Bismuth–indium two-dimensional compounds on Si(111) surface

• Published in: Surface science 2016-09, Vol.651, p.105-111
• Main Authors: Denisov, N.V., Alekseev, A.A., Utas, O.A., Azatyan, S.G., Zotov, A.V., Saranin, A.A.
• Format: Article
• Language: English
• Subjects: Annealing; Atom–solid interactions; Bismuth; Codeposition; Computer simulation; DFT calculations; Formations; Indium; Mathematical models; Scanning tunneling microscopy; Silicon
• ISSN: 0039-6028; 1879-2758
• DOI: 10.1016/j.susc.2016.03.031

Using scanning tunneling microscopy (STM) observations, it has been found that codeposition of Bi and In onto Si(111)7×7 surface, followed by 250–550°C annealing, induces formation of a set of the ordered (Bi, In)/Si(111) stable structures, including 2√3×3, 5×5, √7×√7 and 2×2. Under appropriate conditions, the structures can occupy almost the entire surface, except for 2√3×3 which is formed only locally. Scanning tunneling spectroscopy has demonstrated that the 5×5 and √7×√7 structures are semiconducting, while the 2×2 is metallic. The 5×5, √7×√7, and 2×2 structural models have been proposed on the basis of DFT calculations and comparison of simulated and experimental STM images. [Display omitted] •Formation of a set of ordered structures is detected in the (Bi, In)/Si(111) system.•The 5×5-(Bi, In), √7×√7-(Bi, In) and 2×2-(Bi, In) structures can occupy the entire surface.•Among all the structures, only the 2×2-(Bi, In) one is metallic.•Atomic models of the found (Bi, In)/Si(111) structures were proposed.