摘要
Atomically thin layered 2D semiconductors have inspired intense interest in building hybrid liquid–semiconductor electronic systems for next-generation biological/chemical sensing applications. There remains, however, a lack of understanding of the electrical characteristics of 2D materials in aqueous environments and, thereby, much useful information for advancing the development of such emerging sensor systems. In this study, the effects of aqueous environments on the field-effect electron mobility (µ FE ) of monolayer molybdenum disulfide (MoS 2 ) field-effect transistors (FETs), using various operational modes (back-gating, liquid-gating, and dual-gating), are explored at room temperature. The value of µ FE of the MoS 2 exposed to deionized (DI) water is much greater than that treated merely under ambient conditions, presumably the result of a dielectric screening effect. When the DI water is changed to a biologically compatible buffer (0.01 or 0.1 m potassium phosphate buffer) at pH 7, the value of µ FE decreases significantly. Further investigation into the possible origin of the degraded mobility suggests that the ions in the aqueous solutions play an important role as additional scatterers. This report should enhance the understanding of the mechanisms of mobility scattering in liquid–semiconductor 2D FET systems for applications in hybrid electronics, bioelectronics, and nanosensors.