Light-Intensity Dependence of the Staebler-Wronski Effect in a-Si:H with Various Densities of Defects

2005 ◽  
Vol 862 ◽  
Author(s):  
Minoru Kumeda ◽  
Ryohei Sakai ◽  
Akiharu Morimoto ◽  
Tatsuo Shimizu
Keyword(s):  
Light Intensity ◽  
Weak Dependence ◽  
Rate Equations ◽  
Dangling Bonds ◽  
Illumination Time ◽  
Intensity Dependence ◽  
Weak Light ◽  
Staebler Wronski Effect

AbstractThe light-intensity dependence of the photocreation of dangling bonds (DBs) were investigated for a-Si:H films with increasing density of defects before light soaking. Samples in which the density of neutral DBs had been increased by annealing at 400 C for 1 h exhibited a weak light-intensity dependence of the photocreated DBs compared to that for the as-deposited sample. Furthermore, the sample which had been illuminated with a light intensity of 1 W/cm2 for 1 h also showed a weak dependence. The results can be qualitatively explained by using rate equations for the densities of DBs and floating bonds (FBs) based on the FB-mediated photocreation of DBs. When both the densities of DBs and FBs before illumination increase, the light-intensity dependence of the DB density for a moderate value of the illumination time becomes weaker, qualitatively consistent with the observed results.

Radial Oxygen Loss and Pollutants Removal of Plants Cultivated on Ecological Floating Beds

2012 ◽  
Vol 610-613 ◽  
pp. 1354-1358 ◽  
Author(s):  
Hai Bo Li ◽  
Xin Wang ◽  
Ying Hua Li
Keyword(s):  
Light Intensity ◽  
Wild Rice ◽  
Pilot Test ◽  
Radial Oxygen Loss ◽  
Removal Rates ◽  
Oxygen Loss ◽  
Illumination Time ◽  
Light Intensities ◽  
Weak Light ◽  
Pollutants Removal

Radial oxygen loss (ROL) from roots of reed, typha and wild rice stem was investigated. Root excretion oxygen showed that the rates of the ROL increased with the illumination time under hard light intensity. For each plant, the ability that roots excreting oxygen under different light intensities decreased successively in the order of hard light, non-light and weak light. The ROL was different with the increased sequence of typha, wild rice stem and reed. The local available reed and typha could remove the pollutants effectively in the pilot test with the average removal rates of 41.99%, 28.47%, 48.38% and 48.76%, respectively.

The Tail States as Sensitizing Recombination Centers for Holes Lifetime in a-Si:H

1998 ◽  
Vol 507 ◽  
Author(s):  
Y. Lubianiker ◽  
R. Rapaport ◽  
I. Balberg ◽  
L. Fonseca ◽  
S.Z. Weisz
Keyword(s):  
Light Intensity ◽  
Thermal Quenching ◽  
Charge Carriers ◽  
Numerical Calculations ◽  
Dangling Bonds ◽  
Intensity Dependence ◽  
Recombination Model ◽  
Light Intensities ◽  
Recombination Centers

ABSTRACTWe have measured the dependence of the holes mobility-lifetime product on temperature under various light intensities in intrinsic a-Si:H. We find that this product exhibits thermal quenching which is accompanied by a superlinear light intensity dependence. Numerical calculations that we have carried out show that these results can be accounted for within the framework of the conventional recombination model. However, to yield such an agreement the capture coefficients for both charge carriers at the tail states must be smaller than the corresponding coefficients for the dangling bonds. Thus the sensitizing nature of the tail states is revealed.

scholarly journals Response of Photosynthesis and Chlorophyll Fluorescence Parameters of Castanopsis kawakamii Seedlings to Forest Gaps

Forests ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 21
Author(s):  
Zhong-sheng He ◽  
Rong Tang ◽  
Meng-jia Li ◽  
Meng-ran Jin ◽  
Cong Xin ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Light Intensity ◽  
Seedling Growth ◽  
Group Treatment ◽  
Control Group ◽  
Low Light ◽  
Chlorophyll Fluorescence Parameters ◽  
Forest Gaps ◽  
Low Light Intensity ◽  
Weak Light

Light is a major environmental factor limiting the growth and survival of plants. The heterogeneity of the light environment after gap formation in forest influences the leaf chlorophyll contents, net photosynthetic rate (Pn), and chlorophyll fluorescence, thus influencing the growth and regeneration of Castanopsis kawakamii seedlings. The aim of this study was to explore the effects of weak light on the photosynthetic physiology of C. kawakamii seedlings in forest gaps and non-gaps. The results showed that (1) the contents of chlorophyll a (Chl-a), chlorophyll b (Chl-b), and total chlorophyll (Chl-T) in forest gaps were lower than in non-gaps. Seedlings tended to increase chlorophyll content to absorb light energy to adapt to low light intensity in non-gap environments. (2) The Pn values of C. kawakamii seedlings in forest gaps were significantly higher than in non-gaps, and forest gaps could improve the seedlings’ photosynthetic capacity. (3) The C. kawakamii seedlings in forest gaps were more sensitive to weak light and control group treatment, especially the tall seedlings, indicating that seedlings require more light to satisfy their growth needs in the winter. The seedlings in non-gaps demonstrated better adaptability to low light intensity. The light intensity was not adequate in weak light conditions and limited seedling growth. We suggest that partial forest selection cutting could improve light intensity in non-gaps, thus promoting seedling growth and regeneration of C. kawakamii more effectively in this forest.

Light-Intensity Dependence In The Kinetics Of N-Gap Photoelectrode Stabilization

2010 ◽  
Vol 89 (3) ◽  
pp. 181-186 ◽  
Author(s):  
F. van Overmeire ◽  
F. Vanden Kerchove ◽  
W. P. Gomes ◽  
F. Cardon
Keyword(s):  
Light Intensity ◽  
Intensity Dependence ◽  
Kinetics Of

Light-intensity dependence in photocatalytic decomposition of water over K4Nb6O17 catalyst

1994 ◽  
Vol 28 (2-4) ◽  
pp. 417-422 ◽  
Author(s):  
S. Tabata ◽  
H. Ohnishi ◽  
E. Yagasaki ◽  
M. Ippommatsu ◽  
K. Domen
Keyword(s):  
Light Intensity ◽  
Photocatalytic Decomposition ◽  
Intensity Dependence ◽  
Decomposition Of Water
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