Organosilanes are used routinely to functionalize various support materials for further modifications. Nevertheless, reliable quantitative information about surface functional group densities after layer formation is rarely available. Here, we present the analysis of thin organic nanolayers made from nitrogen containing silane molecules on naturally oxidized silicon wafers with reference-free total reflection X-ray fluorescence (TXRF) and X-ray photoelectron spectroscopy (XPS). An areic density of 2-4 silane molecules per nm(2) was calculated from the layer's nitrogen mass deposition per area unit obtained by reference-free TXRF. Complementary energy and angle-resolved XPS (ER/AR-XPS) in the Si 2p core-level region was used to analyze the outermost surface region of the organic (silane layer)-inorganic (silicon wafer) interface. Different coexisting silicon species as silicon, native silicon oxide, and silane were identified and quantified. As a result of the presented proof-of-concept, absolute and traceable values for the areic density of silanes containing nitrogen as intrinsic marker are obtained by calibration of the XPS methods with reference-free TXRF. Furthermore, ER/AR-XPS is shown to facilitate the determination of areic densities in (mono)layers made from silanes having no heteroatomic marker other than silicon. After calibration with reference-free TXRF, these areic densities of silane molecules can be determined when using the XPS component intensity of the silane's silicon atom.

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In this study, hydrogenated titanium dioxide (TiO 2 :H) thin films of thicknesses between 33 and 300 nm were grown via the reactive radiofrequency magnetron sputter deposition technique. These thin films were characterized with respect to electrical resistivity, Seebeck coefficient, and optical absorption coefficient. However, heating to temperatures above 430 K results in irreversible property changes of the thin films. The characteristics of these changes depended on the atmosphere, in which the samples were thermally treated (10 −7 mbar vacuum or 1 bar of 99.99% N 2 ). In order to explain these findings, we investigated our samples not only in the asdeposited state but also after thermal cycling over different temperature ranges. Mott's three-dimensional (3D) variable range hopping model was identified as the most appropriate electrical conductivity model in the asdeposited state for the temperature range of 223−430 K, after which it changes irreversibly to the small polaron hopping model in the 223−615 K temperature range. This thermally induced change appears to be due to changes in the number of intrinsic (interstitial titanium Ti int , titanium vacancies V Ti , and oxygen vacancies V o ) and extrinsic (hydrogen dopants) defects in the material. Spectroscopic ellipsometry measurements support this assumption. For this, we developed a dielectric dispersion model for TiO 2 :H thin films, which combines the Cody−Lorentz model with an additional Lorentz oscillator. In the as-deposited state, an additional peak of the absorption coefficient appears at 1.3−1.4 eV, which disappears for samples thermally treated in N 2 atmosphere but is retained for samples thermally treated in vacuum.