Adsorption of S on Si(111) with M-4 x 4 superstructure

TAYRAN C., ÇAKMAK M., Srivastava G. P.

SURFACE SCIENCE, cilt.701, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 701
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.susc.2020.121694
  • Dergi Adı: SURFACE SCIENCE
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, PASCAL, Aerospace Database, Chimica, Communication Abstracts, Compendex, INSPEC, Metadex, Civil Engineering Abstracts
  • Gazi Üniversitesi Adresli: Evet

Özet

The atomic and electronic structures are calculated for the M-4 x 4 superstructure of S/Si(111), which was recently identified by Schmidt et al. [Surf. Sci.694 (2020) 121561] by using the spot profile analysis low-energy electron diffraction (SPALEED) and confirmed by scanning tunneling microscopy (STM). The electronic band structures are found to be semiconducting in nature for three different S structures: monomer, Dimer-A and Dimer-B, each of which saturates all the Si dangling bonds. Due to the varying numbers of S atoms per unit cell, we have calculated the lowest energy phase in the accessible S chemical potential range. Dimer-A and Dimer-B are the lower energy phase and their accessible chemical potential value is less than the monomer case, in excellent agreement with the results of Schmidt et al. Dimer-B is slightly more stable geometry than Dimer-A. Application of the nudged elastic band (NEB) method suggests that there is a rotational activation barrier of 40 meV along the Dimer-A-Dimer-B reaction path.