Influence of laser crystallization on the hydrogen density-of-states distribution

2004 ◽  
Vol 338-340 ◽  
pp. 295-298
Author(s):  
N.H. Nickel ◽  
K. Brendel
1997 ◽  
Vol 467 ◽  
Author(s):  
A. J. Franz ◽  
W. B. Jackson ◽  
J. L. Gland

ABSTRACTHydrogen plays an important role in the electronic behavior, structure and stability of amorphous silicon films. Therefore, determination of the hydrogen density of states (DOS) and correlation of the hydrogen DOS with the electronic film properties are important research goals. We have developed a novel method for determination of hydrogen DOS in silicon films, based on fractional evolution experiments. Fractional evolution experiments are performed by subjecting a silicon film to a series of linear, alternating heating and cooling ramps, while monitoring the hydrogen evolution rate. The fractional evolution data can be analyzed using two complementary memods, the fixed frequency factor approach and Arrhenius analysis. Using a rigorous, mean-field evolution model, we demonstrate the applicability of the two approaches to obtaining the hydrogen DOS in silicon films. We further validate both methods by analyzing experimental fractional evolution data foran amorphous silicon carbide film. Both types of analysis yield a similar double peaked density of states for the a-Si:C:H:D film.


1994 ◽  
Vol 336 ◽  
Author(s):  
S.C. Deane ◽  
M.J. Powell

ABSTRACTWe derive the hydrogen density of states for hydrogenated Amorphous silicon (a-Si:H), which is completely consistent with the electronic density of states for the defect pool model. If silicon dangling bond energies are distributed in energy, as in a defect pool model, then the hydrogen density of states becomes quite complex, with the hydrogen binding energy dependent on the Fermi level and dangling bond transition energy. We demonstrate that the electronic density of states for dangling bonds is almost identical to our previous defect pool model, while the hydrogen density of states can account for the results of hydrogenation-dehydrogenation experiments. The effective hydrogen correlation energy is variable, being negative for most hydrogen binding sites, but positive for most defect sites.


2006 ◽  
Vol 910 ◽  
Author(s):  
Rosari Saleh ◽  
Norbert H Nickel

AbstractA series of boron doped polycrystalline silicon were produced using step-by-step laser crystallization process from amorphous silicon. The influence of doping concentrations on laser- induced dehydrogenation and crystallization of amorphous silicon and on hydrogen bonding have been investigated employing Raman spectroscopy and hydrogen effusion measurements. From hydrogen effusion spectra the hydrogen chemical potential is determined as a function of hydrogen concentration, which can be related to the hydrogen density-of-states distribution. The results from hydrogen effusion are consistent with the results obtained from Raman spectroscopy.


2021 ◽  
Vol 129 (19) ◽  
pp. 195704
Author(s):  
N. H. Nickel ◽  
K. Geilert

2005 ◽  
Vol 19 (15) ◽  
pp. 683-695 ◽  
Author(s):  
BLAIR R. TUTTLE

Microscopic aspects of the behavior of hydrogen in amorphous silicon are reviewed in the context of density functional electronic structure calculations. The relative energetics of various hydrogen complexes are presented. Also, a hydrogen density of states picture is used to describe hydrogen-related phenomena including diffusion and defect formation. A microscopic theory for hydrogen-related metastability will be discussed in detail.


1998 ◽  
Vol 227-230 ◽  
pp. 143-147 ◽  
Author(s):  
W.B Jackson ◽  
A.J Franz ◽  
H.-C Jin ◽  
J.R Abelson ◽  
J.L Gland

2003 ◽  
Vol 82 (18) ◽  
pp. 3029-3031 ◽  
Author(s):  
N. H. Nickel ◽  
K. Brendel

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