退火对二氧化钛薄膜光学性能的影响

The Effect of Annealing on the Optical Properties of TiO_2 Thin Films

采用改进的溶胶-凝胶(sol_gel)法在载玻片上制备了TiO2薄膜。对TiO2干凝胶粉末进行了差热分析(DTA);用分光光度计测试了TiO2薄膜500℃退火前后的透射谱,采用"包络法"计算了TiO2薄膜的折射率、厚度和带隙。结果表明:当波长从700nm减小到400nm时,薄膜的折射率从1.465增加到1.485。退火前后TiO2薄膜的厚度分别为595.836nm和652.4547nm。未退火TiO2薄膜的光学带隙为3.85eV,500℃退火后TiO2薄膜的光学带隙为3.67eV。与未退火薄膜相比,500℃退火后TiO2薄膜的吸收边出现了"红移",光响应区范围变大,提高了可见光的利用率。

A TiO2 film was prepared on the glass slide by a modified sol-gel method.The TiO2 powder was analyzed by DTA.The transmission spectra of the film without annealing and after 500 ℃ annealing were tested by spectrophotometer,and the refractive index,thickness and band gap of the film were calculated using envelope method.The results show that the refractive index increases from 1.465 to 1.485 when the wavelength decreases from 700 nm to 400 nm.The thickness of the film without and after 500 ℃ annealing is 595.836 nm and 652.454 7 nm,respectively.The band gap of the film without annealing is 3.85 eV,and that after 500℃ annealing is 3.67 eV.Compared with the film without annealing,the absorption boundary of the film after 500 ℃ annealing has a red shift,and the light response area is enlarged,which increases the utilization ratio of visible light.