Zn–Sn–Sb–O thin film sensor for ppm-level NO2 detection

Various composition of Zn–Sn–Sb–O thin film was deposited on an alumina substrate by sputtering in O2 and Ar mixture from constituent metal targets. The electrical resistance of Zn–Sn–Sb–O films that compositions were Zn/Sn=2.3 and the Sb/(Zn+Sn+Sb)=0.4 to 0.6 were remarkably low, and showed high sensitivity to 5 ppm NO2 in air at 400 and 600°C. In addition, almost no sensitivity to 50 ppm i-C4H10 and 50 ppm CO was observed.