Low-Frequency 1/f Noise in MoS2 Thin-Film Transistors: Comparison of Single and Multilayer Structures

TL;DR

This study compares low-frequency 1/f noise in MoS2 thin-film transistors with different channel thicknesses, revealing that thicker channels exhibit lower noise and higher mobility, aligning with the McWhorter model, which is important for device optimization.

Contribution

It demonstrates that channel thickness significantly affects noise and mobility in MoS2 transistors, with thicker channels showing improved performance and noise characteristics.

Findings

Thicker MoS2 channels have lower 1/f noise levels.

Mobility is higher in thick-channel MoS2 transistors.

Noise in thick MoS2 transistors follows the McWhorter model.

Abstract

We report on the transport and low-frequency noise measurements of MoS2 thin-film transistors with "thin" (2-3 atomic layers) and "thick" (15-18 atomic layers) channels. The back-gated transistors made with the relatively thick MoS2 channels have advantages of the higher electron mobility and lower noise level. The normalized noise spectral density of the low-frequency 1/f noise in "thick" MoS2 transistors is of the same level as that in graphene. The MoS2 transistors with the atomically thin channels have substantially higher noise levels. It was established that, unlike in graphene devices, the noise characteristics of MoS2 transistors with "thick" channels (15-18 atomic planes) could be described by the McWhorter model. Our results indicate that the channel thickness optimization is crucial for practical applications of MoS2 thin-film transistors.