Chemical Vapor Sensing\nwith Monolayer MoS₂

Abstract

Two-dimensional materials such as graphene show great\npotential\nfor future nanoscale electronic devices. The high surface-to-volume\nratio is a natural asset for applications such as chemical sensing,\nwhere perturbations to the surface resulting in charge redistribution\nare readily manifested in the transport characteristics. Here we show\nthat single monolayer MoS₂ functions effectively as a chemical\nsensor, exhibiting highly selective reactivity to a range of analytes\nand providing sensitive transduction of transient surface physisorption\nevents to the conductance of the monolayer channel. We find strong\nresponse upon exposure to triethylamine, a decomposition product of\nthe V-series nerve gas agents. We discuss these results in the context\nof analyte/sensor interaction in which the analyte serves as either\nan electron donor or acceptor, producing a temporary charge perturbation\nof the sensor material. We find highly selective response to electron\ndonors and little response to electron acceptors, consistent with\nthe weak <i>n</i>-type character of our MoS₂.\nThe MoS₂ sensor exhibits a much higher selectivity than\ncarbon nanotube-based sensors.