Dynamic properties of SnO2 semiconductor gas sensors sensing of hydrogen contained in air

The dynamic properties of SnO2 semiconductor gas sensors were studied by measuring the transient response conductivity after rapid changes in the concentration of H2 in air at 773 K using pulse reaction technique. The sensor used was a thin film SnO2 semiconductor without other additives, which was produced by reactive sputtering. Transient response conductivity after a rapid change from pure air to H2 in air was measured. In the initial period, the square of sensor conductivity values increased linearly, and after the initial period, the difference between the values and steady-state values decreased exponentially. The transient response conductivity from H2 in air to pure air was measured. The sensor conductivity values decreased exponentially. To explain these and steady-state results, the authors suggest an overall relationship between H2 concentration and conductivity of the sensor for both steady-state and transient response, which is in satisfactory agreement with the experiment. 14 refs.