Humidity-Dependent Characteristics of Few-Layer MoS2Field Effect Transistors

2D semiconductors, such as molybdenum disulfide (MoS2), are emerging materials for field effect transistor (FET) channels in the field of nano-electronics. These atomically thin 2D films are particularly sensitive to moisture due to their large specific surface area, making them promising candidates for humidity sensing applications. Studies on MoS2FET humidity sensor have indicated that there are two key factors contributing to the performance of such devices: the number of MoS(2)layer and the gate bias. However, no existing work has revealed the exact relation between humidity and electrical properties for few-layer MoS2FETs. Here, the effect of humidity on the electrical transport properties for back-gated tri- and six-layer MoS2FETs is explored. The on-state current of the tri-layer MoS2FET is heavily dependent on the relative humidity while that of the six-layer MoS2FET remains nearly unchanged when relative humidity varies. Moreover, a linear relationship between the hysteresis and relative humidity is found in both tri-layer and six-layer MoS2FETs. These results advance the understanding of the dependence of electronic properties on relative humidity for few-layer MoS2FET.