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Gradient a-Si1−xGex layers have been deposited by ”one-sample concept” combinatorial direct current (DC) magnetron sputtering onto one-inch-long Si slabs. Characterizations by electron microscopy, ion beam analysis and ellipsometry show that the layers are amorphous with a uniform thickness, small roughness and compositions from x = 0 to x = 1 changing linearly with the lateral position. By focused-beam mapping ellipsometry, we show that the optical constants also vary linearly with the lateral position, implying that the optical constants are linear functions of the composition. Both the refractive index and the extinction coefficient can be varied in a broad range for a large spectral region. The precise control and the knowledge of layer properties as a function of composition is of primary importance in many applications from solar cells to sensors. [ABSTRACT FROM AUTHOR]

The optical parameters of hydrogenated amorphous a- Si 1 - x Ge x :H layers were measured with focused beam mapping ellipsometry for photon energies from 0.7 to 6.5 eV. The applied single-sample micro-combinatorial technique enables the preparation of a- Si 1 - x Ge x :H with full range composition spread. Linearly variable composition profile was revealed along the 20 mm long gradient part of the sample by Rutherford backscattering spectrometry and elastic recoil detection analysis. The Cody-Lorentz approach was identified as the best method to describe the optical dispersion of the alloy. The effect of incorporated H on the optical absorption is explained by the lowering of the density of localized states in the mobility gap. It is shown that in the low-dispersion near infrared range the refractive index of the a- Si 1 - x Ge x alloy can be comprehended as a linear combination of the optical parameters of the components. The micro-combinatorial sample preparation with mapping ellipsometry is not only suitable for the fabrication of samples with controlled lateral distribution of the concentrations, but also opens new prospects in creating databases of compounds for optical and optoelectonic applications. [ABSTRACT FROM AUTHOR]

To characterize zirconium surfaces in forms of tubes and plates for nuclear applications, ellipsometry has been used. It has been shown earlier that ellipsometry can be used even on the surface of tubes with a diameter of 9.1 mm, when applying proper focusing. Reference refractive indices have also been determined for both zirconium and zirconium oxide, and demonstrated the capability of ellipsometry for the determination of the thickness and refractive index of the surface oxide applying different oxidation parameters. In this study, processed zirconium surfaces using the technique developed in author's previous work is characterized. Both ultra violet‐visible‐near infrared and mid‐infrared ellipsometry to study the thicknesses of the surface layers as well as the dielectric functions of both the layers and the substrate are used. A heat cell that allows multiple angle of incidence ellipsometry measurement at elevated temperatures is also developed. This setup is used to monitor the temporal behavior of hydrogenated and oxidized zirconium surfaces. [ABSTRACT FROM AUTHOR]