Abstract
Angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) was measured for one-monolayer coronene films deposited on Ag(111). The (kx,ky)-dependent photoelectron momentum maps (PMMs), which were extracted from the ARUPS data by cuts at fixed binding energies, show finely structured patterns for the highest and the second-highest occupied molecular orbitals. While the substructure of the PMM main features is related to the 4 × 4 commensurate film structure, various features with three-fold symmetry imply an additional influence of the substrate. PMM simulations on the basis of both free-standing coronene assemblies and coronene monolayers on the Ag(111) substrate confirm a sizable molecule–molecule interaction because no substructure was observed for PMM simulations using free coronene molecules.
Highlights
As has been shown for a number of well-ordered organic adsorbates on crystalline surfaces, the photoelectron angular distributions of adsorbate-derived molecular states, termed photoelectron momentum maps (PMMs), can be essentially described by a Fourier transform of the molecular orbitals computed for the free molecule.[1−5] By considering band structure and Bloch states, substructures of the main PMM features can be explained with high precision.[6]
It was shown that the main features of the-dependent PMMs of 1 ML coronene films on Ag(111) can be described by a photoemission process originating from coupled orbitals of neighboring molecules
The measured PMMs carry the signatures of both that of a single molecular orbital and that of the adsorbate lattice. It can be concluded from our calculations that already the inclusion of the nearest and the second-nearest neighbors is sufficient to account for the additional lattice features in the measured momentum maps
Summary
As has been shown for a number of well-ordered organic adsorbates on crystalline surfaces, the photoelectron angular distributions of adsorbate-derived molecular states, termed photoelectron momentum maps (PMMs), can be essentially described by a Fourier transform of the molecular orbitals computed for the free molecule.[1−5] By considering band structure and Bloch states, substructures of the main PMM features can be explained with high precision.[6]. In contrast with the samples investigated here (epitaxially grown molecular layers on a single-crystalline substrate), the samples of ref 9 were powder samples prepared by annealing nominal compositions of dopant and organic compound. In the case of epitaxially grown films, effects of charge transfer, that is, doping of the molecular layer, can be caused by the interaction with the substrate.[10]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
