Journal articles: 'Graphene NanoRibbon'

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Zhang, Ji, Tarek Ragab, and Cemal Basaran. "Comparison of fracture behavior of defective armchair and zigzag graphene nanoribbons." International Journal of Damage Mechanics 28, no. 3 (March 27, 2018): 325–45. http://dx.doi.org/10.1177/1056789518764282.

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Molecular dynamics simulations of armchair graphene nanoribbons and zigzag graphene nanoribbons with different sizes were performed at room temperature. Double vacancy defects were introduced in each graphene nanoribbon at its center or at its edge. The effect of defect on the mechanical behavior was studied by comparing the stress–strain response and the fracture toughness of each pair of pristine and defective graphene nanoribbon. Results show that the effect of vacancies in zigzag graphene nanoribbon is more profound than in armchair graphene nanoribbon. Also, the effect of double vacancy defect on the ultimate failure stress is greater in zigzag graphene nanoribbons than in armchair graphene nanoribbon due to bond orientation with respect to loading direction. Strength reduction can be as high as 17.5% in armchair graphene nanoribbon with no significant difference between single and double vacancies, while for zigzag graphene nanoribbon, the strength reduction is up to 30% for single vacancy and 43% for double vacancy defects. It is observed that for zigzag graphene nanoribbon with double vacancy at the edge, the direction of the failure plane is oriented at ±30° with respect to the loading direction while it is always perpendicular to the direction of loading in armchair graphene nanoribbon. Results have been verified through studying the fracture toughness parameters in each case as well.

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Barkov, Pavel V., and Olga E. Glukhova. "Carboxylated Graphene Nanoribbons for Highly-Selective Ammonia Gas Sensors: Ab Initio Study." Chemosensors 9, no. 4 (April 18, 2021): 84. http://dx.doi.org/10.3390/chemosensors9040084.

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The character and degree of influence of carboxylic acid groups (COOH) on the sensory properties (particularly on the chemoresistive response) of a gas sensor based on zigzag and armchair graphene nanoribbons are shown. Using density functional theory (DFT) calculations, it is found that it is more promising to use a carboxylated zigzag nanoribbon as a sensor element. The chemoresistive response of these nanoribbons is higher than uncarboxylated and carboxylated nanoribbons. It is also revealed that the wet nanoribbon reacts more noticeably to the adsorption of ammonia. In this case, carboxyl groups primarily attract water molecules, which are energetically favorable to land precisely on these regions and then on the nanoribbon’s basal surface. Moreover, the COOH groups with water are adsorption centers for ammonia molecules. That is, the carboxylated zigzag nanoribbon can be the most promising.

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Савин, А. В., and М. А. Мазо. "Двумерная модель рулонных упаковок молекулярных нанолент." Физика твердого тела 60, no. 4 (2018): 821. http://dx.doi.org/10.21883/ftt.2018.04.45700.318.

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AbstractA simplified model of the in-plane molecular chain, allowing the description of folded and scrolled packings of molecular nanoribbons of different structures, is proposed. Using this model, possible steady states of single-layer nanoribbons scrolls of graphene, graphane, fluorographene, and fluorographane (graphene hydrogenated on the one side and fluorinated on the other side) are obtained. Their stability is demonstrated and their energy is calculated as a function of the nanoribbon length. It is shown that the scrolled packing is the most energetically favorable nanoribbon conformation at long lengths. The existences of scrolled packings for fluorographene nanoribbons and the existence of two different scroll types corresponding to left- and right-hand Archimedean spirals for fluorographane nanoribbons in the chain model are shown for the first time. The simplicity of the proposed model makes it possible to consider the dynamics of scrolls of rather long molecular nanoribbons at long enough time intervals.

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Kolli, Venkata Sai Pavan Choudary, Vipin Kumar, Shobha Shukla, and Sumit Saxena. "Electronic Transport in Oxidized Zigzag Graphene Nanoribbons." MRS Advances 2, no. 02 (2017): 97–101. http://dx.doi.org/10.1557/adv.2017.55.

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ABSTRACT The electronic and transport properties of graphene nanoribbons strongly depends on different types of adatoms. Oxygen as adatom on graphene is expected to resemble oxidized graphene sheets and enable in understanding their transport properties. Here, we report the transport properties of oxygen adsorbed zigzag edge saturated graphene nanoribbon. It is interesting to note that increasing the number of oxygen adatoms on graphene sheets lift the spin degeneracy as observed in the transmission profile of graphene nanoribbons. The relative orientation of the oxygen atom on the graphene basal plane is detrimental to flow of spin current in the nanoribbon.

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Guo, Hong, and Jing Wang. "Effect of Vacancy Defects on the Vibration Frequency of Graphene Nanoribbons." Nanomaterials 12, no. 5 (February 24, 2022): 764. http://dx.doi.org/10.3390/nano12050764.

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Graphene is a type of two-dimensional material with special properties and complex mechanical behavior. In the process of growth or processing, graphene inevitably has various defects, which greatly influence the mechanical properties of graphene. In this paper, the mechanical properties of ideal monolayer graphene nanoribbons and monolayer graphene nanoribbons with vacancy defects were simulated using the molecular dynamics method. The effect of different defect concentrations and defect positions on the vibration frequency of nanoribbons was investigated, respectively. The results show that the vacancy defect decreases the vibration frequency of the graphene nanoribbon. The vacancy concentration and vacancy position have a certain effect on the vibration frequency of graphene nanoribbons. The vibration frequency not only decreases significantly with the increase of nanoribbon length but also with the increase of vacancy concentration. As the vacancy concentration is constant, the vacancy position has a certain effect on the vibration frequency of graphene nanoribbons. For nanoribbons with similar dispersed vacancy, the trend of vibration frequency variation is similar.

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Tian, Wenchao, and Wenhua Li. "Molecular Dynamics Study on Vibrational Properties of Graphene Nanoribbon Resonator." Journal of Computational and Theoretical Nanoscience 13, no. 10 (October 1, 2016): 7460–66. http://dx.doi.org/10.1166/jctn.2016.5740.

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The vibrational properties of nanoelectromechanical system (NMES) resonator based on the defect-free graphene nanoribbon are investigated via classic molecular dynamics simulations. The graphene nanoribbons show ultrahigh fundamental resonant frequencies which can reach 189.6 GHz. The resonant frequencies increase non-monotonically with increasing externally applied force. When the external forces are between 15.912 nN and 44.2 nN, the resonant frequencies of the graphene nanoribbons remain constant at 132.9 GHz. And when the external stress is greater than 44.2 nN, the resonant frequencies show an incremental variation tendency. Temperature has a little influence on resonant frequencies. When the temperature is greater than 75 K, the resonant frequencies of the graphene nanoribbons remain constant at 132.9 GHz. The resonant characteristics of graphene nanoribbons are insensitive to the chirality. The resonant frequencies of the graphene nanoribbon exhibit significant decrease as the length-width ratio increases.

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Савин, А. В. "Краевые колебания нанолент графана." Физика твердого тела 60, no. 5 (2018): 1029. http://dx.doi.org/10.21883/ftt.2018.05.45808.328.

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AbstractUsing the COMPASS force field, natural linear vibrations of graphane (graphene hydrogenated on both sides) nanoribbons are simulated. The frequency spectrum of a graphane sheet consists of three continuous intervals (low-frequency, mid-frequency, and narrow high-frequency) and two gaps between them. The construction of dispersion curves for nanoribbons with a zigzag and chair structure of the edges show that the frequencies of edge vibrations (edge phonons) can be present in the gaps of the frequency spectrum. In the first type of nanoribbons, two dispersion curves are in the low-frequency gap of the spectrum and four dispersion curves in the second gap. These curves correspond to phonons moving only along the nanoribbon edges (the mean depth of their penetration toward the nanoribbon center does not exceed 0.15 nm).

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Kalosakas, George, Nektarios N. Lathiotakis, and Konstantinos Papagelis. "Width Dependent Elastic Properties of Graphene Nanoribbons." Materials 14, no. 17 (September 3, 2021): 5042. http://dx.doi.org/10.3390/ma14175042.

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The mechanical response of graphene nanoribbons under uniaxial tension, as well as its dependence on the nanoribbon width, is presented by means of numerical simulations. Both armchair and zigzag edged graphene nanoribbons are considered. We discuss results obtained through two different theoretical approaches, viz. density functional methods and molecular dynamics atomistic simulations using empirical force fields especially designed to describe interactions within graphene sheets. Apart from the stress-strain curves, we calculate several elastic parameters, such as the Young’s modulus, the third-order elastic modulus, the intrinsic strength, the fracture strain, and the Poisson’s ratio versus strain, presenting their variation with the width of the nanoribbon.

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Paudel, Raj Kumar, Chung-Yuan Ren, and Yia-Chung Chang. "Semi-Empirical Pseudopotential Method for Graphene and Graphene Nanoribbons." Nanomaterials 13, no. 14 (July 13, 2023): 2066. http://dx.doi.org/10.3390/nano13142066.

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We implemented a semi-empirical pseudopotential (SEP) method for calculating the band structures of graphene and graphene nanoribbons. The basis functions adopted are two-dimensional plane waves multiplied by several B-spline functions along the perpendicular direction. The SEP includes both local and non-local terms, which were parametrized to fit relevant quantities obtained from the first-principles calculations based on the density-functional theory (DFT). With only a handful of parameters, we were able to reproduce the full band structure of graphene obtained by DFT with a negligible difference. Our method is simple to use and much more efficient than the DFT calculation. We then applied this SEP method to calculate the band structures of graphene nanoribbons. By adding a simple correction term to the local pseudopotentials on the edges of the nanoribbon (which mimics the effect caused by edge creation), we again obtained band structures of the armchair nanoribbon fairly close to the results obtained by DFT. Our approach allows the simulation of optical and transport properties of realistic nanodevices made of graphene nanoribbons with very little computation effort.

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Savin A. V. and Klinov A. P. "Delamination of multilayer graphene nanoribbons on flat substrates." Physics of the Solid State 64, no. 10 (2022): 1573. http://dx.doi.org/10.21883/pss.2022.10.54252.390.

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Using molecular dynamics simulation, we have shown that multilayer graphene nanoribbons located on the flat surface of the h-BN crystal (on the flat substrate) delaminate due to thermal activation into a parquet of single-layer nanoribbons on the substrate. The delamination of graphene nanoribbons requires overcoming the energy barrier associated with the initial shift of its upper layer. After overcoming the barrier, the delamination proceeds spontaneously with the release of energy. The value of this barrier has been estimated and the delamination of two-layer nanofilms has been simulated. The existence of two delamination scenarios has been shown. The first scenario is the longitudinal (along the long side of the nanoribbon) sliding of the upper layer. The second one is in the sliding of the upper layer with the rotation of the layers relative to each other. The first scenario is common for elongated nanoribbons, the second --- for two-layer graphene flakes having close to a square shape. Keywords: graphene, multilayer nanoribbons, flat substrate, nanoribbon delamination.

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Zhang, Jian, Liu Qian, Gabriela Borin Barin, Abdalghani H. S. Daaoub, Peipei Chen, Klaus Müllen, Sara Sangtarash, et al. "Contacting individual graphene nanoribbons using carbon nanotube electrodes." Nature Electronics 6, no. 8 (August 14, 2023): 572–81. http://dx.doi.org/10.1038/s41928-023-00991-3.

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AbstractGraphene nanoribbons synthesized using bottom-up approaches can be structured with atomic precision, allowing their physical properties to be precisely controlled. For applications in quantum technology, the manipulation of single charges, spins or photons is required. However, achieving this at the level of single graphene nanoribbons is experimentally challenging due to the difficulty of contacting individual nanoribbons, particularly on-surface synthesized ones. Here we report the contacting and electrical characterization of on-surface synthesized graphene nanoribbons in a multigate device architecture using single-walled carbon nanotubes as the electrodes. The approach relies on the self-aligned nature of both nanotubes, which have diameters as small as 1 nm, and the nanoribbon growth on their respective growth substrates. The resulting nanoribbon–nanotube devices exhibit quantum transport phenomena—including Coulomb blockade, excited states of vibrational origin and Franck–Condon blockade—that indicate the contacting of individual graphene nanoribbons.

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Liu, Yang, Xuzhen Wang, Wubo Wan, Lingli Li, Yanfeng Dong, Zongbin Zhao, and Jieshan Qiu. "Multifunctional nitrogen-doped graphene nanoribbon aerogels for superior lithium storage and cell culture." Nanoscale 8, no. 4 (2016): 2159–67. http://dx.doi.org/10.1039/c5nr05909g.

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13

Савин, А. В., and О. И. Савина. "Влияние взаимодействия слоев на жесткость изгибных деформаций многослойных углеродных нанолент." Физика твердого тела 61, no. 4 (2019): 799. http://dx.doi.org/10.21883/ftt.2019.04.47433.329.

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AbstractThe effect of a weak nonbonded layers interaction on the bending resistance of a multilayered graphene nanoribbon is studied. A numerical simulation of bending of a finite multilayered nanoribbon and analysis of its bending vibrations show that interaction of layers significantly increases bending stiffness normalized to a number of layers only for nanoribbons with length L > 12 nm. The greater the length, the stronger this increase. Thus, at length L = 24 nm, layers interaction increases bending stiffness three times for a two-layer nanoribbon and six times for a nine-layer nanoribbon. Therefore, the use of multilayered nanoribbons can significantly increase the bending resistance of extended nanoconstructions.

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Ziliang, Guo. "A Study on Different Bandwidths and Rim Decorations’ Influence on the Mechanical Properties of Graphene Nanoribbon." Journal of Physics: Conference Series 2083, no. 2 (November 1, 2021): 022108. http://dx.doi.org/10.1088/1742-6596/2083/2/022108.

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Abstract This paper structured the Graphene Nanoribbon with different bandwidths and rim decorations and obtained the ideal strength and modulus of elasticity based on the calculation under the First Principle. It can be known that the mechanical properties of Graphene Nanoribbon are close to that of graphene, which have less changes with different bandwidth. However, the mechanical properties would be influenced by different decorations which may change the electronic connection state of edge carbon atoms. The results found in this paper can provide some reference for researchers to study the mechanical properties of graphene nanoribbons in the future.

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Elias, Watheq, M. Elliott, and C. C. Matthai. "Electrical transport of zig-zag and folded graphene nanoribbons." MRS Proceedings 1549 (2013): 41–46. http://dx.doi.org/10.1557/opl.2013.950.

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ABSTRACTIn recent years, there has been much interest in modelling graphene nanoribbons as they have great potential for use in molecular electronics. We have employed the NEGF formalism to determine the conductivity of graphene nanoribbons in various configurations. The electronic structure calculations were performed within the framework of the Extended Huckel Approximation. Both zigzag and armchair nanoribbons have been considered. In addition, we have also computed the transmission and conductance using the non-equilibrium Greens function formalism for these structures. We also investigated the effect of defects by considering a zigzag nanoribbon with six carbon atoms removed. Finally, the effect of embedding boron nitride aromatic molecules in the nanoribbon has been considered. The results of our calculations are compared with that obtained from recent work carried out using tight-binding model Hamiltonians.

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Bashirpour, Mohammad, Ali Kefayati, Mohammadreza Kolahdouz, and Hossein Aghababa. "Tuning the Electronic Properties of Symetrical and Asymetrical Boron Nitride Passivated Graphene Nanoribbons: Density Function Theory." Journal of Nano Research 54 (August 2018): 35–41. http://dx.doi.org/10.4028/www.scientific.net/jnanor.54.35.

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—Density function theory (DFT) based simulation combined with non-equilibrium green function (NEGF) was used to theoretically investigate electrical properties of symmetrical and asymmetrical boron nitride (BN) passivated graphene nanoribbons. Using density function theory method, it is demonstrated that the band gap of armchair (A) graphene nanoribbon (GNR) can be widened with boron nitride passivation. five symmetrical and five asymmetrical structures were considered, for which we obtained band gaps from 0.45 eV to 2 eV for symmetrical structures and 0.3 eV to 1.5 eV for asymmetrical structures. For the same width of graphene nanoribbon, our results showed that asymmetrical structure has a smaller band gap and almost the same conductance in comparison with the symmetrical one. Finally, comparison between the asymmetrical structure and the hydrogenated armchair graphene (h-AGNR) nanoribbon showed that, hBN-AGNR exhibited a higher conductance compared to an h-AGNR for the same width of GNR.

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Xue, Yuhua, Janice M. Baek, Hao Chen, Jia Qu, and Liming Dai. "N-doped graphene nanoribbons as efficient metal-free counter electrodes for disulfide/thiolate redox mediated DSSCs." Nanoscale 7, no. 16 (2015): 7078–83. http://dx.doi.org/10.1039/c4nr06969b.

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Nitrogen-doped graphene nanoribbons (N-GNRs) were prepared by thermal treatment of the as-zipped graphene oxide nanoribbon in NH₃ gas. The resultant N-GNRs were found to act as efficient metal-free counter electrodes in DSSCs.

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Fülep, Dávid, Ibolya Zsoldos, and István László. "Position Sensitivity Study in Molecular Dynamics Simulations of Self-Organized Development of 3D Nanostructures." Materials Science Forum 885 (February 2017): 216–21. http://dx.doi.org/10.4028/www.scientific.net/msf.885.216.

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The sensitivity of defect free fusion of straight carbon nanotubes from graphene nanoribbons to the position of the nanoribbon edge positions has been investigated. A basic difference between the behavior of armchair and zigzag type nanoribbons was observed. When placing armchair type graphene nanoribbons above each other identical, fitting positions are obtained automatically. Zigzag type graphene nanoribbons, however, must not be placed above each other in identical positions. From the viewpoint of defect-free fusion, according to the MD simulations symmetric on nearly symmetric positions of the ribbon edges are favorable.

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Yang, S. R. Eric. "Soliton Fractional Charges in Graphene Nanoribbon and Polyacetylene: Similarities and Differences." Nanomaterials 9, no. 6 (June 14, 2019): 885. http://dx.doi.org/10.3390/nano9060885.

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An introductory overview of current research developments regarding solitons and fractional boundary charges in graphene nanoribbons is presented. Graphene nanoribbons and polyacetylene have chiral symmetry and share numerous similar properties, e.g., the bulk-edge correspondence between the Zak phase and the existence of edge states, along with the presence of chiral boundary states, which are important for charge fractionalization. In polyacetylene, a fermion mass potential in the Dirac equation produces an excitation gap, and a twist in this scalar potential produces a zero-energy chiral soliton. Similarly, in a gapful armchair graphene nanoribbon, a distortion in the chiral gauge field can produce soliton states. In polyacetylene, a soliton is bound to a domain wall connecting two different dimerized phases. In graphene nanoribbons, a domain-wall soliton connects two topological zigzag edges with different chiralities. However, such a soliton does not display spin-charge separation. The existence of a soliton in finite-length polyacetylene can induce formation of fractional charges on the opposite ends. In contrast, for gapful graphene nanoribbons, the antiferromagnetic coupling between the opposite zigzag edges induces integer boundary charges. The presence of disorder in graphene nanoribbons partly mitigates antiferromagnetic coupling effect. Hence, the average edge charge of gap states with energies within a small interval is e / 2 , with significant charge fluctuations. However, midgap states exhibit a well-defined charge fractionalization between the opposite zigzag edges in the weak-disorder regime. Numerous occupied soliton states in a disorder-free and doped zigzag graphene nanoribbon form a solitonic phase.

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Wang, Hanxi, Yuanzhi Ding, Guojun Li, and Yuxuan Song. "Construction and properties analysis of Z-A-Z graphene nanoribbons transistors." Journal of Physics: Conference Series 2313, no. 1 (July 1, 2022): 012015. http://dx.doi.org/10.1088/1742-6596/2313/1/012015.

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Abstract Based on the first-principles theory combining density-functional theory and non-equilibrium Green’s function, A zigzag-armchair-zigzag (Z-A-Z) graphene nanoribbon transistor model was constructed using the quantumATK tool, and Stone-Wales (SW) defects were introduced. The transmission spectrum, electrical conductivity, gate potential and current-voltage (I-V) characteristics of Z-A-Z graphene nanoribbons were analyzed. By constructing Z-A-Z graphene nanoribbons with SW defects, the effect of defects on their transport properties was explored. The research results can provide a reference for the research on the characteristics of Z-A-Z graphene nanoribbons.

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Mathew, Sobin, Saadman Abedin, Vladislav Kurtash, Sergei P. Lebedev, Alexander A. Lebedev, Bernd Hähnlein, Jaqueline Stauffenberg, Heiko O. Jacobs, and Jörg Pezoldt. "Evaluation of Hysteresis Response in Achiral Edges of Graphene Nanoribbons on Semi-Insulating SiC." Materials Science Forum 1089 (May 26, 2023): 15–22. http://dx.doi.org/10.4028/p-i2s1cm.

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Hysteresis response of epitaxially grown graphene nanoribbons devices on semi-insulating 4H-SiC in the armchair and zigzag directions is evaluated and studied. The influence of the orientation of fabrication and dimensions of graphene nanoribbons on the hysteresis effect reveals the metallic and semiconducting nature graphene nanoribbons. The hysteresis response of armchair based graphene nanoribbon side gate and top gated devices implies the influence of gate field electric strength and the contribution of surface traps, adsorbents, and initial defects on graphene as the primary sources of hysteresis. Additionally, passivation with AlOx and top gate modulation decreased the hysteresis and improved the current-voltage characteristics.

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Tosic, Dragana, Zoran Markovic, Svetlana Jovanovic, Momir Milosavljevic, and Biljana Todorovic-Markovic. "Comparative analysis of different methods for graphene nanoribbon synthesis." Chemical Industry 67, no. 1 (2013): 147–56. http://dx.doi.org/10.2298/hemind120403056t.

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Graphene nanoribbons (GNRs) are thin strips of graphene that have captured the interest of scientists due to their unique structure and promising applications in electronics. This paper presents the results of a comparative analysis of morphological properties of graphene nanoribbons synthesized by different methods. Various methods have been reported for graphene nanoribons synthesis. Lithography methods usually include electron-beam (e-beam) lithography, atomic force microscopy (AFM) lithography, and scanning tunnelling microscopy (STM) lithography. Sonochemical and chemical methods exist as well, namely chemical vapour deposition (CVD) and anisotropic etching. Graphene nanoribbons can also be fabricated from unzipping carbon nanotubes (CNTs). We propose a new highly efficient method for graphene nanoribbons production by gamma irradiation of graphene dispersed in cyclopentanone (CPO). Surface morphology of graphene nanoribbons was visualized with atomic force and transmission electron microscopy. It was determined that dimensions of graphene nanoribbons are inversely proportional to applied gamma irradiation dose. It was established that the narrowest nanoribbons were 10-20 nm wide and 1 nm high with regular and smooth edges. In comparison to other synthesis methods, dimensions of graphene nanoribbons synthesized by gamma irradiation are slightly larger, but the yield of nanoribbons is much higher. Fourier transform infrared spectroscopy was used for structural analysis of graphene nanoribbons. Results of photoluminescence spectroscopy revealed for the first time that synthesized nanoribbons showed photoluminescence in the blue region of visible light in contrast to graphene nanoribbons synthesized by other methods. Based on disclosed facts, we believe that our synthesis method has good prospects for potential future mass production of graphene nanoribbons with uniform size, as well as for future investigations of carbon nanomaterials for applications in optoelectronics and biological labeling.

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Li, Wenhua, and Wenchao Tian. "Molecular Dynamics Analysis of Graphene Nanoelectromechanical Resonators Based on Vacancy Defects." Nanomaterials 12, no. 10 (May 18, 2022): 1722. http://dx.doi.org/10.3390/nano12101722.

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Due to the limitation of graphene processing technology, the prepared graphene inevitably contains various defects. The defects will have a particular influence on the macroscopic characteristics of the graphene. In this paper, the defect-based graphene nanoresonators are studied. In this study, the resonant properties of graphene were investigated via molecular dynamic simulations. The effect of vacancy defects and hole defects at different positions, numbers, and concentrations on the resonance frequency of graphene nanoribbons was studied. The results indicated that single monatomic vacancy has no effect on graphene resonant frequency, and the concentration of the resonant frequency of graphene decreases almost linearly with the increase of single-atom vacancy concentration. When the vacancy concentration is 5%, the resonance frequency is reduced by 12.77% compared to the perfect graphene. Holes on the graphene cause the resonance frequency to decrease. As the circular hole defect is closer to the center of the graphene nanoribbon, not only does its resonant frequency increase, but the tuning range is also expanded accordingly. Under the external force of 10.715 nN, the resonant frequency of graphene reaches 429.57 GHz when the circular hole is located at the center of the graphene nanoribbon, which is 40 GHz lower than that of single vacancy defect graphene. When the circular hole is close to the fixed end of graphene, the resonant frequency is 379.62 GHz, which is 90 GHz lower than that of single vacancy graphene. When the hole defect is at the center of nanoribbon, the frequency tunable range of graphene reaches 120 GHz. The tunable frequency range of graphene is 100.12 GHz when the hole defect is near the fixed ends of the graphene nanoribbon. This work is of great significance for design and performance optimization of graphene-based nanoelectro-mechanical system (NEMS) resonators.

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Saraswat, Vivek, Austin Way, Robert Jacobberger, and Michael Arnold. "CVD Synthesis of Graphene Nanomesh on Ge(001)." ECS Meeting Abstracts MA2022-01, no. 12 (July 7, 2022): 876. http://dx.doi.org/10.1149/ma2022-0112876mtgabs.

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Bottom-up synthesis of functional graphene nanostructures on industry-compatible semiconductors such as Si and Ge is the key to unlocking the tremendous potential of graphene in electronic applications. Herein, we demonstrate the growth of graphene nanomesh on Ge using chemical vapor deposition – a technique used widely in the semiconductor industry. Graphene nanomesh is a promsing material in semiconductor electronics because of its ability to simultaneously achieve a large drive current and on/off ratio – one of the key challenges in graphene nanoribbon electronics[1]. However, in order to realize a nanomesh with desired and tunable electrical characteristics – an accurate control over the nanoribbon width, presence of atomically smooth edges, and nanoribbon placement is desired. In the literature, several techniques have been demonstrated to fabricate graphene nanomesh such as top-down lithography[2], bottom-up polymerization[3], and molecule-assisted CVD[4]; yet, a combination of accurate placement, tunable widths and atomically smooth edges has been challenging to achieve. We attempt to overcome this bottleneck by initiating CVD nanoribbon synthesis from deterministically placed arrays of graphene nanoseeds on Ge. We are able to tune the nanoribbon widths by changing the starting seed size and array pitch. The nanoribbons evolved from these nanoseeds fuse into each other when grown long enough – forming a nanomesh. These nanomeshes have atomically smooth edges and exhibit semiconducting characteristics. We also perform extensive simulations to identify the seed-sizes and pitches and demonstrate that this technique allows us to synthesize nanomeshes of desired architecture and electrical characteristics and thus can be used as channel materials in high performance / RF applications as well as BEOL interconnects. References Saraswat et al. ACS Nano, 15,3674-3708 (2021) Bai et al. Nature Nanotechnology, 5, 190–194 (2010) Moreno et al. Science, 360, 199-203 (2018) Kim et al. ACS Applied Materials & Interfaces, 13, 28593-28599 (2021)

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Armaghani, Sahar, Ali Rostami, and Peyman Mirtaheri. "Graphene Nanoribbon Bending (Nanotubes): Interaction Force between QDs and Graphene." Coatings 12, no. 9 (September 15, 2022): 1341. http://dx.doi.org/10.3390/coatings12091341.

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Carbon materials in different shapes—such as fullerene molecules (0D), nanotubes and graphene nanoribbons (1D), graphene sheets (2D), and nanodiamonds (3D)—each have distinct electrical and optical properties. All graphene-based nanostructures are expected to exhibit extraordinary electronic, thermal, and mechanical properties. Moreover, they are therefore promising candidates for a wide range of nanoscience and nanotechnology applications. In this work, we theoretically studied and analyzed how an array of quantum dots affects a charged graphene plate. To that end, the array of quantum dots was embedded on the graphene plate. Then, considering the interaction between QDs and graphene nanoribbons, we transformed the charged plate of a graphene capacitor into a nanotube using the bipolar-induced interaction and the application of an external electromagnetic field. In this work, the dimensions of the graphene plate were 40 nm × 3100 nm. The bending process of a charged graphene plate is controlled by the induced force due to the applied electromagnetic field and the electric field induced by the quantum dots. Finally, using the predetermined frequency and amplitude of the electromagnetic field, the graphene nanoribbon was converted into a graphene nanotube. Since the electrical and optical properties of nanotubes are different from those of graphene plates, this achievement has many practical potential applications in the electro-optical industry.

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DOBRINSKY, A., A. SADRZADEH, B. I. YAKOBSON, and J. XU. "ELECTRONIC STRUCTURE OF GRAPHENE NANORIBBONS SUBJECTED TO TWIST AND NONUNIFORM STRAIN." International Journal of High Speed Electronics and Systems 20, no. 01 (March 2011): 153–60. http://dx.doi.org/10.1142/s0129156411006489.

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Graphene nanoribbons exhibit band gap modulation when subjected to strain. While band gap creation has been theoretically investigated for uniaxial strains, other deformations such as nanoribbon twist have not been considered. Our main objective in this paper is to explore band gap opening in twisted graphene nanoribbons that have metallic properties under tight-binding approximation. While simple considerations based on the Hückel model allow to conclude that zigzag graphene nanoribbons exhibit no band gap when subjected to twist, the Hückel model overall may be inaccurate for band gap prediction in metallic nanoribbons. We utilize Density Functional Theory Tight-Binding Approximation together with a requirement that energy of twisted nanoribbons is minimized to evaluate band gap of metalic armchair nanoribbons. Besides considering twisting deformations, we also explore the possibility of creating band gap when graphene nanoribbons are subject to inhomogeneous deformation such as sinusoidal deformations.

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KAN, ERJUN, ZHENYU LI, and JINLONG YANG. "MAGNETISM IN GRAPHENE SYSTEMS." Nano 03, no. 06 (December 2008): 433–42. http://dx.doi.org/10.1142/s1793292008001350.

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Graphene has attracted great interest in materials science, owing to its novel electronic structures. Recently, magnetism discovered in graphene-based systems has opened up the possibility of their spintronics application. This paper provides a comprehensive review of the magnetic behaviors and electronic structures of graphene systems, including two-dimensional graphene, one-dimensional graphene nanoribbons, and zero-dimensional graphene nanoclusters. Theoretical research suggests that such metal-free magnetism mainly comes from the localized states or edges states. By applying an external electric field, or by chemical modification, we can turn the zigzag nanoribbon systems into half metal, thus obtaining a perfect spin filter.

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Zhang, Ji, Tarek Ragab, and Cemal Basaran. "Influence of vacancy defects on the damage mechanics of graphene nanoribbons." International Journal of Damage Mechanics 26, no. 1 (July 28, 2016): 29–49. http://dx.doi.org/10.1177/1056789516645645.

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Using molecular dynamics simulations, graphene nanoribbons with armchair chirality were subjected to displacement-controlled uniaxial tension until complete fracture at 300 K in order to understand their damage mechanics. Graphene nanoribbons with and without a vacancy defect were simulated to compare the effect of the defect on the fracture behavior. Simulations were performed for graphene nanoribbons with lengths ranging from 2.5 to 15 nm. The stress–strain curve of each case is reported, and the influence of defect on the material properties is discussed. For each sample, damage mechanics types were observed and discussed. Results show a negligible effect of the single vacancy defect on the ultimate strength of the graphene nanoribbon. However, having a single vacancy defect does influence the failure strain, as well as the damage mechanics past the ultimate stress point.

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Rashidian, Zeinab, Parvin Bayati, and Zeinab Lorestaniwiess. "Effects of Rashba spin–orbit coupling on the conductance of graphene-based nanoribbons." International Journal of Modern Physics B 31, no. 06 (March 5, 2017): 1750043. http://dx.doi.org/10.1142/s0217979217500436.

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The transmission properties of armchair- and zigzag-edged graphene nanoribbon junctions between graphene electrodes are examined by means of the standard nonequilibrium Green’s function (NEGF) technique. The quantum transport of electrons is studied through a monolayer graphene strip in the presence of Rashba spin–orbit coupling that acts as a barrier between the two normal leads. The present work compares the conductances of nanoribbons with zigzag and armchair edges. Since the nature of induced gap for zigzag edge is different from armchair, it is expected to give rise to different types of conductance for each edge. Findings indicate that the Rashba strength has more pronounced influence on armchair ribbons than on zigzag ribbons, and the minimum conductance of [Formula: see text] for nanoribbon remains intact even in the presence of the Rashba spin–orbit coupling. It is predicted that controllability of spin transport in the monolayer graphene may contribute to the development of well-known spintronics.

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Давыдов, С. Ю. "О магнитных состояниях зигзагообразной кромки графеновой наноленты." Физика твердого тела 62, no. 1 (2020): 180. http://dx.doi.org/10.21883/ftt.2020.01.48757.502.

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Abstract Using a simple structural model and the multicenter Anderson Hamiltonian, Green’s functions are obtained for the atoms of the zigzag edge of an epitaxial graphene nanoribbon. The electronic structure of the free nanoribbon is discussed in detail. Specifically, expressions for the band spectrum and density of states are found and estimates of the occupation numbers and magnetic moments are given. For a nanoribbon strongly bonded to a metal substrate, the criteria for the appearance of magnetic moments are determined. As it is shown for both free and epitaxial nanoribbons, the probability of the appearance of magnetic moments and their magnitude for zigzag edge atoms that have two nearest neighbors is higher than for atoms with three nearest neighbors.

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Farrokhi, Maryam, Rahim Faez, Saeed Haji Nasiri, and Bita Davoodi. "Effect of Varying Dielectric Constant on Relative Stability for Graphene Nanoribbon Interconnects." Applied Mechanics and Materials 229-231 (November 2012): 201–4. http://dx.doi.org/10.4028/www.scientific.net/amm.229-231.201.

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The remarkable properties of graphene nanoribbons (GNRs) make them attractive for nano-scale devices applications, especially for transistor and interconnect. Furthermore, for reduction interconnects signal delay, low dielectric constant materials are being introduced to replace conventional dielectrics in next generation IC technologies. With these regards, studding the effect of varying dielectric constant (ɛr) on relative stability of graphene nanoribbons interconnect is an important viewpoint in performance evaluation of system. In this paper, Nyquist stability analysis based on transmission line modeling (TLM) for graphene nanoribbon interconnects is investigated. In this analysis, the dependence of the degree of relative stability for multilayer GNR (MLGNR) interconnects on the dielectric constant has been acquired. It is shown that, increasing the dielectric constant of each ribbon, MLGNR interconnects become more stable.

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Slepchenkov, Michael M., Pavel V. Barkov, and Olga E. Glukhova. "Hybrid Films Based on Bilayer Graphene and Single-Walled Carbon Nanotubes: Simulation of Atomic Structure and Study of Electrically Conductive Properties." Nanomaterials 11, no. 8 (July 27, 2021): 1934. http://dx.doi.org/10.3390/nano11081934.

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One of the urgent problems of materials science is the search for the optimal combination of graphene modifications and carbon nanotubes (CNTs) for the formation of layered hybrid material with specified physical properties. High electrical conductivity and stability are one of the main optimality criteria for a graphene/CNT hybrid structure. This paper presents results of a theoretical and computational study of the peculiarities of the atomic structure and the regularities of current flow in hybrid films based on single-walled carbon nanotubes (SWCNTs) with a diameter of 1.2 nm and bilayer zigzag graphene nanoribbons, where the layers are shifted relative to the other. It is found that the maximum stresses on atoms of hybrid film do not exceed ~0.46 GPa for all considered topological models. It is shown that the electrical conductivity anisotropy takes place in graphene/SWCNT hybrid films at a graphene nanoribbon width of 4 hexagons. In the direction along the extended edge of the graphene nanoribbon, the electrical resistance of graphene/SWCNT hybrid film reaches ~125 kOhm; in the direction along the nanotube axis, the electrical resistance is about 16 kOhm. The prospects for the use of graphene/SWCNT hybrid films in electronics are predicted based on the obtained results.

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Rahmani, Meisam, Razali Ismail, Mohammad Taghi Ahmadi, Mohammad Javad Kiani, Mehdi Saeidmanesh, F. A. Hediyeh Karimi, Elnaz Akbari, and Komeil Rahmani. "The Effect of Bilayer Graphene Nanoribbon Geometry on Schottky-Barrier Diode Performance." Journal of Nanomaterials 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/636239.

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Bilayer graphene nanoribbon is a promising material with outstanding physical and electrical properties that offers a wide range of opportunities for advanced applications in future nanoelectronics. In this study, the application of bilayer graphene nanoribbon in schottky-barrier diode is explored due to its different stacking arrangements. In other words, bilayer graphene nanoribbon schottky-barrier diode is proposed as a result of contact between a semiconductor (AB stacking) and metal (AA stacking) layers. To this end, an analytical model joint with numerical solution of carrier concentration for bilayer graphene nanoribbon in the degenerate and nondegenerate regimes is presented. Moreover, to determine the proposed diode performance, the carrier concentration model is adopted to derive the current-voltage characteristic of the device. The simulated results indicate a strong bilayer graphene nanoribbon geometry and temperature dependence of current-voltage characteristic showing that the forward current of the diode rises by increasing of width. In addition, the lower value of turn-on voltage appears as the more temperature increases. Finally, comparative study indicates that the proposed diode has a better performance compared to the silicon schottky diode, graphene nanoribbon homo-junction contact, and graphene-silicon schottky diode in terms of electrical parameters such as turn-on voltage and forward current.

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Armaghani, Sahar, Ali Rostami, and Peyman Mirtaheri. "Analysis and Simulation of the Optical Properties of a Quantum Dot on a Graphene Nanoribbon System." Photonics 9, no. 4 (March 27, 2022): 220. http://dx.doi.org/10.3390/photonics9040220.

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In this work, we theoretically study the optical properties of a graphene nanoribbon with a quantum dot (QD) on it. The system consists of a graphene nanoribbon with dimensions of 400 × 3100 (nm2) and a quantum dot with a nanoscale radius. The quantum dot is symmetrically located at the center of the graphene nanoribbon to simplify the mathematical model. To calculate the optical properties (susceptibility) of the system, a broadband electromagnetic wave (0.5–2.5 μm) is applied to the structure to model dipole-dipole interaction. Considering the input field and calculating the total induced polarization, the optical susceptibility of the system is calculated. The applied electromagnetic field excites the surface plasmon on the graphene nanoribbon and the excitons of QDs. The induced dipoles in the graphene nanoribbon and the QD will interact with each other. We show that the parameters of both materials strongly influence dipole-dipole interaction. In particular, the effect of QDs (location on graphene and radius) on the optical properties of the considered system was studied. The obtained results can be used to introduce periodic optical structures in nanoscale by inserting QDs in a periodic array on graphene nanoribbon. Additionally, applications such as reflectors, couplers, and wavelength filters can be designed. Considering the presented theoretical framework, we can describe all the optoelectronic and optomechanical applications of complex nanoscale graphene and QD systems.

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Tene, Talia, Marco Guevara, Jiří Svozilík, Diana Coello-Fiallos, Jorge Briceño, and Cristian Vacacela Gomez. "Proving Surface Plasmons in Graphene Nanoribbons Organized as 2D Periodic Arrays and Potential Applications in Biosensors." Chemosensors 10, no. 12 (December 3, 2022): 514. http://dx.doi.org/10.3390/chemosensors10120514.

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Surface-plasmon-based biosensors have become excellent platforms for detecting biomolecular interactions. While there are several methods to exciting surface plasmons, the major challenge is improving their sensitivity. In relation to this, graphene-based nanomaterials have been theoretically and experimentally proven to increase the sensitivity of surface plasmons. Notably, graphene nanoribbons display more versatile electronic and optical properties due to their controllable bandgaps in comparison to those of zero-gap graphene. In this work, we use a semi-analytical approach to investigate the plasmonic character of two-dimensional graphene nanoribbon arrays, considering free-standing models, i.e., models in which contact with the supporting substrate does not affect their electronic properties. Our findings provide evidence that the plasmon frequency and plasmon dispersion are highly sensitive to geometrical factors or the experimental setup within the terahertz regime. More importantly, possible applications in the molecular detection of lactose, α-thrombin, chlorpyrifos-methyl, glucose, and malaria are discussed. These predictions can be used in future experiments, which, according to what is reported here, can be correctly fitted to the input parameters of possible biosensors based on graphene nanoribbon arrays.

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36

Cai, Jinming, Carlo A. Pignedoli, Leopold Talirz, Pascal Ruffieux, Hajo Söde, Liangbo Liang, Vincent Meunier, et al. "Graphene nanoribbon heterojunctions." Nature Nanotechnology 9, no. 11 (September 7, 2014): 896–900. http://dx.doi.org/10.1038/nnano.2014.184.

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37

Rafiee, Mohammad A., Wei Lu, Abhay V. Thomas, Ardavan Zandiatashbar, Javad Rafiee, James M. Tour, and Nikhil A. Koratkar. "Graphene Nanoribbon Composites." ACS Nano 4, no. 12 (November 16, 2010): 7415–20. http://dx.doi.org/10.1021/nn102529n.

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38

Mousavi, Hamze, and Marek Grabowski. "Graphene Nanoribbon Superconductor." Journal of Low Temperature Physics 193, no. 1-2 (June 26, 2018): 12–20. http://dx.doi.org/10.1007/s10909-018-2011-3.

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Ezawa, Motohiko. "Graphene Nanoribbon and Graphene Nanodisk." Physica E: Low-dimensional Systems and Nanostructures 40, no. 5 (March 2008): 1421–23. http://dx.doi.org/10.1016/j.physe.2007.09.031.

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40

Majid, M. J., and M. H. Alaa. "Trembling motion of the wave packet in armchair graphene nanoribbons (AGNRs)." International Journal of Modern Physics B 32, no. 32 (December 30, 2018): 1850364. http://dx.doi.org/10.1142/s0217979218503642.

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A treatment of the trembling motion or Zitterbewegung (ZB) phenomena in the armchair graphene nanoribbons (AGNRs) by using long-wave approximation is presented theoretically. We are first interested to study the time dependence of the average values for the current density in AGNR. The longitudinal and transversal components of the current density operator are derived analytically in the Heisenberg representation. The wave packet in a Gaussian distribution is considered with half-width d and a carrier wave vector in the longitudinal orientation k[Formula: see text]. The average values of the current density which represent the current induced by the motion of the electrons along the nanoribbon are calculated numerically. The interference between two energy branches, or the corresponding upper and lower energy states, leads to the trembling motion in the armchair graphene nanoribbon, and hence, our results emphasized that the phenomena of ZB has an aperiodic and nontransient oscillation in the longitudinal and transversal direction, respectively. The average values for the current density for AGNRs are calculated with extremely large value of N and compared with infinite pristine graphene.

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Cui, Xing-Qian, Qian Liu, Zhi-Qiang Fan, and Zhen-Hua Zhang. "Effects of oxygen adsorption on spin transport properties of single anthracene molecular devices." Acta Physica Sinica 69, no. 24 (2020): 248501. http://dx.doi.org/10.7498/aps.69.20201028.

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With the miniaturization of molecular devices, high-performance nano devices can be fabricated by controlling the spin states of electrons. Because of their advantages such as low energy consumption, easy integration and long decoherence time, more and more attention has been paid to them. So far, the spin filtration efficiency of molecular device with graphene electrode is not very stable, which will decrease with the increase of voltage, and thus affecting its applications. Therefore, how to enhance the spin filtration efficiency of molecular device with graphene electrode becomes a scientific research problem. Using the first principle calculations based on density functional theory combined with non-equilibrium Green’s function, the physical mechanism of regulating the spin polarization transport properties of single anthracene molecule device with graphene nanoribon as electrode is investigated by molecular oxygen adsorption. In order to explore the effect of the change of the connection mode between single anthracene molecule and zigzag graphene nanoribbon electrode on the spin transport properties of the device, we establish two models. The first model is the model M1, which is the single anthracene molecule longitudinal connection, and the second model is the model M2, which is the single anthracene molecule lateral connection. The adsorption model of single oxygen molecule is denoted by M1O and M2O respectively. The results show that when none of oxygen molecules is adsorbed, the spin filtering effect of single anthracene molecule connecting graphene nanoribbons laterally (M2) is better than that of single anthracene molecule connecting graphene nanoribbons longitudinally (M1). After oxygen molecules are adsorbed on single anthracene molecule, the enhanced localized degree of transport eigenstate will make the spin current of the two kinds of devices decrease by nearly two orders of magnitude. However, molecular oxygen adsorption significantly improves the spin filtering efficiency of the device and enhances the application performance of the device. The maximal spin filtering efficiency of single anthracene molecule connecting graphene nanoribbons longitudinal (M1O) can be increased from 72% to 80%. More importantly, the device with single anthracene molecule connecting graphene nanoribbons laterally (M2) maintains nearly 100% spin filtering efficiency in a bias range from –0.5 V to +0.5 V. These results provide more theoretical guidance for practically fabricating spin molecular devices and regulating their spin transport properties.

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Cammarata, Simone, Andrea Fontana, Ali Emre Kaplan, Samuele Cornia, Thu Ha Dao, Cosimo Lacava, Valeria Demontis, et al. "Polarization Control in Integrated Graphene-Silicon Quantum Photonics Waveguides." Materials 15, no. 24 (December 7, 2022): 8739. http://dx.doi.org/10.3390/ma15248739.

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We numerically investigated the use of graphene nanoribbons placed on top of silicon-on-insulator (SOI) strip waveguides for light polarization control in silicon photonic-integrated waveguides. We found that two factors mainly affected the polarization control: the graphene chemical potential and the geometrical parameters of the waveguide, such as the waveguide and nanoribbon widths and distance. We show that the graphene chemical potential influences both TE and TM polarizations almost in the same way, while the waveguide width tapering enables both TE-pass and TM-pass polarizing functionalities. Overall, by increasing the oxide spacer thickness between the silicon waveguide and the top graphene layer, the device insertion losses can be reduced, while preserving a high polarization extinction ratio.

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Aydin, Alhun, Altug Sisman, Jonas Fransson, Annica M. Black-Schaffer, and Paramita Dutta. "Thermodefect voltage in graphene nanoribbon junctions." Journal of Physics: Condensed Matter 34, no. 19 (March 14, 2022): 195304. http://dx.doi.org/10.1088/1361-648x/ac553b.

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Abstract Thermoelectric junctions are often made of components of different materials characterized by distinct transport properties. Single material junctions, with the same type of charge carriers, have also been considered to investigate various classical and quantum effects on the thermoelectric properties of nanostructured materials. We here introduce the concept of defect-induced thermoelectric voltage, namely, thermodefect voltage, in graphene nanoribbon (GNR) junctions under a temperature gradient. Our thermodefect junction is formed by two GNRs with identical properties except the existence of defects in one of the nanoribbons. At room temperature the thermodefect voltage is highly sensitive to the types of defects, their locations, as well as the width and edge configurations of the GNRs. We computationally demonstrate that the thermodefect voltage can be as high as 1.7 mV K−1 for 555–777 defects in semiconducting armchair GNRs. We further investigate the Seebeck coefficient, electrical conductance, and electronic thermal conductance, and also the power factor of the individual junction components to explain the thermodefect effect. Taken together, our study presents a new pathway to enhance the thermoelectric properties of nanomaterials.

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Liu, Hongda, Jiongjiang Liu, Qi Liu, Yinghui Li, Guo Zhang, and Chunying He. "Conductometric Gas Sensor Based on MoO3 Nanoribbon Modified with rGO Nanosheets for Ethylenediamine Detection at Room Temperature." Nanomaterials 13, no. 15 (July 31, 2023): 2220. http://dx.doi.org/10.3390/nano13152220.

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An ethylenediamine (EDA) gas sensor based on a composite of MoO3 nanoribbon and reduced graphene oxide (rGO) was fabricated in this work. MoO3 nanoribbon/rGO composites were synthesized using a hydrothermal process. The crystal structure, morphology, and elemental composition of MoO3/rGO were analyzed via XRD, FT-IR, Raman, TEM, SEM, XPS, and EPR characterization. The response value of MoO3/rGO to 100 ppm ethylenediamine was 843.7 at room temperature, 1.9 times higher than that of MoO3 nanoribbons. The MoO3/rGO sensor has a low detection limit (LOD) of 0.235 ppm, short response time (8 s), good selectivity, and long-term stability. The improved gas-sensitive performance of MoO3/rGO composites is mainly due to the excellent electron transport properties of graphene, the generation of heterojunctions, the higher content of oxygen vacancies, and the large specific surface area in the composites. This study presents a new approach to efficiently and selectively detect ethylenediamine vapor with low power.

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Yan, Zhendong, Qi Zhu, Xue Lu, Wei Du, Xingting Pu, Taoping Hu, Lili Yu, Zhong Huang, Pinggen Cai, and Chaojun Tang. "Multipolar Plasmonic Resonances of Aluminum Nanoantenna Tuned by Graphene." Nanomaterials 11, no. 1 (January 13, 2021): 185. http://dx.doi.org/10.3390/nano11010185.

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We numerically investigate the multipolar plasmonic resonances of Aluminum nanoantenna tuned by a monolayer graphene from ultraviolet (UV) to visible regime. It is shown that the absorbance of the plasmonic odd modes (l = 1 and l = 3) of graphene–Al nanoribbon structure is enhanced while the absorption at the plasmonic even modes (l = 2) is suppressed, compared to the pure Al nanoribbon structure. With the presence of the monolayer graphene, a change in the resonance strength of the multipolar plasmonic modes results from the near field interactions of the monolayer graphene with the electric fields of the multipolar plasmonic resonances of the Al resonator. In particular, a clear absorption peak with a high quality (Q)-factor of 27 of the plasmonic third-order mode (l = 3) is realized in the graphene–Al nanoribbon structure. The sensitivity and figure of merit of the plasmonic third-order mode of the proposed Graphene–Al nanoribbon structure can reach 25 nm/RIU and 3, respectively, providing potential applications in optical refractive-index sensing.

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Tamersit, Khalil, Jaya Madan, Abdellah Kouzou, Rahul Pandey, Ralph Kennel, and Mohamed Abdelrahem. "Role of Junctionless Mode in Improving the Photosensitivity of Sub-10 nm Carbon Nanotube/Nanoribbon Field-Effect Phototransistors: Quantum Simulation, Performance Assessment, and Comparison." Nanomaterials 12, no. 10 (May 11, 2022): 1639. http://dx.doi.org/10.3390/nano12101639.

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In this article, ultrascaled junctionless (JL) field-effect phototransistors based on carbon nanotube/nanoribbons with sub-10 nm photogate lengths were computationally assessed using a rigorous quantum simulation. This latter self-consistently solves the Poisson equation with the mode space (MS) non-equilibrium Green’s function (NEGF) formalism in the ballistic limit. The adopted photosensing principle is based on the light-induced photovoltage, which alters the electrostatics of the carbon-based junctionless nano-phototransistors. The investigations included the photovoltage behavior, the I-V characteristics, the potential profile, the energy-position-resolved electron density, and the photosensitivity. In addition, the subthreshold swing–photosensitivity dependence as a function of change in carbon nanotube (graphene nanoribbon) diameter (width) was thoroughly analyzed while considering the electronic proprieties and the quantum physics in carbon nanotube/nanoribbon-based channels. As a result, the junctionless paradigm substantially boosted the photosensitivity and improved the scaling capability of both carbon phototransistors. Moreover, from the point of view of comparison, it was found that the junctionless graphene nanoribbon field-effect phototransistors exhibited higher photosensitivity and better scaling capability than the junctionless carbon nanotube field-effect phototransistors. The obtained results are promising for modern nano-optoelectronic devices, which are in dire need of high-performance ultra-miniature phototransistors.

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Vacacela Gomez, Cristian, Michele Pisarra, Mario Gravina, and Antonello Sindona. "Tunable plasmons in regular planar arrays of graphene nanoribbons with armchair and zigzag-shaped edges." Beilstein Journal of Nanotechnology 8 (January 17, 2017): 172–82. http://dx.doi.org/10.3762/bjnano.8.18.

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Recent experimental evidence for and the theoretical confirmation of tunable edge plasmons and surface plasmons in graphene nanoribbons have opened up new opportunities to scrutinize the main geometric and conformation factors, which can be used to modulate these collective modes in the infrared-to-terahertz frequency band. Here, we show how the extrinsic plasmon structure of regular planar arrays of graphene nanoribbons, with perfectly symmetric edges, is influenced by the width, chirality and unit-cell length of each ribbon, as well as the in-plane vacuum distance between two contiguous ribbons. Our predictions, based on time-dependent density functional theory, in the random phase approximation, are expected to be of immediate help for measurements of plasmonic features in nanoscale architectures of nanoribbon devices.

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Bian, Baoan, Jingjuan Yang, Xiaoxiao Han, Peipei Yuan, and Yuqiang Ding. "Rectification in zigzag graphene/BN nanoribbon heterojunction." Modern Physics Letters B 32, no. 32 (November 20, 2018): 1850395. http://dx.doi.org/10.1142/s0217984918503955.

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We investigate the effect of changed BN nanoribbon on the rectifying behavior in zigzag graphene/BN nanoribbon heterojunction using first principles based on non-equilibrium Green’s function and density functional theory. The increased BN length in the scattering region reduces the rectifying performance of the device, and the maximum rectifying ratio is [Formula: see text] in the heterojunction. We discuss the different rectifying characteristics for the designed models by calculating the transmission spectra at different biases. The rectifying phenomenon is further investigated by the projected density of state of device. Furthermore, we explain the observed negative differential resistance effect by the transmission spectra and transmission eigenstates. The results suggest that the zigzag graphene/BN nanoribbon heterojunction leads to the asymmetric current, causing the rectifying phenomenon, and the BN length in the scattering region can modulate the rectifying performance of zigzag graphene/BN nanoribbon heterojunction.

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Ujjain, Sanjeev K., Preety Ahuja, and Raj Kishore Sharma. "Facile preparation of graphene nanoribbon/cobalt coordination polymer nanohybrid for non-enzymatic H2O2 sensing by dual transduction: electrochemical and fluorescence." Journal of Materials Chemistry B 3, no. 38 (2015): 7614–22. http://dx.doi.org/10.1039/c5tb00857c.

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A novel graphene nanoribbon (GNR)/cobalt coordination polymer (MCPs) composite (MCPs@GNR) is prepared by in situ reduction of graphene oxide nanoribbon (GONR) with simultaneous growth of MCPs nanoparticles on its surface demonstrating high H₂O₂ sensing.

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Konobeeva, Natalia, and Mikhail Belonenko. "Conductivity of impurity graphene nanoribbons and gate electric field." Modern Physics Letters B 31, no. 36 (December 13, 2017): 1750340. http://dx.doi.org/10.1142/s0217984917503407.

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In this paper, we investigate the influence of a gate electric field on the tunneling current for the contact of impurity graphene nanoribbon with a metal or quantum dots. Based on the Hamiltonian for graphene in the tight-binding approximation, the density of states is calculated, which allows us to obtain a tunneling current. We analyze the effect of the field magnitude on the detecting possibility of an impurity in the graphene nanoribbon. A sufficient change of current–voltage characteristic (CVC) of the contact is observed, with an increase in the constant electric field applied parallel to the nanoribbon plane.

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Journal articles on the topic 'Graphene NanoRibbon'

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