Controlling Tunneling Characteristics via Bias Voltage in Bilayer Graphene/WS2/Metal Heterojunctions

Abstract

Van der Waals heterojunctions, formed by stacking two-dimensional materials with various structural and electronic properties, opens a new way to design new functional devices for future applications and provides an ideal research platform for exploring novel physical phenomena. In this work, bilayer graphene/WS2/metal heterojunctions (GWMHs) with vertical architecture were designed and fabricated. The tunneling current–bias voltage (It − Vb) properties of GWMHs can be tuned by 5 × 106 times in magnitude for current increasing from 0.2 nA to 1 mA with applied bias voltage increasing from 10 mV to 2 V. Moreover, the transfer properties of GWMHs exhibit n-type conduction at Vb = 0.1 V and bipolar conduction at Vb = 2 V; these findings are explained well by direct tunneling (DT) and Fowler–Nordheim tunneling (FNT), respectively. The results show the great potential of GWMHs for high-power field-effect transistors (FETs) and next-generation logic electronic devices.

Emulating synaptic behavior in surface-functionalized MoS2through modulation of interfacial charge transferviaexternal stimuli

“…We note that the applied voltage in an experimental setup is usually not as strong. 30 We started from the neutral optimized structure at 0 K (no field applied) and sequentially geometry optimizing the electric field strength in intervals of 0.1 V Å −1 until the minimum and maximum values of −0.5 V Å −1 to 0.5 V Å −1 were reached, respectively. As discussed below, with these simulations we achieve our primary goal of tuning the electronic structure of the system by controlling external stimuli—in this case, a directionally applied electric field.…”

Band‐to‐Band Tunneling Control by External Forces: A Key Principle and Applications

“…Many research groups have attempted to induce various carrier transport mechanisms by modulating the energy band structure of a semiconductor using an electric field. [60][61][62][63][64] In particular, the electrical field has been utilized as a key factor in TFET switching. In TFET comprising the p-i-n band structure, the tunneling probability between p-channel and n-channel is easily controlled by adjusting the energy band level of the insulator layer based on the gating effect.…”