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.

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.

2D Self-assembly and Electronic Characterization of Oxygen-Boron-Oxygen-Doped Chiral Graphene Nanoribbons

2021 ◽  
Author(s):  
Lei Jin ◽  
Nerea Bilbao ◽  
Yang Lv ◽  
Xiao-Ye Wang ◽  
Soltani Paniz ◽  
...  
Keyword(s):  
Edge Effects ◽  
Self Assembly ◽  
Quantum Confinement ◽  
Graphene Nanoribbons ◽  
One Dimensional ◽  
The Past ◽  
Different Types

Graphene nanoribbons (GNRs), quasi-one-dimensional strips of graphene, exhibit a nonzero bandgap due to quantum confinement and edge effects. In the past decade, different types of GNRs with atomically precise structures...

scholarly journals Analytical Predictions of Liquid and Air Photovoltaic/Thermal, Flat-Plate Collector Performance

1981 ◽  
Vol 103 (4) ◽  
pp. 291-298 ◽  
Author(s):  
P. Raghuraman
Keyword(s):  
Total Energy ◽  
Flat Plate ◽  
Temperature Difference ◽  
Photovoltaic Cells ◽  
Electrical Performance ◽  
One Dimensional ◽  
Design Recommendations ◽  
Flat Plate Collector

Two separate one-dimensional analyses have been developed for the prediction of the thermal and electrical performance of both liquid and air flat-plate, photovoltaic/thermal (PV/T) collectors. The analyses account for the temperature difference between the primary insolation absorber (the photovoltaic cells) and secondary absorber (a thermal absorber flat plate). The results of the analyses are compared with test measurements, and therefrom design recommendations are made to maximize the total energy extracted from the collectors.

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