Light-Assisted and Gate-Tunable Oxygen Gas Sensor based on Rhenium Disulfide (ReS2) Field-Effect Transistors

TL;DR

This paper demonstrates a light-assisted and gate-tunable ReS2 FET-based oxygen sensor with enhanced responsivity, stability under humid conditions, and practical sensitivity, advancing the development of versatile TMDC gas sensors.

Contribution

It provides a systematic study of ReS2 FETs under light and gate bias, revealing their combined effect on oxygen sensing performance and mechanism, which was previously not well understood.

Findings

Responsivity increased by over 100% with light and gate bias.

Achieved a practical sensitivity of 0.01% ppm-1.

Device showed long-term stability under humid conditions.

Abstract

Gas sensors based on transition metal dichalcogenides (TMDCs) have attracted much attention from a new perspective involving light-assisted or gate-voltage operation. However, their combined roles as regards the gas sensing performance and mechanism have not yet been understood due to the lack of controlled studies. This study systematically investigates the oxygen sensor performance and mechanism of few-layer-thick rhenium disulfide (ReS2) field-effect transistors (FETs) under light illumination and gate biasing. As a result, a combination of light illumination and positive gate voltage enhanced the device responsivity over 100% at a 1% oxygen concentration, that is, the approach achieved a practical sensitivity of 0.01% ppm-1, which outperform over most of the reports available in the literature. Furthermore, the fabricated devices exhibited long-term stability and stable operation even under humid conditions, indicating the ability of the sensor device to operate in a real-time application. These results contribute to the development of versatile tunable oxygen sensors based on TMDC FETs.