Growth of bilayer MoTe<sub>2</sub> single crystals with strong non-linear Hall effect.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36115861.
- Also identified by DOI 10.1038/s41467-022-33201-3 and PMC identifier 9482631.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The reduced symmetry in strong spin-orbit coupling materials such as transition metal ditellurides (TMDTs) gives rise to non-trivial topology, unique spin texture, and large charge-to-spin conversion efficiencies. Bilayer TMDTs are non-centrosymmetric and have unique topological properties compared to monolayer or trilayer, but a controllable way to prepare bilayer MoTe<sub>2</sub> crystal has not been achieved to date. Herein, we achieve the layer-by-layer growth of large-area bilayer and trilayer 1T' MoTe<sub>2</sub> single crystals and centimetre-scale films by a two-stage chemical vapor deposition process. The as-grown bilayer MoTe<sub>2</sub> shows out-of-plane ferroelectric polarization, whereas the monolayer and trilayer crystals are non-polar. In addition, we observed large in-plane nonlinear Hall (NLH) effect for the bilayer and trilayer T<sub>d</sub> phase MoTe<sub>2</sub> under time reversal-symmetric conditions, while these vanish for thicker layers. For a fixed input current, bilayer T<sub>d</sub> MoTe<sub>2</sub> produces the largest second harmonic output voltage among the thicker crystals tested. Our work therefore highlights the importance of thickness-dependent Berry curvature effects in TMDTs that are underscored by the ability to grow thickness-precise layers.