Figure 2.

Electronic band structures, along K–Γ–M in the hexagonal Brillouin zone (BZ), of bulk (solid blue curves) and monolayer (dotted red curves) (a) β-GaS, (b) ε-GaSe, and (c) ε-InSe. The zero energy is set at the valence band maximum.

Electronic band structures, along K–Γ–M in the hexagonal Brillouin zone (BZ), of bulk (solid blue curves) and monolayer (dotted red curves) (a) β-GaS, (b) ε-GaSe, and (c) ε-InSe. The zero energy is set at the valence band maximum.