Density of localized states in amorphous semiconductors

1989 ◽  
Vol 67 (4) ◽  
pp. 425-429 ◽  
Author(s):  
Louis de Ladurantaye ◽  
Yves Lépine ◽  
Laurent J. Lewis
Keyword(s):  
Linear Algebra ◽  
Density Of States ◽  
Transport Model ◽  
Amorphous Semiconductors ◽  
Localized States ◽  
Trap Level ◽  
Trap States ◽  
Density Of Localized States ◽  
Multiple Trapping ◽  
Photo Current

A procedure is described for extracting the density of localized states of amorphous semiconductors from transient photo-current measurements. Based on a discretized multiple-trapping transport model, our deconvolution scheme determines, for each trap level, the time–temperature combination such that the activity is a maximum for that level. The density of the trap states is then obtained using linear-algebra techniques. As an example, our procedure is applied to computer-generated signals obtained using an exponential density of states. The deconvoluted distribution of levels is found to be in excellent agreement with the original one.

Determination of Density of Localized States in Amorphous Silicon Alloys From the Low Field Conductance of Thin N-I-N Diodes

1985 ◽  
Vol 49 ◽  
Author(s):  
Michael Shur ◽  
Michael Hack
Keyword(s):  
Temperature Dependence ◽  
Amorphous Silicon ◽  
Bulk Density ◽  
Density Of States ◽  
Energy Gap ◽  
Localized States ◽  
New Technique ◽  
Silicon Alloys ◽  
Low Field ◽  
Density Of Localized States

AbstractWe describe a new technique to determine the bulk density of localized states in the energy gap of amorphous silicon alloys from the temperature dependence of the low field conductance of n-i-n diodes. This new technique allows us to determine the bulk density of states in the centre of a device, and is very straightforward, involving fewer assumptions than other established techniques. Varying the intrinsic layer thickness allows us to measure the,density of states within approximately 400 meV of midgap.We measured the temperature dependence of the low field conductance of an amorphous silicon alloy n-i-n diode with an intrinsic layer thjckness of 0.45 microns and deduced the density of localised states to be 3xlO16cm−3 eV−1 at approximately 0.5 eV below the bottom of the conduction band. We have also considered the high bias region (the space charge limited current regime) and proposed an interpolation formula which describes the current-voltage characteristics of these structures at all biases and agrees well with our computer simulation based on the solution of the complete system of transport equations.

Thermostimulated Conductivity in Amorphous Semiconductors with Non-Exponential Density of Localized States

1988 ◽  
Vol 10 (3) ◽  
pp. 269-274
Author(s):  
Xu Zheng-yi ◽  
Yang Hua-guang ◽  
Gu Ben-yuan
Keyword(s):  
Amorphous Semiconductors ◽  
Localized States ◽  
Density Of Localized States ◽  
Exponential Density

DIFFUSION AND HIGH-FREQUENCY NOISE OF ELECTRONS IN AMORPHOUS SEMICONDUCTORS AT LOW ELECTRIC FIELDS

2012 ◽  
Vol 11 (03) ◽  
pp. 1242004 ◽  
Author(s):  
FABRIZIO BUSCEMI ◽  
ENRICO PICCININI ◽  
MASSIMO RUDAN ◽  
ROSSELLA BRUNETTI ◽  
CARLO JACOBONI
Keyword(s):  
Electric Fields ◽  
High Frequency ◽  
Transport Model ◽  
Amorphous Semiconductors ◽  
Localized States ◽  
Velocity Autocorrelation Function ◽  
Frequency Noise ◽  
Noise Power ◽  
Hopping Transport ◽  
High Frequency Noise

The Ohmic conduction, diffusion, and high-frequency noise in amorphous semiconductors are here investigated by means of a Monte Carlo implementation of a full three-dimensional variable-range hopping transport model between localized states. Quantities like the carrier-velocity autocorrelation function, the noise power spectrum, the diffusion coefficient and the ohmic conductivity are obtained from numerical simulations at room and lower temperatures. Some interesting features of the linear-response regime typical of hopping transport are observed and discussed.

Two frequency light induced absorption and energy density of localized states in amorphous semiconductors

1983 ◽  
Vol 45 (5) ◽  
pp. 441-444
Author(s):  
V.G. Kudryavtsev ◽  
M.I. Ryazanov ◽  
S.N. Taraskin
Keyword(s):  
Energy Density ◽  
Amorphous Semiconductors ◽  
Localized States ◽  
Induced Absorption ◽  
Density Of Localized States

scholarly journals Solutions of q-deformed multiple-trapping model (MTM) for charge carrier transport from time-of-flight transient (TOF) photo-current in amorphous semiconductors

2020 ◽  
Vol 66 (5 Sept-Oct) ◽  
pp. 643
Author(s):  
F. Serdouk ◽  
A. Boumali ◽  
A. Makhlouf ◽  
M.L. Benkhedi
Keyword(s):  
Charge Carrier ◽  
Carrier Transport ◽  
Time Of Flight ◽  
Amorphous Semiconductors ◽  
Charge Carrier Transport ◽  
Multiple Trapping ◽  
Multiple Trapping Model ◽  
Trapping Model ◽  
A Current ◽  
Photo Current

This paper is devoted to investigating the description of the q-deformed multiple-trapping equation for charge carrier transport in amorphous semiconductors. For this, we at first modified the multi–trapping model (MTM) of charge carriers in amorphous semiconductors from time-of-flight (TOF) transient photo-current in the framework of the q-derivative formalism, and then, we have constructed, our simulated current by using a method based on the Laplace method. This method is implemented in a program proposed recently by [14] which allows us to construct a current using the Padé approximation expansion.

Transient photodecay measurements as a probe of the density of localized states in amorphous semiconductors

1985 ◽  
Vol 53 (8) ◽  
pp. 637-640 ◽  
Author(s):  
M. Silver ◽  
Eric Snow ◽  
David Adler
Keyword(s):  
Amorphous Semiconductors ◽  
Localized States ◽  
Density Of Localized States

Variable Temperature Measurement on Operating Pentacene-Based OTFT

2008 ◽  
Vol 1091 ◽  
Author(s):  
Hung-Keng Chen ◽  
Po-Tsun Liu ◽  
Ting-Chang Chang ◽  
S.-L. Shy
Keyword(s):  
Conduction Mechanism ◽  
Variable Temperature ◽  
Electrical Measurement ◽  
Isokinetic Temperature ◽  
Trap States ◽  
Band Tail ◽  
Thermally Activated ◽  
Multiple Trapping ◽  
Higher Temperature ◽  
Release Model

AbstractVariable temperature electrical measurement is well-established and used for determining the conduction mechanism in semiconductors. There is a Meyer¡VNeldel relationship between the activation energy and the prefactor with a Meyer¡VNeldel energy of 30.03 meV, which corresponds well with the isokinetic temperature of about 350 K. Therefore, the multiple trapping and release model is properly used to explain the thermally activated phenomenon. By the method, an exponential distribution of traps is assumed to be a better representation of trap states in band tail. Samples with higher temperature during measurement are observed to show better mobility, higher on-current and lower resistance, which agree well with the multiple trapping and release model proposed to explain the conduction mechanism in pentacene-based OTFTs.

Influence of the Distribution of Tail States in a-Si:H on the Field Dependence of Carrier Drift Mobilities

2004 ◽  
Vol 808 ◽  
Author(s):  
Monica Brinza ◽  
Evguenia V. Emelianova ◽  
André Stesmans ◽  
Guy J. Adriaenssens
Keyword(s):  
Field Dependence ◽  
Carrier Mobility ◽  
Transport Model ◽  
Chemical Vapor ◽  
Gaussian Component ◽  
Dispersive Transport ◽  
Exponential Distributions ◽  
Band Tail ◽  
Multiple Trapping ◽  
Gaussian Density

ABSTRACTExponential distributions of tail states have been able, within the framework of a multiple-trapping transport model, to account rather well for the time-of-flight photoconductivity transients that are measured with ‘standard’ a-Si:H, i.e. material prepared by plasma-enhanced chemical vapor deposition at ∼250°C. A field-dependent carrier mobility in the dispersive transport regime is part of the observations. However, samples prepared in an expanding thermal plasma, although still exhibiting the dispersive transients, fail to show this field dependence. The presence of a Gaussian component in the density of valence-band tail states can account for such behavior for the hole transients. Nanoscale ordered inclusions in the amorphous matrix are thought to be responsible for the Gaussian density of states contribution.

scholarly journals Band-fluctuations model for the fundamental absorption of crystalline and amorphous semiconductors: a dimensionless joint density of states analysis

2019 ◽  
Vol 52 (10) ◽  
pp. 105303 ◽  
Author(s):  
J A Guerra ◽  
A Tejada ◽  
J A Töfflinger ◽  
R Grieseler ◽  
L Korte
Keyword(s):  
Density Of States ◽  
Amorphous Semiconductors ◽  
Joint Density
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