Electrostatic shielding effects and binding energy shifts and topological phases of bilayer molybdenum chalcogenides

By combining binding energy and bond-charge (BBC) model and density functional theory (DFT) calculations, the electrostatic shielding effects and binding energy shifts of bilayer MoS2, MoSe2, and MoTe2 are studied. In this study, the bilayer MoS2, MoSe2, and MoTe2 had bandgaps of 1.38, 1.28, and 1.01 eV, respectively. It is found that electrostatic shielding by electron exchange is the main cause of density fluctuation and determine the bonding state. We found that the edge polarization exactly vanishes after the bulk phase transition, just as we saw the corner-localized modes disappear in a system with full open boundaries of bilayer MoTe2. Finally, this study establishes a method for calculating the lattice density with Green's function with energy level shift and provides new methods and ideas for the further study of the electrostatic shielding, bond states and topological phases of nanomaterials. This study establishes a method for calculating the lattice density with Green's function with energy level shift and provides new methods and ideas for the further study of the electrostatic shielding, bond states and topological phases of nanomaterials. image