posted on 2020-03-10, 08:43authored byFiliberto Ricciardella, Kangho Lee, Tobias Stelz, Oliver Hartwig, Maximilian Prechtl, Mark McCrystall, Niall McEvoy, Georg S. Duesberg
Two-dimensional materials (2DMs)
have high potential in gas sensing,
due to their large surface-to-volume ratio. However, most sensors
based on 2DMs suffer from the lack of a steady state during gas exposure,
hampering sensor calibration. Here, we demonstrate that analysis of
the time differential of the signal output enables the calibration
of chemiresistors based on platinum or tungsten diselenide (PtSe2, WSe2) and molybdenum disulfide (MoS2), which present nonstationary behavior. 2DMs are synthesized by
thermally assisted conversion of predeposited metals on a silicon/silicon
dioxide substrate and therefore are integrable with standard complementary
metal–oxide semiconductor (CMOS) technology. We analyze the
behavior of the sensors at room temperature toward nitrogen dioxide
(NO2) in a narrow range from 0.1 to 1 ppm. This study overcomes
the problem of the absence of steady-state signals in 2DM gas sensors
and thus facilitates their usage in this highly important application.