Development Of Formaldehyde Gas Sensor

Formaldehyde is widely present in industrial manufacturing and home decoration,it is harmful to human health especially for the carcinogenicity.Therefore,rapid detection of formaldehyde is related to people’s lives and health,which has far-reaching significance.According to the excellent features of SnO2 materials and doping processes on SnO2,formaldehyde sensor is produced in this paper.Finally, I test the formaldehyde sensor performance.Au electrode on the Si is manufactured by oxidation, photolithography, sputtering, peeling process. SnO2 thin films,Ti-doped SnO2 thin films and Cu-doped SnO2 thin films are manufactured by Sol-gel,the films are coated on the electrode before drying process and annealing process.The films are also analyzed by XRD,SEM and AFM.By comparison,550 is the best annealing temperature.Diameter of the particles Cu doped ℃is about 25 nm.The thickness of the film is 180 nm.The particles disperse well which meet the test requirements.Ti-doped SnO2 thin film is manufactured by magnetron sputtering too.By gas sensing properties,240 ℃is the best optimum temperature for doped element.and 230℃ is for the doped.Undoped, Ti-doped and Cu-doped components are measured sensitivity,reproducibility,response time and recovery time etc.By comparison,Ti-doped element is better than Cu-doped element, Cu-doped element is better than the undoped element, especially the sensitivity is more obvious.Compared with the case of the undoped, response time and recovery time of the doped element has a significantly shorter.In this paper, the principle of difference is discussed.