Development Of WO₃ Thin Film Gas Sensor And Its Detection Device

Tungsten trioxide?WO₃?is a common n-type semiconductor,which is widely used in the field of gas sensing because of its simple synthesis method and low cost.In this paper,WO₃thin film gas sensor was fabricated on porous silicon substrate,its gas sensing characteristics were studied,and the corresponding detection device is designed.In this paper,firstly,porous silicon substrate was prepared by metal chemical etching,and then tungsten oxide thin films were grown on porous silicon substrate by hydrothermal method and magnetron sputtering method respectively to form porous silicon based WO₃thin film gas sensor.XRD,SEM and EDS were used to characterize the composite structure of the porous silicon-based tungsten oxide film,and the gas sensing performance of the film was tested and analyzed by the gas sensor detection device.The experimental results show that the porous silicon substrate tungsten oxide thin film gas sensor formed by this method has good selectivity for NO₂gas and can reduce the optimal operating temperature of tungsten oxide to room temperature.The sensitivity of WO₃thin film sensor based on porous silicon to 1 ppm NO₂is 2 and 2.5respectively at room temperature.The results show that the gas sensing performance of the tungsten oxide thin film gas sensor prepared on porous silicon substrate by sputtering method is better than that by hydrothermal method.According to the performance of gas sensor,the corresponding gas sensor detection device is designed and its feasibility is verified by simulation.