Bis(triisopropylsilylethynyl)pentacene/Au(111) interface: Coupling, molecular orientation, and thermal stability

Andrea Gnoli, Hande Üstünel, Daniele Toffoli, Liyang Yu, D. Catone, Stefano Turchini, Silvano Lizzit, Natalie Stingelin, Rosanna Larciprête

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


The assembly and the orientation of functionalized pentacene at the interface with inorganics strongly influence both the electric contact and the charge transport in organic electronic devices. In this study electronic spectroscopies and theoretical modeling are combined to investigate the properties of the bis(triisopropylsilylethynyl)pentacene (TIPS-Pc)/Au(111) interface as a function of the molecular coverage to compare the molecular state in the gas phase and in the adsorbed phase and to determine the thermal stability of TIPS-Pc in contact with gold. Our results show that in the free molecule only the acene atoms directly bonded to the ligands are affected by the functionalization. Adsorption on Au(111) leads to a weak coupling which causes only modest binding energy shifts in the TIPS-Pc and substrate core level spectra. In the first monolayer the acene plane form an angle of 33 ± 2° with the Au(111) surface at variance with the vertical geometry reported for thicker solution-processed or evaporated films, whereas the presence of configurational disorder was observed in the multilayer. The thermal annealing of the TIPS-Pc/Au(111) interface reveals the ligand desorption at ∼470 K, which leaves the backbone of the decomposed molecule flat-lying on the metal surface as in the case of the unmodified pentacene. The weak interaction with the metal substrate causes the molecular dissociation to occur 60 K below the thermal decomposition taking place in thick drop-cast films.
Original languageEnglish (US)
Pages (from-to)22522-22532
Number of pages11
JournalThe Journal of Physical Chemistry C
Issue number39
StatePublished - Sep 19 2014

Bibliographical note

KAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The authors dedicate this paper to the memory of Gianluca Latini, who had initiated this project with passion and enthusiasm. The support of the SuperESCA and CiPo beamline staffs of Elettra is deeply acknowledged. The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 226716.

ASJC Scopus subject areas

  • Surfaces, Coatings and Films
  • General Energy
  • Physical and Theoretical Chemistry
  • Electronic, Optical and Magnetic Materials


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