The role of interdigital electrodes on sensing performances with p-type NiO-based gas sensors -link to experiments

The effect of interdigital gap distance on the sensing performance was evaluated towards carbon monoxide target gas with p-type NiO-based gas sensors. Both base electrical resistance and sensor signal increase with the interdigital gap distance increase. While the former is a direct consequence of the high resistive bulk component, the latter was attributed to the decrease in the gas-insensitive metal-semiconductor contacts. A numerical simulation of the sensor signal concerning the interdigital gap and grain size revealed the “dead” role played by the metal-semiconductor contacts in the overall gas sensing performance.