Silicene’s pervasive surface alloy on Ag(111): a scaffold for two-dimensional growth

Küchle, Johannes T; Baklanov, Aleksandr; Seitsonen, Ari P; Ryan, Paul T P; Feulner, Peter; Pendem, Prashanth; Lee, Tien-Lin; Muntwiler, Matthias; Schwarz, Martin; Haag, Felix; Barth, Johannes V; Auwärter, Willi; Duncan, David A; Allegretti, Francesco

Abstract

Silicene, the two-dimensional (2D) allotrope of silicon, is a promising material for electronics. So far, the most direct synthesis strategy has been to grow it epitaxially on metal surfaces; however, the effect of the strong silicon-metal interaction on the structure and electronic properties of the metal-supported silicene is generally poorly understood. In this work, we consider the
-silicene monolayer (ML) grown on Ag(111), probably the most illustrious representative of the 2D silicon family, and show that our experimental results refute the common interpretation of this system as a simple buckled, honeycomb ML with a sharp interface to the Ag substrate. Instead, the presented analysis demonstrates the pervasive presence of a second silicon species, which we conclude to be a Si–Ag alloy stacked between the 2D silicene and the silver substrate and scaffolding the 2D silicene layer. These findings question the current structural understanding of the silicene/Ag(111) interface and may raise expectations of analogous alloy systems in the stabilization of other 2D materials grown epitaxially on metal surfaces.

Citation

Küchle, J. T., Baklanov, A., Seitsonen, A. P., Ryan, P. T. P., Feulner, P., Pendem, P., Lee, T.-L., Muntwiler, M., Schwarz, M., Haag, F., Barth, J. V., Auwärter, W., Duncan, D. A., & Allegretti, F. (2022). Silicene’s pervasive surface alloy on Ag(111): a scaffold for two-dimensional growth. 2D Materials, 9(4), Article 045021. https://doi.org/10.1088/2053-1583/ac8a01

• Journal Article Type: Article
• Acceptance Date: Sep 15, 2022
• Online Publication Date: Sep 6, 2022
• Publication Date: 2022-10
• Deposit Date: Dec 16, 2024
• Publicly Available Date: Dec 17, 2024
• Journal: 2D Materials
• Electronic ISSN: 2053-1583
• Publisher: IOP Publishing
• Peer Reviewed: Peer Reviewed
• Volume: 9
• Issue: 4
• Article Number: 045021
• DOI: https://doi.org/10.1088/2053-1583/ac8a01
• Public URL: https://nottingham-repository.worktribe.com/output/41931953
• Publisher URL: https://iopscience.iop.org/article/10.1088/2053-1583/ac8a01
• Additional Information: Article Title: Silicene’s pervasive surface alloy on Ag(111): a scaffold for two-dimensional growth; Journal Title: 2D Materials; Article Type: paper; Copyright Information: © 2022 The Author(s). Published by IOP Publishing Ltd; Date Received: 2022-06-02; Date Accepted: 2022-08-15; Online publication date: 2022-09-06