Intrinsic ferroelectric switching in two-dimension $\alpha$-In$_2$Se$_3
Two-dimensional (2D) ferroelectric semiconductors present opportunities for integrating ferroelectrics into high-density ultrathin nanoelectronics. Among the few synthesized 2D ferroelectrics, $\alpha$-In$_2$Se$_3$, known for its electrically addressable vertical polarization has attracted significa...
Gespeichert in:
Hauptverfasser: | , , , , , |
---|---|
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
Online-Zugang: | Volltext bestellen |
Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
Zusammenfassung: | Two-dimensional (2D) ferroelectric semiconductors present opportunities for
integrating ferroelectrics into high-density ultrathin nanoelectronics. Among
the few synthesized 2D ferroelectrics, $\alpha$-In$_2$Se$_3$, known for its
electrically addressable vertical polarization has attracted significant
interest. However, the understanding of many fundamental characteristics of
this material, such as the existence of spontaneous in-plane polarization and
switching mechanisms, remains controversial, marked by conflicting experimental
and theoretical results. Here, our combined experimental characterizations with
piezoresponse force microscope and symmetry analysis conclusively dismiss
previous claims of in-plane ferroelectricity in $\alpha$-In$_2$Se$_3$. The
processes of vertical polarization switching in monolayer $\alpha$-In$_2$Se$_3$
are explored with deep-learning-assisted large-scale molecular dynamics
simulations, revealing atomistic mechanisms fundamentally different from those
of bulk ferroelectrics. Despite lacking in-plane effective polarization, 1D
domain walls can be moved by both out-of-plane and in-plane fields, exhibiting
unusual avalanche dynamics characterized by abrupt, intermittent moving
patterns. The propagating velocity at various temperatures, field orientations,
and strengths can be statistically described with a universal creep equation,
featuring a dynamical exponent of 2 that is distinct from all known values for
elastic interfaces moving in disordered media. This work rectifies a long-held
misunderstanding regarding the in-plane ferroelectricity of
$\alpha$-In$_2$Se$_3$, and the quantitative characterizations of domain wall
velocity will hold broad implications for both the fundamental understanding
and technological applications of 2D ferroelectrics. |
---|---|
DOI: | 10.48550/arxiv.2307.09211 |