Figure 2: Bandgap varying with MoS 2 layer thickness.
From: Bandgap tunability at single-layer molybdenum disulphide grain boundaries

(a) Large-scale STM image shows a MoS2 flake containing single-layer (SL), bilayer (BL) and trilayer (TL) thickness (150 × 150 nm2; VTip=2.4 V). (b) Highly resolved STM image recorded at the BL region, where the honeycomb feature is similar to that observed for SL MoS2 (8 × 8 nm2; VTip=1.5 V). (c) Lateral profile corresponding to the white line in panel a, revealing a 7 Å height for each MoS2 layer. (d) dI/dV spectra taken at the SL, BL and TL MoS2, respectively, reveals the bandgap decrease with the increasing thickness (set point: VTip=1.5 V, ITip=80 pA).