Exploring novel CrSSe-N2CO2 (N = Ti, Zr, Hf) van der Waals heterostructures for multifunctional optoelectronic and thermoelectric applications

Abstract

Due to their tunable bandgaps and excellent exciton activity, van der Waals heterostructures are ideal for optical applications and provide design flexibility for thermoelectric applications. A comprehensive investigation of the structural, electronic, optical, and thermoelectric properties of novel CrSSe-N₂CO₂ (N = Ti, Zr, Hf) van der Waals (vdW) heterostructures was carried out in the present work. The generalized gradient approximations (GGA) were employed within the framework of density functional theory. The optimized lattice constants revealed a small lattice discrepancy of approximately 1 % which is consistent with previously available experimental and theoretical data. Six distinct stacking patterns were considered to control monolayer orientation and the atomic positions were optimized to determine the most thermally stable configurations at 300 K using ab initio molecular dynamics (AIMD) which confirms that these vdW heterostructures can be synthesized experimentally. The electronic properties, particularly the band structures, revealed direct and indirect band gaps between 0.1 and 1.2 eV. The current study serves as a foundation for developing these vdW heterostructures specifically CrSSe-Hf₂CO₂, which was found dynamically, and thermally stable with desired properties for future technological applications.