Name: Saleh Ghoreishi Amiri
Department: Engineering
Faculty: Power
Academic Rank: Assistant Professor
Email: s . g h o r e i s h i @ i a u n o u r . a c . i r

Studies

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Journal Articles 25 Papers

Title
Authors
Publication Date
Numerical Study of Ohmic-Schottky Carbon Nanotube Field Effect Transistor
Reza Yousefi, Seyed Saleh Ghoreishi
3/18/2012
Conference
Journal
Modern Physics Letter B (MPLB)
Volume
26
Issue
15
Pages
12500961-12500969
Publisher
World Scientific
Description
MOS-like transistors are one of the transistor topologies based on the carbon nanotubes. Some modified structures have been proposed to improve their electrical characteristics, such as band to band tunneling (BTBT) and switching behavior. Unfortunately, most of them increase the transistor length due to the use of additional regions. In this paper, we propose a structure that improves the OFF state and switching behavior of the transistor without increase in the transistor length. The proposed structure is constructed by a modification of the conventional structure in a way that its drain high-doped extension part is replaced by a lightly linear doped region. Then, the proposed structure has a Schottky contact at the drain side. With a nonequilibrium Green’s function (NEGF) formalism, we have studied the characteristics of the proposed device and compared them with those obtained by a conventional structure with the same channel length. The results show that the proposed structure enjoys from better switching characteristics and OFF-state behavior, especially at low currents, in comparison to the main structure and, as a result, can be a good candidate for the low-power applications.
A COMPUTATIONAL STUDY OF STRAIN EFFECTS IN THE BAND-TO-BAND-TUNNELING CARBON NANOTUBE FIELD-EFFECT TRANSISTORS
Reza Yousefi, Seyed Saleh Ghoreishi
9/30/2012
Conference
Journal
Modern Physics Letter B (MPLB)
Volume
26
Issue
15
Pages
12500961-12500969
Publisher
World Scientific
Description
Abstract: In this paper, the transport properties of the band-to-band-tunneling carbon nanotube field-effect transistors (BTBT-CNTFETs) under uniaxial strain are studied, with the nonequilibrium Green’s function (NEGF) formalism. The effects of the uniaxial strain on the electrical properties, such as the ON current (ION), OFF current (IOFF), ION/IOFF ratio, subthreshold swing and intrinsic delay are evaluated. It was observed that the uniaxial strain has strong effects on the transport properties of these transistors. The results show that appropriate uniaxial strain, although degrades the ON current and the intrinsic delay, it also decreases the power consumption of the BTBT-CNTFETs and as a result can be used for low-power applications.
A computational study on electrical characteristics of a novel band-to-band tunneling graphene nanoribbon FET
Reza Yousefi, Mohammad Shabani, Mehrzad Arjmandi, Seyed Saleh Ghoreishi Amiri
5/13/2013
Conference
Journal
Superlattices and Microstructures
Volume
60
Issue
Pages
169-178
Publisher
Elsevier
Description
Abstract: In this study, a modified structure was proposed for the band-toband tunneling field-effect transistor (BTBT–FET) mainly to suppress the ambipolar current with the assumption that theONstate characteristics, especially sub-threshold swing, must not be degraded. The proposed structure uses a dual-material gate as gate contact and a narrow lightly doped region at the drain side of the channel. Electrical characteristics of the proposed device were explored by a mode space non-equilibrium Green’s function (NEGF) formalism in the ballistic limit. A significant reduction in the ambipolar current was seen in simulation results for different values of the drain–source voltages. The results also revealed that the ON current remained the same and the sub-threshold swing got slightly better than that of the main structure. The comparison with the main structure showed that the proposed structure benefited from improved switching characteristics such as delay, switching power-delay product and ION/IOFF ratio. Further comparison indicated that the new structure had improved hot electron effect.
A New Dual-Frequency LC oscillator: Analysis and Design
Habib Aderang, Seyed Saleh Ghoreishi
7/17/2013
Conference
Journal
Majlesi Journal of Telecommunication Devices
Volume
2
Issue
3
Pages
225-231
Publisher
Description
Abstract: In this paper, a new dual-frequency LC oscillator is introduced. This new architecture is designed taking the advantage of a Wheatstone-bridge LC resonator concept that enables the oscillator to generate two different frequencies simultaneously. In contrast to previous designs, no transistor switches are incorporated in the structure of this dual-frequency circuit. So, the proposed configuration is suitable for low phase noise applications. The performance of the oscillator has been verified using circuit simulations in 0.18 μm CMOS technology. Circuit simulations show phase noises of -109 dBc/Hz and -105 dBc/Hz for 1.8 GHz and 2.7 GHz frequency bands respectively in 100 kHz offset frequency.
Modeling of jitter in bang-bang clock and data recovery circuits
Habib Aderang, Seyed Saleh Ghoreishi
9/10/2013
Conference
Journal
The International Journal for Computation and Mathematics in Electrical and Electronic Engineering (COMPEL)
Volume
32
Issue
3
Pages
1151-1158
Publisher
Description
A NOVEL GRAPHENE NANO-RIBBON FIELD EFFECT TRANSISTOR WITH SCHOTTKY TUNNELING DRAIN AND OHMIC TUNNELING SOURCE
Seyed Saleh Ghoreishi, Kamyar Saghafi, Mohammad Kazem Moravvej Farshi
10/9/2013
Conference
Journal
Modern Physics Letters B (MPLB)
Volume
27
Issue
26
Pages
13501891-135018910
Publisher
World Scientific
Description
Abstract: In this paper, we propose a novel tunneling graphene nanoribbon field effect transistor by modification of the conventional structure in a way that its drain high-doped extension part is replaced by lightly linear doped region. Then the proposed structure has a Schottky contact at the drain side. As the source contact is ohmic and the drain contact is Schottky, this structure is called Schottky–Ohmic tunneling graphene nanoribbon field effect transistor. Electrical behaviors of the proposed device are investigated by mode space nonequilibrium Green’s function (NEGF) formalism in the ballistic limit. Simulation results show that without increasing transistor length, IOFF, ION/IOFF, ambipolar behavior, delay time and PDP of the proposed structure improve, in comparison with the conventional tunneling graphene nanoribbon field effect transistor with the same dimension. Also subthreshold swing which is one of the evident characteristics of the tunneling FET is preserved in this structure.
Graphene Nanoribbon Tunnel Field Effect Transistor with Lightly Doped Drain: Numerical Simulations
Seyed Saleh Ghoreishi, Kamyar Saghafi, Reza Yousefi, Mohammad Kazem Moravvej-Farshi
8/7/2014
Conference
Journal
Superlattices and Microstructures
Volume
75
Issue
Pages
245–256
Publisher
Elsevier
Description
Effect of uniaxial strain on electrical properties of CNT-based junctionless field-effect transistor: Numerical study
Parisa Pourian, Reza Yousefi, Seyed Saleh Ghoreishi
3/14/2016
Conference
Journal
Superlattices and Microstructures
Volume
93
Issue
Pages
92-100
Publisher
Elsevier
Description
Abstract: Numerical studies on junctionless carbon nanotube field-effect transistors (JL-CNTFETs) have indicated that these devices produce more ON current than silicon junctionless transistors in comparable dimensions. Nevertheless, due to the smaller bandgap and quantum confinement effects, they provide weaker results in the OFF state. Since the change of energy bandgap is one of the effects of applying uniaxial strain on CNTs, in this paper, using non-equilibrium Green's function method (NEGF), the effects of applying strain on electrical characteristics of JL-CNTFETs, such as ION and IOFF, intrinsic delay, ION/IOFF ratio, power-delay product, unity-gain frequency, gate transconductance, and output resistance are investigated. The simulation results show that uniaxial stain, significantly alters the OFF state behavior and as a result the electrical properties of the device.
A novel Tunneling Graphene Nano Ribbon Field Effect Transistor with dual material gate: Numerical studies
Seyed Saleh Ghoreishi, Kamyar Saghafi, Reza Yousefi, Mohammad Kazem Moravvej-Farshi
6/23/2016
Conference
Journal
Superlattices and Microstructures
Volume
97
Issue
Pages
277-286
Publisher
Elsevier
Description
Abstract: In this work, we present Dual Material Gate Tunneling Graphene Nano-Ribbon Field Effect Transistors (DMG-T-GNRFET)mainly to suppress the am-bipolar current with assumption that sub-threshold swing which is one of the important characteristics of tunneling transistors must not be degraded. In the proposed structure, dual material gates with different work functions are used. Our investigations are based on numerical simulations which self-consistently solves the 2D Poisson based on an atomistic mode-space approach and Schrodinger equations, within the Non-Equilibrium Green’s (NEGF). The proposed device shows lower off-current and on-off ratio becomes 5order ofmagnitude greater than the conventional device. Also two different short channel effects: Drain Induced Barrier Shortening (DIBS) and hot-electron effect are improved in the proposed device compare to the main structure.
A computational study of a novel graphene nanoribbon fi eld effect transistor
Seyed Saleh Ghoreishi, Reza Yousefi
2/1/2017
Conference
Journal
International Journal Of Modern Physics Letter B (IJMPLB)
Volume
9
Issue
31
Pages
17500561-175005614
Publisher
World Scientific
Description
Performance Evaluation and Design Considerations of Electrically Activated Drain Extension Tunneling GNRFET: A Quantum Simulation Study
Seyed Saleh Ghoreishi, Reza Yousefi, Neda Taghavi
7/24/2017
Conference
Journal
Journal of Electronic Material (springer)
Volume
46
Issue
11
Pages
6508-6517
Publisher
Springer
Description
Abstract: In this paper, a tunneling graphene nanoribbon field effect transistor with electrically activated drain extension, namely, EA-T-GNRFET, is proposed. The proposed structure includes a side gate at the drain side with a constant voltage and length of 0.4 V and 15 nm, respectively. Simulations are performed based on the non-equilibrium Green’s function method coupled with the Poisson equation in the mode space representation. This side gate creates an additional step in potential profile at the drain side, which increases and decreases the width of tunneling barrier and leakage current, respectively. Furthermore, the proposed structure has lower drain induced barrier thinning, lower sub-threshold swing (SS) and higher ION/IOFF ratio than the conventional structure. Also, other characteristics of the device such as switching delay (s), power delay product (PDP) and unity-gain frequency (ft) are improved in the proposed device. These advantages make EA-T-GNRFET more suitable for digital and analog applications.
A numerical study of the nanoribbon field-effect transistors under the ballistic and dissipative transport
Seyed Saleh Ghoreishi, Reza Yousefi, Kamyar Saghafi, Habib Aderang
8/20/2017
Conference
Journal
International Nano Letter
Volume
Issue
Pages
Publisher
Springer
Description
Abstract: In this article, a detailed performance comparison is made between ballistic and dissipative quantum transport of metal oxide semicondutor-like graphene nanoribbon field-effect transistor, in ON and OFF-state conditions. By the self-consistent mode-space non-equilibrium Green’s function approach, inter- and intraband scattering is accounted and the role of acoustic and optical phonon scattering on the performance of the devices is evaluated. We found that in this structure the dominant mechanism of scattering changes according to the ranges of voltage bias. Under large biasing conditions, the influence of optical phonon scattering becomes important. Also, the ambipolar and OFF-current are impressed by the phonon assisted band-to-band tunneling and increased considerably compared to the ballistic conditions, although sub-threshold swing degrades due to optical phonon scattering.
An Analytical Model for Ballistic Carbon Nanotube Field Effect Transistor Applicable to Circuit Simulators
Reza yousefi, Seyed Saleh Ghoreishi, Mostafa taghavi
9/2/2017
Conference
Journal
ECS journal of Solid State Science and Technology
Volume
6
Issue
9
Pages
M109-M113
Publisher
Description
Abstract: FETToy is a numerical reference method used for modeling of the nano-transistors in the purely ballistic transport limit. Because of the existence of integral equation in the calculation of the charge distribution, there is no possibility of using this model in the commercially available circuit simulators, such as SPICE. A number of different analytical solutions for estimating the charge integral equation have been proposed. In this research, one of these models is modified in such a way that the proposed model has a higher accuracy in different conditions. Simulation results show that in terms of various physical parameters and bias values, the modified model exhibits superior accuracy in comparison with the abovementioned reference.
Gate structural engineering of MOS-like junctionless Carbon nanotube field effect transistor (MOS-like J-CNTFET)
Maryam Faraji Seyed Saleh Ghoreishi, Reza Yousefi
1/3/2018
Conference
Journal
Int. J. Nano Dimens
Volume
9
Issue
1
Pages
32-40
Publisher
Description
Abstract In this article, a new structure is presented for MOS (Metal Oxide Semiconductor)-like junctionless carbon nanotube field effect transistor (MOS-like J-CNTFET), in which dual material gate with different workfunctions are used. In the aforementioned structure, the size of the gates near the source and the drain are 14 and 6 nm, respectively, and the work-functions are equal and 0.5 eV less than the work-function of the intrinsic carbon nanotube. The simulation is carried out in the ballistic regime using the non-equilibrium Green’s function (NEGF) in the mode space approach. The simulation results show that the proposed structure has a better am-bipolar behavior and less OFF current compared to a conventional junctionless structure with the same dimensions. In the new structure, the hot carrier effect is also reduced due to the reduced electric field near the drain, and with regard to a peak in the electric field curve at the junction of two gates, the gate control on the channel will be increased. Keywords: Carbon Nanotubes (CNTs); Drain Induced Barrier Lowering (DIBL); Field Effect Transistor (FET); Junctionless; Non-Equilibrium Green’s Function (NEGF).
A Computational Study of an Optimized MOS-Like Graphene Nano Ribbon Field Effect Transistor (GNRFET)
Amin Khorshidsavar, Seyed saleh ghoreishi, Reza Yousefi
2/17/2018
Conference
Journal
ECS Journal of Solid State Science and Technology
Volume
7
Issue
3
Pages
96-101
Publisher
Description
The present paper introduces a metal-oxide-semiconductor graphene nanoribbon field-effect transistor (MOS-GNRFET), in which heterogeneous gates with different work functions have been used. In this structure, length of each gate was selected equal to 15 nm; moreover, work function of the gate close to the source and drain was selected equal to and 0.4 eV less than the graphene nanoribbon’s work function, respectively. The simulation was performed using the non-equilibrium Green’s function (NEGF) in the mode space approach. According to the simulation results, the proposed structure exhibited better ambipolar behavior and had less off-current compared with the conventional structure with the same dimensions. In addition, the hot electron effect is reduced in the proposed structure. © 2018 The Electrochemical Society. [DOI: 10.1149/2.0111803jss]
A Computational Study of an Optimized MOS-Like Graphene Nano Ribbon Field Effect Transistor (GNRFET)
M. A. Khorshidsavar, S. S. Ghoreishi, R. Yousefi
5/1/2018
Conference
Journal
ECS Journal of Solid State Science and Technology
Volume
7
Issue
3
Pages
Publisher
Description
A computational study of a carbon nanotube junctionless tunneling field-effect transistor (CNT-JLTFET) based on the charge plasma concept
S. H. Tahaei, S. S. Ghoreishi, R. Yousefi, H. Aderang,
5/6/2019
Conference
Journal
Superlattices and Microstructures
Volume
125
Issue
Pages
168-176
Publisher
Description
A Computational Study of a Heterostructure Tunneling Carbon Nanotube Field-Effect Transistor
S. H. Tahaei, S. S. Ghoreishi, R. Yousefi, H. Aderang,
5/6/2019
Conference
Journal
Journal of ELECTRONIC MATERIALS
Volume
48
Issue
11
Pages
Publisher
Description
Performance evaluation of Carbon nanotube junctionless tunneling field effect transistor (CNT-JLTFET) under torsional strain: A quantum simulation study
S. moghadam, S. S. Ghoreishi, R. Yousefi, H. Aderang,
3/2/2020
Conference
Journal
International Journal of Nano Dimension
Volume
11
Issue
3
Pages
258-266
Publisher
Description
All-optical OR, NOT and XOR gates based on linear photonic crystal with high port-to-port isolation
SE Kordi, R Yousefi, SS Ghoreishi, H Adrang
4/6/2020
Conference
Journal
Applied Physics B
Volume
126
Issue
10
Pages
1-9
Publisher
Description
Computational study of bandgap-engineered Graphene nano ribbon tunneling field-effect transistor (BE-GNR-TFET)
S. Abbaszadeh, S. S. Ghoreishi, R. Yousefi, H. Aderang
5/5/2020
Conference
Journal
International Journal of Nano Dimension
Volume
11
Issue
4
Pages
392-398
Publisher
Description
mprovement in Electrical Characteristics of Silicon on Insulator Junctionless Field Effect Transistor (SOI-JLFET) Using the Auxiliary Gate
M, Vadizadeh, SS Ghoreishi,
5/5/2020
Conference
Journal
NASHRIYYAH-I MUHANDISI-I BARQ VA MUHANDISI-I KAMPYUTAR-I IRAN, A-MUHANDISI-I BARQ
Volume
18
Issue
Pages
67-72
Publisher
Description
Performance Improvement of Ultrathin CIGS Solar Cells using Al Plasmonic Nanoparticles: The Effect of Position of NanoParticles
S.Royanian, A. Abdollahzadeh Ziabari, Reza Yousefi, S.S. Ghoreishi
5/5/2020
Conference
Journal
Volume
5
Issue
Pages
Publisher
Description
Quantum simulation of a Junctionless Carbon Nano tube field-effect transistor under torsional strain
S. moghadam, S. S. Ghoreishi, R. Yousefi, H. Aderang
5/5/2020
Conference
Journal
Superlattices and Microstructures
Volume
138
Issue
Pages
Publisher
Description
Theoretical Analysis of Tunneling GNRFET under Local Compressive Uniaxial Strain
S. Abbaszadeh, S. S. Ghoreishi, R. Yousefi, H. Aderang,
5/5/2020
Conference
Journal
ECS Journal of Solid State Science and Technology
Volume
9
Issue
2
Pages
Publisher
Description

Researches 5 Researches

Title
Carbon Nano Tube Field Effect Transistor (CNTFET)
Graphene Nano Ribbon Field Effect Transistor (GNRFET)
Junction-less Field Effect Transistor (JL-FET)
Photonic Crystal Fiber (PCF)
Photonic Crystal Gate