EFFECTIVE MOBILITY MODEL OF GRAPHENE NANORIBBON IN PARABOLIC BAND ENERGY

2011 ◽  
Vol 25 (10) ◽  
pp. 739-745 ◽  
Author(s):  
N. A. AMIN ◽  
M. T. AHMADI ◽  
Z. JOHARI ◽  
S. M. MOUSAVI ◽  
R. ISMAIL
Keyword(s):  
Experimental Data ◽  
Band Structure ◽  
Transport Properties ◽  
Conventional Method ◽  
Dirac Point ◽  
Graphene Nanoribbons ◽  
Mobility Model ◽  
Band Energy ◽  
One Dimensional ◽  
Effective Mobility

In this letter, we investigate the transport properties of one-dimensional semiconducting Graphene nanoribbons (GNRs) with parabolic band structure near the Dirac point. The analytical model of effective mobility is developed by using the conductance approach, which differs from the conventional method of extracting the effective mobility using the well-known Matthiessen rule. Graphene nanoribbons conductance model developed was applied in the Drude model to obtain the effective mobility, which then gives nearly close comparison with the experimental data.

scholarly journals Metallization-Induced Quantum Limits of Contact Resistance in Graphene Nanoribbons with One-Dimensional Contacts

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3670
Author(s):  
Mirko Poljak ◽  
Mislav Matić
Keyword(s):  
Integrated Circuits ◽  
Contact Resistance ◽  
Transport Properties ◽  
Graphene Nanoribbons ◽  
Wide Band ◽  
Quantum Limit ◽  
Metal Contacts ◽  
Worst Case ◽  
One Dimensional ◽  
Quantum Limits

Graphene has attracted a lot of interest as a potential replacement for silicon in future integrated circuits due to its remarkable electronic and transport properties. In order to meet technology requirements for an acceptable bandgap, graphene needs to be patterned into graphene nanoribbons (GNRs), while one-dimensional (1D) edge metal contacts (MCs) are needed to allow for the encapsulation and preservation of the transport properties. While the properties of GNRs with ideal contacts have been studied extensively, little is known about the electronic and transport properties of GNRs with 1D edge MCs, including contact resistance (RC), which is one of the key device parameters. In this work, we employ atomistic quantum transport simulations of GNRs with MCs modeled with the wide-band limit (WBL) approach to explore their metallization effects and contact resistance. By studying density of states (DOS), transmission and conductance, we find that metallization decreases transmission and conductance, and either enlarges or diminishes the transport gap depending on GNR dimensions. We calculate the intrinsic quantum limit of width-normalized RC and find that the limit depends on GNR dimensions, decreasing with width downscaling to ~3 Ω∙µm in 0.4 nm-wide GNRs, and increasing with length downscaling up to ~30 Ω∙µm in 5 nm-long GNRs. The worst-case total RC is only ~40 Ω∙µm, which demonstrates that there is room for RC improvement in comparison to the published experimental data, and that GNRs present a promising channel material for future extremely-scaled electronic nanodevices.

scholarly journals Bipolar Magnetic and Thermospin Transport Properties of Graphene Nanoribbons with Zigzag and Klein Edges

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Xingyi Tan ◽  
Gang Xu ◽  
Youchang Jiang ◽  
Dahua Ren
Keyword(s):  
Transport Properties ◽  
Temperature Difference ◽  
Graphene Nanoribbons ◽  
Seebeck Effect ◽  
One Dimensional ◽  
Spin Caloritronics ◽  
Flow Directions

Magnetic nanoribbons based on one-dimensional materials are potential candidates for spin caloritronics devices. Here, we constructed ferromagnetic graphene nanoribbons with zigzag and Klein edges (N-ZKGNRs, N = 4–21) and found that the N-ZKGNRs are in the indirect-gap bipolar magnetic semiconducting state (BMS). Moreover, when a temperature difference is applied through the nanoribbons, spin-dependent currents with opposite flow directions and opposite spin directions are generated, indicating the occurrence of the spin-dependent Seebeck effect (SDSE). In addition, the spin-dependent Seebeck diode effect (SDSD) also appeared in these devices. More importantly, we found that the BMS with a larger bandgap is promising for generating the SDSD, while the BMS with a smaller bandgap is promising for generating the SDSE. These findings show that ZKGNRs are promising candidates for spin caloritronics devices.

scholarly journals Modelling of Graphene Nanoribbon Fermi Energy

2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Zaharah Johari ◽  
Mohammad Taghi Ahmadi ◽  
Desmond Chang Yih Chek ◽  
N. Aziziah Amin ◽  
Razali Ismail
Keyword(s):  
Band Structure ◽  
Carrier Concentration ◽  
Fermi Energy ◽  
Minimum Energy ◽  
Graphene Nanoribbon ◽  
Promising Alternative ◽  
Band Energy ◽  
One Dimensional ◽  
Statistic Study ◽  
Degenerate Regime

Graphene nanoribbon (GNR) is a promising alternative to carbon nanotube (CNT) to overcome the chirality challenge as a nanoscale device channel. Due to the one-dimensional behavior of plane GNR, the carrier statistic study is attractive. Research works have been done on carrier statistic study of GNR especially in the parabolic part of the band structure using Boltzmann approximation (nondegenerate regime). Based on the quantum confinement effect, we have improved the fundamental study in degenerate regime for both the parabolic and nonparabolic parts of GNR band energy. Our results demonstrate that the band energy of GNR near to the minimum band energy is parabolic. In this part of the band structure, the Fermi-Dirac integrals are sufficient for the carrier concentration study. The Fermi energy showed the temperature-dependent behavior similar to any other one-dimensional device in nondegenerate regime. However in the degenerate regime, the normalized Fermi energy with respect to the band edge is a function of carrier concentration. The numerical solution of Fermi-Dirac integrals for nonparabolic region, which is away from the minimum energy band structure of GNR, is also presented.

scholarly journals Tight-binding Calculations of Band Structure and Conductance in Graphene Nano-ribbons

2009 ◽  
Vol 19 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Hoang Manh Tien ◽  
Nguyen Hai Chau ◽  
Phan Thi Kim Loan
Keyword(s):  
Band Structure ◽  
Electronic Properties ◽  
Nearest Neighbor ◽  
Graphene Nanoribbons ◽  
Tight Binding ◽  
Numerical Calculations ◽  
Dimensional System ◽  
Tight Binding Approximation ◽  
One Dimensional ◽  
Edge Conditions

We suggest a general approach based on the nearest-neighbor tight-binding approximation (TB) to investigate the band structure and conductance of a quasi-one dimensional system. Numerical calculations carried out for Graphene nanoribbons (GNRs) with different widths and edge conditions (zigzag and armchair) reveal the well-known results that the electronic properties of GNRs depend strongly on the size and geometry of the sample.

scholarly journals Unconventional magnetic anisotropy in one-dimensional Rashba system realized by adsorbing Gd atom on zigzag graphene nanoribbons

Nanoscale ◽  
2017 ◽  
Vol 9 (32) ◽  
pp. 11657-11666 ◽  
Author(s):  
Zhenzhen Qin ◽  
Guangzhao Qin ◽  
Bin Shao ◽  
Xu Zuo
Keyword(s):  
Band Structure ◽  
Magnetic Anisotropy ◽  
Electronic Band Structure ◽  
Graphene Nanoribbons ◽  
Spin Splitting ◽  
Rashba Effect ◽  
Electronic Band ◽  
One Dimensional ◽  
Electronic Field ◽  
Zigzag Graphene Nanoribbons

The Rashba effect, a spin splitting in electronic band structure, can be induced to the graphene nanoribbon by the transverse electronic field due to the asymmetric adsorption of Gd atom, which would impact the magnetic anisotropy distribution in k-space.

Electrical transport and band structure of GaAs

1979 ◽  
Vol 57 (2) ◽  
pp. 233-242 ◽  
Author(s):  
H. J. Lee ◽  
J. Basinski ◽  
L. Y. Juravel ◽  
J. C. Woolley
Keyword(s):  
Experimental Data ◽  
Electrical Conductivity ◽  
Band Structure ◽  
Hall Coefficient ◽  
Electrical Transport ◽  
Theoretical Calculations ◽  
Deformation Potential ◽  
Coupling Coefficients ◽  
Band Energy ◽  
Temperature Coefficients

Measurements of electrical conductivity σ and Hall coefficient RH have been made as a function of temperature in the range room to 500 °C on single crystal n-type tellurium doped samples of GaAs with carrier concentrations in the range 7.9 × 1021 to 4.7 × 1024/m3. Theoretical calculations of σ and RH have been made on a three band (Γ, L, X) model using the method of Fletcher and Butcher and the resulting values fitted to the experimental data by using the temperature coefficients of the band energy differences and various deformation potentials and band coupling coefficients as adjustable parameters. The results confirm the band ordering proposed by Aspnes but give slightly different temperature coefficient values. Values are given for the deformation potentials and band coupling coefficients and in particular the deformation potential of the Γ band is found to be 16.0 ± 0.5 eV.

scholarly journals A Simple Electron Mobility Model Considering the Silicon-Dielectric Interface Orientation for Circular Surrounding-Gate Transistor

2012 ◽  
Vol 7 (2) ◽  
pp. 100-106
Author(s):  
André L. Perin ◽  
Arianne S. N. Pereira ◽  
Paula Ghedini Der Agopian ◽  
João Antonio Martino ◽  
Renato Giacomini
Keyword(s):  
Experimental Data ◽  
Simple Model ◽  
Electron Mobility ◽  
Crystallographic Orientation ◽  
Mobility Model ◽  
Dielectric Interface ◽  
Proposed Model ◽  
Surrounding Gate ◽  
Effective Mobility ◽  
Interface Orientation

In this work, a simple model that accounts for the variation of electron mobility as a function of the silicondielectric interface crystallographic orientation is presented. Simulations were conducted in order to compute the effective mobility of planar devices and its results were compared to experimental data for several interface orientations. The error between experimental data and the proposed model remained bellow 4%. The model has been applied to nMOS circular surrounding gate (thin-pillar transistor - CYNTHIA) and allowed the observation of current density variations as a function of the interface orientation around the silicon pillar.

Effect of Electron-Phonon Coupling on Transport Properties of Monolayers of ZrS2, BiI3 and PbI2: A thermoelectric Perspective

2021 ◽  
Author(s):  
Gautam Sharma ◽  
Vineet Kumar Pandey ◽  
Shouvik Datta ◽  
Prasenjit Ghosh
Keyword(s):  
Relaxation Time ◽  
Band Structure ◽  
Transport Properties ◽  
Thermoelectric Properties ◽  
Thermoelectric Materials ◽  
Waste Heat ◽  
Transport Coefficients ◽  
Electrical Energy ◽  
Phonon Coupling ◽  
Electron Phonon Coupling

Thermoelectric materials are used for conversion of waste heat to electrical energy. The transport coefficients that determine their thermoelectric properties depend on the band structure and the relaxation time of...

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