Comparative Study of Unmodified WO3-ZnO and Au-Modified WO3-ZnO Based Thin Film Sensor Fabrication for Enhanced CH4 Gas Sensing Performance

WO
₃
-ZnO and gold modified WO
₃
-ZnO based thin film sensors were successfully fabricated and prepared by sol-gel process at room temperature. The prepared and deposited film was characterized by field emission scanning electron microscopy(FESEM), X-ray diffraction (XRD)and TEM (transmission electron microscopy). The gas sensing properties of Au modified WO
₃
-ZnO thin film showed that deposited metal oxides have greatly influenced on enhanced response towards CH4 gases. The response magnitude was determined by various methane gas concentration and different operating temperature ranges of 50°C-350°C. It was establish that at the operating temperature of 150°C, gold- modified WO
₃
-ZnO thin film sensor has the highest response (65%)as compared to WO
₃
-ZnO samples.