Atomic-Scale Visualization and Manipulation of Domain boundaries in 2D Ferroelectric In2Se3

TL;DR

This study visualizes and manipulates atomic-scale domain boundaries in 2D ferroelectric In2Se3, revealing their structure and controllability, which advances understanding and potential nanoelectronic applications.

Contribution

The paper provides the first atomic-scale visualization of domain boundaries in 2D ferroelectric In2Se3 and demonstrates precise manipulation using STM, revealing new insights into their structure and dynamics.

Findings

Atomic structure of domain boundaries visualized at monolayer level.

Double-barrier energy potential identified at 60° tail-to-tail boundaries.

Domain boundaries manipulated with atomic precision using STM and electric fields.

Abstract

Domain boundaries in ferroelectric materials exhibit rich and diverse physical properties distinct from their parent materials and have been proposed for novel applications in nanoelectronics and quantum information technology. Due to their complexity and diversity, the internal atomic and electronic structure of domain boundaries that governs the electronic properties as well as the kinetics of domain switching remains far from being elucidated. By using scanning tunneling microscopy and spectroscopy (STM/S) combined with density functional theory (DFT) calculations, we directly visualize the atomic structure of domain boundaries in two-dimensional (2D) ferroelectric beta' In2Se3 down to the monolayer limit and reveal a double-barrier energy potential of the 60{\deg} tail to tail domain boundaries for the first time. We further controllably manipulate the domain boundaries with atomic precision by STM and show that the movements of domain boundaries can be driven by the electric field from an STM tip and proceed by the collective shifting of atoms at the domain boundaries. The results will deepen our understanding of domain boundaries in 2D ferroelectric materials and stimulate innovative applications of these materials.