Quantitative Assessment of Monolayer MoS₂'s Gas Sensing Behavior

Transition metal dichalcogenides (TMDs) gas sensing research encounters a persistent challenge: irrecoverable responses. Efforts to improve recoverability, heating or complex heterostructures for instance, may cause surface damage or risk increasing sensor size. In gas sensing research, repeatability is essential. In our innovative study, we leverage TMDs' surface molecule trapping properties to explore gas adsorption for repeatable gas sensors. Our approach fine-tunes the material's surface with high concentrations of the target adsorbent to occupy inactive sites. To assess our approach, we've developed a comprehensive two-trap model for physical and chemical adsorption. Systematic variations in target adsorbent concentrations establish a linear relationship and consistent results. This robust correlation demonstrates our method's repeatability of gas sensing signals. Our study reveals a link between sensor response and target adsorbent presence, addressing irrecoverable responses. This research underscores repeatability's vital role in advancing gas sensing technologies. In conclusion, our method offers a promising solution, opening new horizons in gas sensing research.