ZrTe 2 Compound Dirac Semimetal Contacts for High-Performance MoS 2 Transistors.

Recent investigations reveal elemental semimetal (Bi and Sb) contacts fabricated with conventional deposition processes exhibit a remarkable capacity of approaching the quantum limit in two-dimensional (2D) semiconductor contacts, implying it might be an optimal option to solve the contact issue of 2D semiconductor electronics. Here, we demonstrate novel compound Dirac semimetal ZrTe ₂ contacts to MoS ₂ constructed by a nondestructive van der Waals (vdW) transfer process, exhibiting excellent ohmic contact characteristics with a negligible Schottky barrier. The band hybridization between ZrTe ₂ and MoS ₂ was verified. The bilayer MoS ₂ transistor with a 250 nm channel length on a 20 nm thick hexagonal boron nitride (h-BN) exhibits an I _ON / I _OFF current ratio over 10 ⁵ and an on-state current of 259 μA μm ^-1 . The current results reveal that 2D compound semimetals with vdW contacts can offer a diverse selection of proper semimetals with adjustable work functions for the next-generation 2D-based beyond-silicon electronics.