1. Emergence of Layer Stacking Disorder in c-axis Confined MoTe$_2$
- Author
-
Hart, James L, Bhatt, Lopa, Zhu, Yanbing, Han, Myung-Geun, Bianco, Elisabeth, Li, Shunran, Hynek, David J, Schneeloch, John A, Tao, Yu, Louca, Despina, Guo, Peijun, Zhu, Yimei, Jornada, Felipe, Reed, Evan J, Kourkoutis, Lena F, and Cha, Judy J
- Subjects
Condensed Matter - Materials Science ,Condensed Matter - Mesoscale and Nanoscale Physics ,Mesoscale and Nanoscale Physics (cond-mat.mes-hall) ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences - Abstract
The layer stacking order in 2D materials strongly affects functional properties and holds promise for next generation electronic devices. In bulk, octahedral MoTe$_2$ possesses two stacking arrangements, the Weyl semimetal T$_d$ phase, and the higher-order topological insulator 1T' phase; however, it remains unclear if thin exfoliated flakes of MoTe$_2$ follow the T$_d$, 1T', or an alternative stacking sequence. Here, we resolve this debate using atomic-resolution imaging within the transmission electron microscope. We find that the layer stacking in thin flakes of MoTe$_2$ is highly disordered and pseudo-random, which we attribute to intrinsic confinement effects. Conversely, WTe$_2$, which is isostructural and isoelectronic to MoTe$_2$, displays ordered stacking even for thin exfoliated flakes. Our results are important for understanding the quantum properties of MoTe$_2$ devices, and suggest that thickness may be used to alter the layer stacking in other 2D materials., Comment: 6 figures, 2 tables
- Published
- 2022
- Full Text
- View/download PDF