Photonics / Fotonik

Permanent URI for this collectionhttps://hdl.handle.net/11147/2590

Browse

Filters

2016 - 20172

Settings

Author: search.filters.author.Bacaksız, CihanSubject: search.filters.subject.Monolayers

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 31
    Citation - Scopus: 31
    Hydrogen-Induced Structural Transition in Single Layer Res2
    (IOP Publishing Ltd., 2017) Yağmurcukardeş, Mehmet; Bacaksız, Cihan; Senger, Ramazan Tuğrul; Şahin, Hasan
    By performing density functional theory-based calculations, we investigate how structural, electronic and mechanical properties of single layer ReS2 can be tuned upon hydrogenation of its surfaces. It is found that a stable, fully hydrogenated structure can be obtained by formation of strong S-H bonds. The optimized atomic structure of ReS2H2 is considerably different than that of the monolayer ReS2 which has a distorted-1T phase. By performing phonon dispersion calculations, we also predict that the Re2-dimerized 1T structure (called 1TRe2) of the ReS2H2 is dynamically stable. Unlike the bare ReS2 the 1TRe2–ReS2H2 structure which is formed by breaking the Re4 clusters into separated Re2 dimers, is an indirect-gap semiconductor. Furthermore, mechanical properties of the 1TRe2 phase in terms of elastic constants, in-plane stiffness (C) and Poisson ratio (ν) are investigated. It is found that full hydrogenation not only enhances the flexibility of the single layer ReS2 crystal but also increases anisotropy of the elastic constants
  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    Structural Changes in a Schiff Base Molecular Assembly Initiated by Scanning Tunneling Microscopy Tip
    (IOP Publishing Ltd., 2016) Tomak, Aysel; Bacaksız, Cihan; Mendirek, Gizem; Şahin, Hasan; Hür, Deniz; Görgün, Kamuran; Senger, Ramazan Tuğrul; Birer, Özgür; Peeters, François M.; Zareie, Hadi M.
    We report the controlled self-organization and switching of newly designed Schiff base (E)-4-((4-(phenylethynyl) benzylidene) amino) benzenethiol (EPBB) molecules on a Au (111) surface at room temperature. Scanning tunneling microscopy and spectroscopy (STM/STS) were used to image and analyze the conformational changes of the EPBB molecules. The conformational change of the molecules was induced by using the STM tip while increasing the tunneling current. The switching of a domain or island of molecules was shown to be induced by the STM tip during scanning. Unambiguous fingerprints of the switching mechanism were observed via STM/STS measurements. Surface-enhanced Raman scattering was employed, to control and identify quantitatively the switching mechanism of molecules in a monolayer. Density functional theory calculations were also performed in order to understand the microscopic details of the switching mechanism. These calculations revealed that the molecular switching behavior stemmed from the strong interaction of the EPBB molecules with the STM tip. Our approach to controlling intermolecular mechanics provides a path towards the bottom-up assembly of more sophisticated molecular machines.