Negative dispersion parameter of hydrogen diffusion in hydrogenated amorphous silicon

1993 ◽  
Vol 47 (15) ◽  
pp. 9361-9365 ◽  
Author(s):  
R. Shinar ◽  
J. Shinar ◽  
H. Jia ◽  
X.-L. Wu
Keyword(s):  
Amorphous Silicon ◽  
Hydrogen Diffusion ◽  
Hydrogenated Amorphous Silicon ◽  
Dispersion Parameter ◽  
Negative Dispersion ◽  
Hydrogenated Amorphous

Role of Hydrogen Microstructure in Amorphous Silicon

1992 ◽  
Vol 258 ◽  
Author(s):  
Sufi Zafar ◽  
E. A. Schiff
Keyword(s):  
Amorphous Silicon ◽  
Hydrogen Evolution ◽  
Hydrogen Diffusion ◽  
Hydrogenated Amorphous Silicon ◽  
Hydrogenated Amorphous ◽  
Unified Description

ABSTRACTA model for correlating the observed properties of hydrogenated amorphous silicon (a-Si:H) with the underlying hydrogen microstructure is reviewed. The model provides a unified description of defect equilibration, hydrogen evolution, rehydrogenation and hydrogen diffusion measurements.

Separation of Nucleation and Growth Processes of Nanocrystalline Silicon by Hydrogen Radical Treatment of Hydrogenated Amorphous Silicon

1992 ◽  
Vol 283 ◽  
Author(s):  
Masanori Otobe ◽  
Shunri Oda
Keyword(s):  
Amorphous Silicon ◽  
Hydrogen Diffusion ◽  
Hydrogenated Amorphous Silicon ◽  
Nanocrystalline Silicon ◽  
Nucleation And Growth ◽  
Growth Processes ◽  
Plan View ◽  
Hydrogen Radical ◽  
Hydrogen Radicals ◽  
Hydrogenated Amorphous

ABSTRACTWe have investigated nucleation and growth mechanism of nanocrystalline silicon (nc-Si) based on the experimental observation of plan-view transmission electron microscopy. Nanocrystalline Si has been prepared by hydrogen radical annealing of hydrogenated amorphous silicon (a-Si:H) layer, which is deposited on hydrogen radical treated a-Si:H buffer layer. Nanocrystallization depends critically upon hydrogen radical annealing time and the thickness ofa-Si:H layer. Hydrogen radicals play important roles in both nucleation and growth processes in a different way. Growth of nc-Si can be explained by “hydrogen diffusion model”, in which hydrogen radicals diffusing through a-Si:H layer to interface cause nanocrystallization. Our results imply that nuclei for nc-Si are generated at the interface between a-Si:H and under layer when treated by hydrogen radicals.

Hydrogen Diffusion in Boron-Doped Hydrogenated Amorphous Silicon Films: Crystallization and Induced Structural Changes

2005 ◽  
Vol 864 ◽  
Author(s):  
F. Kail ◽  
A. Hadjadj ◽  
P. Roca i Cabarrocas
Keyword(s):  
Amorphous Silicon ◽  
Structural Changes ◽  
Hydrogen Diffusion ◽  
Hydrogen Plasma ◽  
Hydrogenated Amorphous Silicon ◽  
Silicon Films ◽  
Hydrogen Atoms ◽  
Boron Doped ◽  
Hydrogenated Amorphous ◽  
Positively Charged

AbstractWe have studied the evolution of the structure of boron-doped hydrogenated amorphous silicon films exposed to a hydrogen plasma. From the early stages of exposure, hydrogen diffuses and forms a thick H-rich subsurface. At longer times, hydrogen plasma leads to the formation of a microcrystalline layer via chemical transport without crystallization of the initial layer. We observe that the hydrogen content increases in the films during a plasma exposure and once the microcrystalline layer is formed hydrogen diffuses out of the sample accompanied with a decrease in the boron content. This effect can be attributed to the electric field developed within the heterojunction a-Si:H/μc-Si:H that drives the positively charged hydrogen atoms in the boron-doped layer towards the μc-Si:H layer.

Enhanced Hydrogen Diffusion Under Illumination in Hydrogenated Amorphous Silicon

1992 ◽  
Vol 258 ◽  
Author(s):  
P.V. Santos ◽  
N.M. Johnson ◽  
R.A. Street
Keyword(s):  
Diffusion Coefficient ◽  
Electric Field ◽  
Experimental Evidence ◽  
Amorphous Silicon ◽  
Hydrogen Diffusion ◽  
Hydrogenated Amorphous Silicon ◽  
Diffusion Region ◽  
Hydrogen Diffusion Coefficient ◽  
Hydrogenated Amorphous ◽  
Carrier Population

ABSTRACTWe provide experimental evidence for the fact that hydrogen diffusion in hydroge-nated amorphous silicon is controlled by the concentration of electronic carriers. It is experimentally demonstrated that the hydrogen diffusion coefficient (a) is enhanced if the carrier population is increased by illumination and (b) is strongly suppressed if carriers are extracted from the diffusion region by the application of an electric field.

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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