P2GS.14 - ZnO nanoarray based conductometric acetone sensor: a bias and light assisted performance enhancement

17th International Meeting on Chemical Sensors - IMCS 2018
2018-07-15 - 2018-07-19
Vienna, Austria
P-2 - Gas Sensors
S. Rashid, Y. Sabri, A. Kandjani, S. Bhargava - Centre for Advanced Materials and Industrial Chemistry (CAMIC), School of Applied Sciences, RMIT University, Melbourne (Australia), A. Tricoli - Nanotechnology Research Laboratory, Research School of Engineering, The Australian National University, Canberra (Australia), W. Wlodarski, S. Ippolito - Sensor Technology Laboratory, School of Electrical and Computer Engineering, RMIT University, Melbourne (Australia)
794 - 795


In this work, a combination of different bias potentials (0.1 – 9 V) along with 365 nm UV light is applied to enhance the sensing performance of a chemo-resistive device consisting of zinc oxide (ZnO) nanoarrays (NAs) as the sensitive layer for measuring acetone concentrations between 1.2 and 12.5 ppm. To the best of the authors’ knowledge, the application of this double enhancement principle towards chemo-resistive acetone sensors is the first such report in the literature. It was found that an increment in applied bias increased the sensitivity of the device toward acetone. Furthermore, when the sensor was stimulated with a 365 nm UV light source in the presence of 12.5 ppm acetone, the sensitivity was increased by 1.8 times when compared to operating in the dark. The significant sensitivity enhancements are effects of both light and bias, which can be highlighted by the calculated 1 ppb limit of detection (LoD) of the sensor when excited by UV light at 350 °C with a 9 V bias. Additionally the adsorption time (t90-a) and desorption time (t90-d) of the sensor can be greatly improved with bias and light. The t90-a decreased to from 75 s to 9 s and the t90-d from 93 s to 14 s under light for an operating bias of 0.1 and 9 V, respectively.