Chemical Vapor Sensing with Monolayer MoS₂

TLDR

Two‑dimensional materials such as graphene, with their high surface‑to‑volume ratio, hold great promise for nanoscale electronics and chemical sensing, where surface perturbations readily alter charge transport. The MoS₂ sensor operates by transient charge perturbations when analytes act as electron donors or acceptors. Monolayer MoS₂ functions as a highly selective chemical sensor, showing strong, conductance‑based responses to electron‑donating analytes such as triethylamine and outperforming carbon‑nanotube sensors.

Abstract

Two-dimensional materials such as graphene show great potential for future nanoscale electronic devices. The high surface-to-volume ratio is a natural asset for applications such as chemical sensing, where perturbations to the surface resulting in charge redistribution are readily manifested in the transport characteristics. Here we show that single monolayer MoS(2) functions effectively as a chemical sensor, exhibiting highly selective reactivity to a range of analytes and providing sensitive transduction of transient surface physisorption events to the conductance of the monolayer channel. We find strong response upon exposure to triethylamine, a decomposition product of the V-series nerve gas agents. We discuss these results in the context of analyte/sensor interaction in which the analyte serves as either an electron donor or acceptor, producing a temporary charge perturbation of the sensor material. We find highly selective response to electron donors and little response to electron acceptors, consistent with the weak n-type character of our MoS(2). The MoS(2) sensor exhibits a much higher selectivity than carbon nanotube-based sensors.