Figure 3.

Experimental characterization of MoS₂ on Cu at various annealing temperatures. a,b) Synchrotron‐based X‐ray photoemission spectra of Mo3d, S2s, and S2p core‐level peak regions for MoS₂ on Cu film annealed at various temperatures. These spectra can be well fitted by two components with constant peak positions and full width at half maximum. c) Valence band and d) narrow valence band for MoS₂ on Cu film annealed at various temperatures. The Fermi surface feature is indicated by the dashed red circle while the mid‐gap feature positions denoted by the black vertical markings (see the Experimental Section for details). e) Device structure schematic of a MoS₂ field‐effect transistor. f) I _d–V _g of the MoS₂ device as functions of annealing temperature. g) Mobility versus temperature at different gate voltages of the device as functions of annealing temperature.