Quasiparticle band structure calculation of monolayer, bilayer, and bulk MoS 2

Quasiparticle self-consistent $GW$ calculations of the band structures and related effective-mass parameters are carried out for bulk, monolayer, and bilayer MoS${}_{2}$. Including excitonic effects within the Mott-Wannier theory, quantitative agreement is obtained between the $A$, $B$ excitons, measured by absorption [Phys. Rev. Lett. 105, 136805 (2010)], and the calculated exciton gap energies at $K$. The $A$-$B$ splitting arises from the valence-band splitting which in the monolayer is entirely due to spin-orbit coupling and leads to spin-split states, while in the bilayer it is a combined effect of interlayer and spin-orbit coupling.

• NS
  National Science Foundation
• CW
  Case Western Reserve University
• DO
  Division of Materials Research