透射光谱法测试双面薄膜的光学参数

由于普通的化学气相沉积法制作高掺Sn的二氧化硅薄膜比较容易产生结晶,而溶胶-凝胶法制备薄膜化学组成比较容易控制,可以制作出掺Sn浓度较大的材料。文章采用了溶胶-凝胶的方法制备出了66mol%和75 mol%两种不同浓度的掺Sn的SiO2薄膜,用浸渍法多次提拉薄膜以增加薄膜的厚度,之后用紫外-可见分光光度计测量了薄膜的透射光谱。之前基于透射光谱的方法计算玻璃基底上薄膜的光学参数都是针对单面薄膜,该文针对浸渍法产生的双面薄膜,建立了相对应的薄膜模型,并分别用包络线法计算出了两种不同薄膜样品的光学参数。计算结果表明两种不同薄膜样品的折射率随着波长的增加而增加,薄膜的厚度都为900 nm左右。

Determination of Optical Parameters in Thin Films by Transmittance Spectra

The high tin-doped SiO2 films prepared by CVD will bring some crystals,but sol gel can control the accurate chemical component of the films.So it can produce high tin-doped materials.In the present paper,the tin-doped SiO2 films were prepared by a sol gel dip-coating process on glass substrates at concentrations of 66 mol% and 75 mol%.Then dipping was performed several times to enhance the thickness of the films.The transmittance spectrum was obtained by spectrophotometer.Compared with the films prepared in a thin film on a thick substrate previously,the model here has been modified to describe the transmittance of a thick film(substrate) sandwiched between two thin films(coating method).The authors used the curves method to calculate the film's parameters.The result showed that uhe refractive index of different samples was increased with the wavelength.And the film thickness was about 900 nm.