First-principles Simulation of Piezoresistivity of Transition Metal Dichalcogenide Monolayers

Longitudinal gauge factors of transition metal dichalcogenide (TMDC) monolayer models have been evaluated by first-principles calculation. TMDC monolayers have a multivalley/ multipeak electronic structure, and uniaxial tensile strain causes a significant change in electrical conductivity through carrier redistribution in conduction-band valleys or valenceband peaks for some species of doped TMDC monolayers. A high piezoresistivity was observed selectively depending on the combination of transition metal and chalcogen atoms. In this simulation, a p-doped MoS 2 monolayer model gave high longitudinal gauge factors of 94.2 and 87.4 at 20 C in the carrier concentration range of 10 17 -10 19 cm -3 .