Preparation Of Doped Tin Oxide Thin Films By Spray Pyrolysis Process

The preparation process of thin films by spray prolysis was studied.By using SnCl4 · 5H2O,SnCl3 and ZnO as raw materials, the doped SnO2 thin films have been prepared on the quartz glass tube substrates. The effects of Sb and Zn contents, as well as annealing treatment on resistance of the SnO2 thin films were studied. Using SnCl4·5H2O and NH4F as raw materials,the Flourine-doped SnO2 thin films also have been prepared on the Soda-lime glass and quartz glass flat substrates. The effects of F contents,deposition temperature as well as deposition time on the sheet ressitance and average transmission ratio in visual spectra of the thin films were investigated.The sheet resisttance of the doped tin films was tested by four-point probe meter.The average transmission ratio in visual spectra of the doped tin films was measured throught visible spectrophotometer. The element and the crystal structure of the thin films was charactered using XRD,and surface morphology of the thin films was charactered using SEM.The results shown that the sheet ressitance of the Sb and Zn doped SnO2 thin films could reach at 30 Ω/□ and that the coefficient between temperature and resistance is zero , when the Sb and Zn were doped as 8.2at.% and 4.3at.% respectively in the initial solution and deposited for 12s at 550℃. With the NH4F doped as 32wt.% SnCl4 · 5H2O in the initial solution and deposited for 15s at 450 ℃,the R of the F doped SnO2 thin films could reach at 10Ω/□ and that average transmission ratio in visual spectra is 80%.The results of the calefacting experiment on the the Sb and Zn doped SnO2 thinfilms indicated that the film can be heated up more than 500 houres normally and suit for practical application when the power density of the films is less than 4W · cm-2.After heat treatment the Sb and Zn doped SnO2 thin films becam more compact,at the same time the sheet resistance increased.To the F doped SnO2 thin films,annealing have not distinct influence on the surface morphology of the thin films.After heat-treated 0.5h at 600℃,the sheet resistance of the F doped SnO2 thin films was trebled,but the average transmission ratio in visual spectra is nearly unchangeable.