sol-gel法制备纳米TiO_2-SiO_2宽带高增透膜

通过模拟计算设计出一种透射比为99%、包含一层TiO2薄膜和一层SiO2薄膜的宽带高增透膜。两层薄膜均由溶胶-凝胶法制得并采用提拉法成形于玻璃基片上。对增透膜样品的透射比、表面形貌、膜厚等进行了表征,考察了提拉速度、退火温度、催化条件等对其透射比、表面均匀性的影响。结果表明:增透膜的使用提高了玻璃基片的透射比;当提拉速度为9cm/min,增透膜厚约为255nm时,基片在400～800nm波段的透射比提高了7%。控制退火温度,可以使增透膜在某些波段的透射比增强。增透膜样品的表面均匀性良好,室温下膜层的均方根表面粗糙度(RMS)为1.682,平均粗糙度(RA)为1.208,在550℃的温度以下,随着退火温度升高,表面粗糙度降低。

Preparation of broadband and high-transmissivity nano TiO2-SiO2 anti-reflection coating via sol-gel method

A kind of broadband and high-transmissivity anti-reflection coating with a transmissivity of 99% was designed with MASS software and prepared in the laboratory.The AR coating was composed of a layer of TiO2 film and a layer of SiO2 film prepared using sol-gel method.Both films were coated on glass slides via the dip-coating method with an annealing treatment.The transmissivity,surface morphology and thickness of prepared AR coating samples were characterized.And the effects of withdrawal speed,annealing temperature and catalysis on the transmissivity and surface morphology of AR coating were studied.The results indicate that the average transmissivity of glass slide at the band of 400～800 nm increases with the application of TiO2-SiO2 AR coating.An increasement of 7% is reached when the withdrawal speed is 9 cm/min and the coating thickness is 255 nm.The transmissivity of AR coating at some wave bands is enhanced through controlling the annealing temperature.The surface of coating samples is smooth and even,with a root mean square(RMS) roughness of 1.682 and an average roughness of 1.208 at room temperature.With increasing annealing temperature up to 550 ℃,the surface roughness of AR coating deceases.