Figure 3

Band structure determination by optical and electrical characterizations. (a) UV-vis spectrum from a MoS2 film with thickness of 20 nm. The inset shows the extraction of band gap (Eg). (b) UPS measurement for the determination of VB position in the MoS2 film. (c) Surface potentials of MoS2 and reference Au measured by scanning kelvin probe microscopy. (d) Band structure of the MoS2 film with respect to the redox potentials for hydrogen- or oxygen evolution reactions. (e) Current-voltage characteristics of a MoS2 film on a SiO2/Si substrate. Inset shows the optical image of the corresponding device.