Metal oxide semiconductor N2O sensor for medical use

Abstract In order to develop a semiconductor type gas sensor applicable to the monitoring of N 2 O in air, a search for the semiconducting oxides sensitive to N 2 O was carried out. Among the 23 kinds of single oxides tested, SnO 2 turned out to give the highest sensitivity to N 2 O, although the sensitivity was not high enough. The N 2 O sensitivity was found to be promoted effectively when SnO 2 was loaded with a small amount of a basic oxide such as SrO, CaO, BaO, Bi 2 O 3 and Sm 2 O 3 . The promotion was particularly conspicuous with SrO loading. For example, 0.5 wt.% SrO-loaded SnO 2 , exhibited the N 2 O sensitivity about three times as high as that of pure SnO 2 , and could detect N 2 O in air fairly well in the concentration range of 10–300 ppm at 500°C.