Study On The Process Of Preparing SnO₂ Based Thermal Insulation Film By Sol-gel Method

Tin oxide?Sn O₂?is an n-type wide band gap semiconductor material with good chemical stability and excellent optoelectronic properties.It is a good transparent conductive material.It is widely used in solar cells,flat panel displays,gas sensors,infrared detection protection and other fields.In this paper,Sn O₂ film,ATO film and ATO/YTO composite film were prepared by sol-gel method and dip-pull coating technology.The structure and properties of the film were investigated by Scanning electron microscope,X-ray diffractometer,Hall effect tester and UV-Vis-NIR.In this paper,the thermal insulation performance of the film is characterized by the near-infrared transmittance of the film.The lower the near-infrared transmittance of the film,the better the insulation of the film.The main research contents and results are as follows:?1?The effect of Sn Cl₂·2H₂O:Et OH molar ratio on the structure and properties of Sn O₂ films was investigated.With the change of Sn Cl₂·2H₂O:Et OH from 1:50 to 1:70,the particle size of the Sn O₂ film gradually decreases,the sheet resistance and resistivity decreases first and then increases,the carrier concentration increases and then decreases,and the average visible light transmittance increases first and then decreases.When Sn Cl₂·2H₂O:Et OH=1:60,the sheet resistance and resistivity of the film are the smallest,which are 4.98×10⁵?/?and 30.5?·cm,respectively.The carrier concentration is the largest,2.28×10¹⁸ cm^-3.The average transmittance of visible light is the highest,87.71%,and the average transmittance of near-infrared light is 92.72%.?2?The effect of heat treatment temperature on the structure and properties of Sn O₂films was investigated.With the increase of the heat treatment temperature,the particle size of the Sn O₂ film increases significantly,the full width at half maximum becomes narrower and narrower,and the degree of crystallization becomes better and better.In addition,as the heat treatment temperature increases from 400°C to 800°C,the sheet resistance of the film decreases first and then increases,the resistivity decreases first and then increases,and the carrier concentration increases first and then decreases.That is to say,the conductivity of the film increases first and then decreases.The average visible light transmittance of the film also reached the highest when the heat treatment temperature was 600°C.?3?The effect of Sb doping amount on the microstructure and photoelectric properties of ATO films was investigated.The results show that the doping of Sb will reduce the crystallinity of the film,the?110?diffraction peak of the film becomes significantly wider.The particle size of the film gradually decreases with the increase of the Sb doping amount,and remaines basically unchanges when the Sb doping amount reaches 9 mol%.When the Sb doping amount is 11 mol%,the average visible light transmittance of the film is more than 80%,and the average transmittance of near-infrared light is 60.48%,which is 32.24%lower than that of Sn O₂ film.This indicates that Sb doped Sn O₂ film has an obvious thermal insulation effect.?4?The effect of Yb doping amount on the microstructure and photoelectric properties of ATO/YTO composite films was investigated.With the increase of the Yb doping amount,the grain size of the film gradually increases,and the conductivity of the film increases first and then decreases.When the Yb doping amount is 9 mol%,the average visible light transmittance of the film is 78.98%,and the average transmittance of near-infrared light is 27.86%.Compared with ATO film,it has better thermal insulation effect.