Temperature dependence of velocity saturation in a multilayer molybdenum disulfide transistor

Velocity saturation in semiconducting devices is an important parameter that involves in the determination of the upper limit of the operational speed. The large contact resistance in two-dimensional semiconducting nano-devices is troublesome for extracting the saturation velocity from the electrical transport measurements, particularly at low temperatures. We obtain the saturation velocity for multilayer MoS2 from 10 to 300 K using the four-probe method to exclude contact effects. The saturation velocity exhibits strong temperature dependence, with a substantial enhancement at low temperature similar to the mobility, that is, ~5.2×105 cm/s at 300 K and ~4.8×106 cm/s at 10 K. The overall temperature dependence of the saturation velocity can be well represented using an empirical model previously used for Si.