Bonding and Release of Hydrogen in a-Si:C:H Alloys

1985 ◽  
Vol 49 ◽  
Author(s):  
W. Beyer ◽  
H. Wagner ◽  
H. Mell
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Content ◽  
Thermal Instability ◽  
Amorphous Material ◽  
Discharge Process ◽  
Hydrogen Atoms ◽  
Hydrogen Density ◽  
Optical Gap ◽  
Absorption Studies

AbstractHydrogen evolution and infrared absorption studies of a-Si:C:H films prepared from mixtures of hydrocarbon (CH4' C2H6' C2H4) and silane gases (SiH4 'Si2H6)by the glow-discharge process show that both the absolute hydrogen content and the hydrogen bonding is uniquely determined by the carbon content. Up to a carbon concentration of ∼45 % the widening of the optical gap is mainly due to an increase of the hydrogen content. For a hydrogen density NH > 1- 2x1022cm-3 the incorporated hydrogen atoms lead to the formation of voids, resulting in thermal instability of the bonded hydrogen and in a deterioration of the electronic quality of the amorphous material.

Improved Passivation of a-Si:H / c-Si Interfaces Through Film Restructuring

2008 ◽  
Vol 1066 ◽  
Author(s):  
Michael Zanoni Burrows ◽  
U. K. Das ◽  
S. Bowden ◽  
S. S. Hegedus ◽  
R. L. Opila ◽  
...  
Keyword(s):  
Hydrogen Bonding ◽  
Surface Passivation ◽  
Crystalline Silicon ◽  
Silicon Surfaces ◽  
Initial Surface ◽  
Effective Lifetime ◽  
Bonding Structure ◽  
First Time ◽  
Post Deposition

ABSTRACTThe as-deposited passivation quality of amorphous silicon films on crystalline silicon surfaces is dependent on deposition conditions and resulting hydrogen bonding structure. However the initial surface passivation can be significantly improved by low temperature post-deposition anneal. For example an improvement in effective lifetime from 780 μsec as-deposited to 2080 μsec post-anneal is reported in the present work. This work probes the hydrogen bonding environment using monolayer resolution Brewster angle transmission Fourier transform infrared spectroscopy of 100 Å thick films. It is found that there is significant restructuring at the a-Si:H / c-Si interface upon annealing and a gain of mono-hydride bonding at the c-Si surface is detected. Calculations show an additional 3.56 − 4.50 × 1014 cm−2 mono-hydride bonding at c-Si surface due to annealing. The estimation of the surface hydride oscillator strength in transmission mode is reported for the first time to be 7.2 × 10−18 cm on Si (100) surface and 7.5 × 10−18 cm on Si (111).

Effects of Dodecanoic Acid Modified SIO2 on Filler Dispersion and Ionic Conductivity of PMMA/ENR 50/LIBF4 Electrolytes

2016 ◽  
Vol 846 ◽  
pp. 528-533 ◽  
Author(s):  
Siti Izzati Husna Mohd Azuan ◽  
Famiza Abdul Latif ◽  
Sharil Fadli Mohamad Zamri
Keyword(s):  
Hydrogen Bonding ◽  
Surface Modification ◽  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Dodecanoic Acid ◽  
Hydrogen Atoms ◽  
Casting Technique ◽  
Bonding Interaction ◽  
Filler Dispersion ◽  
Overall Performance

Previously, the addition of silicon dioxide (SiO2) improved the homogeneity of polymethyl methacrylate/50 % epoxidised natural rubber (PMMA/ENR 50) blend. However, the presence of SiO2 agglomerates limits its overall performance. The formation of these agglomerates was due to the hydrogen bonding interaction that form between the oxygen atoms in silanol groups (Si-OH) and hydrogen atoms from the surrounding moisture. Therefore, in this study, SiO2 were modified with dodecanoic acid (DOA) to reduce the number of Si-OH on the SiO2 surface using esterification technique. Interestingly, it was found that the addition of DOA modified SiO2 (D-SiO2) improves the homogeneity of PMMA/ENR 50 blend. However, the amount of DOA used in the modification affect the capability of forming hydrogen bonding with the neighbouring of polymer chain. Different amounts of DOA were used upon the surface modification of SiO2 filler and then were added into PMMA/ENR 50 blends doped with lithium tetrafluoroborate (LiBF4). The films were prepared by solvent casting technique. CHNS analysis proven the increases of percentage of carbon atoms in D-SiO2. The attachment of DOA on SiO2 surface was confirmed using Fourier transform infrared spectroscopy (FTIR) and ionic conductivity of PMMA/ENR 50/LiBF4 filled D-SiO2 films was measured by electrochemical impedance spectroscopy (EIS). The result shows the blend properties and ionic conductivity of PMMA/ENR 50 filled D-SiO2 films was improved due to surface modification of SiO2 filler.

Improved Light Soaking Stability of R.F. Sputter Deposited Amorphous Silicon

1991 ◽  
Vol 219 ◽  
Author(s):  
A. Wynveen ◽  
J. Fan ◽  
J. Kakalios ◽  
J. Shinar
Keyword(s):  
Amorphous Silicon ◽  
Hydrogen Content ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Dark Conductivity ◽  
Initial Defect ◽  
Optical Gap ◽  
Sputter Deposited ◽  
Staebler Wronski Effect ◽  
Hydrogenated Amorphous

ABSTRACTStudies of r.f. sputter deposited hydrogenated amorphous silicon (a-Si:H) find that the light induced decrease in the dark conductivity and photoconductivity (the Staebler-Wronski effect) is reduced when the r.f. power used during deposition is increased. The slower Staebler-Wronski effect is not due to an increase in the initial defect density in the high r.f. power samples, but may result from either the lower hydrogen content or the smaller optical gap found in these films.

scholarly journals Notizen: Hydrogen Bonding in MoO2Cl2 · H2O Determined by Electrostatic Energy Calculations

1977 ◽  
Vol 32 (11) ◽  
pp. 1358-1359 ◽  
Author(s):  
Werner H. Baur
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Systematic Variation ◽  
Electrostatic Energy ◽  
Water Molecules ◽  
Hydrogen Atoms ◽  
Energy Calculations ◽  
Internal Geometry

The configuration of least electrostatic energy for the hydrogen atoms in both polytypes of MoO2Cl2 · H2O was obtained by systematic variation of the orientations of the water molecules. The internal geometry of the H2O group was kept constant throughout the variation. The hydrogen bonds are of the bifurcated type: [xxx]

Lateral, Chiral Tin(IV) Porphyrin Assemblies

1998 ◽  
Vol 02 (03) ◽  
pp. 273-284 ◽  
Author(s):  
BIANCA ROSENGARTEN ◽  
CHRISTOPH BÖTTCHER ◽  
ANDREA SCHULZ ◽  
J.-H. FUHRHOP ◽  
ULRICH SIGGEL
Keyword(s):  
Hydrogen Bonding ◽  
Lactic Acid ◽  
Circular Dichroism ◽  
Hydrochloric Acid ◽  
Protoporphyrin Ix ◽  
Mirror Image ◽  
Chloride Ions ◽  
Hydrogen Atoms ◽  
Circular Dichroism Spectra ◽  
Circular Dichroïsm

The μ-Oxo stacks of tin(IV) porphyrins rearrange to staircase-type and lateral aggregates upon replacement of the oxygen ligands by chloride ions. The lateral aggregation of tin(IV) 2,18-dipropionate porphyrins in hydrochloric acid at pH 0–0.5 is favoured by 8,13-ethyl groups instead of the natural 8,13-vinyl groups of protoporphyrin IX and is impeded by hydrogen atoms at these positions. Replacement of axial chloride counterions to the tin(IV) central ions by cyanate counterions at pH 4.5 leads to similar aggregates if the cyanate ions are connected by hydrogen bonding to acetic or lactic acid. In this case, aggregation is not necessarily impeded by hydrogen atoms at positions 8 and 13. D- and L-lactic acid enforce chiral assemblies of the tin(IV) deuteroporphyrin 1a with mirror image CD (circular dichroism) spectra (θ ≈ 8 × 105 deg cm 2 dmol −1), whereas the gluconoyl hydrazide-substituted tin(IV) deuteroporphyrin 1d does not form aggregates at all.

scholarly journals The crystal structure of cyanotrichite

2015 ◽  
Vol 79 (2) ◽  
pp. 321-335 ◽  
Author(s):  
Stuart J. Mills ◽  
Andrew G. Christy ◽  
Fernando Colombo ◽  
Jason R. Price
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Local Structure ◽  
Unit Cell ◽  
Group Symmetry ◽  
Hydrogen Atoms ◽  
Unit Cell Parameters ◽  
Space Group ◽  
Cell Parameters ◽  
Bonding Scheme

AbstractWe report the single-crystal average structure of cyanotrichite, Cu4Al2[SO4](OH)12(H2O)2, from the Maid of Sunshine mine, Arizona, USA. Cyanotrichite crystallizes in space group C2/m, with the unit-cell parameters a = 12.625(3), b = 2.8950(6), c = 10.153(2) Å and β = 92.17(3)o. All non-hydrogen atoms were located and refined to R1 = 0.0394 for all 584 observed reflections [Fo > 4σFo] and 0.0424 for all 622 unique reflections. The cyanotrichite structure consists of a principal building unit of a three-wide [Cu2Al(OH)6] ribbon of edge-sharing Cu and Al polyhedra || b, similar to that found for camerolaite. The ribbons lie in layers || (001) and between these layers, while SO4 tetrahedra and H2O molecules form rods running || b. A hydrogen-bonding scheme is also proposed.A sample of cyanotrichite from the Cap Garonne mine, Le Pradet, France, showed a 4b superstructure with the following unit cell: space group P2/m, a = 12.611(2) Å, b = 11.584(16) = 4 × 2.896(4) Å, c = 10.190(1) Å and β = 92.29(6)o. The supercell could not be refined in detail, but nevertheless imposes constraints on the local structure in that while the space-group symmetry prevents full order of SO4 and H2O in the 4b supercell, it requires that the sequence of species along any given rod is [-SO4-SO4-(H2O)2-(H2O)2-] rather than [-SO4-(H2O)2-SO4-(H2O)2-].

LIGHT ABSORPTION STUDIES: PART XV. THE ULTRAVIOLET ABSORPTION SPECTRA OF ANISOLES

1959 ◽  
Vol 37 (8) ◽  
pp. 1305-1314 ◽  
Author(s):  
J. C. Dearden ◽  
W. F. Forbes
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Atom ◽  
Absorption Spectra ◽  
Hydroxy Group ◽  
Light Absorption ◽  
Spectral Properties ◽  
Ultraviolet Absorption ◽  
Steric Interactions ◽  
Absorption Studies ◽  
Methoxy Groups

Anisoles, compared with phenols, possess similar spectral properties, except that properties determined mainly by the hydrogen atom of the hydroxy group are modified. In this way, comparison of the ultraviolet absorption spectra of phenols and anisoles permits, for example, the study of the spectral effects of hydrogen bonding and the study of steric interactions involving the hydroxy and methoxy groups.

Deposition of Fluorinated Silicon Nitride using Plasma Enhanced Chemical Vapor Deposition Technique

1991 ◽  
Vol 219 ◽  
Author(s):  
Ibrahim Khan ◽  
H. A. Naseem ◽  
S. S. Ang ◽  
W. D. Brown
Keyword(s):  
Silicon Nitride ◽  
Hydrogen Content ◽  
Electronic Devices ◽  
Chemical Vapor ◽  
Dielectric Strength ◽  
Optical And Electrical Properties ◽  
High Hydrogen ◽  
Optical Gap ◽  
Silicon Nitride Films ◽  
Vapor Deposition Technique

ABSTRACTHigh hydrogen content of ammonia/silane deposited silicon nitride films has been linked to instability in electronic devices such as MOSFET's MNOSFET's and TFT's. Fluorine has been proposed to help reduce the hydrogen content of these films. In this work, NF3 was used as a fluorinating agent. Optical and electrical properties were studied as a function of NF3 flow rate. A maximum optical gap of 5.3 eV was obtained with NF3 as compared to 3.2 eV without. The dielectric strength improved from 4 to 10 MV/cm with the addition of NF3. FTIR data show that the Si-N peak shifts to higher wave numbers and the Si-H peak drops below the detection limit with the addition of NF3. Also, the broad Si-N peak at 850 cm-1 is composed of many individual peaks which become discernable when a stainless steel screen is placed in front of the substrate. As the NF3 concentration is increased, a new peak at 1030–1060 cm-1 appears. This may be associated with a N-F vibration (1030 cm-1).

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