浸渍式提拉法制备TiO2薄膜的微观结构和润湿性

目的研究工艺参数与TiO_2薄膜的微观结构、光学性质及润湿性的关系。方法以钛酸四丁酯为原料,乙醇为溶剂,采用溶胶-凝胶浸渍式提拉法,改变工艺参数(提拉次数、提拉速度),在玻璃衬底上制备了TiO_2薄膜,并通过光学表面形貌仪、紫外可见分光光度计及接触角测试仪分析了不同参数下制备的TiO_2薄膜的微观结构、光学性质和润湿性。结果提拉次数和提拉速度都会影响薄膜的微观结构,提拉2次,提拉速度在3~7 cm/min之间制备的TiO_2薄膜表面平整、致密。在提拉方向上,存在厚度梯度,厚度梯度为1 nm/μm。透射光谱显示TiO_2薄膜在可见光区透明,吸收边与提拉工艺有关,提拉速度为7 cm/min,提拉2次制备的TiO_2薄膜,禁带宽度为3.57 e V,此时,接触角为14.8°。结论提拉速度、提拉次数影响TiO_2薄膜的微观结构、光学性质和润湿性。通过提拉工艺参数的调整,可以制备均匀致密、具有亲水性的半导体TiO_2薄膜。

Microstructure and Wettability of TiO2 Thin Films Prepared by Dip Coating Method

The work aims to investigate the relationship between process parameters and microstructure, optical properties, or wettability of TiO2 thin films. With tetrabutyl titanate as raw materials and ethanol as solvent, the TiO2 thin films were pre-pared on glass substrates with different process parameters (withdrawal times and withdrawal speed) by virtue of sol-gel dip coating method. The microstructure, optical properties and wettability of TiO2 thin films prepared with different process para-meters were analyzed by optical surface microscopy, ultraviolet and visible spectrophotometer and contact angle tester. Micro-structure of TiO2 thin films was influenced by withdrawal times and withdrawal speed. Uniform and dense films were produced provided with withdrawal times of 2 times and withdrawal speed of 3 to 7 cm/min. Thickness gradient (1 nm/μm) was present in the withdrawal direction. Transmitted spectrum showed that the TiO2 thin films were transparent in visible region. The absorp-tion edge related to the withdrawal process. The forbidden band width of TiO2 film prepared at withdrawal speed of 7 cm/min and withdrawal times of 2 times was 3.57 eV while contact angle was 14.8°. The microstructure, optical properties and wettabil-ity of TiO2 thin films are influenced by withdrawal speed and withdrawal times. Uniform, dense and hydrophilic semiconductor TiO2 thin can be fabricated by adjusting the withdrawal process parameters.