Fig. 4

Atomic structure and band structure of the bilayer MoS₂ crystals. The calculated energy band structures of a MoS₂ monolayer, b AA-stacking MoS₂ bilayer and c AB stacking MoS₂ bilayer. d The side view and e top view in ball-and-stick model as well as f top view in MITSUBISHI column model of the atomic structures for AA stacking MoS₂ bilayer; the counterpart views g, h, and i for AB stacking MoS₂ bilayer. In d, e, g, and h, the blue solid spheres represent Mo atoms and the yellow ones S atoms. In f and i, the red and blue triangles stand for the bottom and upper MoS₂ layer, respectively, where Mo atoms locate at the center of each triangle and S atoms at the apex of each triangle