Toward a Practical Model of a-Si:H Defects in Intensity-Time-Temperature Space

ABSTRACTIn this paper we develop a model of the defect kinetics in hydrogenated Amorphous silicon (a:Si:H) with the goal of predicting the density of defect states g (E) established by any given light intensity I, for arbitrary times t and temperatures T. While we build on widely accepted expressions for the the rates of light-induced and thermal annealing, we examine in more detail the light induced annealing (LIA) term. The model shows that the LIA process can be described with the thermal annealing term if a suitable reduction to the annealing energy is introduced. This reduction depends on the light intensity such as to suggest a relation to the shift of the electron quasi-Fermi level under illumination.

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Changes of Drift Mobility in a-Si:H with Light Exposure and Doping

MRS Proceedings ◽

10.1557/proc-95-571 ◽

1987 ◽

Vol 95 ◽

Cited By ~ 2

Author(s):

J. Takada ◽

H. Fritzsche

Keyword(s):

Light Intensity ◽

Amorphous Silicon ◽

Light Exposure ◽

Hydrogenated Amorphous Silicon ◽

Drift Mobility ◽

Mobility Edge ◽

Strong Light ◽

Quasi Fermi Level ◽

Multiple Trapping ◽

Hydrogenated Amorphous

AbstractMeasurements of the drift mobility μ of photo-excited electrons in n-type hydrogenated amorphous silicon (a-Si:H) as a function of light intensity are reported. The value of μ increases as the quasi Fermi level is moved closer to the transport states in accordance with the multiple trapping theory. The drift mobility decreases with increasing doping as well as with an increase in the concentration of metastable dangling bonds defects by strong light exposures. This decrease in μ between 300 and 360K can be explained by a corresponding decrease in the microscopic mobility, by an increase in the density of tail states within 0.35eV below the electron mobility edge, or by a combination of both these effects.

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Time evolution of surface defect states in hydrogenated amorphous silicon studied by photothermal and photocurrent spectroscopy and optical simulation

Journal of Non-Crystalline Solids ◽

10.1016/j.jnoncrysol.2011.12.031 ◽

2012 ◽

Vol 358 (17) ◽

pp. 2035-2038 ◽

Cited By ~ 13

Author(s):

J. Holovský ◽

M. Schmid ◽

M. Stuckelberger ◽

M. Despeisse ◽

C. Ballif ◽

...

Keyword(s):

Amorphous Silicon ◽

Time Evolution ◽

Surface Defect ◽

Hydrogenated Amorphous Silicon ◽

Optical Simulation ◽

Defect States ◽

Photocurrent Spectroscopy ◽

Hydrogenated Amorphous

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Thermal annealing of light−induced metastable defects in hydrogenated amorphous silicon nitride

Applied Physics Letters ◽

10.1063/1.106230 ◽

1991 ◽

Vol 59 (14) ◽

pp. 1723-1725 ◽

Cited By ~ 44

Author(s):

E. D. Tober ◽

J. Kanicki ◽

M. S. Crowder

Keyword(s):

Silicon Nitride ◽

Amorphous Silicon ◽

Thermal Annealing ◽

Hydrogenated Amorphous Silicon ◽

Amorphous Silicon Nitride ◽

Hydrogenated Amorphous

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Radiation hard amorphous silicon particle sensors

MRS Proceedings ◽

10.1557/proc-862-a15.4 ◽

2005 ◽

Vol 862 ◽

Cited By ~ 3

Author(s):

N. Wyrsch ◽

C. Miazza ◽

S. Dunand ◽

C. Ballif ◽

A. Shah ◽

...

Keyword(s):

Amorphous Silicon ◽

Proton Beam ◽

Thermal Annealing ◽

Silicon Particle ◽

Hydrogenated Amorphous Silicon ◽

High Energy ◽

Significant Drop ◽

Radiation Hard ◽

Hydrogenated Amorphous ◽

Subsequent Thermal Annealing

AbstractRadiation tests of 32 μm thick hydrogenated amorphous silicon n-i-p diodes have been performed using a high energy 24 GeV proton beam up to fluences in excess of 1016 protons/cm2. The results are compared to irradiation of similar 1 μm and 32 μm thick n-i-p diodes using a proton beam of 280 keV at a fluence of 3x1013 protons/cm2. Even though both types of irradiation cause a significant drop in photoconductivity of thin or thick diodes, all samples survived the experiment and recover almost fully after a subsequent thermal annealing.

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Theoretical Studies of Structure and Doping of Hydrogenated Amorphous Silicon

MRS Proceedings ◽

10.1557/opl.2011.1095 ◽

2011 ◽

Vol 1321 ◽

Cited By ~ 4

Author(s):

Bin Cai ◽

D. A. Drabold

Keyword(s):

Amorphous Silicon ◽

Hydrogenated Amorphous Silicon ◽

Theoretical Studies ◽

Defect States ◽

High Impurity ◽

Bond Center ◽

B Doping ◽

Hydrogenated Amorphous ◽

Center Site

ABSTRACTIn a-Si:H, large concentrations of B or P (of order 1%) are required to dope the material, suggesting that doping mechanisms are very different than for the crystal for which much smaller concentrations are required. In this paper, we report simulations on B and P introduced into realistic models of a-Si:H and a-Si, with concentrations ranging from 1.6% to 12.5% of B or P in the amorphous host. The results indicate that tetrahedral B and P are effective doping configurations in a-Si, but high impurity concentrations introduce many defect states. For a-Si:H, we report that both B(3,1) and P(3,1) (B or P atom bonded with three Si atoms and one H atom) are effective doping configurations. We investigate H passivation in both cases. For both B and P, there exists a “hydrogen poison range” of order 6 Å for which H in a bond-center site can suppress doping. For B doping, nearby H prefers to stay at the bond-center of Si-Si, leaves B four-fold and neutralizes the doping configuration; for P doping, nearby H spoils the doping by inducing a reconstruction rendering initially tetrahedral P three-fold.

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Crystallization of Hydrogenated Amorphous Silicon by Rapid Thermal Method

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.428-429.444 ◽

2010 ◽

Vol 428-429 ◽

pp. 444-446 ◽

Cited By ~ 2

Author(s):

Rui Min Jin ◽

Ding Zhen Li ◽

Lan Li Chen ◽

Xin Feng Guo ◽

Jing Xiao Lu

Keyword(s):

Thin Film ◽

Amorphous Silicon ◽

Thermal Annealing ◽

Raman Spectra ◽

Rapid Thermal Annealing ◽

Glass Substrate ◽

Hydrogenated Amorphous Silicon ◽

Thermal Method ◽

Hydrogenated Amorphous ◽

Electronic Microscope

Amorphous silicon films prepared by PECVD on silex glass substrate has been crystallized by rapid thermal annealing (RTA), From the Raman spectra and scanning electronic microscope (SEM), it was found that the Raman spectra wa best crystallized at 950°C for 5 min. The thin film made by RTA was smoothly and perfect structure.

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Defect States in Hydrogenated Amorphous Silicon-Sulphur Alloys by ESR and PAS

MRS Proceedings ◽

10.1557/proc-219-593 ◽

1991 ◽

Vol 219 ◽

Author(s):

Gaorong Han ◽

Jianmin Qiao ◽

Piyi Du ◽

Zhonghua Jiang ◽

Zishang Ding

Keyword(s):

Glow Discharge ◽

Amorphous Silicon ◽

Spin Density ◽

Molecular Hydrogen ◽

Annealing Temperature ◽

Hydrogenated Amorphous Silicon ◽

Sulphur Content ◽

Defect States ◽

Hydrogenated Amorphous

ABSTRACTWe have presented ESR and PAS measurements for a series of a-SiS:H and a-Si: H films deposited by glow discharge at different parameters. The spin density in a-SiS:H alloys measured by ESR is essentially independent of the sulphur content, while the density of defects measured by PAS increases significantly with the increasing of sulphur content. The ESR signals in a-SiS:H alloys strongly depend on both annealing and illumination. The spin density increases up to 540°C and then decreases with raising annealing temperature for a-SiS:H and a-Si:H alloys. The results suggest that some new defects such as molecular hydrogen and microvoids are appeared when addition of sulphur to a-Si:H films.

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