Two-dimensional ferroelectrics, with unique electronic and geometric structures, provide a solution to the size effect in miniaturizing and integrating ferroelectric components, emerging as a prominent research focus within functional materials. However, most investigations primarily concentrate on the ferroelectric properties of specific structures, disregarding the mechanisms linking these properties to the physicochemical attributes of constituent elements. This work aims to manipulate and regulate ferroelectric performance through leveraging the disparities in physicochemical characteristics of elements. To achieve this, a comprehensive investigation is conducted on group-III monochalcogenide monolayers (MX, M = B, Ga, In; X = O, S, Se, Te) using first-principles calculations. The stabilities, ferroelectric properties, electronic properties and polarization switching pathways are systematically analyzed. The findings demonstrate that these monolayers can exist stably with significant in-plane polarization intensity ranging from 5.78~8.85 (10^-10 C/m). The potential mechanisms governing ferroelectric properties are further explored in terms of electronic structures. Moreover, polarization switching prefers layer-by-layer migration of group-VI atoms over simultaneous bilayer migration. Further analysis demonstrates a strong positive correlation between elemental physicochemical properties and polarization intensity, enabling the identification of a reliable descriptor for polarization intensity. This work validates the reliability of selecting elements from groups III and VI with significant electronegativity differences to form MX compounds with high polarization intensity.

中文翻译：

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III 类单硫属化物单层中可控的铁电性和独特的逐层迁移行为

二维铁电体具有独特的电子和几何结构，为铁电元件的小型化和集成化提供了尺寸效应的解决方案，成为功能材料中的重要研究重点。然而，大多数研究主要集中在特定结构的铁电性质上，而忽略了将这些性质与组成元素的物理化学属性联系起来的机制。这项工作旨在通过利用元素物理化学特性的差异来纵和调节铁电性能。为了实现这一目标，对 III 族单硫属化物单层 （MX， M = B， Ga， In;X = O， S， Se， Te） 使用第一性原理计算。系统分析了稳定性、铁电性质、电子性质和极化开关路径。结果表明，这些单层可以稳定存在，具有显著的面内极化强度，范围为 5.78~8.85 （10 ^-10  C/m）。从电子结构的角度进一步探讨了控制铁电性能的潜在机制。此外，偏振切换更喜欢 VI 族原子的逐层迁移，而不是同时进行双层迁移。进一步的分析表明，元素物理化学性质和极化强度之间存在很强的正相关关系，从而能够确定极化强度的可靠描述符。这项工作验证了从具有显着电负性差异的 III 组和 VI 组中选择元素形成具有高极化强度的 MX 化合物的可靠性。