(ZnO)_1-x(SnO₂)_x/c-nSi gas sensors prepared by pulsed laser deposition technique for selective detection of nitrogen dioxide

Compounds of (ZnO)_1-x(SnO₂)_x were prepared with various proportions of tin oxide (SiO₂) (x = 0.0, 0.2, 0.4, 0.6, 0.8, 1.0) by mixing zinc oxide (ZnO) with high-purity tin oxide and then sintering the mixture in an oven at a temperature of 1000 °C for a period of 1 h. The resulting powders were ground and pressed into tablets of 1 cm diameter and 0.5 cm thickness. The properties of (ZnO)_1-x(SnO₂)_x composites films were prepared and studied as sensitive to the different gases NO₂ and H₂S. Thin films were prepared from (ZnO)_1-x(SnO₂)_x via pulsed laser deposition method using glass and single crystal silicon for investigation the morphology and gas sensing properties with a thickness of 150 nm. The morphology examination was done using atomic force microscopy. The results show the average grain size change in non-regular manner while and surface roughness increase by increasing of tin oxide ratio. The sensitivity measurements showed that the highest sensitivity 85.6% and 66.6% was obtained from SnO₂/c-Si at room temperature toward NO₂ and H₂S with the lowest response time 14 and 26 s respectively.