Ng, D. K. T., Chen, W., Xu, L., Lau, H. J. E., Tobing, L., Ho, C. P., Chung, W. W., Jaafar, N., Fu, H., & Zhang, Q. (2024). SF6 mixed in N2 gas sensing responses from CMOS-compatible AlN and ScAlN pyroelectric detectors. In W. Piyawattanametha, Y.-H. Park, & H. Zappe (Eds.), MOEMS and Miniaturized Systems XXIII. SPIE. https://doi.org/10.1117/12.3002138
Abstract:
SF6 gas sensor is developed to measure SF6 gas at different concentrations mixed with N2 based on mid-IR absorption of SF6 at a wavelength of ~10.6 μm. An optical bandpass filter of ~10.6 μm is put in front of a thermal emitter source to allow light of this wavelength to pass through. A CMOS compatible pyroelectric detector is put on the other end of the gas channel to measure the voltage change due to presence of SF6 gas. Here, we use AlN-based and 12% ScAlN-based pyroelectric detectors respectively. The results show for 100% SF6 gas sensing, 12% ScAlN-based pyroelectric detector gives ~73% higher response compared to when using AlN-based pyroelectric detector. The voltage drop between reference N2 gas and different SF6 gas concentrations is also higher (up to 2x) when using 12% ScAlN-based pyroelectric detector. Based on the measured SF6 gas responses, we try to estimate the lower limit of detection of our gas sensors when using AlN- and ScAlN- based pyroelectric detectors respectively. Response times taken for both detectors to detect SF6 concentrations are measured to be ~6.26 s for AlN-based pyroelectric detector and ~1.99 s for 12% ScAlNbased pyroelectric detector. Finally, both pyroelectric detectors’ electrical responses across different frequencies are measured and their 3-dB frequency cutoffs are extracted to be ~13.5 Hz and ~12.6 Hz for AlN- and 12% ScAlN- based pyroelectric detector respectively. The results provide more understanding on characteristics of pyroelectric detectors in SF6 greenhouse gas sensing based on mid-IR absorption.
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Publisher Copyright
Funding Info:
This research / project is supported by the National Research Foundation / A*STAR - Low-Carbon Energy Research (LCER) Funding Initiative (FI)
Grant Reference no. : U2102d2012
This research / project is supported by the A*STAR - RIE2020 Advanced Manufacturing and Engineering (AME) IAF-PP Grant
Grant Reference no. : A1789a0024
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