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I Martil - One of the best experts on this subject based on the ideXlab platform.
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Optical Constant calculation of non uniform thickness thin films of the ge10as15se75 chalcogenide glassy alloy in the sub band gap region 0 1 1 8 ev
Materials Chemistry and Physics, 1999Co-Authors: E Marquez, A M Bernaloliva, J M Gonzalezleal, R Prietoalcon, A Ledesma, R Jimenezgaray, I MartilAbstract:Abstract Optical-transmission spectra are very sensitive to inhomogeneities in thin films. In particular, a non-uniform thickness produces a clear shrinking in the transmission spectrum at normal incidence. If this deformation is not taken into account, it may lead to serious errors in the calculated values of the refractive index and film thickness. In this paper, a method first applied by Swanepoel for enabling the transformation of an Optical-transmission spectrum of a thin film of wedge-shaped thickness into the spectrum of a uniform film, whose thickness is equal to the average thickness of the non-uniform layer, has been employed. This leads subsequently to the accurate derivation of the refractive index in the subgap region (0.1–1.8 eV), the average thickness, as well as a parameter indicating the degree of film-thickness uniformity. This Optical procedure is applied to the particular case of freshly-prepared films of the Ge10As15Se75 ternary chalcogenide glassy alloy. The dispersion of the refractive index is discussed in terms of the Wemple–DiDomenico single-oscillator model. The Optical-absorption edge is described using the `non-direct transition' model proposed by Tauc, and the Optical energy gap is calculated by Tauc's extrapolation. Finally, the photo-induced and thermally induced changes in the Optical properties of the a-Ge10As15Se75 layers are also studied.
E Marquez - One of the best experts on this subject based on the ideXlab platform.
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Optical Constant calculation of non uniform thickness thin films of the ge10as15se75 chalcogenide glassy alloy in the sub band gap region 0 1 1 8 ev
Materials Chemistry and Physics, 1999Co-Authors: E Marquez, A M Bernaloliva, J M Gonzalezleal, R Prietoalcon, A Ledesma, R Jimenezgaray, I MartilAbstract:Abstract Optical-transmission spectra are very sensitive to inhomogeneities in thin films. In particular, a non-uniform thickness produces a clear shrinking in the transmission spectrum at normal incidence. If this deformation is not taken into account, it may lead to serious errors in the calculated values of the refractive index and film thickness. In this paper, a method first applied by Swanepoel for enabling the transformation of an Optical-transmission spectrum of a thin film of wedge-shaped thickness into the spectrum of a uniform film, whose thickness is equal to the average thickness of the non-uniform layer, has been employed. This leads subsequently to the accurate derivation of the refractive index in the subgap region (0.1–1.8 eV), the average thickness, as well as a parameter indicating the degree of film-thickness uniformity. This Optical procedure is applied to the particular case of freshly-prepared films of the Ge10As15Se75 ternary chalcogenide glassy alloy. The dispersion of the refractive index is discussed in terms of the Wemple–DiDomenico single-oscillator model. The Optical-absorption edge is described using the `non-direct transition' model proposed by Tauc, and the Optical energy gap is calculated by Tauc's extrapolation. Finally, the photo-induced and thermally induced changes in the Optical properties of the a-Ge10As15Se75 layers are also studied.
Jennifer L Macdonald - One of the best experts on this subject based on the ideXlab platform.
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Optical Constant molar absorption coefficient and imaginary molar polarizability spectra of liquid hexane at 25 c extended to 100 cm 1 and vibrational assignment and absolute integrated intensities between 4000 and 100 cm 1
Vibrational Spectroscopy, 2007Co-Authors: Dale C Keefe, Jennifer L MacdonaldAbstract:Abstract The infrared refractive index, molar absorption coefficient and imaginary polarizability spectra of hexane presented in a previous paper are extended to 100 cm −1 . The vibrational assignment and curve fit of the imaginary molar polarizability spectrum of liquid hexane are presented between 4000 and 100 cm −1 . A total of 157 peaks are required to fit the imaginary molar polarizability spectrum. An excellent fit was obtained which has an R 2 -value equal to 0.9997, the χ 2 is 0.082 cm 6 mol −2 and the RMS error is 0.0033 cm 3 mol −1 . Also the area under the experimental spectrum and the fitted spectrum only differ by 0.08%, where the fit is larger. With the aid of ab initio calculations and the gas phase spectrum, the liquid phase fundamentals and integrated intensities have been assigned for most of the infrared active fundamentals, and the dipole moment derivatives with respect to normal coordinates and the transition moments are reported.
Xiaodong Tang - One of the best experts on this subject based on the ideXlab platform.
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synthesis and Optical properties of an azo metal chelate compound for Optical recording medium
Dyes and Pigments, 1999Co-Authors: Shuangqing Wang, Shuyin Shen, Jinlong Yin, Xiaodong TangAbstract:Abstract An azo nickel chelate compound has been synthesized. Smooth thin films have been prepared by spin-coating. The absorption, transmission and reflection spectra of the films were measured. The Optical Constant (complex refractive index N = n + ik ) of the film on single-crystal silicon has been determined using scanning ellipsometer, and the complex dielectric function ( e ) as well as absorption coefficient ( α ) were then calculated. The Optical recording medium was prepared by spin-coating on a PC substrate with aluminium as reflective layer. Dynamic Optical recording test of the disc showed that the carrier-to-noise (CNR) of 45dB was obtained.
A Ledesma - One of the best experts on this subject based on the ideXlab platform.
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Optical Constant calculation of non uniform thickness thin films of the ge10as15se75 chalcogenide glassy alloy in the sub band gap region 0 1 1 8 ev
Materials Chemistry and Physics, 1999Co-Authors: E Marquez, A M Bernaloliva, J M Gonzalezleal, R Prietoalcon, A Ledesma, R Jimenezgaray, I MartilAbstract:Abstract Optical-transmission spectra are very sensitive to inhomogeneities in thin films. In particular, a non-uniform thickness produces a clear shrinking in the transmission spectrum at normal incidence. If this deformation is not taken into account, it may lead to serious errors in the calculated values of the refractive index and film thickness. In this paper, a method first applied by Swanepoel for enabling the transformation of an Optical-transmission spectrum of a thin film of wedge-shaped thickness into the spectrum of a uniform film, whose thickness is equal to the average thickness of the non-uniform layer, has been employed. This leads subsequently to the accurate derivation of the refractive index in the subgap region (0.1–1.8 eV), the average thickness, as well as a parameter indicating the degree of film-thickness uniformity. This Optical procedure is applied to the particular case of freshly-prepared films of the Ge10As15Se75 ternary chalcogenide glassy alloy. The dispersion of the refractive index is discussed in terms of the Wemple–DiDomenico single-oscillator model. The Optical-absorption edge is described using the `non-direct transition' model proposed by Tauc, and the Optical energy gap is calculated by Tauc's extrapolation. Finally, the photo-induced and thermally induced changes in the Optical properties of the a-Ge10As15Se75 layers are also studied.