Figure 34.

(a) and (b) Electronic band structures of 2H and 1T’ MoS₂ and their atomic structures. The 2H band structure shows a bandgap of approximately 1.8 eV, while the conduction and valance bands of 1T’ MoS₂ overlap. Therefore, 1T’ MoS₂ has metallic gapless characteristics. (c) Transfer characteristics of three MoS₂ FETs with different thicknesses of MoS₂ before and after phase transition treatment. The intrinsic 2H MoS₂ FETs show strong semiconducting behavior with large gate modulation, while the phase transition shows constant current with almost no gate modulation featuring, and (d) PL (photoluminescence)spectra of the monolayer 2H and 1T’ MoS₂. The 2H phase shows a strong PL peak at 1.85 eV generated by its bandgap, while the PL of the 1T’ phase is completely quenched due to its gapless metallic characteristics [207].