Figure 4. Schematic diagram of band alignments and constant Z spectroscopy for valence band of ML WSe₂.

(a) Schematic diagram showing the generic band alignment in BL–ML TMDs HJs. The magnitude of the band bending is labelled as Δ_bend, and the gap of interface states is Δ_intf. (b,c) Two modes of constant Z spectroscopy—(∂I/∂V)_I and (∂Z/∂V)_I for valence band of monolayer WSe₂. The actual valence band maximum at K point is labelled as K_V, which is about 0.65 eV above Γ point. See ref. 29 for details.