Nanocomposite NiO:Au hydrogen sensors with high sensitivity and low operating temperature

• Published in: Materials research bulletin 2014-01, Vol.49, p.552-559
• Main Authors: Kandyla, M., Chatzimanolis-Moustakas, C., Koumoulos, E.P., Charitidis, C., Kompitsas, M.
• Format: Article
• Language: English
• Subjects: A. Composites; A. Oxides; B. Laser deposition; B. Sputtering; D. Electrochemical properties
• ISSN: 0025-5408; 1873-4227
• DOI: 10.1016/j.materresbull.2013.09.044

•The sensors were able to detect 2ppm of hydrogen concentration in air.•The operating temperature was as low as 125°C.•Performance of sensors improved significantly in the presence of Au nanoparticles.•The nanomechnical properties of the sensors can be controlled by annealing. We present results on the development of nanocomposite NiO:Au thin-film hydrogen sensors, which are able to detect hydrogen concentrations as low as 2ppm in air, operating at low temperatures in the range 125–150°C. Thin NiO films were sputter-deposited on oxidized silicon substrates. The structural, morphological, and nanomechanical properties of the films were investigated with respect to post-deposition annealing. Au nanoparticles were added on the NiO surface via pulsed laser deposition and the films were tested as hydrogen sensors before and after Au deposition. The performance of the NiO films as hydrogen sensors improved significantly in the presence of Au nanoparticles on the surface. The detection limit (lowest detectable hydrogen concentration) decreased by two orders of magnitude, while the response time also decreased by a factor of three.