溶胶-凝胶法制备TiO_2薄膜及其光学性能的研究

Study on the optical properties of TiO_2 thin films by preparation of sol-gel method

采用溶胶-凝胶法在K9玻璃上制备了均匀、透明、裂纹较少的纳米TiO2薄膜,以无水乙醇用量、涂层数、煅烧温度为影响因素,设计L9（3）4正交试验,以薄膜的透明度、微观致密程度作为评价标准,讨论了无水乙醇用量、涂层数和煅烧温度对制备TiO2薄膜光学性能的影响.用反射式椭圆偏振光谱仪测试最佳制备工艺下制得的TiO2薄膜的椭偏参数,并用Cauchy模型对椭偏参数进行数据拟合.结果表明,薄膜最优制备工艺参数为无水乙醇用量30mL、涂层数为2层、煅烧温度为550℃;Cauchy模型能较好的描述溶胶G凝胶薄膜在300-700nm波段的光学性能;薄膜的折射率和消光系数都有随波长增大而减小的趋势且制备的薄膜具有随着膜层数的增加,折射率增加,而最大峰值透光率、孔隙率减小的规律.

Uniform,transparent and crack less TiO2thin films on K9 glass were prepared by using the sol-gel method.The influernce of absolute ethyl alcohol,coating layers and annealing temperature on optical properties of TiO2thin films were investigated by orthogonal table-L9( 3)4,the transparency of thin film and the degree of microscopic dense as evaluation criteria. Spectroscopic ellipsometer was used to characterize the optical properties of the film and the Cauchy model was presented in fitting spectroscopic ellipsometric data. The results showed that the optimum conditions as follows: absolute ethyl alcohol was 30 mL,coating layers was 2 and annealing temperature was 550 ℃. Cauchy model could describe optical properties of TiO2 film very well in 300-700 nm waveband. The modified films have a law that with increased the number of layers,the refractive index increased,and the maximum peak transmittance porosity reduced.