Tunable electronic properties and negative differential resistance effect of the intrinsic type-III ZrS2/WTe2 van der Waals heterostructure

Van der Waals heterostructure (vdWH) has attracted considerable interest because of its ability to combine the excellent properties of stacked materials to suit different application requirements. The limited presence of type-III vdWH is a serious barrier for the development of two-dimensional materials in the field of tunneling field effect transistors. Herein, we propose a novel ZrS2/WTe2 vdWH with type-III band alignment and investigate its structural, electronic and quantum transport properties using first-principles calculations. The physical mechanism of type-III band alignment is analyzed. The electronic structures of this vdWH can be adjusted to enhance the band-to-band tunneling effect or achieve an interesting transition from type-III to type-II band alignment via external vertical electric field and different strains. Finally, we study the quantum transport properties and confirm again the type-III band alignment. The I-V curve shows apparent negative differential resistance (NDR) behaviors under low bias voltages, which provides substantial evidence supporting the applicability of this vdWH to low power devices. Our study not only expands the field of type-III band alignment heterostructures in 2D materials, but also provides a remarkable candidate material with tunable electronic properties and the favorable NDR effect for experimental designs and practical applications of novel multi-functional nanoelectronic devices.