Non-Lithographic Fabrication of All-2D α-MoTe₂ Dual Gate Transistors

As one of the emerging new transition-metal dichalcogenides materials, molybdenum ditelluride (α-MoTe₂) is attracting much attention due to its optical and electrical properties. This study fabricates all-2D MoTe₂-based field effect transistors (FETs) on glass, using thin hexagonal boron nitride and thin graphene in consideration of good dielectric/channel interface and source/drain contacts, respectively. Distinguished from previous works, in this study, all 2D FETs with α-MoTe₂ nanoflakes are dual-gated for driving higher current. Moreover, for the present 2D dual gate FET fabrications on glass, all thermal annealing and lithography processes are intentionally exempted for fully non-lithographic method using only van der Waal's forces. The dual-gate MoTe₂ FET displays quite a high hole and electron mobility over ≈20 cm² V^-1 s^-1 along with ON/OFF ratio of ≈10⁵ in maximum as an ambipolar FET and also demonstrates high drain current of a few tens-to-hundred μA at a low operation voltage. It appears promising enough to drive organic light emitting diode pixels and NOR logic functions on glass.