Hybrid density functional theory calculations are performed for the first time to compare the stability, structural and electronic properties of monolayers and single-wall nanotubes based on pure Mo(W)S(Se)2 and mixed (Janus) Mo(W)SSe dichalcogenides. The stability, structural and electronic properties of Mo and W dichalcogenide nanotubes have been compared at different wall compositions, chiralities and diameters using the same calculation scheme. Different types of mixed nanotubes are considered – with S or Se atoms on the outer (inner) shell of the nanotube. It was found that nanotubes Se(out)WS(in) with average diameter (Davr) greater than ≈40 Å have the negative strain energy. Our calculations show that the band gap is direct for zigzag MS2 and S(out)MSe(in) nanotubes (M = Mo, W) but it becomes indirect in armchair nanotubes. For the MSe2 and Se(out)MS(in) nanotubes of both chiralities, the band gap is mostly direct, except the armchair tubes with Davr < 18 Å and zigzag tubes with Davr in interval from 18 to 26 Å where it is indirect.
|Journal||Physica E: Low-Dimensional Systems and Nanostructures|
|Early online date||9 Aug 2019|
|Publication status||Published - Jan 2020|
Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics