Domain-dependent strain and stacking in two-dimensional van der Waals ferroelectrics. Academic Article uri icon

abstract

  • Van der Waals (vdW) ferroelectrics have attracted significant attention for their potential in next-generation nano-electronics. Two-dimensional (2D) group-IV monochalcogenides have emerged as a promising candidate due to their strong room temperature in-plane polarization down to a monolayer limit. However, their polarization is strongly coupled with the lattice strain and stacking orders, which impact their electronic properties. Here, we utilize four-dimensional scanning transmission electron microscopy (4D-STEM) to simultaneously probe the in-plane strain and out-of-plane stacking in vdW SnSe. Specifically, we observe large lattice strain up to 4% with a gradient across ~50nm to compensate lattice mismatch at domain walls, mitigating defects initiation. Additionally, we discover the unusual ferroelectric-to-antiferroelectric domain walls stabilized by vdW force and may lead to anisotropic nonlinear optical responses. Our findings provide a comprehensive understanding of in-plane and out-of-plane structures affecting domain properties in vdW SnSe, laying the foundation for domain wall engineering in vdW ferroelectrics.

published proceedings

  • Nat Commun

altmetric score

  • 68.25

author list (cited authors)

  • Shi, C., Mao, N., Zhang, K., Zhang, T., Chiu, M., Ashen, K., ... Han, Y.

citation count

  • 1

complete list of authors

  • Shi, Chuqiao||Mao, Nannan||Zhang, Kena||Zhang, Tianyi||Chiu, Ming-Hui||Ashen, Kenna||Wang, Bo||Tang, Xiuyu||Guo, Galio||Lei, Shiming||Chen, Longqing||Cao, Ye||Qian, Xiaofeng||Kong, Jing||Han, Yimo

publication date

  • November 2023