Preparation Of Nanocrystalline Doped WO₃/ITO Bilayer Films And Their Eletrochromic Characteristics

The electrochromic glass is a kind of functional coating glass which can be colored and bleaches between negative and positive electric fields.It is made of three parts,which are the transparent conductive layer,electrochromic layer and the electrolyte.And,the application prospects of the electrochromic glasses are wide,such as "smart",winds,vehicle rear view mirrors,display devices and so on.However,there are some problem.s to the materials,such as the slow response time,low coloring efficiency,narrow modulation spectrum of the solar spectrum and so on,which are limited to its application.The main reasons among these problems are the low performance of the transparent conductive materials and weaker color-switching behavior of electrochromic materials.This paper focused on modifying the tin doped indium oxide films(ITO)and amorphous tungsten oxide films(WO3)to enhance their performances.The(400)orientation ITO film and its optic-electro properties have been studied.Simultaneously,the modification rules of nano-In2O3 for amorphous WO3 films have also been researched.And a better performance electrochromic glass device with wide broadband modulation m odified has been fabricated,and the specific work and results in this paper as follows:1.The ITO sols were prepared of In(NO3)3·4.5H2O,SnCl4·5H2O as raw materials,acetyl acetone(Ac AcH)as chelating agent,ethanol(EtOH)as solvent.And ITO films were deposited on the soda lime glass substrates by spray pyrolysis.Furthermore,the ef'fects of AcAcH contents to the crystal structure,surface morphology and photoelectric properties of ITO films have been studied.The results show the ITO film is a polycrystalline film wirth cubic bixbyite structure,its surface morphologies is smooth.And the resistivity and average visible light transmittance rate are 5,19×10-4·cm and 81.4%,respectively.2.In order to improve the electrical and optical properties of ITO films,the(100)orientation ITO films have been,prepared of InCl3·4H2O?SnCI4·5H2O as raw materials,EtOH as solvent.And theirs orientation,surface morphology and photoelectric properties have been investigated.The results reveal the electrical property of ITO films with(400)orientation is better than the ones with random orientation.The values of resistivity and average visible light transmittance rate are 3.86×10-4?·cm and 81.2%,respectively.3.Nano-In2O3 doped WO3 composite films have been fabricated of WC16 as raw materials,ln(NO3)3·4.5H2O as doped materials,EtOH as solvent under the heat-treatment temperature of 250? by sol-gel method.The nano-In2O3 crystals with 7nm in the amorphous WO3 film are exhibited from TEM images,and enhanced its coloring-bleaching performance of amorphous WO3 film greatly in visible band,shortened its response time,added the near-infrared(NIR)modulation behavior to it.4.The electrochromic WO3 glass device was be fabricated using the excellent ITO substrate as counter electrode,nano-In2O3 doped amorphous WO3 electrochromic films as work electrode,LiClO4 propylene carbonate solution as electrolyte,sarin resin as packaging materials.Its performance has tested through the self-made circuit.The measurement data indicate the electrochromic WO3 glass device has a good behavior from NIR to visible light range,and the coloring and bleaching times are 4s and 2s,respectively.5.To extend the application of WO3 thin film in micro electronics semiconductor field,this paper also discusses a novel method for patterning the WO3 thin film.A stable photosensitive In2O3 doped WO3 sol was prepared using WC16 as raw materials,In(NO3)3.4.5H20 as doped materials,2,2-dipyridyl(bpy)as chemical modifier and EtOH as solvent.The sol has a good photosensitive behavior due to a stable W/bpy metal chelate in this sol,and can be utilized to fabricate the inorganic In2O3 doped WO3 micro-patterns.