Indirect-direct bandgap transition and gap width tuning in bilayer MoS2 superlattices

- The indirect-direct bandgap transition can be realized in bilayer MoS2 superlattices.
- Interlayer interaction affects the p orbital valence band of sulfur atom at Г point.
- The bottom of conduction band could be folded from K to Г points.
- The in-plane stretching can tune gap width by affecting the intralayer interaction.
- Reducing layer interval can tune gap width by affecting the interlayer interaction.