Reverse bias annealing of Schottky diodes: evidence for the lower defect density and better stability of polymorphous silicon compared to amorphous silicon

Metastable defect creation by illumination and by a forward current in p-i-n devices are compared using CPM and reverse current measurements of the defect density. The data show that the same defects are formed by the two mechanisms, but with different spatial profiles. Numerical modelling shows how the spatial profile influences the reverse bias current.

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Inhomogeneous spatial distribution of reverse bias leakage in GaN Schottky diodes

Applied Physics Letters ◽

10.1063/1.1356450 ◽

2001 ◽

Vol 78 (12) ◽

pp. 1685-1687 ◽

Cited By ~ 225

Author(s):

J. W. P. Hsu ◽

M. J. Manfra ◽

D. V. Lang ◽

S. Richter ◽

S. N. G. Chu ◽

...

Keyword(s):

Spatial Distribution ◽

Reverse Bias ◽

Schottky Diodes

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Annealing Kinetics of Amorphous Silicon Alloy Solar Cells Made at Various Deposition Rates

MRS Proceedings ◽

10.1557/proc-664-a25.2.1 ◽

2001 ◽

Vol 664 ◽

Cited By ~ 3

Author(s):

Baojie Yana ◽

Jeffrey Yanga ◽

Kenneth Lord ◽

Subhendu Guha

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Amorphous Silicon ◽

High Frequency ◽

Room Temperature ◽

Defect Density ◽

Very High Frequency ◽

Solar Cell Performance ◽

Kinetics Of ◽

Very High

ABSTRACTA systematic study has been made of the annealing kinetics of amorphous silicon (a-Si) alloy solar cells. The cells were deposited at various rates using H2 dilution with radio frequency (RF) and modified very high frequency (MVHF) glow discharge. In order to minimize the effect of annealing during light soaking, the solar cells were degraded under 30 suns at room temperature to quickly reach their saturated states. The samples were then annealed at an elevated temperature. The J-V characteristics were recorded as a function of annealing time. The correlation of solar cell performance and defect density in the intrinsic layer was obtained by computer simulation. Finally, the annealing activation energy distribution (Ea) was deduced by fitting the experimental data to a theoretical model. The results show that the RF low rate solar cell with high H2 dilution has the lowest Ea and the narrowest distribution, while the RF cell with no H2 dilution has the highest Ea and the broadest distribution. The MVHF cell made at 8Å/s withhigh H2 dilution shows a lower Ea and a narrower distribution than the RF cell made at 3 Å/s, despite the higher rate. We conclude that different annealing kinetics plays an important role in determining the stabilized performance of a-Si alloy solar cells.

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Numerical Design of Ultrathin Hydrogenated Amorphous Silicon-Based Solar Cell

International Journal of Photoenergy ◽

10.1155/2021/7506837 ◽

2021 ◽

Vol 2021 ◽

pp. 1-13

Author(s):

F. X. Abomo Abega ◽

A. Teyou Ngoupo ◽

J. M. B. Ndjaka

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Amorphous Silicon ◽

Buffer Layer ◽

Defect Density ◽

Hydrogenated Amorphous Silicon ◽

Theoretical Work ◽

Silicon Based ◽

The Impact ◽

Hydrogenated Amorphous

Numerical modelling is used to confirm experimental and theoretical work. The aim of this work is to present how to simulate ultrathin hydrogenated amorphous silicon- (a-Si:H-) based solar cells with a ITO BRL in their architectures. The results obtained in this study come from SCAPS-1D software. In the first step, the comparison between the J-V characteristics of simulation and experiment of the ultrathin a-Si:H-based solar cell is in agreement. Secondly, to explore the impact of certain properties of the solar cell, investigations focus on the study of the influence of the intrinsic layer and the buffer layer/absorber interface on the electrical parameters ( J SC , V OC , FF, and η ). The increase of the intrinsic layer thickness improves performance, while the bulk defect density of the intrinsic layer and the surface defect density of the buffer layer/ i -(a-Si:H) interface, respectively, in the ranges [109 cm-3, 1015 cm-3] and [1010 cm-2, 5 × 10 13 cm-2], do not affect the performance of the ultrathin a-Si:H-based solar cell. Analysis also shows that with approximately 1 μm thickness of the intrinsic layer, the optimum conversion efficiency is 12.71% ( J SC = 18.95 mA · c m − 2 , V OC = 0.973 V , and FF = 68.95 % ). This work presents a contribution to improving the performance of a-Si-based solar cells.

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Midgap electroabsorption in amorphous silicon-based schottky diodes

Journal of Non-Crystalline Solids ◽

10.1016/0022-3093(85)90722-7 ◽

1985 ◽

Vol 77-78 ◽

pp. 559-562 ◽

Cited By ~ 1

Author(s):

J.R. Eggert ◽

W. Paul

Keyword(s):

Amorphous Silicon ◽

Schottky Diodes ◽

Silicon Based

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The Role of Charged Defects In Current Transport Through Hydrogenated Amorphous Silicon Alloys

MRS Proceedings ◽

10.1557/proc-507-655 ◽

1998 ◽

Vol 507 ◽

Cited By ~ 5

Author(s):

S.P. Lau ◽

J.M. Shannon ◽

B.J. Sealy ◽

J.M. Marshall

Keyword(s):

Silicon Nitride ◽

Amorphous Silicon ◽

Defect Density ◽

Current Transport ◽

Dangling Bond ◽

Silicon Alloys ◽

Metal Structures ◽

Bond State ◽

Donor States ◽

Charged Defects

ABSTRACTCurrent transport in metal-semiconductor-metal structures based on amorphous silicon alloys has been studied in relation to the density of dangling bond state defects. The density of defects was changed by varying alloy composition or by current stressing. We show that the change of current-voltage characteristics and activation energy with defect density and the onset of Poole-Frenkel conduction with composition require charged defects. It is found that there are more charged defects in amorphous silicon nitride (a-Si1−xNx:H) than in amorphous silicon carbide (a-Si1−xCx:H). In addition, an excess of negatively charged dangling bond defects compared to positively charged dangling bond defects is observed in a-Si1−xNx:H films. This is attributed to the presence of N4+ act as the donor states in silicon nitride. We find that the density of charged dangling bond defects can be higher than 1019cm−3.

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Correlation between film and cell properties for DC plasma deposited amorphous silicon

MRS Proceedings ◽

10.1557/proc-664-a25.3.1 ◽

2001 ◽

Vol 664 ◽

Cited By ~ 3

Author(s):

Jennifer Heath ◽

Suman B. Iyer ◽

Yoram Lubianiker ◽

J. David Cohen ◽

Gautam Ganguly

Keyword(s):

Growth Rate ◽

Amorphous Silicon ◽

Defect Density ◽

Silicon Film ◽

Device Performance ◽

Solar Cell Device ◽

Film Properties ◽

Dc Plasma ◽

Hydrogen Dilution ◽

Photocurrent Spectroscopy

ABSTRACTWe have carried out measurements to try to correlate amorphous silicon film properties with companion solar cell device performance. The dc plasma deposited intrinsic films were prepared with various hydrogen dilution levels, and increasing power levels to increase growth rate. The electronic properties were determined using admittance spectroscopy and drive-level capacitance profiling (DLCP) techniques as well as transient photocapacitance and photocurrent spectroscopy. Cell and film performance were explored in both as-grown and light-soaked states. We observed that, although cell performance decreased systematiclly with increasing growth rate, it depended on factors other than the deep defect density in the matched films. On the other hand, we did observe that increases in defect density caused by the light-induced degradation led to fairly predictable decreases in the cell fill factors.

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

MRS Proceedings ◽

10.1557/proc-297-91 ◽

1993 ◽

Vol 297 ◽

Cited By ~ 4

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.

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Improved Light Soaking Stability of R.F. Sputter Deposited Amorphous Silicon

MRS Proceedings ◽

10.1557/proc-219-105 ◽

1991 ◽

Vol 219 ◽

Author(s):

A. Wynveen ◽

J. Fan ◽

J. Kakalios ◽

J. Shinar

Keyword(s):

Amorphous Silicon ◽

Hydrogen Content ◽

Defect Density ◽

Hydrogenated Amorphous Silicon ◽

Dark Conductivity ◽

Initial Defect ◽

Optical Gap ◽

Sputter Deposited ◽

Staebler Wronski Effect ◽

Hydrogenated Amorphous

ABSTRACTStudies of r.f. sputter deposited hydrogenated amorphous silicon (a-Si:H) find that the light induced decrease in the dark conductivity and photoconductivity (the Staebler-Wronski effect) is reduced when the r.f. power used during deposition is increased. The slower Staebler-Wronski effect is not due to an increase in the initial defect density in the high r.f. power samples, but may result from either the lower hydrogen content or the smaller optical gap found in these films.

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