An anisotropic van der Waals dielectric for symmetry engineering in functionalized heterointerfaces.

ABSTRACT: Van der Waals dielectrics are fundamental materials for condensed matter physics and advanced electronic applications. Most dielectrics host isotropic structures in crystalline or amorphous forms, and only a few studies have considered the role of anisotropic crystal symmetry in dielectrics as a delicate way to tune electronic properties of channel materials. Here, we demonstrate a layered anisotropic dielectric, SiP₂, with non-symmorphic twofold-rotational C₂ symmetry as a gate medium which can break the original threefold-rotational C₃ symmetry of MoS₂ to achieve unexpected linearly-polarized photoluminescence and anisotropic second harmonic generation at SiP₂/MoS₂ interfaces. In contrast to the isotropic behavior of pristine MoS₂, a large conductance anisotropy with an anisotropy index up to 1000 can be achieved and modulated in SiP₂-gated MoS₂ transistors. Theoretical calculations reveal that the anisotropic moiré potential at such interfaces is responsible for the giant anisotropic conductance and optical response. Our results provide a strategy for generating exotic functionalities at dielectric/semiconductor interfaces via symmetry engineering.

SUBMITTER: Li Z 

PROVIDER: S-EPMC10492835 | biostudies-literature | 2023 Sep

REPOSITORIES: biostudies-literature