Preparation And Characteristic Of Doped Vanadium Oxide

As a high-quality optoelectronic material, vanadium oxide has shown great potentialfor semiconductor devices and optical devices. Vanadium oxide has dozens of differentcrystal phase. And in these structures, VO₂and V₂O₅have the most concerns because oftheir scientific value and potential of application. VO₂is a thermo-sensitive materialwhich has thermal phase transition properties. With the increase of temperature, thesemiconductor-to-metal phase transition will occur at approximately68°C, with anabrupt change of optical and electric properties. And because of these changes, VO₂hasgreat potential for smart window, micro bolometer, information storage and so on. V₂O₅has good catalytic property, and it is widely used as catalyst in various electrochromicmaterials. And these years, V₂O₅has received much attention for it’s great potential formicro bolometer.Pure vanadium oxide material can not meet the actual demand, so vanadium oxidewas usually doped to improve it’s performance. In this dissertation, VO₂/VMoOX/VO₂and V₂O₅/Mo/V₂O₅thin films were deposited by DC magnetron sputtering method. Inthe experiments, The structure, TCR and optical transmission of the vanadium oxidefilms will be analyzed. The paper includes the following aspects:1. According to the solid atoms diffusion effect, the diffusion-concentration of Moatoms will be changed by altering the annealing time or the deposition time of Momiddle layer to change the microstructures, electrical and optical properties of films.Results show that the sheet resistance and phase-transition temperature was reducedeffectively and TCR of the films was increased by Mo-doping. It’s also found thatO₂/Ar had remarkable effects on the phase-transition and optical properties ofVO₂/VMoOX/VO₂films. The optical transmittance will increase with increasing O₂/Ar,and the semiconductor-metal transition characteristic will decline with increasing O₂/Ar,when O₂/Ar=5.0, the characteristic disappeared.2. The same method was used to prepare V₂O₅/Mo/V₂O₅film. According to theanalysis, molybdenum can restrain the growth of high-valence vanadium ions, and thesheet resistance was reduced by Mo-doping. Annealing can reduce the film’s defects， enhance the TCR of the film, but if the annealing time is too long, the TCR willdecrease then.On the basis of the above researches, preparation and characterization of thevanadium oxide doped with molybdenum were further acquainted and comprehended.And the results show that doping is an effective way to improve the properties ofvanadium oxide thin film.