Device simulation study of multilayer MoS 2 Schottky barrier field-effect transistors.

Molybdenum disulfide (MoS ₂ ) is a representative two-dimensional layered transition-metal dichalcogenide semiconductor. Layer-number-dependent electronic properties are attractive in the development of nanomaterial-based electronics for a wide range of applications including sensors, switches, and amplifiers. MoS ₂ field-effect transistors (FETs) have been studied as promising future nanoelectronic devices with desirable features of atomic-level thickness and high electrical properties. When a naturally n -doped MoS ₂ is contacted with metals, a strong Fermi-level pinning effect adjusts a Schottky barrier and influences its electronic characteristics significantly. In this study, we investigate multilayer MoS ₂ Schottky barrier FETs (SBFETs), emphasizing the metal-contact impact on device performance via computational device modeling. We find that p -type MoS ₂ SBFETs may be built with appropriate metals and gate voltage control. Furthermore, we propose ambipolar multilayer MoS ₂ SBFETs with asymmetric metal electrodes, which exhibit gate-voltage dependent ambipolar transport behavior through optimizing metal contacts in MoS ₂ device. Introducing a dual-split gate geometry, the MoS ₂ SBFETs can further operate in four distinct configurations: p  -  p , n  -  n , p  -  n , and n  -  p . Electrical characteristics are calculated, and improved performance of a high rectification ratio can be feasible as an attractive feature for efficient electrical and photonic devices.
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