Resonant Tunneling through Discrete Quantum States in Stacked Atomic-Layered MoS₂

Abstract

Two-dimensional crystals can be assembled into three-dimensional stacks with atomic layer precision, which have already shown plenty of fascinating physical phenomena and been used for prototype vertical-field-effect-transistors.1,2 In this work, interlayer electron tunneling in stacked high-quality crystalline MoS2 films were investigated. A trilayered MoS2 film was sandwiched between top and bottom electrodes with an adjacent bottom gate, and the discrete energy levels in each layer could be tuned by bias and gate voltages. When the discrete energy levels aligned, a resonant tunneling peak appeared in the current-voltage characteristics. The peak position shifts linearly with perpendicular magnetic field, indicating formation of Landau levels. From this linear dependence, the effective mass and Fermi velocity are determined and are confirmed by electronic structure calculations. These fundamental parameters are useful for exploitation of its unique properties.

Phosphorene/rhenium disulfide heterojunction-based negative differential resistance device for multi-valued logic

“…Figure 2b shows the current–voltage ( I – V ) characteristic of the NDR device on a linear scale. Here, the NDR behaviour was observed between 0.4 V and 0.9 V with a PVCR of 4.2, which is the highest value in previously reported NDR devices based on 2D materials56716171819. We also note that similar electrical characteristics were observed in three different BP/ReS 2 NDR devices with PVCR values between 3.8 and 4.1 (Inset of Fig.…”

“…Recently, negative differential resistance (NDR) devices have attracted considerable attention owing to their folded current–voltage ( I – V ) characteristic (N-shaped I – V curve), which presents multiple threshold voltage values123456789101112131415161718192021222324252627. Because of this remarkable property, studies associated with the NDR devices have been explored for realizing multi-valued logic (MVL) applications17111326.…”

“…For example, a ternary logic system is theoretically able to reduce the number of interconnect lines by nearly 45% as compared with binary logic28. The NDR devices that have been researched for the implementation of this MVL system are Esaki diodes234567, resonant tunnelling diodes891011121314151617181920, Gunn diodes, single electron transistors2122 and molecular devices2324. However, at the current stage of research, because most of the Esaki diodes and resonant tunnelling diodes were fabricated in Si–Ge and III–V semiconductors234891011121314, the formation of various types of heterojunctions (type-I, II and III) is limited by threading dislocations, which are normally caused at the junction interface by lattice mismatch during film growth.…”

Dual-mode operation of 2D material-base hot electron transistors

“…SiO 2 field oxide) so that the particular 2D material covered several arrays of active areas of the 2D material-HETs. The large-area monolayers of MoS 2 and graphene were grown using CVD methods4142 and transferred onto the substrates using PMMA transfer methods4344. Subsequently, a photolithography step was performed to mask circular regions of the 2D material covering the active areas.…”

N-state random switching based on quantum tunnelling

“…Beyond the tunnelling barriers, highly-doped regions of the narrow band-gap semiconductor act as an electron source/sink and are usually referred to as the emitter/collector regions, analogous to traditional bipolar transistors. Recently, resonant tunnelling devices using quantum dots 11,12 , atomic-scale defects 13 , graphene 14,15 and other two-dimensional materials 16,17 have been demonstrated, and this has renewed the interest in investigating resonant tunnelling and its applications using new materials.…”