First principles insight on the stability and multiple properties of the Nb₂CS₂ MXene/MS₂ (M=W, Mo, Ta) heterojunction structure

In the present study, the structural stability, mechanical, thermal physical, and electronic properties of the Nb₂CS₂/MS₂ (M=Mo, W, Ta) vdW heterojunctions with three stacking modes were investigated by first principles calculations. We evaluated the structural stability with energetic, mechanical, and dynamical criteria. The thermal physical properties of the stable heterojunctions were obtained with the calculated phonon spectrums. Compared with the elastic properties of the single layers, the moduli of the heterojunctions are greater. The projected band structures show metallic character, while the Fermi energy level is mainly contributed by Nb. The ELF maps of the interfaces indicate that there only exists vdW interaction, and the asymmetric ELF could also be observed.