Versatile Physical Properties of a Novel Two-Dimensional Materials Composed of Group IV-V Elements

TL;DR

This study introduces a new class of 2D materials composed of group IV and V elements, demonstrating their stability and diverse physical properties, including electrical, thermal, and topological features, based on first-principles calculations.

Contribution

The paper proposes a novel family of 2D materials with specific compositions and stable phases, expanding the landscape of 2D materials with diverse physical properties.

Findings

40 stable A₂B₂ compounds identified

Materials exhibit insulating, semiconducting, or metallic behavior

Some compounds show non-trivial topological properties

Abstract

Owing to the fascinating physical characteristics of two-dimensional (2D) materials and their heterostructure, much effort has been devoted to exploring their basic physical properties as well as discovering other novel 2D materials. Herein, based on first-principles calculations, we propose novel 2D material groups with the form A$_2$B$_2$, composed of group IV (A = C, Si, Ge, or Sn) and V (B = N, P, As, Sb, or Bi) elements; the group forms two stable phases with the $P\bar{6}m2$ ($\mathcal{M}$ phase) and $P\bar{3}m1$ ($\mathcal{I}$ phase) crystal symmetries. We found that a total of 40 different freestanding A$_2$B$_2$ compounds were dynamically stable and displayed versatile physical properties, such as insulating, semiconducting, or metallic properties, depending on their elemental compositions. Our calculation results further revealed that the newly proposed 2D materials expressed high electrical and thermal transport properties. Additionally, some of the compounds that contained heavy elements exhibited non-trivial topological properties due to strong spin-orbit interactions.