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Title: Encapsulated silicene: A robust large-gap topological insulator

The quantum spin Hall (QSH) effect predicted in silicene has raised exciting prospects of new device applications compatible with current microelectronic technology. Efforts to explore this novel phenomenon, however, have been impeded by fundamental challenges imposed by silicene’s small topologically nontrivial band gap and fragile electronic properties susceptible to environmental degradation effects. Here we propose a strategy to circumvent these challenges by encapsulating silicene between transition-metal dichalcogenides (TMDCs) layers. First-principles calculations show that such encapsulated silicene exhibit a two-orders-of-magnitude enhancement in its nontrivial band gap, which is driven by the strong spin–orbit coupling effect in TMDCs via the proximity effect. Moreover, the cladding TMDCs layers also shield silicene from environmental gases that are detrimental to the QSH state in free-standing silicene. In conclusion, the encapsulated silicene represents a novel two-dimensional topological insulator with a robust nontrivial band gap suitable for room-temperature applications, which has significant implications for innovative QSH device design and fabrication.
Authors:
 [1] ;  [2] ;  [3] ;  [1] ;  [4] ;  [1]
  1. Univ. of New South Wales, Sydney, NSW (Australia)
  2. Jacobs Univ. Bremen, Bremen (Germany)
  3. Max Planck Institute for Chemical Physics of Solids, Dresden (Germany)
  4. Univ. of Nevada, Las Vegas, NV (United States)
Publication Date:
Grant/Contract Number:
NA0001982
Type:
Accepted Manuscript
Journal Name:
ACS Applied Materials and Interfaces
Additional Journal Information:
Journal Volume: 7; Journal Issue: 34; Journal ID: ISSN 1944-8244
Publisher:
American Chemical Society
Research Org:
Univ. of Nevada, Las Vegas, NV (United States)
Sponsoring Org:
USDOE National Nuclear Security Administration (NNSA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE
OSTI Identifier:
1332446