Search results for "Oxide films"

Physicochemical characterization and photoelectrochemical analysis of iron oxide films

2013

Iron oxide films with a nanoporous structure were grown by anodizing sputter-deposited Fe in a fluoride containing ethylene glycol solution and annealed under air exposure at different temperatures. X-ray diffraction and Raman spectroscopy allowed to identify the presence of hematite and/or magnetite after thermal treatment for films annealed at T ≥ 400 °C under air exposure. According to GDOES compositional depth profiles, the thermal treatment sensitively reduced the amount of fluoride species incorporated into the film during the anodizing process. A band gap value of ~2.0 eV was estimated for all the investigated layers, while a flat band potential dependent on both the growth condition…

In situ monitoring of pulsed laser indium–tin-oxide film deposition by optical emission spectroscopy

2001

We performed optical emission spectroscopy to monitor the plasma produced during the ablation of indium-tin-oxide targets under different oxygen pressure conditions using a pulsed UV laser. Molecular bands of InO were identified in the fluorescent spectra produced by pulsed laser ablation. InO line monitoring allowed obtaining the optimal conditions for good-quality ITO film deposition. We demonstrated that it is possible to correlate InO line spectroscopic parameters with the conditions required to fabricate a high-conductivity and high-transparent ITO thin film. In particular, low resistivity (10-4 to 10-3 Ω cm) was obtained in films deposited at room temperature by regulating oxygen pres…

Nucleation and growth of ZnO on PMMA by low-temperature atomic layer deposition

2015

ZnO films were grown by atomic layer deposition at 35 °C on poly(methyl methacrylate) substrates using diethylzinc and water precursors. The film growth, morphology, and crystallinity were studied using Rutherford backscattering spectrometry, time-of-flight elastic recoil detection analysis, atomic force microscopy, scanning electron microscopy, and x-ray diffraction. The uniform film growth was reached after several hundreds of deposition cycles, preceded by the precursor penetration into the porous bulk and island-type growth. After the full surface coverage, the ZnO films were stoichiometric, and consisted of large grains (diameter 30 nm) with a film surface roughness up to 6 nm (RMS). T…

Nanostructuring thin Au films on transparent conductive oxide substrates

2013

Fabrication processes of Au nanostructures on indium-tin-oxide (ITO) surface by simple, versatile, and low-cost bottom-up methodologies are investigated in this work. A first methodology exploits the patterning effects induced by nanosecond laser irradiations on thin Au films deposited on ITO surface. We show that after the laser irradiations, the Au film break-up into nanoclusters whose mean size and surface density are tunable by the laser fluence. A second methodology exploits, instead, the patterning effects of standard furnace thermal processes on the Au film deposited on the ITO. We observe, in this case, a peculiar shape evolution from pre-formed nanoclusters during the Au deposition…

Photoelectrochemical Synthesis of Conducting Polymers on Large Band Gap Nb2O5 and Ta2O5 Anodic Oxide Films

2008

Physico-chemical Properties of Anodic Oxide Films: from Passivity to Electronics

2014

Graphene Field-Effect Transistors Employing Different Thin Oxide Films: A Comparative Study

2019

In this work, we report on a comparison among graphene field-effect transistors (GFETs) employing different dielectrics as gate layers to evaluate their microwave response. In particular, aluminum oxide (Al$_{2}$O$_{3}$), titanium oxide (TiO$_{2}$), and hafnium oxide (HfO$_{2}$) have been tested. GFETs have been fabricated on a single chip and a statistical analysis has been performed on a set of 24 devices for each type of oxide. Direct current and microwave measurements have been carried out on such GFETs and short circuit current gain and maximum available gain have been chosen as quality factors to evaluate their microwave performance. Our results show that all of the devices belonging …

Characterization of rhenium oxide films and their application to liquid crystal cells

2009

Rhenium trioxide exhibits high electronic conductivity, while its open cubic crystal structure allows an appreciable hydrogen intercalation, generating disordered solid phases, with protonic conductivity. Rhenium oxide thin films have been obtained by thermal evaporation of ReO3 powders on different substrates, maintained at different temperatures, and also by reactive magnetron sputtering of a Re metallic target. A comparative investigation has been carried out on these films, by using micro-Raman spectroscopy and x-ray diffraction. Two basic types of solid phases appear to grow in the films: a red metallic HxReO3 compound, with distorted perovskite structures, like in the bulk material, a…