Core level excitations--a fingerprint of structural and electronic properties of epitaxial silicene

• Published in: The Journal of chemical physics 2014-05, Vol.140 (18), p.184704-184704
• Main Authors: Friedlein, R, Fleurence, A, Aoyagi, K, de Jong, M P, Van Bui, H, Wiggers, F B, Yoshimoto, S, Koitaya, T, Shimizu, S, Noritake, H, Mukai, K, Yoshinobu, J, Yamada-Takamura, Y
• Format: Article
• Language: English
• Subjects: ABSORPTION; ABSORPTION SPECTROSCOPY; BINDING ENERGY; Domains; Electronic properties; ELECTRONS; EPITAXY; EXCITATION; FINE STRUCTURE; INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; Organic chemistry; Physics; SCANNING TUNNELING MICROSCOPY; Silicene; SILICON; SPECTRA; THIN FILMS; X RADIATION; X ray absorption; X ray spectra; X-RAY SPECTROSCOPY; ZIRCONIUM BORIDES
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.4875075

From the analysis of high-resolution Si 2p photoelectron and near-edge x-ray absorption fine structure (NEXAFS) spectra, we show that core level excitations of epitaxial silicene on ZrB2(0001) thin films are characteristically different from those of sp(3)-hybridized silicon. In particular, it is revealed that the lower Si 2p binding energies and the low onset in the NEXAFS spectra as well as the occurrence of satellite features in the core level spectra are attributed to the screening by low-energy valence electrons and interband transitions between π bands, respectively. The analysis of observed Si 2p intensities related to chemically distinct Si atoms indicates the presence of at least one previously unidentified component. The presence of this component suggests that the observation of stress-related stripe domains in scanning tunnelling microscopy images is intrinsically linked to the relaxation of Si atoms away from energetically unfavourable positions.