K. Walzer et al., FORMATION AND CHARACTERIZATION OF CORONENE MONOLAYERS ON HOPG(0001) AND MOS2(0001) - A COMBINED STM STS AND TIGHT-BINDING STUDY/, Surface science, 415(3), 1998, pp. 376-384
Ordered monolayers of the highly symmetric organic molecule coronene (
C24H12) have been deposited under ultrahigh vacuum conditions onto sev
eral atomically flat surfaces, such as HOPG(0001) and MoS2(0001). The
adsorbates have been investigated by scanning tunneling microscopy (ST
M) and scanning tunneling spectroscopy (STS). We were able to achieve
submolecular resolution in the STM images, also while doing STS experi
ments. Reproducible STS characteristics could also be measured. Monola
yer adsorbates of coronene on graphite are found to form a commensurat
e (root 21 x root 21)R10.9 degrees superlattice, which is in agreement
with LEED data from the literature. By applying a density-functional
tight-binding method we have calculated the electronic structure of th
e coronene molecule. These calculations of the spatial distribution of
the charge densities and the energetic distribution of the electronic
orbitals are compared with our STS measurement data. (C) 1998 Elsevie
r Science B.V. All rights reserved.