Andrii Kovalchuk

Mr. Andrii Kovalchuk

Lodz University of Technology

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 February 2021 in Journal of Computational Electronics
Verified
Journal Article
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JWJanusz Wozny
Janusz Wozny
AKAndrii Kovalchuk
Andrii Kovalchuk
ZLZbigniew Lisik
Zbigniew Lisik
Jacek PodgorskiJacek Podgorski
Jacek Podgorski
PBPiotr Bugalski
Piotr Bugalski
LRLukasz Ruta
Lukasz Ruta
We carry out Monte Carlo simulations of electron transport in 4H-silicon carbide (4H-SiC) based on the numerically calculated density of states (DOS) to obtain the electron mobility at low electric fields. From the results, it can be concluded that a correct calculation of the DOS requires a very dense wavevector k-mesh when low electron kinetic energies are considered. The crucial issue is the numerical efficiency of the DOS calculation. We investigate the scaling efficiency when different numbers of cores are used.

6 March 2021 in Materials
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Journal Article
Open access
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JWJanusz Wozny
Janusz Wozny
AKAndrii Kovalchuk
Andrii Kovalchuk
Jacek PodgorskiJacek Podgorski
Jacek Podgorski
ZLZbigniew Lisik
Zbigniew Lisik
This paper presents an efficient method to calculate the influence of structural defects on the energy levels and energy band-gap for the 4H-SiC semiconductor. The semi-empirical extended Hückel method was applied to both ideal 4H-SiC crystal and different structures with defects like vacancies, stacking faults, and threading edge dislocations. The Synopsys QuatumATK package was used to perform the simulations. The results are in good agreement with standard density functional theory (DFT) methods and the computing time is much lower. This means that a structure with ca. 1000 atoms could be easily modeled on typical computing servers within a few hours of computing time, enabling fast and accurate simulation of non-ideal atomic structures.

1 November 2014 in Materials Chemistry and Physics
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Journal Article
Closed access
GRG.Yu. Rudko
G.Yu. Rudko
AKAndrii Kovalchuk
Andrii Kovalchuk
VBV.A. Bondarenko
V.A. Bondarenko
VFV.I. Fediv
V.I. Fediv
EGE.G. Gule
E.G. Gule

1 April 2020 in Journal of Physics: Conference Series
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Conference Paper
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AKAndrii Kovalchuk
Andrii Kovalchuk
JWJanusz Wozny
Janusz Wozny
ZLZbigniew Lisik
Zbigniew Lisik
Jacek PodgorskiJacek Podgorski
Jacek Podgorski
LRLukasz Ruta
Lukasz Ruta
ABArmen Boiadzhian
Armen Boiadzhian
In this article we show results of 4H-SiC Monte Carlo simulation of hole transport based on numerically calculated density of states. As a result of these simulations the hole mobility for low electric field is obtained. To properly include scattering on ionized acceptor dopants the Brooks-Herring and Conwell-Weisskopf models are used.