相关论文: Giant piezoelectricity in group IV monochalcogenid…
We predict enormous piezoelectric effects in intrinsic monolayer group IV monochalcogenides (MX, M=Sn or Ge, X=Se or S), including SnSe, SnS, GeSe and GeS. Using first-principle simulations based on the modern theory of polarization, we…
We use first principles calculations to investigate the lattice properties of group-IV monochalcogenides. These include static dielectric permittivity, elastic and piezoelectric tensors. For the monolayer, it is found that the static…
We find that several layer-phase group-III monochalcogenides, including GaS, GaSe and InSe, are piezoelectric in the monolayer form. First-principles calculations reveal that the piezoelectric coefficients of monolayer GaS, GaSe and InSe…
Ferroelectricity usually fades away when materials are thinned down below a critical value. Employing the first-principles density functional theory and modern theory of polarization, we show that the unique ionic-potential anharmonicity…
Monolayer group-IV monochalcogenides (MX, M = Ge, Sn, Pb; X = S, Se, Te) are a family of novel two-dimensional (2D) materials that have atomic structures closely related to that of the staggered black phosphorus lattice. The structure of…
2D Ferroelectric materials are promising for designing low-dimensional memory devices. Here, we explore strain tunable ferroelectric properties of group-IV monochalcogenides MX (M=Ge, Sn; X=S, Se) and their potential application in lateral…
Two-dimensional heterostructure of WSe2/MoS2 atomic layers has unique piezoelectric characteristics which depends on the number of atomic layer, stacking type, and interlayer interaction size. The van der Waals heterostructure of p- and…
Two-dimensional materials with ferroelectric properties break the size effect of conventional ferroelectric materials and unlock unprecedented potentials of ferroelectric-related application at small length scales. In this work, using…
Two-dimensional materials that exhibit spontaneous electric polarization are of notable interest for functional materials. However, despite many two-dimensional polar materials are predicted in theory, the number of experimentally confirmed…
Lead and tin chalcogenides have been studied widely due to their promising thermoelectric (TE) properties. Further enhancement in their TE efficiency has been reported upon the reduction of the dimension, which is an important feature in…
Photostriction is predicted for SnS and SnSe monolayers, two-dimensional ferroelectrics with rectangular unit cells (the lattice vector $\mathbf{a}_1$ is larger than $\mathbf{a}_2$) and an intrinsic dipole moment parallel to $\mathbf{a}_1$.…
Van der Waals (vdW) materials have greatly expanded our design space of heterostructures by allowing individual layers to be stacked at non-equilibrium configurations, for example via control of the twist angle. Such heterostructures not…
Ferroelectricity (Valasek, J. Phys. Rev. 1921, 17, 475) - a spontaneous formation of electric polarisation - is a solid state phenomenon, usually, associated with ionic compounds or complex materials. Here we show that, atypically for…
Ferroelectricity is usually found in compound materials composed by different elements. Here, based on first-principles calculations, we reveal the first example of spontaneous electrical polarization and ferroelectricity in stable…
We present a comprehensive first-principles study of hydrogenated M2X (M = Mo, V, Zr; X = C, N) MXene monolayers, focusing on their structural stability, electronic properties, and superconducting behavior. Structural optimizations combined…
Charge-order-driven ferroelectrics are an emerging class of functional materials, distinct from conventional ferroelectrics, where electron-dominated switching can occur at high frequency. Despite their promise, only a few systems…
We survey the state-of-the-art knowledge of ferroelectric and ferroelastic group-IV monochalcogenide monolayers. These semiconductors feature remarkable structural and mechanical properties, such as a switchable in-plane spontaneous…
Low-dimensional ferroelectricity and polar materials have attracted considerable attentions for their fascinating physics and potential applications. Based on first-principles calculations, here we investigate the stacking modes and polar…
Recent studies have reported emergent ferroelectric behavior in twisted or moir\'e-engineered graphene-based van der Waals heterostructures, yet the microscopic origin of this effect remains under debate. Pristine mono- or few-layer…
The stability of high-symmetry $P4mm$ polar phase in eleven ferroelectric perovskite superlattices with the polar discontinuity is studied from first principles. In most superlattices, this phase exhibits either the ferroelectric or the…