Emergent layer stacking arrangements in c-axis confined MoTe2

Journal article

The layer stacking order in 2D materials strongly affects functional properties and holds promise for next-generation electronic devices. In bulk, octahedral MoTe₂ possesses two stacking arrangements, the ferroelectric Weyl semimetal T_d phase and the higher-order topological insulator 1T' phase. However, in thin flakes of MoTe₂, it is unclear if the layer stacking follows the T_d, 1T', or an alternative stacking sequence. Here, we use atomic-resolution scanning transmission electron microscopy to directly visualize the MoTe₂ layer stacking. In thin flakes, we observe highly disordered stacking, with nanoscale 1T' and T_d domains, as well as alternative stacking arrangements not found in the bulk. We attribute these findings to intrinsic confinement effects on the MoTe₂ stacking-dependent free energy. Our results are important for the understanding of exotic physics displayed in MoTe₂ flakes. More broadly, this work suggests c-axis confinement as a method to influence layer stacking in other 2D materials.

Authors: Hart, JL; Bhatt, L; Han, M-G; Bianco, E; Li, S

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Nature Research
• Journal: Nature Communications
• Volume: 14
• Issue: 1
• Pages: 4803-4803
• Publication date: 2023-08-09
• DOI: 10.1038/s41467-023-40528-y
• EISSN: 2041-1723
• ISSN: 2041-1723
• Language: English
• Keywords: Crystallography; Layer (electronics); Transmission electron microscopy; Physics; Scanning transmission electron microscopy; Stacking; Nuclear magnetic resonance; Thin film; Nanoscopic scale; Chemistry; Nanotechnology; Chemical physics; High-resolution transmission electron microscopy; Condensed matter physics; Materials science