The Research On Fabrication And Methane Gas Sensitivity Performance Of Noble Metal Doped VO₂ Thin Films

Over the years,natural gas and gas explosion bring huge personal injury and property loss to miners and urban residents.And the main components of the natural gas and the gas are methane?CH4?.CH4 is a colorless,odorless gas and it is very difficult to test.At present,the semiconductor oxide CH4 sensor with high sensitivity,stable performance and low cost advantages,has been paid great attention in many scientific researchers.However,the materials of traditional mainstream methane semiconductor oxide sensor such as ZnO and SnO₂,need high working temperature.That means that the preparation of the sensor requires heating device,higher cost,and high temperature testing,which will make the life of the sensor shorter,stability,power consumption increase.Therefore,developing the methane sensor with high sensitivity,low temperature detection has become a top priority.The recent study found that vanadium dioxide?VO₂?could detect CH₄ at lower temperatures.This attracts the attention of the many researchers.But the response sensitivity of VO₂ is not high.The concept for the above problems,this topic mainly studies a new type based on the composite structure of VO₂ sensor sensitive materials to detect CH₄,especially for the design and preparation process were studied.This paper content mainly includes two parts:one is precious metals gold?Au?of VO₂ thin film of CH₄ gas sensitive properties of doped,another part is for VO₂ thin film precious metal platinum?Pt?doping of methane gas sensitive properties.Using X-ray diffractometer?XRD?,field emission scanning electron microscopy?FESEM?research the morphology and size of the VO₂ film.With a four-point test VO₂ thin film phase transition properties and gas sensitive test system on the properties of VO₂ thin film gas sensor research.This experiment,mainly by magnetron sputtering and rapid annealing furnace prepare VO₂ thin films.And the doped is by sputtering method.Experiment using a single variable method,by changing the sputtering time,annealing temperature,holding time to study each of doped VO₂ thin film of gold and platinum on methane gas sensitive properties.Form the improving the sensitivity of CH₄,the Au/VO₂thin film is higher than Pt/VO₂ thin film.The study found that the optimal test CH₄concentration of the Au/VO₂ thin film is 1500ppm and the maximum response is 25.3.On the other hand,from the aspects of changing topography,Pt/VO₂composite film is better than Au/VO₂ thin films.