Determination of optical constants of solgel-derived inhomogeneous TiO2 thin films by spectroscopic ellipsometry and transmission spectroscopy

被引:45
作者
Mosaddeq-Ur-Rahman, M
Yu, GL
Krishna, KM
Soga, T
Watanabe, JJ
Jimbo, T
Umeno, M
机构
[1] Nagoya Inst Technol, Dept Elect & Comp Engn, Showa Ku, Nagoya, Aichi 466, Japan
[2] Nagoya Inst Technol, Res Ctr Microstruct Devices, Showa Ku, Nagoya, Aichi 466, Japan
[3] Nagoya Inst Technol, Dept Environm Technol & Urban Planning, Showa Ku, Nagoya, Aichi 466, Japan
来源
APPLIED OPTICS | 1998年 / 37卷 / 04期
关键词
D O I
10.1364/AO.37.000691
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
Amorphous and nanocrystalline TiO2 thin films coated on a vitreous silica substrate by a solgel dip coating method are investigated for optical properties by spectroscopic ellipsometry (SE) together with transmission spectroscopy. A method of analysis of SE data to determine the degree of inhomogeneity of TiO2 films has also been presented. Instead of the refractive index, the volume fraction of void has been assumed to vary along the thickness of the films and an excellent agreement between the experimental and calculated data of SE below the fundamental band gap has been obtained. The transmission spectrum of these samples is inverted to obtain the extinction coefficient k spectrum in the wavelength range of 300-1600 nm by using the refractive indices and parameters of structure determined by SE. The nonzero extinction coefficient below the fundamental band-gap energy (3.2 eV) has been obtained for the nanocrystalline TiO2 and shows the presence of optical scattering in the film. (C) 1998 Optical Society of America.
引用
收藏
页码:691 / 697
页数:7
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