Speaker
Description
The tunability of the stacking order in van der Waals materials provides a new and powerful method to engineer their physical properties. In parallel-stacked transition metal dichalcogenides, also known as the rhombohedral stacking order, the equilibrium atomic structure is asymmetric between layers, leading to a spontaneous electrical polarization across the vdW gap. Under an external electric field, the layer configuration and its associated polarization can be switched - a phenomenon recently termed as sliding ferroelectricity. We experimentally measured the polarization strength and its spatial distribution in chemically synthesized rhombohedral MoS2. We observed that the domain size distribution follows a power-law distribution, suggesting that the shear strain occurring during the mechanical exfoliation can induce an avalanche of domain wall motion. These pre-existing domain walls were found to be crucial for the polarization switching behavior and we leveraged them to achieve a non-volatile control over the optical response of these layered semiconductors.
| Keyword-1 | 2D materials |
|---|---|
| Keyword-2 | Sliding ferroelectricity |
