Quantum-mechanical effect in atomically thin MoS2 FET

TL;DR

This study demonstrates that monolayer MoS2 FETs exhibit strong quantum-mechanical effects that enhance device performance, confirmed by experiments and calculations, highlighting the advantages of atomically thin channels for future electronics.

Contribution

The paper provides experimental and theoretical evidence of quantum confinement effects in monolayer MoS2 FETs, emphasizing their potential for improved on-current and gate control.

Findings

Quantum confinement in monolayer MoS2 enhances on-current.

Capacitance analysis shows ideal gate insulator capacitance achievement.

Experimental results confirm strong quantum-mechanical effects in monolayer channels.

Abstract

Two-dimensional (2D) layered materials-based field-effect transistors (FETs) are promising for ultimate scaled electron device applications because of the improved electrostatics to atomically thin body thickness. However, compared with the typical thickness of ~5-nm for Si-on-insulator (SOI), the advantage of the ultimate thickness limit of monolayer for the device performance has not been fully proved yet, especially for the on-state at the accumulation region. Here, we present much stronger quantum-mechanical effect at the accumulation region based on the C-V analysis for top-gate MoS2 FETs. The self-consistent calculation elucidated that the electrons are confined in the monolayer thickness, unlike in the triangle potential formed by the electric field for SOI, the gate-channel capacitance is ideally maximized to the gate insulator capacitance since the capacitive contribution of the channel can be neglected due to the negligible channel thickness. This quantum-mechanical effect agreed well with the experimental results. Therefore, monolayer 2D channels are suggested to be used to enhance the on-current as well as the gate modulation ability.