Highly sensitive and selective WO3 nanoparticle gas sensor operating in thermally modulated dynamic mode

R. Ionescu, A. Hoel, C. G. Granqvist, E. Llobet, P. Heszler

Research output: Contribution to journalConference article

1 Citation (Scopus)


Nanoparticle films of crystalline WO3, designed for gas sensing applications, were deposited on alumina substrates b reactive gas deposition. 2S, ethanol vapour, and binary mixtures of ethanol/H 2S, ethanol/NO2 and H2S/NO2 were used in different concentrations for testing the performance of the sensor device. The sensor was operated in dynamic mode by modulating its temperature between 150 and 250°C. Coefficients were extracted by applying Fast Fourier Transfer (FFT) and Discrete Wavelet Transform (DWT) methods to the dynamic resistance response of the sensor. These coefficients were then used as inputs for pattern recognition methods to extract both quantitative (concentration) and qualitative (chemical selectivity) information about the test gases. After sensor calibration, it was possible to detect as little as 200 ppb of ethanol and 20 ppb of H2S with good accuracy. Furthermore, ethanol and 2S could be detected with good sensitivity and selectivity in the presence of both reducing and oxidising gases.

Original languageEnglish
Pages (from-to)347-358
Number of pages12
JournalProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - Sep 13 2004
EventNoise and Information in Nanoelectronics, Sensors, and Standards II - Maspalomas
Duration: May 26 2004May 28 2004



  • Discrete Wavelet Transform
  • Fast Fourier Transform
  • Gas sensor
  • Pattern recognition
  • Temperature modulation
  • Wo nanoparticle

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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