Changes in hydrogen concentration and defect state density at the poly-Si/SiOx/c-Si interface due to firing

2021 ◽  
Vol 231 ◽  
pp. 111297
Author(s):  
Christina Hollemann ◽  
Nils Folchert ◽  
Steven P. Harvey ◽  
Paul Stradins ◽  
David L. Young ◽  
...  
Keyword(s):  
Hydrogen Concentration ◽  
State Density ◽  
Defect State

Characterization of chemical bonding features and defect state density in HfSiOx Ny/SiO2 gate stack

2007 ◽  
Vol 84 (9-10) ◽  
pp. 2386-2389 ◽  
Author(s):  
A. Ohta ◽  
Y. Munetaka ◽  
A. Tsugou ◽  
K. Makihara ◽  
H. Murakami ◽  
...  
Keyword(s):  
Chemical Bonding ◽  
State Density ◽  
Defect State ◽  
Gate Stack

Non-Local Recombination in “Tunnel Junctions” of Multijunction Amorphous Si Alloy Solar Cells

1994 ◽  
Vol 336 ◽  
Author(s):  
Jingya Hou ◽  
Jianping Xi ◽  
Frank Kampas ◽  
Sanghoon Bae ◽  
S. J. Fonash
Keyword(s):  
Solar Cells ◽  
Tunnel Junction ◽  
Tunnel Junctions ◽  
Energy Conversion Efficiency ◽  
State Density ◽  
Defect State ◽  
Large Defect ◽  
Recombination Mechanism ◽  
Non Local ◽  
Amorphous Si

ABSTRACTThis paper analyzes the charge transport in “tunnel junctions” of amorphous Si Material based multijunction solar cells and proposes some guidelines for making good “tunnel junctions” based on the analysis. The Mechanism of the current flow in these “tunnel” junctions is recombination. However, the recombination mechanism is not the usual localized recombination but is non-localized recombination. The energy analysis shows that the usual localized recombination will cause a large energy loss and result in much lower energy conversion efficiency and Voc than the experimentally measured values. In non-local recombination, opposite charge carriers located at different locations can recombine by tunneling into a defect state. Based on this Mechanism, a good “tunnel junction” should be thin, with a large defect state density in the middle region of the “tunnel junction”. Broad tail states material and a thin layer small band gap material in tunnel junctions may improve the non-local recombination by providing more intermediate states for charge to tunnel through.

The Study of Deep Levels in CdS/CdTe Solar Cells Using Admittance Spectroscopy and its Modifications

2003 ◽  
Vol 763 ◽  
Author(s):  
A.S. Gilmore ◽  
V. Kaydanov ◽  
T.R. Ohno
Keyword(s):  
Solar Cells ◽  
Energy Levels ◽  
Wide Frequency Range ◽  
State Density ◽  
Defect State ◽  
Stress Tests ◽  
Frequency Range ◽  
Cdte Solar Cells ◽  
State Densities ◽  
As Stress

AbstractMeasurements of an admittance over a wide frequency range were used to detect the defect electronic states and evaluate their properties in CdTe based solar cells. Cells prepared in various ways, from various facilities all exhibited a high defect state density (>1014cm-3, and often >1015cm-3). Two distinct energy levels or bands were observed at approximately 0.37eV and 0.61eV above the valence band. These were tentatively attributed to CuCd- and VCd-- respectively. Various post-CdTe deposition treatments, as well as stress tests, were applied to alter the defect state densities. The high defect concentration measured was not observed to inhibit cell performance in any way.

Estimation of Defect State Densities from Bulk Photoelectronic Properties of a-Si,Ge:H Alloys

1987 ◽  
Vol 95 ◽  
Author(s):  
G. N. Parsons ◽  
G. Lucovsky
Keyword(s):  
Activation Energy ◽  
Incident Light ◽  
Film Surface ◽  
Dark Conductivity ◽  
State Density ◽  
Defect State ◽  
Oxide Interface ◽  
Conductivity Activation Energy ◽  
State Densities

AbstractWe have studied the photoelectronic properities of a- Si(x),Ge(1−x):H alloy films and have concluded that there are depletion layers at the film surface and film/oxide interface that effect the determination of bulk quantum effieciencymobility- lifetime (nuT) products. From changes in dark conductivity activation energy with film thickness and the nuT product with wavelength of incident light we have estimated defeci sta:e lensitles. Our best x=0.5 film has an nuT value of 9×10−8 cm2 V−1 andaj defect state density near the Fermi level of approximately 5×10 cm−3 eV−1.

Temperature Dependent Defect Density Calculated from Activated Conductivity of a-Si:H

1991 ◽  
Vol 219 ◽  
Author(s):  
T. Drusedau ◽  
V. Kirbs ◽  
H. Fiedler
Keyword(s):  
Fermi Level ◽  
Density Of States ◽  
Defect Density ◽  
State Density ◽  
Level Shift ◽  
Defect State ◽  
Temperature Dependent ◽  
Slow Cooling ◽  
Thermally Activated ◽  
Gap States

ABSTRACTThermally activated conductivity of a—Si:H at a slow cooling rate of 0.3 K/min is connected with temperature dependent changes of the mobility gap states. By means of the Fermi—level shift calculated from these data and a density of states model it is possible to determine this dependence. The results mainly reveal a decrease of the defect state density by about a tenth between 375 K and 400 K.

Decreasing Defect-State Density of Al2 O3 /Ga x In1− x As Device Interfaces with InO x Structures

2017 ◽  
Vol 4 (22) ◽  
pp. 1700722 ◽  
Author(s):  
Jaakko Mäkelä ◽  
Marjukka Tuominen ◽  
Johnny Dahl ◽  
Sari Granroth ◽  
Muhammad Yasir ◽  
...  
Keyword(s):  
State Density ◽  
Defect State

scholarly journals Micro/nanostructured gas sensors: the physics behind the nanostructure growth, sensing and selectivity mechanisms

2021 ◽  
Vol 3 (1) ◽  
pp. 73-93
Author(s):  
N. K. Chowdhury ◽  
B. Bhowmik
Keyword(s):  
Gas Sensors ◽  
State Density ◽  
Band Model ◽  
Defect State ◽  
Research Focus ◽  
Lumo Energy ◽  
Sensing Mechanism ◽  
Control Growth

Research focus on control growth of nanostructures, understanding of sensing mechanism through band model, LUMO energy, defect state density. Further, role of electrode for sensing and substrate for devices reliability has been discussed.

Gap States in Hydrogenated Amorphous Silicon—Carbon Alloys

1985 ◽  
Vol 49 ◽  
Author(s):  
P. Fiorini ◽  
F. Evangelisti ◽  
A. Frova
Keyword(s):  
Amorphous Silicon ◽  
Recombination Rate ◽  
Transport Mechanism ◽  
Hydrogenated Amorphous Silicon ◽  
State Density ◽  
Defect State ◽  
Defect States ◽  
Silicon Carbon ◽  
Gap States ◽  
Hydrogenated Amorphous

AbstractTail and defect states in the gap of a-SixCl-x:H alloys have been studied by measurements of spectral photoconductivity. The variation of defect—state density versus x is found to be negligible. By comparison with PDS results the ητ product has been determined and found to be almost independent of photonenergy and to strongly decrease with inclusion of carbon. This effect is attributed to changes in the transport mechanism combined with an increased recombination rate associated with the widening of the gap.

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