# Promising Ferroelectricity in 2D Group IV Tellurides: a First-Principles Study

## TL;DR

This study uses first-principles calculations to explore ferroelectric properties of 2D Group-IV tellurides, especially GeTe, revealing high Curie temperature, strain tunability, and potential for integrated ferroelectric devices.

## Contribution

It provides the first detailed theoretical analysis of ferroelectricity in 2D Group-IV tellurides, highlighting GeTe's high Curie temperature and strain effects.

## Key findings

- Monolayer GeTe has a Curie temperature of 570 K.
- Tensile strain can increase Tc rapidly.
- Bilayer GeTe maintains ferroelectric ground state.

## Abstract

Based on the first-principles calculations, we investigated the ferroelectric properties of two-dimensional (2D) Group-IV tellurides XTe (X=Si, Ge and Sn), with a focus on GeTe. 2D Group-IV tellurides energetically prefer an orthorhombic phase with a hinge-like structure and an in-plane spontaneous polarization. The intrinsic Curie temperature Tc of monolayer GeTe is as high as 570 K and can be raised quickly by applying a tensile strain. An out-of-plane electric field can effectively decrease the coercive field for the reversal of polarization, extending its potential for regulating the polarization switching kinetics. Moreover, for bilayer GeTe the ferroelectric phase is still the ground state. Combined with these advantages, 2D GeTe is a promising candidate material for practical integrated ferroelectric applications.