transition metal dichalcogenides [3,17] molybdenum disulfide (MoS 2 ) is considered a particularly likely candidate to replace the silicon materials that serve as conducting channels in next-generation field-effect transistors (FETs), owing to its applicability for large-area synthesis, [18] its semiconducting properties, [19] and its high mobility. [20,21] Accordingly, many proposals for emerging MoS 2 electronic devices have been conceived, not only offering a potential route toward future high-density integrated circuit applications [3,22,23] but also guiding new directions for adding functions to electronic devices to meet the requirements of multifunctional chip applications. [7,16,24] Upon decreasing the layer number of 2D layered materials to arrive in the ultrathin regime, the extremely large surface-to-volume ratio becomes a decisive factor affecting the electrical behavior of 2D materials, [21,25] while also inducing high sensitivity to charges in proximity to the 2D material surfaces. [16,26] Furthermore, to exploit such strong surface Field-Effect TransistorsIn the past ten years, atomically thin layered 2D material systems featuring interlayer interactions stabilized through van der Waals forces have attracted great attention and have been explored extensively for a variety of promising applications, including electronics, [1][2][3][4] optoelectronics, [5][6][7] piezotronics, [8] spintronics, [9,10] electrocatalysis, [11,12] and environmental/ biological/chemical sensing devices. [13][14][15][16] From the point of view of device physics, among the emerging 2D layered materials-including graphene, [1] group-IV family materials, [17] and