Active-matrix monolithic gas sensor array based on MoS2 thin-film transistors

Sehwan Kim,Jeong Yong Yang,Yena Kwon,Na Liu,Sooho Choo,Sunkook Kim,Cheol-Woong Yang,Heekyeong Park,Geonwook Yoo,Seongho Baek

doi:10.1038/s43246-020-00086-y

Sehwan Kim, Jeong Yong Yang + Show 8 more

Open Access

https://doi.org/10.1038/s43246-020-00086-y

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Abstract

Highly sensitive and system integrable gas sensors play a significant role in industry and daily life, and MoS2 has emerged as one of the most promising two-dimensional nanomaterials for gas sensor technology. In this study, we demonstrate a scalable and monolithically integrated active-matrix gas sensor array based on large-area bilayer MoS2 films synthesized via two-successive steps: radio-frequency magnetron sputtering and thermal sulfurization. The fabricated thin-film transistors exhibit consistent electrical performance over a few centimeters area and resulting gas sensors detect NO2 with ultra-high sensitivity across a wide detection range, from 1 to 256 ppm. This is due to the abundant grain boundaries of the sputtered MoS2 channel, which perform as active sites for absorption of NO2 gas molecules. The demonstrated active-matrix gas sensor arrays display good switching capabilities and are anticipated to be readily integrated with additional circuitry for different gas sensing and monitoring applications.

Highlights

Sensitive and system integrable gas sensors play a significant role in industry and daily life, and MoS2 has emerged as one of the most promising two-dimensional nanomaterials for gas sensor technology
The field-effect transistors (FETs)-based gas sensor works on a principle of carrier transport modulation on the channel induced by gas molecules
The thickness of Mo film, which determines the thickness of the final MoS2 film, is controlled by the sputtering parameters and the deposition time[41]

Summary

Introduction

Sensitive and system integrable gas sensors play a significant role in industry and daily life, and MoS2 has emerged as one of the most promising two-dimensional nanomaterials for gas sensor technology. The fabricated thin-film transistors exhibit consistent electrical performance over a few centimeters area and resulting gas sensors detect NO2 with ultra-high sensitivity across a wide detection range, from 1 to 256 ppm This is due to the abundant grain boundaries of the sputtered MoS2 channel, which perform as active sites for absorption of NO2 gas molecules. Gas sensors, which allow ubiquitous and personal airquality monitoring, pollution tracking, and preventive health care via point-of-care breath analysis, are in great demand and will become one of indispensable internet of things sensors toward the hyper-connected[1–5] To achieve this agenda, development of low-power and monolithically integrated gas sensors without sacrificing their sensitivity is crucial, and various gas-sensing methods have been proposed based on electrochemical, resistive, and nanomechanical system[6–12]. No reports have been conducted on MoS2 gas sensor arrays driven by large-area active-matrix

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