA) grown on Au(111) by organic molecular beam deposition. Although the PTCDA lattice is significantly mismatched to the Au(111) substrate, the films are orientationally aligned and have a well defined film thickness, providing evidence for layer-by-layer “quasi-epitaxial” growth. Furthermore, we have performed the first characterization of the molecular level disorder in these films, and have determined the presence of a significant (3.8%) strain in the 2D lattice parameters. |