Search results for "VAP"
showing 10 items of 1800 documents
Rock-salt CdZnO as a transparent conductive oxide
2018
Transparent conducting oxides (TCOs) are widely used in applications from solar cells to light emitting diodes. Here, we show that the metal organic chemical vapor deposition (MOCVD)-grown, rock-salt CdZnO ternary, has excellent potential as a TCO. To assess this compound, we use a combination of infrared reflectance and ultraviolet-visible absorption spectroscopies, together with Hall effect, to determine its optical and electrical transport characteristics. It is found that the incorporation of Zn produces an increment of the electron concentration and mobility, yielding lower resistivities than those of CdO, with a minimum of 1.96 × 10 − 4 Ω · cm for a Zn content of 10%. Moreover, due to…
Optimization of physicochemical and optical properties of nanocrystalline TiO 2 deposited on porous silicon by metal-organic chemical vapor depositio…
2020
International audience; Titanium dioxide (TiO2) is very employed in solar cells due to its interesting physicochemical and optical properties allowing high device performances. Considering the extension of applications in nanotechnologies, nanocrystalline TiO2 is very promising for nanoscale components. In this work, nanocrystalline TiO2 thin films were successfully deposited on porous silicon (PSi) by metal organic chemical vapor deposition (MOCVD) technique at temperature of 550°C for different periods of times: 5, 10 and 15 min. The objective was to optimize the physicochemical and optical properties of the TiO2/PSi films dedicated for photovoltaic application. The structural, morphologi…
Induced crystallographic changes in Cd1−xZnxO films grown on r-sapphire by AP-MOCVD: the effects of the Zn content when x ≤ 0.5
2020
High-resolution X-ray diffraction, scanning electron microscopy and transmission electron microscopy techniques were used to investigate, as a function of the nominal Zn content in the range of 0–50%, the out-of-plane and in-plane crystallographic characteristics of Cd1−xZnxO films grown on r-plane sapphire substrates via atmospheric pressure metal–organic chemical vapor deposition. The study is conducted to search for knowledge relating to the structural details during the transition process from a rock-salt to a wurtzite structure as the Zn content increases in this CdO–ZnO system. It has been found that it is possible to obtain films exhibiting a single (001) cubic orientation with good …
2018
Damping distances of surface plasmon polariton modes sustained by different thin titanium nitride (TiN) films are measured at the telecom wavelength of 1.55 μm. The damping distances are correlated to the electrical direct current resistivity of the films sustaining the surface plasmon modes. It is found that TiN/Air surface plasmon mode damping distances drop non-linearly from 40 to 16μm as the resistivity of the layers increases from 28 to 130μΩ.cm, respectively. The relevance of the direct current (dc) electrical resistivity for the characterization of TiN plasmonic properties is investigated in the framework of the Drude model, on the basis of parameters extracted from spectroscopic ell…
Atomic Layer Deposition of Osmium
2011
Growth of osmium thin films and nanoparticles by atomic layer deposition is described. The Os thin films were successfully grown between 325 and 375 °C using osmocene and molecular oxygen as precursors. The films consisted of only Os metal as osmium oxides were not detected in X-ray diffraction measurements. Also the impurity contents of oxygen, carbon, and hydrogen were less than 1 at % each at all deposition temperatures. The long nucleation delay of the Os process facilitates either Os nanoparticle or thin film deposition. However, after the nucleation delay of about 350 cycles the film growth proceeded linearly with increasing number of deposition cycles. Also conformal growth of Os thi…
Radiation resistance of nanolayered silicon nitride capacitors
2020
Abstract Single-layered and multi-layered 20–60 nm thick silicon nitride (Si3N4) dielectric nanofilms were fabricated using a low-pressure chemical vapour deposition (LPCVD) method. The X-ray photoelectron spectroscopy (XPS) confirmed less oxygen content in the multi-layered nanofilms. The capacitors with Si3N4 multilayer demonstrated a tendency to a higher breakdown voltage compared to the capacitors with Si3N4 single layer. Si3N4 nanofilms and capacitors with Si3N4 dielectric were exposed to 1 kGy dose of gamma photons. Fourier transform infrared (FTIR) spectroscopy analysis showed that no modifications of the chemical bonds of Si3N4 were present after irradiation. Also, gamma irradiation…
Sub-nanosecond excitonic luminescence in ZnO:In nanocrystals
2019
The financial support of research European Union ERA.NET RUS_ST20170-51 . This work was partly supported by Russian Foundation for Basic Research, Russia , project No. 18-52-76002 . The sample preparation was carried out as part of SFERA II project -Transnational Access activities ( European Union 7th Framework Programme Grant Agreement N3126430 ).
Lead evaporation instabilities and failure mechanisms of the micro oven at the GTS-LHC ECR ion source at CERN
2020
The GTS-LHC ECR ion source (named after the Grenoble Test Source and the Large Hadron Collider) at CERN provides heavy ion beams for the chain of accelerators from Linac3 up to the LHC for high energy collision experiments and to the Super Proton Synchrotron for fixed target experiments. During the standard operation, the oven technique is used to evaporate lead into the source plasma to produce multiple charged lead ion beams. Intensity and stability are key parameters for the beam, and the operational experience is that some of the source instabilities can be linked to the oven performance. Over long operation periods of several weeks, the evaporation is not stable which makes the tuning …
High transparency Bi 2 Se 3 topological insulator nanoribbon Josephson junctions with low resistive noise properties
2019
Bi$_2$Se$_3$ nanoribbons, grown by catalyst-free Physical Vapour Deposition, have been used to fabricate high quality Josephson junctions with Al superconducting electrodes. The conductance spectra (dI/dV) of the junctions show clear dip-peak structures characteristic of multiple Andreev reflections. The temperature dependence of the dip-peak features reveals a highly transparent Al/Bi$_2$Se$_3$ topological insulator nanoribbon interface and Josephson junction barrier. This is supported by the high values of the Bi$_2$Se$_3$ induced gap and of I$_c$R$_n$ (I$_c$ critical current, R$_n$ normal resistance of the junction) product both of the order of 160 $\mu$eV, a value close to the Al gap. T…
Atomic layer deposition of aluminum oxide on modified steel substrates
2016
Abstract Al 2 O 3 thin films were grown by atomic layer deposition to thicknesses ranging from 10 to 90 nm on flexible steel substrates at 300 °C using Al(CH 3 ) 3 and H 2 O as precursors. The films grown to thicknesses 9–90 nm covered the rough steel surfaces uniformly, allowing reliable evaluation of their dielectric permittivity and electrical current densities with appreciable contact yield. Mechanical behavior of the coatings was evaluated by nanoindentation. The maximum hardness values of the Al 2 O 3 films on steel reached 12 GPa and the elastic modulus exceeded 280 GPa.