As opposed to the semimetal graphene, TMDs have shown great potential in the sub-5 nm regime applications due to their dangling bond-free surfaces, satisfied bandgaps, attractive electronic properties, powerful optoelectronic applications, and well mechanical properties. [3-6] MoS 2 is considered to be the most promising one from the family of layered TMDs due to their feasibility in large-scale synthesis. [7] Bulk MoS 2 is known to have an indirect bandgap of ≈1.2 eV, whereas single-layer MoS 2 is a direct gap semiconductor with a bandgap of 1.8 eV. [8-12] The direct bandgap also results in the photoluminescence (PL) of monolayer MoS 2 , which opens the possibility of many optoelectronic applications. [13] However, MoS 2 at both room temperatures (RT) and low temperatures have been found to be substantially below the theoretically predicted intrinsic values, which can be attributed to the scattering of carriers by substrate roughness, charged impurities, and the presence of adsorbates (H 2 O, gas, etc.) on the surface. [14-16] In addition, the high Rc values of the MoS 2 FETs limited their two-terminal field-effect mobility which may have been caused by the Schottky barrier at the interface of MoS 2 and metal. [17-21] In this regard, the Schottky barrier height (SBH) is an important parameter for examining contact properties. The low work function metal contact electrode and molecular doping interface are conventional ways, [22] which aim to reduce contact resistance; however, the charged impurities in ultra-sensitive MoS 2 channel make the methods less efficient in terms of mobility enhancement. Here, we propose a multiple TMDs materials such as the MoS 2 /WS 2 Van der Waals heterostructure FET. With the high electron affinity of MoS 2 , the free electrons in the WS 2 layers are transferred to the MoS 2 layers, resulting in the n-doping of the MoS 2. [23] Within this heterostructure, the electrons can transport through the Van der Waals self-encapsulated channel and easily overcome the barrier at the interface, which is due to the Schottky barrier lowering effect. With the absence of the scattering source, the carrier concentration increases without degrading the mobility of the MoS 2 heterostructure, thus, the ON current and mobility of the device can be significantly enhanced. Moreover, we demonstrated a double Van der Waals heterostructure device where the MoS 2 layer is encapsulated by two WS 2 layers. The combination of the two heterostructures could further boost the mobility at room temperature and achieve a much higher value at 30 K, indicating the suppression of the Coulomb scattering at the oxide of the MoS 2 interface. In this study, a novel van der Waals (vdW) heterostructure field-effect transistor (FET) using vdW stacking as next-generation device architecture is demonstrated. The MoS 2 /WS 2 heterostructure FET exhibits a large improvement in the drain current and field-effect mobility (from 43.3 to 62.4 cm 2 V −1 s −1) compared with single MoS 2 FET. Such significant enhancement is mainly due to...