Comparison of Fast Response and Recovery Pd Nanoparticles and Ni Thin Film Hydrogen Gas Sensors Based on Metal-Oxide-Semiconductor Structure

摘要

In this study, two hydrogen sensors with Pd/SiO2/Si and Ni/SiO2/Si structures have been fabricated. Palladium nanoparticles are synthesized and then deposited on the oxide surface using spin coating. Capacitance-voltage curves for the Pd/SiO2/Si sensor at room temperature and for the Ni/SiO2/Si sensor at 140 degrees C in pure nitrogen and 1% H-2-N-2 mixture are described. The time required for reaching 90% of the steady-state signal magnitude (t(90%)) for Pd/SiO2/Si capacitor was 1.4 s and for Ni/SiO2/Si capacitor was 90 s. The time interval for recovery from 90% to 10% of steady-state signal magnitude (t(10%)) for Pd/SiO2/Si capacitor was 14 s and for Ni/SiO2/Si capacitor was 40 min. For the Pd/SiO2/Si capacitor, the response is 88% and for Ni/SiO2/Si capacitor the response is 29%. Comparison of Pd nanoparticles capacitive-and resistance-based sensors shows that the metal-oxide-semiconductor capacitive is faster and more sensitive than the resistance-based hydrogen gas sensors.