scholarly journals Acoustoelectric current in graphene nanoribbon due to Landau damping

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
K. A. Dompreh ◽  
K. W. Adu ◽  
D. Sakyi-Arthur ◽  
N. G. Mensah ◽  
S. Y. Mensah ◽  
...  
Keyword(s):  
Absorption Coefficient ◽  
Drift Velocity ◽  
Acoustic Phonon ◽  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Graphene Nanoribbon ◽  
Phonon Energy ◽  
Landau Damping ◽  
Potential Candidate ◽  
Acoustoelectric Current

AbstractWe perform self-consistent analysis of the Boltzmann transport equation for momentum and energy in the hypersound regime i.e., $$ql \gg 1$$ q l ≫ 1 ($$q$$ q is the acoustic wavenumber and l is the mean free path). We investigate the Landau damping of acoustic phonons ($$LDOAP$$ LDOAP ) in graphene nanoribbons, which leads to acoustoelectric current generation. Under a non-quantized field with drift velocity, we observed an acoustic phonon energy quantization that depends on the energy gap, the width, and the sub-index of the material. An effect similar to Cerenkov emission was observed, where the electron absorbed the confined acoustic phonon energy, causing the generation of acoustoelectric current in the graphene nanoribbon. A qualitative analysis of the dependence of the absorption coefficient and the acoustoelectric current on the phonon frequency is in agreement with experimental reports. We observed a shift in the peaks when the energy gap and the drift velocity were varied. Most importantly, a transparency window appears when the absorption coefficient is zero, making graphene nanoribbons a potential candidate for use as an acoustic wave filter with applications in tunable gate-controlled quantum information devices and phonon spectrometers.

scholarly journals Acoustoelectric Current in Graphene Nanoribbon due to Landau Damping

2021 ◽  
Author(s):  
K. A. Dompreh ◽  
K.W. Adu ◽  
D. Sakyi-Arthur ◽  
N. G. Mensah ◽  
S. Y. Mensah ◽  
...  
Keyword(s):  
Drift Velocity ◽  
Energy Gap ◽  
Mean Free Path ◽  
Graphene Nanoribbon ◽  
Landau Damping ◽  
Potential Candidate ◽  
Boltzmann Transport ◽  
Acoustic Phonons ◽  
Acoustoelectric Current ◽  
Wave Filter

Abstract We perform self-consistent analysis of the Boltzmann transport equation for momentum and energy in the hypersound regime i.e., ql >> 1 (q is the acoustic wavenumber and l is the mean free path). Here, we investigate Landau damping of acoustic phonons (LDOAP) in graphene nanoribbon that leads to acoustoelectric current generation. Under a non-quantized field with drift velocity, we observed an acoustic phonon energy quantization which depends on the energy gap, the width and the sub-index of the material. An effect similar to Cerenkov emission was observed where the electron absorbs the confined acoustic phonons energy, causing the generation of acoustoelectric current in Graphene Nanoribbon. A qualitative analysis of the absorption and versus phonon frequency is in agreement with experimental reports. We observed a shift in the peaks when the energy gap and the drift velocity were varied. Most importantly, a transparency window appears when making graphene nanoribbon a potential candidate as an acoustic wave filter with applications in phonon spectrometers and also as tunable gate-controlled quantum information device.

Tailoring plasmon excitations in α − T3 armchair nanoribbons

2021 ◽  
Author(s):  
Andrii Iurov ◽  
Liubov Zhemchuzhna ◽  
Godfrey Gumbs ◽  
Danhong Huang ◽  
Paula Fekete ◽  
...  
Keyword(s):  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Electronic States ◽  
Landau Damping ◽  
Next Generation ◽  
Polarization Function ◽  
Edge Termination

Abstract We have calculated and investigated the electronic states, dynamical polarization function and the plasmon excitations for α − T3 nanoribbons with armchair-edge termination. The obtained plasmon dispersions are found to depend significantly on the number of atomic rows across the ribbon and the energy gap which is also determined by the nanoribbon geometry. The bandgap appears to have the strongest effect on both the plasmon dispersions and their Landau damping. We have determined the conditions when relative hopping parameter α of an α − T3 lattice has a strong effect on the plasmons which makes our material distinguished from graphene nanoribbons. Our results for the electronic and collective properties of α − T3 nanoribbons are expected to find numerous applications in the development of the next-generation electronic, nano-optical and plasmonic devices.

scholarly journals Tailoring plasmon excitations in $$\alpha -{\mathcal {T}}_3$$ armchair nanoribbons

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Andrii Iurov ◽  
Liubov Zhemchuzhna ◽  
Godfrey Gumbs ◽  
Danhong Huang ◽  
Paula Fekete ◽  
...  
Keyword(s):  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Electronic States ◽  
Landau Damping ◽  
Next Generation ◽  
Polarization Function ◽  
Edge Termination

AbstractWe have calculated and investigated the electronic states, dynamical polarization function and the plasmon excitations for $$\alpha -{\mathcal {T}}_3$$ α - T 3 nanoribbons with armchair-edge termination. The obtained plasmon dispersions are found to depend significantly on the number of atomic rows across the ribbon and the energy gap which is also determined by the nanoribbon geometry. The bandgap appears to have the strongest effect on both the plasmon dispersions and their Landau damping. We have determined the conditions when relative hopping parameter $$\alpha $$ α of an $$\alpha -{\mathcal {T}}_3$$ α - T 3 lattice has a strong effect on the plasmons which makes our material distinguished from graphene nanoribbons. Our results for the electronic and collective properties of $$\alpha -{\mathcal {T}}_3$$ α - T 3 nanoribbons are expected to find numerous applications in the development of the next-generation electronic, nano-optical and plasmonic devices.

Effect of Varying Aspect Ratio on Relative Stability for Graphene Nanoribbon Interconnects

2012 ◽  
Vol 229-231 ◽  
pp. 205-209 ◽  
Author(s):  
Maryam Farrokhi ◽  
Rahim Faez ◽  
Saeed Haji Nasiri ◽  
Bita Davoodi
Keyword(s):  
Aspect Ratio ◽  
Relative Stability ◽  
Graphene Nanoribbons ◽  
Graphene Nanoribbon ◽  
Electrical Performance ◽  
Potential Candidate ◽  
Transmission Line Modeling ◽  
Alternative Materials ◽  
Nyquist Stability ◽  
Advanced System

Achieving dense off-chip interconnection with satisfactory electrical performance is emerging as a major challenge in advanced system engineering. Graphene nanoribbons (GNRs) have been recently proposed as one of the potential candidate materials for both transistors and interconnect. In addition, development is still underway for alternative materials and processes for high aspect ratio (AR) contacts. Studding the effect of varying aspect ratio on relative stability of graphene nanoribbon interconnects is an important viewpoint in performance evaluation of system. In this paper, Nyquist stability analysis based on transmission line modeling (TLM) for GNR interconnects is investigated. In this analysis, the dependence of the degree of relative stability for multilayer GNR (MLGNR) interconnects on the aspect ratio has been acquired. It is shown that, with increasing the aspect ratio of each ribbon, MLGNR interconnects become more unstable.

scholarly journals Morphological characterization and electronic properties of pristine and oxygen-exposed graphene nanoribbons on Ag(110)

2021 ◽  
Author(s):  
Jose Eduardo Barcelon ◽  
Marco Smerieri ◽  
Giovanni Carraro ◽  
Pawel Wojciechowski ◽  
Luca Vattuone ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Quantum Confinement ◽  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Morphological Characterization

Graphene nanoribbons (GNRs) are at the frontier of research on graphene materials since the 1D quantum confinement of electrons allows for the opening of an energy gap.

Energy gap opening by crossing drop cast single-layer graphene nanoribbons

2018 ◽  
Vol 29 (31) ◽  
pp. 315705 ◽  
Author(s):  
Toyo Kazu Yamada ◽  
Hideto Fukuda ◽  
Taizo Fujiwara ◽  
Polin Liu ◽  
Kohji Nakamura ◽  
...  
Keyword(s):  
Energy Gap ◽  
Graphene Nanoribbons ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Layer Graphene ◽  
Gap Opening

scholarly journals Effects of Cu-Doping on Optical Properties of NiO

2015 ◽  
Vol 48 ◽  
pp. 155-162 ◽  
Author(s):  
Nidhal Nissan Jandow
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Extinction Coefficient ◽  
Energy Gap ◽  
Spray Pyrolysis Technique ◽  
Skin Depth ◽  
Cu Doping ◽  
Uv Visible ◽  
Absorbance Spectra

This work presents the effect of Cu-doping on some optical properties of Cu:NiO thin film prepared by spray pyrolysis technique. UV-Visible spectrophotometer in the range 380-900 nm used to determine the absorbance spectra for various Cu-doping of Cu:NiO thin film. The transmittance and energy gap are decreased with increasing Cu-doping in the prepared films, while absorption coefficient, extinction coefficient, and skin depth are increased with increasing Cu-doping.

scholarly journals A NOVEL FRACTAL GEOMETRY DOPING FOR GRAPHENE NANORIBBON AND THE OPTIMIZATION OF CRYSTAL: A DENSITY FUNCTIONAL THEORY (DFT) STUDY

2020 ◽  
Vol 17 (35) ◽  
pp. 1148-1158
Author(s):  
Mohammed L. JABBAR ◽  
Kadhum J. AL-SHEJAIRY
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Energy Gap ◽  
Minimum Energy ◽  
Graphene Nanoribbon ◽  
Chemical Doping ◽  
Functional Theory ◽  
Lower Reactivity ◽  
The Density Functional Theory ◽  
Semiconductor Behavior

Chemical doping is a promising route to engineering and controlling the electronic properties of the zigzag graphene nanoribbon (ZGNR). By using the first-principles of the density functional theory (DFT) calculations at the B3LYP/ 6-31G, which implemented in the Gaussian 09 software, various properties, such as the geometrical structure, DOS, HOMO, LUMO infrared spectra, and energy gap of the ZGNR, were investigated with various sites and concentrations of the phosphorus (P). It was observed that the ZGNR could be converted from linear to fractal dimension by using phosphorus (P) impurities. Also, the fractal binary tree of the ZGNR and P-ZGNR structures is a highlight. The results demonstrated that the energy gap has different values, which located at this range from 0.51eV to 1.158 eV for pristine ZGNR and P-ZGNR structures. This range of energy gap is variable according to the use of GNRs in any apparatus. Then, the P-ZGNR has semiconductor behavior. Moreover, there are no imaginary wavenumbers on the evaluated vibrational spectrum confirms that the model corresponds to minimum energy. Then, these results make P-ZGNR can be utilized in various applications due to this structure became more stable and lower reactivity.

scholarly journals optical proprties of poly crystaline CdS thin films

2005 ◽  
Vol 2 (2) ◽  
pp. 231-235
Author(s):  
Baghdad Science Journal
Keyword(s):  
Thin Films ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Energy Gap ◽  
Glass Temperature ◽  
Calculated Energy ◽  
Cds Thin Films ◽  
Temperature Preparation

Studied the optical properties of the membranes CdS thin containing different ratios of ions cadmium to sulfur attended models manner spraying chemical gases on the rules of the glass temperature preparation (350c) were calculated energy gap allowed direct these membranes as observed decrease in the value of the energy gap at reducing the proportion ofsulfur ions as absorption coefficient was calculated

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