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Layered hexagonal boron nitride (h-BN) thin film is a dielectric that surpasses carrier mobility by reducing charge scattering with silicon oxide in diverse electronics formed with graphene and transition metal dichalcogenides. However, the h-BN effect on electron doping concentration and Schottky barrier is little known. Here, we report that use of h-BN thin film as a substrate for monolayer MoS can induce ∼6.5 × 10 cm electron doping at room temperature which was determined using theoretical flat band model and interface trap density. The saturated excess electron concentration of MoS on h-BN was found to be ∼5 × 10 cm at high temperature and was significantly reduced at low temperature. Further, the inserted h-BN enables us to reduce the Coulombic charge scattering in MoS/h-BN and lower the effective Schottky barrier height by a factor of 3, which gives rise to four times enhanced the field-effect carrier mobility and an emergence of metal-insulator transition at a much lower charge density of ∼1.0 × 10 cm (T = 25 K). The reduced effective Schottky barrier height in MoS/h-BN is attributed to the decreased effective work function of MoS arisen from h-BN induced n-doping and the reduced effective metal work function due to dipole moments originated from fixed charges in SiO.

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