Ferroelectric properties of van der Waals chalcogenides: a density functional theory perspective

Layered materials with the noncentrosymmetric stacking order are attracting increasing interest due to the presence of ferroelectric polarization, which is dictated by weak interlayer hybridization of atomic orbitals. In this study, we use the density functional theory modeling to systematically build a library of van der Waals chalcogenides that exhibit substantial ferroelectric polarization. For the most promising materials, we also analyze the pressure dependence of the ferroelectric effect and charge accumulation of photo-induced electrons and holes on surfaces and at internal twin boundaries in thin films of such materials.