Ferroelectric Properties of van der Waals Chalcogenides: DFT perspective

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