A Case for Molecular Hydrogen Being the Mobile H Species in a-Si:H

2000 ◽  
Vol 609 ◽  
Author(s):  
P. A. Fedders
Keyword(s):  
Activation Energy ◽  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Molecular Hydrogen ◽  
Hydrogen Diffusion ◽  
Hydrogen Transport ◽  
Mobile Species ◽  
Standard Picture ◽  
Dynamics Simulations ◽  
Induced Defects

ABSTRACTThe mechanism (or mechanisms) of hydrogen transport in a-Si:H is of great intrinsic interest but is also important for the understanding of a number of phenomena such as light induced defects. We find that the literature includes many calculations for the activation energy for hydrogen diffusion that are at best misleading and often interpreted incorrectly. In this paper we summarize a number of calculations that apply to particles hopping in complex media and apply the results to a-Si:H. These calculations, coupled with existing estimates of the energy of various H configurations in a-Si:H, show that the standard picture is likely to be incorrect. However, previous work on the mobility of molecular hydrogen in crystalline Si coupled with some molecular dynamics simulations presented in this paper show that the mobile species of hydrogen in a-Si:H may well be molecular.

Molecular-dynamics simulations of hydrogen diffusion in niobium: Influence of imperfections

1995 ◽  
Vol 52 (6) ◽  
pp. 4162-4170 ◽  
Author(s):  
B. Roux ◽  
H. Jaffrezic ◽  
A. Chevarier ◽  
N. Chevarier ◽  
M. T. Magda
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Hydrogen Diffusion ◽  
Dynamics Simulations

Multi-scale theoretical investigation of molecular hydrogen adsorption over graphene: coronene as a case study

RSC Advances ◽  
2014 ◽  
Vol 4 (97) ◽  
pp. 54447-54453 ◽  
Author(s):  
Md Bin Yeamin ◽  
N. Faginas-Lago ◽  
M. Albertí ◽  
I. G. Cuesta ◽  
J. Sánchez-Marín ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Dft Calculations ◽  
Modeling And Simulation ◽  
Molecular Dynamics Simulations ◽  
Multiscale Modeling ◽  
Molecular Hydrogen ◽  
Hydrogen Adsorption ◽  
Multi Scale ◽  
Dynamics Simulations

Multiscale modeling and simulation (MMS) combining B97-D/TZV2P DFT calculations and molecular dynamics simulations are performed to investigate the adsorption of hydrogen over coronene as a model of graphene.

scholarly journals Molecular Dynamics Simulations of Hydrogen Diffusion in Aluminum

2016 ◽  
Vol 120 (14) ◽  
pp. 7500-7509 ◽  
Author(s):  
X. W. Zhou ◽  
F. El Gabaly ◽  
V. Stavila ◽  
M. D. Allendorf
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Hydrogen Diffusion ◽  
Dynamics Simulations

First Principles Molecular Dynamics Studies of a-Si and a-Si:H

1993 ◽  
Vol 297 ◽  
Author(s):  
P.A. Fedders
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
First Principles ◽  
Energy Gap ◽  
Dangling Bonds ◽  
Dynamics Simulations ◽  
Induced Defects ◽  
First Principles Molecular Dynamics

We give a brief description of the various classes of molecular dynamics simulations and then describe what we have learned from our simulations recently. This includes information on the nature of defects in a-Si:H including positions in the energy gap and localization, relaxation and rearrangement effects, light induced defects, and the motion of H atoms and Si dangling bonds.

scholarly journals Molecular Dynamics Simulations of Heavy Ion Induced Defects in SiC Schottky Diodes

2018 ◽  
Vol 18 (3) ◽  
pp. 481-483 ◽  
Author(s):  
Arto Javanainen ◽  
Henrique Vazquez Muinos ◽  
Kai Nordlund ◽  
Flyura Djurabekova ◽  
Kenneth F. Galloway ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Schottky Diodes ◽  
Heavy Ion ◽  
Dynamics Simulations ◽  
Induced Defects

Polymer Nanocomposites: Molecular Dynamics Simulations of Polystyrene and Polystyrene-Polyisoprene Block Copolymer Nanocomposites

2002 ◽  
Vol 733 ◽  
Author(s):  
D. Shah ◽  
I. A. Bitsanis ◽  
U. Natarajan ◽  
E. Hackett ◽  
E.P. Giannelis
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Electrostatic Interactions ◽  
Polymer Chains ◽  
Aromatic Rings ◽  
Mobile Species ◽  
Minimum Number ◽  
Silicate Surface ◽  
Dynamics Simulations ◽  
Silicate Layers

AbstractMolecular dynamics simulations were used to study the interlayer structure and dynamics of polystyrene (PS) and polystyrene-polyisoprene (PS-PI) block copolymers intercalated in organically modified layered silicates. In the case of PS the polymer chains displace the aliphatic surfactant chains and reside adjacent to the silicate layers. The electrostatic interactions between the aromatic rings on the PS chains and the silicate surface drive the intercalation of the polymer into the host galleries. PI, which lacks such electrostatic interactions, is immiscible (does not intercalate) with the host. There appears to be a minimum number of PS mers for intercalation of PS-PI copolymers to take place. The intercalated copolymer appears to structure inside the host galleries with the PS mers adjacent to the silicate layers and the corresponding PI away from the surface and towards the middle of the gallery. Using the mean square displacements we find that PS is the least mobile species in the galleries with the surfactant chains been the most mobile of all.

Microscopic Nature of Nature Light Induced Defects

1998 ◽  
Vol 507 ◽  
Author(s):  
R. Biswas ◽  
B. C. Pana
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Bond Angle ◽  
Dangling Bonds ◽  
Defect Complexes ◽  
Dynamics Simulations ◽  
Induced Defects

ABSTRACTMolecular dynamics simulations find light-induced metastable defects to be silicon dangling bonds accompanied by (Si-H)2 defect complexes that have two Si-H bonds. These complexes are formed by pairs of hydrogen breaking a silicon bond. This supports the model of Branz. These defects are the analogue of the H2* defect in c-Si and their energy correlates with the bond-angle strain. Several features of annealing including E-field induced effects are well accounted for by the (Si-H)2 defect.

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