Tritium Induced Defects in Amorphous Silicon

2004 ◽  
Vol 808 ◽  
Author(s):  
J. Whitaker ◽  
J. Viner ◽  
S. Zukotynski ◽  
E. Johnson ◽  
P.C. Taylor ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Defect Production ◽  
Photothermal Deflection Spectroscopy ◽  
Spin Resonance ◽  
Photothermal Deflection ◽  
Induced Defects ◽  
Hydrogenated Amorphous ◽  
Accumulation Of Defects ◽  
Insight Into

ABSTRACTWe report the growth of tritium induced defects in tritium doped hydrogenated amorphous silicon (a-Si:H,T) as measured by electron spin resonance (ESR) and photothermal deflection spectroscopy (PDS). The measurements allow one to examine the accumulation of defects in a-Si:H,T where the defect production mechanism is known. Defects produced by tritium decay are found to be much less numerous than the number of decayed tritium atoms and they are metastable like Staebler-Wronski defects. These results provide new insight into the metastable defect creation and the role of hydrogen motion.

Defects in Hydrogenated Amorphous Silicon Carbide Alloys using Electron Spin Resonance and Photothermal Deflection Spectroscopy

2009 ◽  
Vol 1153 ◽  
Author(s):  
Brian J. Simonds ◽  
Feng Zhu ◽  
Josh Gallon ◽  
Jian Hu ◽  
Arun Madan ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Electron Spin Resonance ◽  
Amorphous Silicon ◽  
Electron Spin ◽  
Carbon Concentration ◽  
Hydrogenated Amorphous Silicon ◽  
Photothermal Deflection Spectroscopy ◽  
Spin Resonance ◽  
Photothermal Deflection ◽  
Hydrogenated Amorphous

AbstractHydrogenated amorphous silicon carbide alloys are being investigated as a possible top photoelectrode in photoelectrochemical cells used for hydrogen production through water splitting. In order to be used as such, it is important that the effects of carbon concentration on bonding, and thus on the electronic and optical properties, is well understood. Electron spin resonance experiments were performed under varying experimental conditions to study the defect concentrations. The dominant defects are silicon dangling bonds. At room temperature, the spin densities varied between 1016 and 1018 spins/cm3 depending on the carbon concentration. Photothermal deflection spectroscopy, which is an extremely sensitive measurement of low levels of absorption in thin films, was performed to investigate the slope of the Urbach tail. These slopes are 78 meV for films containing the lowest carbon concentration and 98 meV for those containing the highest carbon concentration.

Hydrogenated Amorphous Silicon Alloyed with Selenium

1998 ◽  
Vol 507 ◽  
Author(s):  
Shenlin Chen ◽  
P. C. Taylor ◽  
J. M. Viner
Keyword(s):  
Amorphous Silicon ◽  
Vapor Deposition ◽  
Hydrogenated Amorphous Silicon ◽  
Chemical Vapor ◽  
Band Tail ◽  
Photothermal Deflection Spectroscopy ◽  
Spin Resonance ◽  
Photo Conductivity ◽  
Photothermal Deflection ◽  
Hydrogenated Amorphous

ABSTRACTHydrogenated amorphous silicon alloyed with selenium has been made by plasma enhanced chemical vapor deposition (PECVD). The activation energy for electrical conduction is essentially unchanged for selenium concentrations < 1 at.%. The photo conductivity changes for selenium concentrations > 0.5 at. %. Photothermal deflection spectroscopy (PDS) and electron spin resonance (ESR), respectively, show that the width of the valence band tail states and the density of neutral silicon dangling bonds also change for selenium concentrations > 0.5 at. %.

Light-Soaking Effects on Photoconductivity in a-Si:H Thin Films

1997 ◽  
Vol 467 ◽  
Author(s):  
E. Morgado ◽  
M. Rebelo da Silva ◽  
R. T. Henriques
Keyword(s):  
Thin Films ◽  
Defect Density ◽  
Light Exposure ◽  
Dangling Bond ◽  
Photothermal Deflection Spectroscopy ◽  
Spin Resonance ◽  
Photo Conductivity ◽  
Photothermal Deflection ◽  
Gap States ◽  
Induced Defects

ABSTRACTMetastable defects have been created by light exposure in thin films of a-Si:H. The samples have been characterized by Photothermal Deflection Spectroscopy, Electron Spin Resonance, dark- and photo-conductivity. The experimental results are consistent with numerical calculations with a recombination model involving band tails and one class of correlated dangling-bond states. The effects of light-soaking on the ligh intensity and defect density dependences of photoconductivity are reproduced by the calculations. The model allows to explain the experimental trends by changes in the electronic occupation of the gap states produced by light-induced defects.

Role of the hydrogen in the light-induced defects in undoped hydrogenated amorphous silicon

1991 ◽  
pp. 265-268
Author(s):  
H. Labidi ◽  
K. Zellama ◽  
P. Germain ◽  
M. Astier ◽  
D. Lortigues ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Hydrogenated Amorphous Silicon ◽  
Induced Defects ◽  
Hydrogenated Amorphous

Contributions of D0 and non-D0 Gap States to the Kinetics of Light Induced Degradation of Amorphous Silicon under 1 sun Illumination

2001 ◽  
Vol 664 ◽  
Author(s):  
J. Pearce ◽  
X. Niu ◽  
R. Koval ◽  
G. Ganguly ◽  
D. Carlson ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Degradation Kinetics ◽  
Hydrogen Dilution ◽  
Spin Resonance ◽  
The Creation ◽  
Staebler Wronski Effect ◽  
Gap States ◽  
Induced Changes ◽  
Induced Defects ◽  
Hydrogenated Amorphous

ABSTRACTLight induced changes to 1 sun degraded steady state (DSS) have been investigated on hydrogenated amorphous silicon (a-Si:H) p-i-n solar cells and corresponding films fabricated with and without hydrogen dilution of silane. Striking similarities are found for the degradation kinetics, between the electron mobility lifetime (μτ) products and the corresponding fill factors (FF). These correlations that exist for both intrinsic materials at temperatures between 25 and 100°C, are present for the DSS as well as in the kinetics, which exihibit distinctly different dependence on temperature. No such correlations are present between μτ, FF and densities of D0 defects, measured with subgap absorption α(E) at 1.2eV, and electron spin resonance (ESR). The creation of non-D0 defects is also clearly indicated by the temperature dependence of the kinetics and the changes in the shape of α(E) with the results suggesting the presence of more than one mechanism for the creation of light induced defects associated with the Staebler-Wronski effect (SWE).

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