Approaching Ideal Schottky Rectification Characteristics in MoS₂ Schottky Diodes

Schottky diodes are one type of fundamental component in modern electronics and optoelectronics. As emerging novel channel materials, two-dimensional (2D) semiconductors, especially transition-metal dichalcogenide (TMD)-based Schottky diodes, are fundamentally important, while they are still far away from the ideally modeled characteristics. In this investigation, we demonstrate that typical molybdenum disulfide (MoS₂) Schottky diodes approaching ideal rectification characteristics (ideality factor ≈ 1.003) can be achieved by engineering both high-quality MoS₂-Pt Schottky contacts and MoS₂-ZrTe₂ ohmic contacts and suppressing the edge effects with MoS₂-channel thickness optimization. As the fundamental components in electronics, the diodes exhibit a maximum rectification ratio exceeding 10⁹ at V_bias = ±5 V and a bias-independent reverse saturation current consistent with the thermionic emission model. As the fundamental components in optoelectronics, the MoS₂ Schottky photodiodes exhibit a linear dynamic range (LDR) of 135 dB, an ultrafast steady-state optical response of ∼2 ns, and a -3 dB bandwidth of 430 MHz, superior to those of commercial Si- and InGaAs-based photodetective devices. The demonstrated device performance presents a solid advance for the TMD-based electronics and optoelectronics.