Fabrication And Photoelectric Properties Of TiN Thin Films By Ultasound Atomization Assisted Vapor Deposition

TiN has the characteristics of low intrinsic resistivity,low emissivity and good mechanical stability.It has a wide application prospect in the field of low-emissivity coating.However,the traditional methods of physical vapor deposition and chemical vapor deposition have very strict requirements on the preparation process and environment.In this paper,TiN coated glass was successfully prepared by ultrasonic atomization spraying with TiN nanoparticles as precursors in low temperature open-loop environment.The dispersion stability and particle size distribution of TiN nanoparticles in organic system and water system were studied.TiN nanoparticles in water system with good stability and small particle size distribution were obtained.The effects of dispersion size of precursors on phase composition,morphology,optical properties and hydrophilicity of TiN films were also studied.Low-emissivity coated glass is a thin film system consisting of single or multi-layers of silver and other metal or compounds with good conductivity.It has high transmittance to visible light and high reflectivity to infrared light,so it has good thermal insulation.In this paper,10 batches of coated glass samples prepared by different processes at home and abroad are selected to study their structure and properties.Based on the theoretical analysis and calculation,a feasible membrane structure design idea for improving the radiation performance of the film is proposed.The results are as follows:(1)By adjusting the pH value of the solution and adding Tween80 dispersant combined with ultrasonic treatment,the isoelectric point of TiN powder in aqueous solution decreased from pH1iep = 5.67 to PH2iep = 4.95,the absolute value of Zeta potential on the surface of the powder was controlled above 40 mV,and the optimum ultrasonic treatment time was 30 min,the stable dispersing solution with particle size distribution around 170 nm could be obtained.Ball milling for 16?20h can promote the combination of Tween80 and powder,and stable dispersions with particle size less than 200 nm can be obtained at higher concentration.(2)The particle size distribution of dispersant has a great influence on the morphology and properties of TiN films deposited by ultrasonic atomization.TiN thin films deposited by dispersions with a particle size of 65 nm are compact and uniform.After vacuum heat treatment,the contact angle increases from 0°to 80° and the surface O content and crystallinity increase.TiN/TiO2 composite films were prepared by air oxidation at 350?500?.The film changed to crystalline TiO2 at 400? or above.Carbides were formed on the surface by oxidation of residual organic matter during oxidation,which affected the hydrophilicity of the films.Porous TiN films were deposited by 170 nm TiN dispersion with strong optical absorption.Vacuum heat treatment changed the films contact angle from 0° to 153° Residual water and organic dispersants in the films were volatilized and decomposed.The amorphous phase of TiOxNy on the surface was gradually transformed to TiO2.The decomposition of the dispersants and reduced surface energy resulted in superhydrophobicity.(3)The emissivity of transparent conductive films has a great relationship with the conductivity and morphology of films.F" ion doping can promote the growth of(200)crystal plane,increase the carrier concentration of films.Increase the thickness of films and reduce the roughness of films,which can further improve the emission properties of films.The results show that the structure design of "barrier layer +functional layer" and the effective doping of F-ions can make absolute reflectance of the film approaches the total reflectance curve so as to minimize the scattering effect.The thickness of the film is controlled over 600 nm,the surface roughness R,<15 nm,and the resistivity is less than 6.×10-4? cm,the emission can be achieved markedly reduced.The above results are of great significance for exploring the improvement of low radiation properties of coated glass,expanding the application fields of preparing thin films with nano-dispersant precursors,and further studying the influence of chemical state of nano-powder surface on the surface properties of thin films.