title: Tuning molecule-substrate coupling via deposition of metal adatoms.
abstract: Organic-inorganic hybrids constitute an important class of functional materials. The fundamentals at the molecular levels are, however, relatively unexplored. PTCDA (perylene-3,4,9,10-tetracarboxylic dianhydride) is a colorant and extensively applied in organic-based optoelectronic devices. PTCDA/Cu(111) and Fe-PTCDA/Cu(111) metal-organic hybrid monolayers are studied by low temperature scanning tunneling microscopy and spectroscopy (STS) and density functional theory (DFT). The former exhibits Moiré pattern-modulated molecular density of states while the latter adapts a commensurate adlattice. Both imaging and spectroscopic results suggest a strong hybridization between PTCDA molecules and Cu(111) substrate. Weak PTCDA-Cu(111) coupling can be obtained by the introduction of Fe adatoms. Compared to PTCDA/Cu(111), STS spectra of Fe-PTCDA/Cu(111) exhibit a higher energy and sharper features of the frontier orbitals. Together with the DFT results, we found that the PTCDA-Cu(111) coupling is attenuated by the presence of Fe adatoms and Fe-PTCDA coordination.
authors.affiliation: Department of Physics, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Hung-Hsiang
authors.initials: HH
authors.lastname: Yang
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Hsu-Han
authors.initials: HH
authors.lastname: Tsai
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Chi-Feng
authors.initials: CF
authors.lastname: Ying
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Tsung-Han
authors.initials: TH
authors.lastname: Yang
authors.affiliation: Research Center for Applied Sciences, Academia Sinica, Taipei 11529, Taiwan.
authors.forename: Chao-Cheng
authors.initials: CC
authors.lastname: Kaun
authors.affiliation: Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Chun-Hsien
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Department of Physics, National Taiwan University, Taipei 10617, Taiwan.
authors.forename: Minn-Tsong
authors.initials: MT
authors.lastname: Lin