Semiconductor gas sensor using SrO-modified SnO₂ for the detection of N₂O in air

A semiconductor-type sensor applicable to the monitoring of N₂O in air was studied. As revealed by a screening test, n-type oxides such as SnO₂, In₂O₃, WO₃, and ZnO were more or less sensitive to N₂O, while the highest sensitivity was obtained with SnO₂. However, the N₂O sensitivity of SnO₂ was not sufficient for practical application. The addition of SrO to SnO₂ was effective for improving N₂O sensitivity. Thus 0.5 wt % SrO-SnO₂ was about three times as sensitive as pure SnO₂, allowing good detection of 10-300 ppm N₂O in air at 500 °C.