Substrate interactions with suspended and supported monolayer MoS2: Angle-resolved photoemission spectroscopy

We report the directly measured electronic structure of exfoliated monolayer molybdenum disulfide (MoS2) using micrometer-scale angle-resolved photoemission spectroscopy. Measurements of both suspended and supported monolayer MoS2 elucidate the effects of interaction with a substrate. A suggested relaxation of the in-plane lattice constant is found for both suspended and supported monolayer MoS2 crystals. For suspended MoS2, a careful investigation of the measured uppermost valence band gives an effective mass at (Gamma) over bar and (K) over bar of 2.00m(0) and 0.43m(0), respectively. We also measure an increase in the band linewidth from the midpoint of (Gamma K) over bar to the vicinity of (K) over bar and briefly discuss its possible origin.