二甲基甲酰胺对多孔SiO_2薄膜结构和光学性能的影响

Effect of N,N-Dimethylformamide on Structure and Optical Properties of Porous Silica Film

在碱性催化条件下正硅酸乙酯的溶胶体系中,引入二甲基甲酰胺(DMF)进行原位共溶胶凝胶,并结合常压干燥工艺制备多孔SiO2增透薄膜。利用Netzsch热分析仪研究了干凝胶在干燥过程中的热稳定性、用扫描电子显微镜(SEM)对样品薄膜的形态结构进行了表征,用分光光度计考察了DMF对膜层增透性能的影响。实验结果表明,DMF能有效防止凝胶的开裂,抑制颗粒团簇的产生,使胶粒聚联成大的网络结构,提高了成膜性能;DMF的加入能提高薄膜的透射率,使膜层在300～1000nm范围内透射率达99%以上。

Using a base catalysis for the hydrolysis of tetraethyl orthosilicate （TEOS）,porous silica antireflective film are prepared by in-situ sol-gel process and normal atmosphere drying with the introduction of N,N-dimethylformamide （DMF）.Thermal stability in drying process of the SiO2 sol is studied by Netzsch thermal analyzer;the structure and morphology of these samples are characterized by scanning electron microscope （SEM）;the effect on optical properties of porous silicon thin films are measured by spectrophotometer.The results show that DMF effectively prevents the gel from cracking and inhibits the formation of particle clusters,which makes silica particles form a network and prepare silica films easily.DMF can also improve the transmittance of film higher than 99% in 300~1000 nm region.