High rectification ratio metal-insulator-semiconductor tunnel diode based on single-layer MoS₂.

Single-layer MoS2, with its ultimate atomic thickness, has shown promise to scale down transistors for modern integrated circuitry. On the way to implementing two-dimensional (2D) electronic devices, controlled wafer-scale synthesis of single-layer MoS2, single-layer MoS2 metal-oxide-semiconductor field-effect transistors, ohmic contact of single-layer MoS2 for low contact resistance, etc, have been extensively studied. However, the most commonly used two-terminal electronic component, a diode, which conducts current primarily in one direction, has rarely been reported based on single-layer MoS2. Here, a two-terminal high rectification ratio metal-insulator-semiconductor (MIS) tunnel diode was reported based on single-layer MoS2. The In/Au (10/70 nm) electrode via thermal evaporation was used to form a good ohmic contact with the single-layer MoS2. The Si3N4/Pd/Au (5/10/70 nm) electrode via electron beam evaporation was used to form an MIS tunneling structure with the MoS2, showing a current rectification ratio of up to 10(7) at room temperature. The high current rectification ratio is realized by controlling the quantum tunneling carrier density and the tunneling barrier width. The single-layer MoS2 MIS tunnel diode fabricated via the silicon technology compatible evaporation method has potential application as a fundamental electronic building block for future 2D electronics.