Quasiparticle band-edge energy and band offsets of monolayer of molybdenum and tungsten chalcogenide

摘要

We report the quasiparticle energy of monolayer of molybdenum and tungstendichalcogenides, MX2 (M=Mo, W; X=S, Se, Te). Beyond calculating bandgaps, wehave achieved converged absolute band energies relative to the vacuum level.Compared with the results from other approaches, the GW calculation revealssubstantially larger bandgaps and different absolute band energies because ofenhanced many-electron effects. Interestingly, our fully-convergedquasiparticle energies ratify the band-gap-center approximation, making it aconvenient way to estimate quasiparticle energy. The absolute quasiparticleenergies and band offsets obtained in this work are important for designingheterojunction devices and chemical catalysts based on monolayerdichalcogenides.