Figure 4: Theoretical and experimental pressure-dependent opto-electronic properties of MoS2.
From: Pressure-induced semiconducting to metallic transition in multilayered molybdenum disulphide
(a) Theoretical calculation of the pressure-dependent band gap of multilayered MoS2. The bandgap—pressure dependence can be modelled as a quadratic function, Eg=Ego+aP+bP2 was used, where a=−70 meV GPa−1 and b=1.13 meV GPa−2. Inset: the unit cell of MoS2. (b) Theoretical band structure of multilayered MoS2 under hydrostatic pressure of 23.8 GPa. VBM and CBM are shown by red lines. (c) Optical switch behaviour before (blue lines at 3.0 GPa) and after (red line at 21.0 GPa) the S–M transition with various laser intensities. (d) Current gain (defined as Ion/Ioff ratio) as a function of pressure when exposed to a 532 nm (2.3 eV) laser light with an intensity of 40 W m−2.
