An FET-based microsensor using a proton conductor for detecting a small concentration of H2 in air at room temperature has been fabricated by attaching an antimonic-acid thick film (≈ 20 μm thick) and a sensing Pt electrode to an ISFET device. Under a constant drain current (ID) at 30°C, the output voltage (VGS) between the sensing electrode and the source is almost linearly correlated with the logarithm of H2 concentration in the range 4-5000 ppm. The slope of the correlation, ≈ - 120 mV/decade, is comparable to that for the non-FET type solid-state potentiometric H2 sensor previously reported. The 90% response time to 5000 ppm H2 is as short as ≈ 5 s. The H2-sensing mechanism of the present microsensor is briefly discussed.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrical and Electronic Engineering
- Materials Chemistry