制备条件对TiO_2薄膜结构和光学性能的影响

借调节sol-gel法中溶胶的pH值,薄膜的热处理温度,研究了它们对TiO2薄膜的晶相组成、晶粒大小、表面结构和紫外及可见光吸收性能的影响。结果表明:pH为7时有利于TiO2由锐钛矿向金红石相转变,薄膜的孔隙度为94nm,有较高的表面粗糙度。pH值升高,TiO2薄膜的孔隙度和颗粒度增大;热处理温度升高,薄膜的紫外吸收发生红移,可见光波段透射率降低,故最佳热处理温度为500℃。

Effects of preparing conditions on structure andoptical property of nano TiO2 thin films

Microporous TiO2 thin films were fabricated by the sol-gel method. The influences of pH and the heat treatment temperature on structure and optical property of films were identified. By control the pH value of sol and the temperature of heat treatment,their crystal structure,grain size,surface morphologies and UV-vis absorption and transmittance were compared. The results indicate that phase of TiO2 has a trend of transforming from anatase to rutile at pH=7,the films have a roughness surface,and the pore size is 94 nm. As the increasing of pH value,the size of pores and grains increase. With the increasing of heat treatment temperature,the films have a red-shift of absorption edge in ultraviolet spectrum and the transmittance decreases in visible spectrum,the optimum therefore,heat treatment temperature is 500 ℃.