Synthesis of ZnO-SnO2 Nano-Thin Films on Porous Silicon as NH Gas Sensing Performance

Abstract

ZnO-SnO2 nano thin films were fabricated by chemical spray pyrolysis technique on glass and porous silicon slides at 400°C. The structural properties of the prepared mixed films were studied by XRD and AFM techniques. It was found that the structure is a polycrystalline with nano grain size for the preferential orientation along (002) of ZnO. The prepared gas sensor of mixed ZnO-SnO2 nano composite give a highest sensing response for 63 ppm NH3 gas with (35%) on glass substrate at 200°C. High response and recovery times of 156 and 210 sec, respectively were found. The sensitivity of the prepared films on the glass is better than on porous silicon. The sensitivity, response time and recovery time were discussed in this study.