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Hydrogen Plasma (hydrogen + plasma)

Distribution by Scientific Domains
Polymers and Materials Science18%
Chemistry18%

Selected Abstracts

Influence of Hydrogen Plasma on the Defect Passivation of Polycrystalline Si Thin Film Solar Cells

PLASMA PROCESSES AND POLYMERS, Issue S1 2009
Benjamin Gorka
Abstract Hydrogen passivation (HP) of polycrystalline silicon (poly-Si) thin film solar cells was performed in a parallel plate radio-frequency (rf) plasma setup. The influence of hydrogen pressure p and electrode gap d on breakdown voltage Vbrk is presented showing that the minimum in Vbrk shifts with higher pressures towards higher p,·,d values. Cell test structures provided by CSG Solar AG were used to examine the influence of p and d on the open circuit voltage VOC. The highest VOC's were achieved for p,·,d values that correspond to a minimum in Vbrk. HP strongly improved the VOC. After the hydrogen plasma treatment the VOC improved significantly by a factor of 2 and amounted to 450 mV. Optimized parameters were then applied to different poly-Si solar cells prepared by electron beam evaporation. [source]

ChemInform Abstract: The Synthesis of Metal Phosphides: Reduction of Oxide Precursors in a Hydrogen Plasma.

CHEMINFORM, Issue 45 2008
Anjie Wang
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Thermodynamics of Hydrogen and Hydrogen-Helium Plasmas: Path Integral Monte Carlo Calculations and Chemical Picture

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 3-4 2005
V. S. Filinov
Abstract In this paper we study thermodynamic properties of hydrogen and hydrogen-helium mixtures with the help of the direct path integral Monte Carlo simulations. The results are compared with available theoretical and experimental methods based, in particular, on chemical picture. We investigate the effects of temperature ionization in low-density hydrogen plasma. We also present a number of calculated isotherms for hydrogenhelium mixture with the mass concentration of helium Y = 0.234 in the range from 104 K to 2 · 105 K. In the density region where a sharp conductivity rise have been observed experimentally the simulations give indications for one or two plasma phase transitions, in accordance with earlier theoretical predictions. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

High Density Cascaded Arc Produced Plasma Expanding in a Low Pressure Region

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2004
R. P. Dahiya
Abstract Experimental measurements made in thermal expanding argon, nitrogen and hydrogen plasmas with particular reference to molecular kinetics, surface nitriding and intense flux in magnetic field are discussed. The plasma is generated in a cascaded arc source. In the presence of molecular species (H2 / N2) dissociative recombination reactions involving rovibrationally excited molecules contribute to a rapid decay of the plasma species, especially for hydrogen system. A combination of nitrogen and hydrogen plasma gives an efficient plasma nitriding process, which has been applied for case hardening of machinery components. In another setup a strong axial magnetic field (0.4 - 1.6 T) contains and substantially prolongs the plasma beam in the chamber. In the presence of the magnetic field, an additional current drawn through the plasma beam using a biased substrate and a ring creates dense low temperature plasma giving a new unexplored plasma regime. The plasma kinetics are modified in this regime from the recombining to the ionising mode. When the additional current in the argon plasma beam exceeds 30 A, its light emission is predominantly in the blue region. With the additional current and magnetic field, the emission intensity of H, and other lines arising from higher energy levels in the hydrogen Balmer series is enhanced. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Pseudopotential theory of a partially ionized hydrogen plasma

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2003
Yu.V. Arkhipov
Abstract In the framework of the BBGKY hierarchy the main features of interparticle interactions in a partially ionized hydrogen plasma are extensively studied. The theory developed is quite analogous to the Debye-Hückel approximation of a fully ionized plasma. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Effects of Polymer Architecture and Composition on the Adhesion of Poly(tetrafluoroethylene)

CHEMPHYSCHEM, Issue 6 2006
Chen-Yuan Tu Dr.
Abstract Poly(glycidyl methacrylate), PGMA, chains in linear and arborescent structures were incorporated onto surfaces of poly(tetrafluoroethylene), PTFE, films by hydrogen plasma and ozone treatment and atom transfer radical polymerization. The epoxide groups of the PGMA chains were further reacted with acetic acid (AAc), oxalic acid (XAc), allyl amine (AA), and ethylenediamine (EDN) to introduce hydroxyl and amine groups to the surfaces of the PTFE films. Surface characterizations performed by Fourier Transform infrared attenuated total reflectance (FTIR-ATR) spectroscopy and X-ray photoelectron spectroscopy (XPS) confirmed the surface modification and the chemical structure. The PGMA chains in arborescent structures show a high effectiveness for the enhancement of the adhesion of PTFE films. The adhesion of PTFE films was also significantly enhanced by ring-opening reactions of the PGMA epoxide groups with acetic acid and amine compounds. A high value of 9.5 N,cm,1 in the optimum 180° peel strength test was observed with PTFE/copper assemblies. [source]

High Density Cascaded Arc Produced Plasma Expanding in a Low Pressure Region

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2004
R. P. Dahiya
Abstract Experimental measurements made in thermal expanding argon, nitrogen and hydrogen plasmas with particular reference to molecular kinetics, surface nitriding and intense flux in magnetic field are discussed. The plasma is generated in a cascaded arc source. In the presence of molecular species (H2 / N2) dissociative recombination reactions involving rovibrationally excited molecules contribute to a rapid decay of the plasma species, especially for hydrogen system. A combination of nitrogen and hydrogen plasma gives an efficient plasma nitriding process, which has been applied for case hardening of machinery components. In another setup a strong axial magnetic field (0.4 - 1.6 T) contains and substantially prolongs the plasma beam in the chamber. In the presence of the magnetic field, an additional current drawn through the plasma beam using a biased substrate and a ring creates dense low temperature plasma giving a new unexplored plasma regime. The plasma kinetics are modified in this regime from the recombining to the ionising mode. When the additional current in the argon plasma beam exceeds 30 A, its light emission is predominantly in the blue region. With the additional current and magnetic field, the emission intensity of H, and other lines arising from higher energy levels in the hydrogen Balmer series is enhanced. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

How correct is the EOS of weakly nonideal hydrogen plasmas?

CONTRIBUTIONS TO PLASMA PHYSICS, Issue 5-6 2003
A.N. Starostin
Abstract Helioseismology opens new possibility to check EOS of weakly nonideal hydrogen plasmas with high precision, using reconstructed local sound velocities within 10-4 accuracy. A comparison of different theoretical models with experiment permits to verify the existing methods of calculation bound states and continuum contribution to the second virial coefficient within the framework of physical nature. The regular way of the deduction expression for EOS is presented and generalization of the EOS for broad atomic states and two temperature non-equilibrium case is proposed. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Electronic and Magnetic Properties of Ligand-Free FePt Nanoparticles,

ADVANCED MATERIALS, Issue 5 2005
H.-G. Boyen
Ligand-free FePt nanoparticles are prepared in densely packed arrays (see Figure) under ultrahigh vacuum conditions, in which oxygen and hydrogen plasmas are used to remove the organic shells that are present after particle synthesis. The electronic structure and magnetic properties of the "bare", face-centered-cubic FePt particles are presented. Applications in high-density magnetic data recording are foreseen. [source]