Determination of the hydrogen diffusion coefficient in hydrogenated amorphous silicon from hydrogen effusion experiments

1982 ◽  
Vol 53 (12) ◽  
pp. 8745-8750 ◽  
Author(s):  
W. Beyer ◽  
H. Wagner
Keyword(s):  
Diffusion Coefficient ◽  
Amorphous Silicon ◽  
Hydrogen Diffusion ◽  
Hydrogenated Amorphous Silicon ◽  
Hydrogen Diffusion Coefficient ◽  
Hydrogenated Amorphous ◽  
Hydrogen Effusion

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.

Diffusion coefficient using pausing time of hydrogen in a-Si:H with exponential energy distribution

2015 ◽  
Vol 29 (14) ◽  
pp. 1550083 ◽  
Author(s):  
Harumi Hikita ◽  
Kazuo Morigaki
Keyword(s):  
Distribution Function ◽  
Diffusion Coefficient ◽  
Brownian Motion ◽  
Energy Distribution ◽  
Amorphous Silicon ◽  
Hydrogen Diffusion ◽  
Hydrogenated Amorphous Silicon ◽  
Diffusion Time ◽  
Energy Distribution Function ◽  
Hydrogenated Amorphous

The diffusion coefficient of hydrogen is obtained for exponential energy distribution in hydrogenated amorphous silicon (a-Si:H). It is shown that the diffusion coefficient follows the form of τα-1 (τ: diffusion time) in the case of α < 1 and a larger τ, in which α is the ratio of hydrogen temperature to width for energy distribution function. In the case of α ≥ 1, as α reaches infinity at the limit, the hydrogen diffusion approaches Brownian motion.

Determination of the Mobile-Hydrogen Charge State in Hydrogenated Amorphous Silicon

2001 ◽  
Vol 664 ◽  
Author(s):  
Brent P. Nelsona ◽  
Yueqin Xu ◽  
Robert C. Reedy ◽  
Richard S. Crandall ◽  
A. Harv Mahan ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Electric Fields ◽  
Correlation Energy ◽  
Hydrogen Charge ◽  
Hydrogenated Amorphous Silicon ◽  
Mobile Hydrogen ◽  
Almost All ◽  
Hydrogenated Amorphous ◽  
Best Fit

ABSTRACTWe find that hydrogen diffuses as H+, H0, or H- in hydrogenated amorphous silicon depending on its location within the i-layer of a p-i-n device. We annealed a set of five p-i-n devices, each with a thin deuterium-doped layer at a different location in the i-layer, and observed the D-diffusion using secondary ionmass spectrometry (SIMS). When H-diffuses in a charged state, electric fields in the device strongly influence the direction and distance of diffusion. When D is incorporated into a device near the p-layer, almost all of the D-diffusion occurs as D+, and when the D is incorporated near the n-layer, most of the D-diffusion occurs as D-. We correlate the preferential direction of D-motion at given depth within the i-layer, with the local Fermi level (as calculated by solar cell simulations), to empirically determine an effective correlation energy for mobile-H electronic transitions of 0.39 ± 0.1 eV. Using this procedure, the best fit to the data produces a disorder broadening of the transition levels of ∼0.25 eV. The midpoint between the H0/+ and the H0/- transition levels is ∼0.20 ± 0.05 eV above midgap.

Reduction of the Defect Density in a-Si:H Deposited at ≤250°C

1993 ◽  
Vol 297 ◽  
Author(s):  
Hitoshi Nishio ◽  
Gautam Ganguly ◽  
Akihisa Matsuda
Keyword(s):  
Diffusion Coefficient ◽  
Amorphous Silicon ◽  
Surface Diffusion ◽  
Film Growth ◽  
Defect Density ◽  
Hydrogenated Amorphous Silicon ◽  
Device Fabrication ◽  
Surface Diffusion Coefficient ◽  
Hydrogenated Amorphous ◽  
Substrate Temperatures

We present a method to reduce the defect density in hydrogenated amorphous silicon (a-Si:H) deposited at low substrate temperatures similar to those used for device fabrication . Film-growth precursors are energized by a heated mesh to enhance their surface diffusion coefficient and this enables them to saturate more surface dangling bonds.

Diffusion and Effusion of Hydrogen in Microcrystalline Silicon

1997 ◽  
Vol 467 ◽  
Author(s):  
W. Beyer ◽  
P. Hapke ◽  
U. Zastrow
Keyword(s):  
Diffusion Coefficient ◽  
Infrared Absorption ◽  
Cyclotron Resonance ◽  
Hydrogen Diffusion ◽  
Electron Cyclotron Resonance ◽  
Microcrystalline Silicon ◽  
Hydrogen Diffusion Coefficient ◽  
Internal Surfaces ◽  
Substrate Temperatures ◽  
Hydrogen Effusion

ABSTRACTThe diffusion and effusion of hydrogen in hydrogenated microcrystalline silicon films deposited in an electron cyclotron resonance reactor were studied for various deposition temperatures Ts. For deposition temperatures below 250°C, hydrogen effusion is found to be dominated by desorption of hydrogen from internal surfaces followed by rapid out-diffusion of H2. Higher substrate temperatures result in an increased hydrogen stability suggesting the growth of a more compact material. For this latter type of samples, a hydrogen diffusion coefficient similar as in compact plasma-grown a-Si:H films is found despite a different predominant bonding of hydrogen according to infrared absorption.

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