Gate-bias tunable humidity sensors based on rhenium disulfide field-effect transistors

Abstract

We investigate the humidity sensing performance and mechanism of few-layer-thick rhenium disulfide (ReS₂) field-effect transistors (FETs) under gate bias operation. Consequently, a negative gate bias exhibits the sensor response, exceeding 90% mainly in the low relative humidity (RH) range. Meanwhile, the threshold voltage change was discovered to be a superior sensing parameter to achieve a broad monitoring of RH range with high response and sensitivity. The approach obtained a practical sensitivity of 0.4 V per 1% RH, which exceed a majority of previous studies with the pristine 2D materials. Besides, our devices display reversible adsorption–desorption and long-term stability operations even after a one-month period. This suggests the sensor capacity to function in real-time applications with a short response and recovery times. These outcomes offer support in the development of adaptable tunable humidity sensors based on ReS₂ FETs.