Preparation,Structural Design And Performance Study Of Titanium Dioxide Films By Magnetron Sputtering

Titanium dioxide（TiO₂）is widely used in various fields because of its excellent photocatalytic performance and high dielectric constant.This article successfully prepares a series of TiO₂ thin films by magnetron sputtering method,and conducts in-depth research and analysis on the microstructure,optical properties,photocatalytic performance,and dielectric response of the films.The main research work of this article is as follows:（1）Multi-crystalline rutile phase TiO₂ thin films are successfully prepared on JGS1 substrate by magnetron sputtering method,and the influence of various sputtering process conditions on the crystal structure of the films is investigated.The study finds that TiO₂ thin films exhibit the best crystallinity under the sputtering conditions of Ar:O₂=32:8 and sputtering pressure of 1 Pa.（2）Based on the optimized preparation conditions,the effects of sputtering temperature,in-situ annealing time,substrate material,and bottom electrode material on the microstructure,optical properties,and electrical properties of TiO₂ thin films are thoroughly studied.Experimental results show that within the range of sputtering temperature of 400-700℃,TiO₂ thin films gradually transform from amorphous to rutile phase.With the increase of temperature,mixed-phase film samples appear,and finally transform into pure rutile phase TiO₂ thin films.TiO₂ thin films in mixed-phase state exhibit the best photocatalytic reduction activity,while pure rutile phase TiO₂ thin films have the best electrical properties.In addition,with the increase of in-situ annealing time,the crystallinity of the film is improved,but the photocatalytic performance decreases and the dielectric constant increases.TiO₂ thin films are prepared on ITO/JGS1 and ITO/Si substrates,and the ITO electrodes exhibit a（222）single high preferential orientation.TiO₂ thin films prepared on these substrates have good crystallinity,and there is no significant difference in photocatalytic performance.Due to the influence of interface effect,the dielectric response curves of the two substrates have anisotropy.In addition,three heterostructures,TiO₂/Cu/JGS1,TiO₂/ITO/JGS1,and TiO₂/LNO/JGS1,are prepared by depositing different bottom electrodes on JGS1,followed by TiO₂ thin film deposition.Among them,TiO₂/Cu/JGS1 has an obvious polycrystalline structure,the highest dielectric constant,and the photocatalytic activity of the three heterostructures is greatly improved compared to the intrinsic TiO₂ thin film.（3）The effects of ZnO film composite and Mo doping on the microstructure,optical properties,and electrical properties of TiO₂ thin films are studied,and first-principles analysis and calculations are performed on Mo-doped TiO₂.The Zn O/JGS1 sample exhibits a（002）high preferential orientation,while the addition of Zn O in the TiO₂/Zn O/JGS1 heterostructure partially inhibits the crystallization of TiO₂ thin film to some extent,reduces the dielectric constant,and enhances the photocatalytic activity.Mo doping replaces some Ti atoms in TiO₂,and with the increase of doping amount,the main peak intensity of TiO₂ XRD spectrum weakens and shifts due to lattice distortion.The photocatalytic performance is improved.In addition,the band gap and state density of Ti₁₆O₃₂ and Ti₁₅Mo O₃₂ models are calculated through first-principle analysis to provide theoretical support for the experimental results.