Ab initio simulation studies on the room-temperature ferroelectricity in two-dimensional β -phase GeS

Abstract

Stable ferroelectricity with an in-plane spontaneous polarization of 2.00 × 10−10 C/m is found in two-dimensional (2D) β-GeS monolayers from theoretical calculations, which can be effectively tuned by the applied tensile strains. The Curie temperature of the monolayer is evaluated to be 358 K by ab initio molecular dynamics simulations. Remarkably, the 2D ferroelectricity is found to exist in 2D few-layer β-GeS nanosheets which could be synthesized in experiments. The strong spontaneous polarization and giant pyroelectric coefficient accompanied by the appearance of phase transition near room temperature facilitate the development of β-GeS monolayers or nanosheets for applications in ferroelectric, pyroelectric, and piezoelectric devices with superior performance.

Two dimensional ferroelectrics: Candidate for controllable physical and chemical applications

“…The successful synthesis and direct demonstration of ferroelectricity in the atomic thick SnTe relived the research enthusiasm of real 2D ferroelectrics. Subsequently, the similar in‐plane ferroelectricity was reported in the family IV monochalcogenides MX (M = Ge, Sn; X = S, Se) monolayers 22,29,47 and similar structures like γ ‐SbX (X = As, P) 48 and β‐GeS 49 monolayers due to the broken structural symmetry along xy ‐plane, where the spontaneous polarization is predicted to be 3.8 × 10 −10 C/m and 2 × 10 −10 C/m, respectively. As seen from Figure 2a–c, these in‐plane ferroelectric materials share the similar structure characteristic, the relative displacements between negative and positive charged atoms are the underlying mechanism of ferroelectric switch, they are therefore generally robust and possess high Curie temperatures.…”

Controlling bimerons as skyrmion analogues by ferroelectric polarization in 2D van der Waals multiferroic heterostructures

“…Since the discovery of graphene, extensive research on twodimensional ferromagnetic (FM) [19][20][21][22][23][24][25] and FE [26][27][28][29][30][31][32] materials has been carried out rapidly. The magnetic anisotropy in 2D materials induced by spin-orbit coupling enables the long-range magnetic ordering, forming easy-axis or easy-plane 2D magnets.…”

Multidirectional Intrinsic Piezoelectricity of 2D Metal Chalcogen–Diphosphate ABP2X6 Monolayers

“…Reduction in the dimensionality of materials may eliminate the symmetric centers and break the inversion symmetry, [ 1–5 ] resulting in piezoelectricity of 2D monolayers, where the mechanical energy is converted into electrical energy and vice versa. Recently, the functional application of 2D piezoelectric materials has been exploited in the field of sensors, [ 6,7 ] actuators, [ 8,9 ] and energy harvesters.…”