Intrinsic defects and their influence on the chemical and optical properties of TiO2x films

International audienceIn this work, TiO2 films produced by rf sputtering of a TiO2 target in argon and argon–oxygen plasmas were studied. The oxygen content in the feed gas was varied in a range 3–20%. The chemical composition and structure of films were characterized by Rutherford backscattering spectrometry, x-ray photoelectron spectroscopy (XPS) and x-ray diffraction. Important information about the intrinsic defects of the films and their effects on the optical properties as well as a scheme of the energy band structure of the films could be derived from a combined use of optical spectroscopy and XPS

Influence of Nd3+ doping on the structural and near-IR photoluminescence properties of nanostructured TiO2 films

n/

Hydrogen effect on structure and mechanical properties of ZnO films deposited in Ar/H2 plasma

In the present work the mechanical properties of the ZnO thin films deposited on Si (100) substrates, were studied using a nanoindentation. The thin films of ZnO were deposited by radiofrequency sputtering with different H2/Ar gas mixture. During the deposition the species of the plasma were in situ monitored using optical emission spectroscopy. The results showed a strong effect of H2 on film hardness and elastic modulus. Using the correlation between the elastic modulus values and materials porosity in the ceramic the porosity of the ZnO was estimated . We found an increased film porosity when H2 is added to the sputtering gas, from 4% to 16% volume. Moreover we found that the porosity could be controlled by the emission intensity ratio of atomic Argon on atomic Hydrogen

RF sputtering of oxide films in Ar and Ar-H2 gas mixtures: role of H incorporation in developing transparent conductive coatings

Oral presentatio

RF sputtering of ZnO films in Ar and Ar-H2 gas mixtures: role of H incorporation in developing transparent conductive coatings

Fundamental and applied investigation of ZnO has been recently experiencing a renaissance due to its prospective use in various technological domains and, in particular, as transparent conductive oxide (TCO) for solar cells applications. In this respect, the present work aims to study the structural and physical properties of ZnO thin films deposited by RF sputtering. Different gas mixtures were explored. Specifically, pure Ar and Ar-H2 at various concentrations were used to grow the films on n-type Si (100) wafers and glass without external heating. The plasma chemical species were followed in function of the different gas mixture settings by optical emission spectroscopy (OES). X-ray photoelectron spectroscopy (XPS) and ATR-FTIR (Attenuated Total Reflection Fourier-Transformed Infrared) spectroscopy were used to study the bulk and surface chemical composition of the films, X-ray Diffraction (XRD) analysis allowed lattice structure and grain size determination while samples morphology was checked with a scanning electron microscope (SEM). The films were also characterized for their electrical and optical properties. The introduction of hydrogen in the plasma phase strongly affected the structural, chemical and physical properties of the films. In particular a pronounced change in the films electrical behaviour was observed which become conductive when H is added in the gas mixture ([H2]>6%). The films transparency was on the other hand maintained. By combining XPS, ATR-FTIR and OES data we could correlate the established conductivity and its variations with intentional hydrogen incorporation in the crystal structure in the form of hydroxide species