Solvothermal Preparation Of Ito (indium-tin Composite Oxide) Nano-sized Powders And Performance Study

The structures, capabilities, widely appliance fields and preparationtechniques of ITO nanopowders were summarized in this paper.ITO nanopowders have been prepared by solvothermal process. Theeffects of solvothermal process parameters on the prepared ITO powders'compose, crystal, granularity, capability were studied, such as solvent,prepared temperature, time, coprecipitate pH, SnO₂ content and so on.The solvent can affect the prepared powders. The results showed thatthe temperature of preparing ITO powders was different when the solventwas different. Dark blue ITO powders with cubic structure could beprepared at 250℃for 6h using ethanol as solvent. TEM showed thepowders were well crystal square nanopowders with the size of～60 nm.The powders' crystallization and dehydration were poor when thesolvothermal temperature was under 250℃or solvothermal time was lessthan 6h. By XRD analysis, it was found that the low alkalinity of solutionwasn't benefit to the coprecipitation of In³⁺ and Sn⁴⁺. The samples wereITO nanopowders at different SnO₂ content even though SnO₂ contentwas 15%The elementary combine state of ITO was examined by XPS. It wasfound that in ITO crystal Sn shifted from +4 to low combine state, andoxygen atom was not simply combined with In³⁺ and Sn⁴⁺, it hadcomplicated electron shift.ITO has characteristics of bandwidth and high carrier concentration,which makes ITO show excellent electric and optical performance. In thisstudy, the resistance rate of ITO nanopowders could reach 0.06Ω·cm. Themaximal microwave absorption was-32dB.The frequency breadth ofunder-10dB could reach 2.4GB.Also the growth mechanism of ITO nanopowders in solvothermalprocess was discussed in this paper.