Non-Hermitian bonding, electronic structure, and mass fluctuation of two-dimensional double-layer transition metal chalcogenide MX2 (M = Mo, W; X = S, Se, Te)

This study systematically investigates the electronic structure and bonding properties of two-dimensional bilayer transition metal chalcogenides MX 2 (M = Mo, W; X = S, Se, Te) using density functional theory calculations. By analyzing band gaps, deformation bond energies, and non-Hermitian bonding characteristics across various MX 2 compounds, we comprehensively examine their electronic properties and atomic bonding behavior. In the MoS₂/WSe₂ heterostructure, the 0.13e charge transfer from Mo to S causes significant fluctuations in electron mass (2.48 × 10 −30 kg for Mo), indicating a direct relationship between charge transfer and electron mass fluctuations, thereby affecting atomic bonds and electronic states; The band gap of the MoS₂/WSe₂ heterojunction is 0.933 eV, which is in sharp contrast to the homogeneous bilayer, indicating that the heterojunction exhibits significant band gap modulation compared to the homogeneous bilayer. These findings provide a theoretical foundation for advancing the application of these materials. • Used density functional theory to systematically study the electronic structure and bonding of 2D bilayer MX₂ (M = Mo, W; X = S, Se, Te). • Analyzed band gaps, deformation bond energies, and non-Hermitian bonding in MX₂ to explore their electronic and bonding behaviors. • Revealed that charge transfer strongly impacts electron mass fluctuations, with conformal geometry analysis validating mass-related effects on bonding and states. • Showed that inter-layer heterojunctions can effectively tune the band gap of bilayer MX₂, providing a theoretical basis for their applications.