Compensating defect centres in semi-insulating 6H-SiC

2009 ◽  
Vol 17 (1) ◽  
pp. 1-7 ◽  
Author(s):  
P. Kamiński ◽  
R. Kozłowski ◽  
M. Miczuga ◽  
M. Pawłowski ◽  
M. Kozubal ◽  
...  
Keyword(s):  
Point Defects ◽  
Emission Rate ◽  
Thermal Emission ◽  
Charge Compensation ◽  
Charge Carriers ◽  
Two Dimensional ◽  
New Approach ◽  
Temperature Dependences ◽  
Transient Spectroscopy ◽  
Defect Centres

AbstractPhotoinduced transient spectroscopy (PITS) has been applied to study electronic properties of point defects associated with charge compensation in semi-insulating (SI) 6H-SiC substrates. The photocurrent relaxation waveforms were digitally recorded in a wide temperature range of 20–800 K and in order to extract the parameters of defect centres, a two-dimensional analysis of the waveforms as a function of time and temperature has been implemented. As a result, the processes of thermal emission of charge carriers from defect centres were seen on the spectral surface as the folds, whose ridgelines depicted the temperature dependences of emission rate for detected defect centres. The new approach was used to compare the defect levels in vanadium-doped and vanadium-free (undoped) SI 6H-SiC wafers.

High-resolution Photoinduced Transient Spectroscopy of Defect Centers in Undoped Semi-Insulating 6H-SiC

2008 ◽  
Vol 1069 ◽  
Author(s):  
Pawel Kaminski ◽  
Roman Kozlowski ◽  
Marcin Miczuga ◽  
Michal Pawlowski ◽  
Michal Kozubal ◽  
...  
Keyword(s):  
High Resolution ◽  
Emission Rate ◽  
Thermal Emission ◽  
Charge Compensation ◽  
New Approach ◽  
Defect Centers ◽  
The Laplace Transform ◽  
Temperature Dependences ◽  
Transient Spectroscopy ◽  
Induced Changes

ABSTRACTHigh-resolution photoinduced transient spectroscopy (HRPITS) has been applied to studying defect centers controlling the charge compensation in semi-insulating (SI), vanadium-free, bulk 6H- SiC. The photocurrent relaxation waveforms were digitally recorded in the temperature range of 50 − 750 K and a new approach to extract the parameters of defect centers from the temperature-induced changes in the time constants of the waveforms has been implemented. It is based on a two-dimensional analysis using the numerical inversion of the Laplace transform. As a result, the images of spectral fringes depicting the temperature dependences of the emission rate of charge carriers for defect centers are created. Using the new procedure for the analysis of the photocurrent relaxation waveforms and the new way of the visualization of the thermal emission rate dependences, a number of shallow and deep defect levels ranging from 80 to 1900 meV have been detected. The obtained results indicate that defect structure of undoped SI bulk 6H-SiC is very complex and the material properties are affected by various point defects occupying the hexagonal and quasi-cubic lattice sites.

Application of Computational Intelligence to Investigation of Defect Centers in Semi-Insulating Materials by Photoinduced Transient Spectroscopy

2007 ◽  
Vol 994 ◽  
Author(s):  
Pawel Kaminski ◽  
Stanislaw Jankowski ◽  
Roman Kozlowski ◽  
Janusz Bedkowski
Keyword(s):  
Computational Intelligence ◽  
Emission Rate ◽  
Thermal Emission ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Inverse Laplace Transform ◽  
Model Complexity ◽  
Support Vector ◽  
Defect Centers ◽  
Temperature Dependences

AbstractA computational intelligence algorithm has been applied to extracting trap parameters from the photocurrent relaxation waveforms recorded at the temperature range of 20-320 K for semi-insulating (SI) InP samples. Using the inverse Laplace transform procedure, the spectral surfaces, visualized in the three dimensional space as functions of temperature and emission rate, are calculated. The processes of thermal emission of charge carriers from defect centers manifest themselves as the sharp folds on the spectral surface. Using a set of Gaussian functions, the approximating surface is created and the ridgelines of the folds, giving the temperature dependences of the emission rate for the detected traps, are determined. The approximation is performed using the support vector machine (SVM) algorithm which allows for trading off between the model complexity and fitting accuracy. The new approach is exemplified by comparing the defect structure of SI InP wafers after annealing in iron phosphide and pure phosphorous atmospheres.

Crystal structure and related electrical properties of ( N,N' -diethyl-4,4'-bipyridylium) 2+ - (7,7,8,8-tetracyanoqumodimethane) 2-/4

1975 ◽  
Vol 343 (1635) ◽  
pp. 461-475 ◽  
Keyword(s):  
Crystal Structure ◽  
Phonon Scattering ◽  
Charge Carriers ◽  
Band Model ◽  
Two Dimensional ◽  
Monoclinic System ◽  
Lattice Constants ◽  
Temperature Dependences ◽  
Electrical Data ◽  
Model Approach

The crystal structure, conductivity and thermoelectric power are reported of N,N' -diethyl-4,4'-bipyridylium (TCNQ) 4 . The complex crystallizes in the monoclinic system with the space group P2 1 /c and lattice constants a = 13.077, b = 25.316, c = 7.838 Å, β = 92.66° and having Z = 2. The anisotropic electrical data are discussed in terms of the crystal structure. A band model approach to conduction is suggested with phonon scattering of charge carriers within a two dimensional TCNQ lattice. Temperature dependences of mobility of T -1.6 and T -1.1 for electron and hole respectively were obtained.

Non-Contact, No Wafer Preparation Deep Level Transient Spectroscopy (DlTS) Based on Surface Photovoltage (SPV)

1992 ◽  
Vol 261 ◽  
Author(s):  
Jacek Lagowski ◽  
Piotr Edelman ◽  
Mark Dexter
Keyword(s):  
Emission Rate ◽  
Thermal Emission ◽  
Deep Level ◽  
Surface States ◽  
Deep Level Defect ◽  
Recombination Lifetime ◽  
Experimental Implementation ◽  
Transient Spectroscopy ◽  
Rate Window ◽  
Minority Carriers

ABSTRACTThis work reports on the theoretical modeling and experimental investigation of isothermal SPV-DLTS based on the rate window concept. Experimental implementation of the technique is done using computer analysis of the SPV transients after ceasing the illumination. The transient involves two processes – a recombination of excess minority carriers and a thermal emission of carriers trapped by surface states and bulk defects. The later process is the key one for deep level defect determination.The upper limit for the measurable deep level emission rate is provided by the recombination lifetime. This limit often exceeds, by orders of magnitude, the standard 103 s−1 limit in capacitance DLTS. The sensitivity of SPV-DLTS is of the same order as that of optical capacitance DLTS.

Two-Dimensional Local Deep-Level Transient Spectroscopy Imaging Using Super-Higher-Order Scanning Nonlinear Dielectric Microscopy

2016 ◽  
Author(s):  
N. Chinone ◽  
Y. Cho ◽  
R. Kosugi ◽  
Y. Tanaka ◽  
S. Harada ◽  
...  
Keyword(s):  
Deep Level Transient Spectroscopy ◽  
Deep Level ◽  
Higher Order ◽  
Trap Density ◽  
New Technique ◽  
Two Dimensional ◽  
Nonlinear Dielectric ◽  
Annealing Conditions ◽  
Transient Spectroscopy ◽  
A New Technique

Abstract A new technique for local deep level transient spectroscopy (DLTS) imaging using super-higher-order scanning nonlinear dielectric microscopy is proposed. Using this technique. SiCVSiC structure samples with different post oxidation annealing conditions were measured. We observed that the local DLTS signal decreases with post oxidation annealing (POA), which agrees with the well-known phenomena that POA reduces trap density. Furthermore, obtained local DLTS images had dark and bright areas, which is considered to show the trap distribution at/near SiCVSiC interface.

scholarly journals Two-color two-dimensional terahertz spectroscopy: A new approach for exploring even-order nonlinearities in the nonperturbative regime

2021 ◽  
Vol 154 (15) ◽  
pp. 154203
Author(s):  
Michael Woerner ◽  
Ahmed Ghalgaoui ◽  
Klaus Reimann ◽  
Thomas Elsaesser
Keyword(s):  
Terahertz Spectroscopy ◽  
Two Dimensional ◽  
New Approach ◽  
Even Order

scholarly journals Point Defects in Two-Dimensional γ-Phosphorus Carbide

2020 ◽  
pp. 620-626
Author(s):  
Andrey A. Kistanov ◽  
Vladimir R. Nikitenko ◽  
Oleg V. Prezhdo
Keyword(s):  
Point Defects ◽  
Two Dimensional

Two-dimensional asynchronous spectrum with auxiliary cross peaks in probing intermolecular interactions

RSC Advances ◽  
2015 ◽  
Vol 5 (107) ◽  
pp. 87739-87749 ◽  
Author(s):  
Xiaopei Li ◽  
Anqi He ◽  
Kun Huang ◽  
Huizhou Liu ◽  
Ying Zhao ◽  
...  
Keyword(s):  
Intermolecular Interaction ◽  
Intermolecular Interactions ◽  
Two Dimensional ◽  
New Approach

A new approach called “asynchronous spectrum with auxiliary peaks (ASAP)” is proposed for generating a 2D asynchronous spectrum to investigate the intermolecular interaction between two solutes (P and Q) dissolved in the same solution.

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