Study On Vanadium Dioxide Film And Laser Protection

The vanadium dioxide film has good characteristics of metal insulation phase transition,and it can occur in a very short time under the action of external excitation(electricity,heat,light,etc.).In this process,there will be a sudden change in physical properties such as resistivity and optical transmittance.It is an ideal material for photoelectric switches,new multifunctional materials,and photoelectric modulation.In this paper,VO₂ thin film with excellent performance was developed by ion beam sputtering,and then researched on VO₂in laser protection.The main content of this thesis are as follows:1.The research background and phase transition theory of VO₂ are introduced in detail.The Drude model and Lorentz model are introduced to study the optical constants of VO₂,which provides a theoretical basis for subsequent theoretical simulations and experiments.2.TFCalc and FDTD Solutions software were used to analyze and design the VO₂-based film structure and planar phase change metalens.The film structure achieves a mid-infrared band 3-5?m normal temperature transmittance of more than 90%and a high temperature transmittance of less than 1%,which solves the problems of low normal temperature transmittance and high high temperature transmittance in VO₂ practical applications.The design of the planar phase change metalens realizes the combination of planar focusing and high switching rate VO₂ laser protection.The switching rate reaches91.5%,which solves the problem of a large space occupation of the VO₂ laser protection system,and also provides the design ideas of diversifies the practicality of VO₂.3 The experimental method of orthogonal experiment is used to analyze the influence of various parameters on the performance of VO₂ film when ion beam sputtering is used to prepare VO₂ film,which provides an experimental basis for the subsequent preparation of the high-performance VO₂ film we need.4.The film structure based on VO₂ was actually prepared by PECVD,electron number evaporation method and ion beam sputtering method,and related performance was tested.5.Using continuous laser,picosecond laser and femtosecond laser,etc.,comprehensively tested the relevant performance of VO₂ laser protection,and also conducted a laser protection experiment of silicon photovoltaic cells,further simulating the application of VO₂ in laser protection.