scholarly journals Lattice and Hydrogen Dynamics in Hydrogenated Amorphous Silicon: First-Principles Molecular Dynamics versus Experiment

2010 ◽  
Author(s):  
A. I. Shkrebtii ◽  
I. M. Kupchak ◽  
F. Gaspari ◽  
Marília Caldas ◽  
Nelson Studart
Keyword(s):  
Molecular Dynamics ◽  
Amorphous Silicon ◽  
First Principles ◽  
Hydrogenated Amorphous Silicon ◽  
Hydrogenated Amorphous ◽  
First Principles Molecular Dynamics

Computer-Generated Structural Models for a-Si:H

1988 ◽  
Vol 141 ◽  
Author(s):  
Laurent J. Lewis ◽  
Normand Mousseau ◽  
FranÇois Drolet
Keyword(s):  
Molecular Dynamics ◽  
Boundary Conditions ◽  
Amorphous Silicon ◽  
Periodic Boundary ◽  
Hydrogenated Amorphous Silicon ◽  
Structural Models ◽  
Periodic Boundary Conditions ◽  
Dynamics Simulations ◽  
Hydrogenated Amorphous ◽  
Good Agreement

AbstractA new algorithm for generating fully-coordinated hydrogenated amorphous silicon models with periodic boundary conditions is presented. The hydrogen is incorporated into an a-Si matrix by a bond-switching process similar to that proposed by Wooten, Winer, and Weaire, making sure that four-fold coordination is preserved and that no rings with less than 5 members are created. After each addition of hydrogen, the structure is fully relaxed. The models so obtained, to be used as input to molecular dynamics simulations, are found to be in good agreement with experiment. A model with 12 at.% H is discussed in detail.

Correlations between higher-order rings and microvoids in hydrogenated amorphous silicon

2015 ◽  
Vol 1757 ◽  
Author(s):  
Parthapratim Biswas ◽  
David Alan Drabold
Keyword(s):  
Amorphous Silicon ◽  
First Principles ◽  
Molecular Hydrogen ◽  
Hydrogenated Amorphous Silicon ◽  
Experimental Information ◽  
Higher Order ◽  
Hydrogenated Amorphous

ABSTRACTIn this paper we report the structure of voids in several thousand atom models of hydrogenated amorphous silicon. The models are produced by jointly employing experimental information from Smets and coworkers [1] and first principles simulations [2]. We demonstrate the existence of a useful correlation between the presence of large irreducible rings and the voids in hydrogenated amorphous silicon networks. Molecular hydrogen is observed in the models, and discussed.

First-principles Modeling of Structure, Vibrations, Electronic Properties and Bond Dynamics in Hydrogenated Amorphous Silicon: Theory versus Experiment

2009 ◽  
Vol 1153 ◽  
Author(s):  
Anatoli Shkrebtii ◽  
Ihor Kupchak ◽  
Franco Gaspari
Keyword(s):  
Amorphous Silicon ◽  
Electronic Properties ◽  
First Principles ◽  
Hydrogen Diffusion ◽  
Hydrogenated Amorphous Silicon ◽  
Amorphous Structure ◽  
Material Structure ◽  
Electron Charge Density ◽  
Wide Range ◽  
Hydrogenated Amorphous

AbstractWe carried out extensive first-principles modeling of microscopic structural, vibrational, electronic properties and chemical bonding in hydrogenated amorphous silicon (a-Si:H) in a wide range of hydrogen concentration and preparation conditions. The theory has been compared with experimental results to comprehensively characterize this semiconductor material. The computer modeling includes ab-initio Molecular Dynamics (MD), atomic structure optimization, advanced signal processing and computer visualization of dynamics. We extracted parameters of hydrogen and silicon bonding, electron charge density and calculated electron density of states (EDOS) and hydrogen diffusion. A good agreement of the theory with various experiments allowed us to correlate microscopic processes at the atomic level with macroscopic properties. Here we focus on correlation of the amorphous structure of the material, atom dynamics and electronic properties. These results are of increasing interest due to extensive application of a-Si:H in modern research and technology and to the significance of detailed understanding of the material structure, bonding, disordering mechanisms and stability.

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