Vihar Georgiev

Vihar Georgiev

orcid

Research Focus & Metrics

Academic Career Length

23Years (2004-Present)

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

Representative Publications

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19 November 2014 in Nature
Verified
Journal Article
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CBChristoph Busche
Christoph Busche
LVLaia Vilà-Nadal
Laia Vilà-Nadal
JYJun Yan
Jun Yan
Haralampos MirasHaralampos Miras
Haralampos Miras
DLDe-Liang Long
De-Liang Long
LCLee Cronin
Lee Cronin

29 July 2019 in IEEE Electron Device Letters
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Journal Article
Closed access
HCHamilton Carrillo-Nunez
Hamilton Carrillo-Nunez
NDNadezhda Dimitrova
Nadezhda Dimitrova
AAAsen Asenov
Asen Asenov
VGVihar Georgiev
Vihar Georgiev
This letter investigates the possibility to replace numerical TCAD device simulations with a multi-layer neural network (NN). We explore if it is possible to train the NN with the required accuracy in order to predict device characteristics of thousands of transistors without executing TCAD simulations. Here, in order to answer this question, we present a hierarchical multi-scale simulation study of a silicon junctionless nanowire field-effect transistor (JL-NWT) with a gate length of 150 nm and diameter of an Si channel of 8 nm. All device simulations are based on the drift-diffusion (DD) formalism with activated density gradient (DG) quantum corrections. For the purpose of this letter, we perform statistical numerical experiments of a set of 1380 automictically different JL-NWTs. Each device has a unique random distribution of discrete dopants (RDD) within the silicon body. From those statistical simulations, we extract important figures of merit (FoM) such as OFF-current (I OFF ) and ON-current (I ON ), subthreshold slope (SS), and voltage threshold (V TH ). Based on those statistical simulations, we train a multi-layer NN and we compare the obtained results with a general linear model (GLM). This shows the potential of using NN in the field of device modeling and simulation with a potential application to significantly reduce the computational cost.

1 January 2013 in Coordination Chemistry Reviews
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Journal Article
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VGVihar Georgiev
Vihar Georgiev
PMP.J. Mohan
P.J. Mohan
DDDaniel DeBrincat
Daniel DeBrincat
JMJohn E. Mcgrady
John E. Mcgrady

8 November 2013 in Chemistry – A European Journal
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Journal Article
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LVLaia Vilà‐Nadal
Laia Vilà‐Nadal
SMScott G Mitchell
Scott G Mitchell
SMStanislav Markov
Stanislav Markov
CBChristoph Busche
Christoph Busche
VGVihar Georgiev
Vihar Georgiev
LCLee Cronin
Lee Cronin


26 September 2023 in Physical Review B
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CVChristian Dam Vedel
Christian Dam Vedel
TGTue Gunst
Tue Gunst
SSSøren Smidstrup
Søren Smidstrup
VGVihar Georgiev
Vihar Georgiev
We present charge state transition levels of 23 intrinsic defects and dopant substitutions in the compound III-V semiconductor In0.53Ga0.47As, calculated with density functional theory. We also report the Shockley-Read-Hall (SRH) recombination rate and capture coefficients for defects found to have deep trap levels. Our calculations show that seven of the considered defects exhibited deep trap levels capable of acting as electron and hole traps in devices: the AsIn/Ga antisites, the VIn/Ga vacancies, the (In/Ga)As−AsIn/Ga double antisites, and the SnAs substitution. We found that the AsIn antisite exhibits the highest electron-capture coefficient of Cn=2.2×10−5cm3s−1 at room temperature. The defect with the highest hole-capture coefficient was found to be the InAs−AsIn double antisite, with Cp=3.4×10−6cm3s−1. Furthermore, this defect also causes the highest recombination rate in the intrinsic semiconductor, owing to its likewise relatively large electron-capture coefficient. The defects which are most likely to occur are argued to be the antisites, due to their low formation energies and matching transition levels with experiments. Additionally, it is found that the SnAs substitution also causes a significant recombination in the semiconductor, but it is argued to only be of importance at very high doping levels.