Room Temperature Negative Differential Resistance with High Peak Current in MoS<sub>2</sub>/WSe<sub>2</sub> Heterostructures
Jung Ho Kim, Soumya Sarkar, Yan Wang, Takashi Taniguchi, Kenji Watanabe, Manish Chhowalla
Abstract
High Resolution Image Download MS PowerPoint Slide Two-dimensional transition metal dichalcogenide (2D TMD) semiconductors allow facile integration of p- and n-type materials without a lattice mismatch. Here, we demonstrate gate-tunable n- and p-type junctions based on vertical heterostructures of MoS 2 and WSe 2 using van der Waals (vdW) contacts. The p–n junction shows negative differential resistance (NDR) due to Fowler–Nordheim (F–N) tunneling through the triangular barrier formed by applying a global back-gate bias ( V GS ). We also show that the integration of hexagonal boron nitride ( h -BN) as an insulating tunnel barrier between MoS 2 and WSe 2 leads to the formation of sharp band edges and unintentional inelastic tunnelling current. The devices based on vdW contacts, global V GS, and h -BN tunnel barriers exhibit NDR with a peak current ( I peak ) of 315 μA, suggesting that the approach may be useful for applications.