Symmetry-Engineering-Induced In-Plane Polarization Enhancement in Ta2NiS5/CrOCl van der Waals Heterostructure

Yue Su; Peng Chen; Xiangrui Xu; Yufeng Zhang; Weiwei Cai; Gang Peng; Xueao Zhang; Chuyun Deng

doi:10.3390/nano13233050

Symmetry-Engineering-Induced In-Plane Polarization Enhancement in Ta₂NiS₅/CrOCl van der Waals Heterostructure

Nanomaterials (Basel). 2023 Nov 29;13(23):3050. doi: 10.3390/nano13233050.

Authors

Yue Su^{1

2}, Peng Chen³, Xiangrui Xu¹, Yufeng Zhang¹, Weiwei Cai¹, Gang Peng², Xueao Zhang¹, Chuyun Deng²

Affiliations

¹ College of Physical Science and Technology, Xiamen University, Xiamen 361005, China.
² College of Science, National University of Defense Technology, Changsha 410073, China.
³ Songshan Lake Materials Laboratory, Dongguan 523808, China.

Abstract

Van der Waals (vdW) interfaces can be formed via layer stacking regardless of the lattice constant or symmetry of the individual building blocks. Herein, we constructed a vdW interface of layered Ta₂NiS₅ and CrOCl, which exhibited remarkably enhanced in-plane anisotropy via polarized Raman spectroscopy and electrical transport measurements. Compared with pristine Ta₂NiS₅, the anisotropy ratio of the Raman intensities for the B_2g, ²A_g, and ³A_g modes increased in the heterostructure. More importantly, the anisotropy ratios of conductivity and mobility in the heterostructure increased by one order of magnitude. Specifically speaking, the conductivity ratio changed from ~2.1 (Ta₂NiS₅) to ~15 (Ta₂NiS₅/CrOCl), while the mobility ratio changed from ~2.7 (Ta₂NiS₅) to ~32 (Ta₂NiS₅/CrOCl). Such prominent enhancement may be attributed to the symmetry reduction caused by lattice mismatch at the heterostructure interface and the introduction of strain into the Ta₂NiS₅. Our research provides a new perspective for enhancing artificial anisotropy physics and offers feasible guidance for future functionalized electronic devices.

Keywords: Ta2NiS5/CrOCl; angle-dependent Raman spectrum; electrical transport; enhanced anisotropy; symmetry engineering; van der Waals heterostructure.

Abstract

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