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Extraordinary performance of semiconducting metal oxide gas sensors using dielectric excitation



Andrei A. Kolmakov, Radislav A. Potyrailo, Steven Go, Daniel Sexton, Xiaxi Li, Nasr Alkadi, Bruce Amm, Richard St-Pierre, Brian Scherer, Majid Nayeri, Guang Wu, Christopher Collazo-Davila, Doug Forman, Chris Calvert, Craig Mack, Philip Mcconnell


Electrical response of metal oxide semiconducting (MOS) materials to gases was discovered 70 years ago [1] and miniature low-cost MOS chemiresistors became the most popular gas sensors when chemical selectivity is not required [2, 3]. When discrimination between different gaseous species is essential, traditional analytical instruments is the choice in established applications that range from environmental surveillance to homeland protection [4, 5]. Those bulky instruments are often inconvenient in a field, even with the reduced carrier gas, vacuum, or power demands [6, 7], but are an unavoidable alternative to existing sensors [8]. However, in emerging applications of wearable and unattended sensing, selectivity advantage of traditional analytical technologies is negated by requirements for small size, low weight, low power, and no consumables, calling for non-traditional concepts for selective gas sensing of multiple gases [9]. Lack of gas discrimination of modern MOS chemiresistors, even with their ultra-low power consumption designs, prevents their adoption for emerging applications where gas discrimination is the top priority [10, 11]. Here, we report an excitation methodology of MOS sensors that enables discrimination between individual gases, their quantification in mixtures, and - as an extra advantage vs. classic non-linear resistive response [3] - provides sensor response over six orders of magnitude of gas concentrations. These exceptional sensing capabilities are achieved by monitoring the high-frequency shoulder of the dielectric relaxation spectrum of MOS materials. This measurement principle provides a framework for tuning gas responses of semiconducting sensing materials and enables selective and broad dynamic range gas monitoring using only a single sensor. We demonstrated this sensor excitation methodology in unobtrusive device architectures and field-validated our systems for greenhouse gases and industrial hazards in a wireless sensor network,
Nature Electronics


Kolmakov, A. , Potyrailo, R. , Go, S. , Sexton, D. , Li, X. , Alkadi, N. , Amm, B. , St-Pierre, R. , Scherer, B. , Nayeri, M. , Wu, G. , Collazo-Davila, C. , Forman, D. , Calvert, C. , Mack, C. and Mcconnell, P. (2020), Extraordinary performance of semiconducting metal oxide gas sensors using dielectric excitation, Nature Electronics, [online], (Accessed February 29, 2024)
Created May 10, 2020, Updated February 23, 2021