The surface properties of indium tin oxynitride films prepared by rf-sputtering in nitrogen atmosphere were investigated by X-ray and ultraviolet photoelectron spectroscopy as well as electron energy ...loss spectroscopy and Auger electron spectroscopy depth profiling. The results are compared to reference measurements on conventional rf-sputtered indium tin oxide films. The incorporated nitrogen is present in different chemical environments. Employing these different spectroscopic techniques, it was found that desorption of nitrogen from the ITON structure upon annealing is the origin of the observed drastical changes in the surface composition and electronic structure. The formation of oxygen vacancies and Sn surface segregation upon annealing is linked to improvements in the physical properties (larger spectral range of transmittance and higher conductivity) of the films.
Different thin fluorocarbon (FC) films were deposited on Si(111) using plasma polymerisation and then exposed to X-ray radiation. Changes in the chemical composition of the deposited fluorocarbon ...films as a function of irradiation time were investigated
in situ using X-ray photoelectron spectroscopy. The evaluation of the C1s and F1s core level induced emission as a function of exposure to X-ray radiation (Mg Kα,
hν
=
1253.6
eV) reveals changes in the surface chemical composition of the FC polymer structure. The presented results indicate a high defluorination under X-ray irradiation. Additionally, binding energy shifts of the F1s and C1s peaks during the exposure associated with surface charging effects were observed. With ongoing exposure the surface charging decreases continuously and the FC surfaces become more conductive due to changes in the polymer structure. Different models have been used to describe the decomposition kinetics and surface composition.
GaN(0001)-2X2 surfaces were investigated by angle-resolved ultraviolet photoelectron spectroscopy (ARUPS) as well as X-ray photoelectron spectroscopy (XPS). Contamination- and metal-free GaN thin ...films with a 2X2 reconstruction and a rms roughness below 1 nm were grown on 6H-SiC(0001) by plasma assisted molecular beam epitaxy (PAMBE). The valence band structure of the surface was investigated in-situ with ARUPS along the and directions of the surface Brillouin zone. Weak dispersive surface states related to the unreconstructed GaN surface or to the 2X2 superstructure as well as the dispersion of electron states of the bulk band structure are identified and compared to available results from density functional theory (DFT) calculations Phys. Rev. B 77, 115120 (2008) for GaN(0001). (copy 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
In this study InN films with wurtzite structure grown by plasma induced molecular beam epitaxy were investigated by X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy ...(UPS), Auger electron spectroscopy (AES), and electron energy loss spectroscopy (EELS) in order to determine the chemical composition of the sample surfaces before and after ion bombardment. Samples which were investigated without any cleaning procedures showed some contaminations (O and C) due to the previous exposure to air. The ratio between In and N was examined by XPS. The surface contaminations were removed by bombarding the surface with Ar
+ ions (
E
kin=500 eV). Due to preferential sputtering an In rich surface is formed. The degree of In enrichment is strongly dependent on the incident angle of the ions.
Modifications of AlGaN surfaces have been carried out in order to tune their wetting properties. A hydrophilic surface is achieved by a wet and dry thermal oxidation, whereas the deposition of ...fluorocarbon (FC) layers leads to a passivation with a hydrophobic behavior. It was found that both surfaces still change their properties in the first days/hours after the modification. For the FC layers, differences are observed in dependence of the deposition method, which are explained by the different chemical-bond structures of the various FC films
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