Figure 3.

(a) Transfer characteristics of a representative transistor with a 30-nm-thick MoS₂ film on a linear scale (left y-axis) and a log scale (right y-axis). The threshold voltage, V_t, is determined by the intercept on the x-axis with the regression fitted line to the linear scale characteristics. The insets represent the energy band diagrams corresponding to the applied V_g in three distinct regions: (1) at flat band, (2) below threshold, and (3) above threshold. ϕ_bn and ϕ_bp indicate electron and hole SBH, respectively. (b) Dependence of I_on and I_off on MoS₂ flake thickness. The grey dashed line serves as a guide to the eye. (c) Thickness-dependence of I_on/I_off. The red dashed line serves as a guide to the eye. Inset is the zoom in for the first 100 nm. The red solid line in the inset is a linear fit on the semi-log scale.