Journal articles: 'Graphene Nanoribbons'

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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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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Wang, Hong Xia, Cheng Lai Yang, You Zhang Zhu, and Ni Chen Yang. "Tight-Binding Approximation Calculation on the Electronic Structure of Graphene and Graphene Nanoribbons." Applied Mechanics and Materials 341-342 (July 2013): 199–203. http://dx.doi.org/10.4028/www.scientific.net/amm.341-342.199.

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The electronic structure expression of graphene was derived using tight-binding approxi-mation method. According to periodic boundary conditions in width direction of graphene nanorib-bons wave vector, the electronic structure analytical expression of armchair graphene nanoribbons was deduced, and the energy band curve were given. The conditions of graphene nanoribbons being metal or semiconductor were obtained. The results show that when nanoribbons width meetsL=3na/2, the energy gap is zero and armchair graphene nanoribbons behave as the metallic. With the increase of the nanoribbons width, the energy gap of semiconducting nanoribbons decreases. The electronic properties of graphene nanoribbons are closely related to their geometry. The graphene nanoribbons can be modulated into metal or semiconductor with different band gap by controlling their width.

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Wu, Cheng-Wei, Xue Ren, Wu-Xing Zhou, and Guo-Feng Xie. "Theoretical study of anisotropy and ultra-low thermal conductance of porous graphene nanoribbons." Acta Physica Sinica 71, no. 2 (2022): 027803. http://dx.doi.org/10.7498/aps.71.20211477.

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The thermal transport properties of porous graphene nanoribbons are studied by the non-equilibrium Green's function method. The results show that owing to the existence of nano-pores, the thermal conductance of porous graphene nanoribbons is much lower than that of graphene nanoribbons. At room temperature, the thermal conductance of zigzag porous graphene nanoribbons is only 12% of that of zigzag graphene nanoribbons of the same size. This is due to the phonon localization caused by the nano-pores in the porous graphene nanoribbons. In addition, the thermal conductance of porous graphene nanoribbons has remarkable anisotropy. With the same size, the thermal conductance of armchair porous graphene nanoribbons is about twice higher than that of zigzag porous graphene nanoribbons. This is because the phonon locality in the zigzag direction is stronger than that in the armchair direction, and even part of the frequency phonons are completely localized.

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Nosrati, Hassan, Rasoul Sarraf-Mamoory, Amir Hossein Ahmadi, and Maria Canillas Perez. "Synthesis of Graphene Nanoribbons–Hydroxyapatite Nanocomposite Applicable in Biomedicine and Theranostics." Journal of Nanotheranostics 1, no. 1 (April 22, 2020): 6–18. http://dx.doi.org/10.3390/jnt1010002.

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In order to investigate the effect of graphene nanoribbons on the final properties of hydroxyapatite-based nanocomposites, a solvothermal method was used at 180 °C and 5 h for the synthesis of graphene nanoribbons–hydroxyapatite nanopowders by employing hydrogen gas injection. Calcium nitrate tetrahydrate and diammonium hydrogenphosphate were used as calcium and phosphate precursors, respectively. To synthesize the powders, a solvent containing diethylene glycol, anhydrous ethanol, dimethylformamide, and water was used. Graphene oxide nanoribbons were synthesized by chemical unzipping of carbon nanotubes under oxidative conditions. The synthesized powders were consolidated by spark plasma sintering methodat 950 °C and a pressure of 50 MPa. The powders and sintered samples were then evaluated using X-ray diffraction, Raman spectroscopy, high-resolution transmission electron microscopy, Vickers microindentation techniques, and biocompatibility assay. The findings of this study showed that the final powders synthesized by the solvothermal method had calcium to phosphate ratio of about 1.67. By adding a small amount of graphene nanoribbon (0.5%W), elastic modulus and hardness of hydroxyapatite increased dramatically. In biological experiments, the difference of hydroxyapatite effect in comparison with the nanocomposite was not significant. The findings of this study showed that graphene nanoribbons have a positive effect on the properties of hydroxyapatite, and these findings would be useful for the medical and theranostic application of this type of nanocomposites.

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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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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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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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Corso, Martina, Rodrigo E. Menchón, Ignacio Piquero-Zulaica, Manuel Vilas-Varela, J. Enrique Ortega, Diego Peña, Aran Garcia-Lekue, and Dimas G. de Oteyza. "Band Structure and Energy Level Alignment of Chiral Graphene Nanoribbons on Silver Surfaces." Nanomaterials 11, no. 12 (December 6, 2021): 3303. http://dx.doi.org/10.3390/nano11123303.

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Chiral graphene nanoribbons are extremely interesting structures due to their narrow band gaps and potential development of spin-polarized edge states. Here, we study their band structure on low work function silver surfaces. The use of a curved Ag single crystal provides, within the same sample, regions of disparate step structure and step density. Whereas the former leads to distinct azimuthal growth orientations of the graphene nanoribbons atop, the latter modulates the substrate’s work function and thereby the interface energy level alignment. In turn, we disclose the associated charge transfer from the substrate to the ribbon and assess its effect on the nanoribbon’s properties and the edge state magnetization.

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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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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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Arnold, Michael S. "Growth and Properties of Graphene and Graphene Nanoribbons on Ge." ECS Meeting Abstracts MA2022-02, no. 32 (October 9, 2022): 1179. http://dx.doi.org/10.1149/ma2022-02321179mtgabs.

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The synthesis of graphene directly on Ge and on Ge deposited on Si provides a scalable route toward integrating graphene onto conventional semiconductors. This presentation will first survey the growth modes of graphene on Ge(001), Ge(011), Ge(111), Ge(112), Ge(001)-6°, and Ge(001)-9° via chemical vapor deposition (CVD), reporting on the effect of Ge surface orientation on graphene island formation and shape, strain in large-area graphene films, and the nanofaceting of the Ge below graphene.[1] We will then focus on the anisotropic growth of semiconducting graphene nanoribbons on Ge(001) and Ge(001)-9° and of nominally single crystal graphene on Ge(110). On Ge(001), we have discovered how to drive graphene crystal growth with a large shape anisotropy through control of kinetics.[2-6] This discovery enables the direct synthesis of narrow, armchair, semiconducting nanoribbons. The ribbons are self-orienting, self-defining, and have smooth edges. The ribbons exhibit excellent transport properties (e.g., high on-state conductance and on/off ratio at room temperature) and provide a promising pathway towards the direct integration of high-performance nanocarbon electronics onto conventional semiconductor wafer platforms. On Ge(001), nominally single crystal graphene has been reported in limited cases; however, conflicting studies have evidenced polycrystallinity. Here, the factors affecting the mosaicity of graphene on Ge(110) will be elucidated using low energy electron diffraction and microscopy data.[7] [1] R. M. Jacobberger, D. E. Savage, X. Zheng, P. Sookchoo, R. R. Delgado, M. G. Lagally, M. S. Arnold, SUBMITTED (2022). [2] R. M. Jacobberger, M. S. Arnold, et al., Direct Oriented Growth of Armchair Graphene Nanoribbons on Germanium, NATURE COMMUNICATIONS, 6, 8006 (2015). [3] B. Kiraly, M. S. Arnold, M. C. Hersam, N. P. Guisinger et al., Sub-5 nm, Globally Aligned Graphene Nanoribbons on Ge (001), APPLIED PHYSICS LETTERS, 108, 213101 (2016). [4] A. J. Way, R. M. Jacobberger, M. S. Arnold, Seed-Initiated Anisotropic Growth of Unidirectional Armchair Graphene Nanoribbon Arrays on Germanium, NANO LETTERS, 18, 898 (2018). [5] V. Saraswat, Y. Yamamoto, H.J. Kim, R.M. Jacobberger, K.R. Jinkins, A.J. Way, N.P. Guisinger, M.S. Arnold Synthesis of armchair graphene nanoribbons on germanium-on-silicon, THE JOURNAL OF PHYSICAL CHEMISTRY C 123 (30), 18445-18454 (2019). [6] A. J. Way, R. M. Jacobberger, N. P. Guisinger, V. Saraswat, X. Zheng, A. Suresh, J. H. Dwyer, P. Gopalan, Michael S. Arnold, SUBMITTED (2022). [7] R. M. Jacobberger, Z. Miao, T. Yu, V. Saraswat, M. G. Lagally, M. S. Altman, M. S. Arnold, SUBMITTED (2022).

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Gorjizadeh, Narjes, and Yoshiyuki Kawazoe. "Chemical Functionalization of Graphene Nanoribbons." Journal of Nanomaterials 2010 (2010): 1–7. http://dx.doi.org/10.1155/2010/513501.

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We review the electronic properties of graphene nanoribbons functionalized by various elements and functional groups. Graphene nanoribbons are strips of graphene, the honeycomb lattice of carbon withsp2hybridization. Basically nanoribbons can be classified into two categories, according to the geometry of their edge, armchair, and zigzag, which determine their electronic structure. Due to their fascinating electronic and magnetic properties many applications has been suggested for these materials. One of the major methods to use graphene nanoribbons in future applications is chemical functionalization of these materials to make an engineering on their band gap. In this review, we introduce various types of modifying graphene nanoribbons to meet their promising applications.

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Chen, A. Qing. "Electronic Structure and Optical Property of Phosphorus Doped Semiconducting Graphene Nanoribbons." Applied Mechanics and Materials 328 (June 2013): 813–16. http://dx.doi.org/10.4028/www.scientific.net/amm.328.813.

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The electronic structure and optical property of phosphorus doped semiconducting graphene nanoribbons were calculated by using the density functional theory. Energy band structure and optical spectra were considered to show the special electronic structure of phosphorus doped semiconducting graphene nanoribbons. Our results showed that the Fermi energy of phosphorus doped semiconducting graphene nanoribbons entered in the conduction bands, and that the optical coefficient depend on the width of armchair graphene nanoribbons. It is concluded that the phosphorus doped semiconducting graphene nanoribbons behave p type semiconducting. Therefore, our results have a great significance in developing nanomaterial for fabricating the nanophotovoltaic devices.

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Jeon, Sangheon, Pyunghwa Han, Jeonghwa Jeong, Wan Sik Hwang, and Suck Won Hong. "Highly Aligned Polymeric Nanowire Etch-Mask Lithography Enabling the Integration of Graphene Nanoribbon Transistors." Nanomaterials 11, no. 1 (December 25, 2020): 33. http://dx.doi.org/10.3390/nano11010033.

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Graphene nanoribbons are a greatly intriguing form of nanomaterials owing to their unique properties that overcome the limitations associated with a zero bandgap of two-dimensional graphene at room temperature. Thus, the fabrication of graphene nanoribbons has garnered much attention for building high-performance field-effect transistors. Consequently, various methodologies reported previously have brought significant progress in the development of highly ordered graphene nanoribbons. Nonetheless, easy control in spatial arrangement and alignment of graphene nanoribbons on a large scale is still limited. In this study, we explored a facile, yet effective method for the fabrication of graphene nanoribbons by employing orientationally controlled electrospun polymeric nanowire etch-mask. We started with a thermal chemical vapor deposition process to prepare graphene monolayer, which was conveniently transferred onto a receiving substrate for electrospun polymer nanowires. The polymeric nanowires act as a robust etching barrier underlying graphene sheets to harvest arrays of the graphene nanoribbons. On varying the parametric control in the process, the size, morphology, and width of electrospun polymer nanowires were easily manipulated. Upon O2 plasma etching, highly aligned arrays of graphene nanoribbons were produced, and the sacrificial polymeric nanowires were completely removed. The graphene nanoribbons were used to implement field-effect transistors in a bottom-gated configuration. Such approaches could realistically yield a relatively improved current on–off ratio of ~30 higher than those associated with the usual micro-ribbon strategy, with the clear potential to realize reproducible high-performance devices.

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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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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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Wu, Jiaqi, Yinghui Zheng, Zhinan Zeng, and Ruxin Li. "High-order harmonic generation from zigzag graphene nanoribbons." Chinese Optics Letters 18, no. 10 (2020): 103201. http://dx.doi.org/10.3788/col202018.103201.

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Shunaev, V. V., A. Yu Gerasimenko, and O. E. Glukhova. "Electronic Properties of Graphene Nanoribbons Doped with Pyrrole-Like Nitrogen." Proceedings of Universities. Electronics 26, no. 6 (December 2021): 447–58. http://dx.doi.org/10.24151/1561-5405-2021-26-6-447-458.

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Doping of graphene nanoribbons with various chemical elements leads to a change in their band structure, which significantly expands the range of applications of these objects in modern electronic devices. In this work, the authors investigate graphene nanoribbons of the «armchair» and «zigzag» types with different concentrations of pyrrole-like nitrogen at the edges. The SCC-DFTB method was used to establish the most energetically favorable configurations of pyrrole-like nitrogen at each edge of graphene nanoribbons. The relationship between the energy gaps of graphene nanoribbons and the content of the considered functional nitrogen-containing groups in them was determined. Calculations have shown that, by incorporating into the atomic lattice, pyrrole-like nitrogen at the «zigzag» edge transfers a greater amount of charge to nearby carbon atoms, which makes such nanoribbons more chemically active in comparison with «armchair» type nanoribbons. Nitrogen doped «zigzag» graphene nanoribbons may be a promising chemoresistive element of nanosensors; however, these conclusions require further calculations.

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Zakharova, Olga V., Elena E. Mastalygina, Kirill S. Golokhvast, and Alexander A. Gusev. "Graphene Nanoribbons: Prospects of Application in Biomedicine and Toxicity." Nanomaterials 11, no. 9 (September 17, 2021): 2425. http://dx.doi.org/10.3390/nano11092425.

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Graphene nanoribbons are a type of graphene characterized by remarkable electrical and mechanical properties. This review considers the prospects for the application of graphene ribbons in biomedicine, taking into account safety aspects. According to the analysis of the recent studies, the topical areas of using graphene nanoribbons include mechanical, chemical, photo- and acoustic sensors, devices for the direct sequencing of biological macromolecules, including DNA, gene and drug delivery vehicles, and tissue engineering. There is evidence of good biocompatibility of graphene nanoribbons with human cell lines, but a number of researchers have revealed toxic effects, including cytotoxicity and genotoxicity. Moreover, the damaging effects of nanoribbons are often higher than those of chemical analogs, for instance, graphene oxide nanoplates. The possible mechanism of toxicity is the ability of graphene nanoribbons to damage the cell membrane mechanically, stimulate reactive oxidative stress (ROS) production, autophagy, and inhibition of proliferation, as well as apoptosis induction, DNA fragmentation, and the formation of chromosomal aberrations. At the same time, the biodegradability of graphene nanoribbons under the environmental factors has been proven. In general, this review allows us to conclude that graphene nanoribbons, as components of high-precision nanodevices and therapeutic agents, have significant potential for biomedical applications; however, additional studies of their safety are needed. Particular emphasis should be placed on the lack of information about the effect of graphene nanoribbons on the organism as a whole obtained from in vivo experiments, as well as about their ecological toxicity, accumulation, migration, and destruction within ecosystems.

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Liu, Wen, Fan-Hua Meng, Jian-Hua Zhao, and Xiao-Hui Jiang. "A first-principles study on the electronic transport properties of zigzag graphane/graphene nanoribbons." Journal of Theoretical and Computational Chemistry 16, no. 04 (April 25, 2017): 1750032. http://dx.doi.org/10.1142/s0219633617500328.

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The electronic transport properties of hybrid nanoribbons constructed by substituting zigzag graphane nanoribbons (ZGaNRs) into zigzag graphene nanoribbons (ZGNRs) are investigated with the non-equilibrium Green’s function method and the density functional theory. Both symmetric and asymmetric ZGNRs are considered. The electronic transport of symmetric and asymmetric ZGNR-based hybrid nanoribbons behave distinctly differently from each other even in the presence of the same substitution positions of ZGaNRs. Moreover, the electronic transport of these hybrid systems is found to be enhanced or weakened compared with pristine ZGNRs depending on the substitution position and proportion. Our results suggest that such hybridization is an effective approach to modulate the transport properties of ZGNRs.

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Wu, Xiang-Feng, Yang Sun, Jie Zhang, Jing Li, Yong-Ke Zhao, Ze-Hua Zhao, Shi-Da Fu, Xiao-Ying Yu, and Sen-Sen Zheng. "Preparation of Reduced-Graphene Nanoribbons via One-Step Solvothermal Process." Journal of Nanoscience and Nanotechnology 16, no. 4 (April 1, 2016): 4191–94. http://dx.doi.org/10.1166/jnn.2016.11715.

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Carbon nanotubes were unzipped to become reduced-graphene nanoribbons via one-step solvothermal process in a Teflon-lined autoclave. The samples were characterized by X-ray diffraction, thermo-gravimetric analysis and transmission electrical microscopy, respectively. Results showed that the solvothermal reaction temperature played an important role in the structure of the samples. When it was 75 °C, carbon nanotubes were completely cutted into graphene oxide nanoribbons. Moreover, when it was 155 °C, they were become reduced-graphene nanoribbons. Furthermore, the as-prepared reduced-graphene nanoribbons could improve mechanical strength of the phenolic resin/hollow glass beads foamed composites. When the reduced-graphene nanoribbons loading was 0.4 wt%, the tensile and compressive strength of the composites were increased by 19.7% and 21.3%, respectively.

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Glukhova, O. E., I. N. Saliy, R. Y. Zhnichkov, I. A. Khvatov, A. S. Kolesnikova, and M. M. Slepchenkov. "Elastic properties of graphene-graphane nanoribbons." Journal of Physics: Conference Series 248 (November 1, 2010): 012004. http://dx.doi.org/10.1088/1742-6596/248/1/012004.

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Li, Hai Dong, and Jin Zhong Niu. "Electron Transport of Right-Angle Graphene Nanoribbons." Advanced Materials Research 295-297 (July 2011): 1451–55. http://dx.doi.org/10.4028/www.scientific.net/amr.295-297.1451.

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By the tight-binding method, we study the transport properties of right-angle L-shaped graphene nanoribbons. We found a universal conclusion is that the resonance of electron tunneling will present at the Dirac point when the system is metallic and the ribbons widths satisfy (NBAB=2NBZB-1). Further research suggests that the conductance resonance effect will be destroyed by impurity scatterer, especially the impurity concentration and strength are nontrivially large. We also found that antiresonance effect will result in a strong conductance suppression when the width difference () of the two ribbons is very big. In addition, when the system is semiconducting, the center of the well-defined insulating band can be easily tuned by a gate bias exerted on the armchair-edged graphene nanoribbon.

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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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Zhang, Xian Bin, Ning Kang Deng, Wen Jie Wu, Xu Yan Wei, and Guan Qi Wang. "The Investigations of Electronic Structure in Armchair Graphene Nanoribbons Doped B at the Edge." Key Engineering Materials 787 (November 2018): 99–103. http://dx.doi.org/10.4028/www.scientific.net/kem.787.99.

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In this paper, the electronic structure in armchair graphene nanoribbons (AGNRs) and graphene nanoribbons doped B at the edge (B-AGNRs) are obtained based on the first principle theory. It shows that the band gap has the oscillation characteristic whose period is 3. The band gap oscillating characteristic gradually vanishes and tends to be stable after doping B at graphene nanoribbons edge. This provides a theoretical guidance for developing the stable graphene nanodevices.

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Bradley, David. "Tuned graphene nanoribbons." Materials Today 20, no. 6 (July 2017): 289. http://dx.doi.org/10.1016/j.mattod.2017.05.014.

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Sanaeepur, Majid. "Effect of substitutional defects on resonant tunneling diodes based on armchair graphene and boron nitride nanoribbons lateral heterojunctions." Beilstein Journal of Nanotechnology 11 (April 24, 2020): 688–94. http://dx.doi.org/10.3762/bjnano.11.56.

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A nanometer-scaled resonant tunneling diode based on lateral heterojunctions of armchair graphene and boron nitride nanoribbons, exhibiting negative differential resistance is proposed. Low-bandgap armchair graphene nanoribbons and high-bandgap armchair boron nitride nanoribbons are used to design the well and the barrier region, respectively. The effect of all possible substitutional defects (including BC, NC, CB, and CN) at the interface of graphene and boron nitride nanoribbons on the negative differential resistance behavior of the proposed resonant tunneling diode is investigated. Transport simulations are carried out in the framework of tight-binding Hamiltonians and non-equilibrium Green’s functions. The results show that a single substitutional defect at the interface of armchair graphene and boron nitride nanoribbons can dramatically affect the negative differential resistance behavior depending on its type and location in the structure.

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Zhang, Bo, Xiao Chun He, Ming Jun Gao, Xing Fa Ma, and Guang Li. "Entanglement of CeO₂ Nanorods and Graphene Nanoribbons and their Properties Studies of Nanocomposites." Materials Science Forum 814 (March 2015): 153–60. http://dx.doi.org/10.4028/www.scientific.net/msf.814.153.

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Nano/Micro-structured CeO2and their nanocomposites have been received considerable attention in basic research and commercial applications, such as, new energy fields, photocatalysts, environmental fields, et al. To extend its visible light response and pave the effective conductive channels for charge transfer and separation in nanoscale is still facing great challenges. To explore these key issues of materials chemistry and physics, CeO2nanorods were prepared with aid of soft templates by wet chemical approach. Graphene nanoribbons were obtained with unzipping method of carbon nanotube (CNTs). Entanglement of CeO2nanorods and graphene nanoribbons oxides was realized based on the supermolecular interactions between surface active groups of CeO2nanorods and graphene nanoribbons oxides and excellent flexibility of graphene nanoribbons. A series of characterizations were examined by SEM (scanning electron microscopy), TEM (transmission electron microscopy), XRD (X-ray diffraction), the Fourier-Transform Infrared (FTIR) spectra, ultraviolet-visible spectroscopy (UV-Vis) and so on. Photocatalytic efficiency was examined by selecting typical organic pollutants. The results indicated that the entanglement of a small amount of graphene nanoribbons on the surface of CeO2nanorods not only expanded the light response of nanocomposite to visible light, but also enhanced the adsorption properties to organic pollutants. Because of excellent charge transfer properties and high mobility of graphene nanoribbons, the nanocomposites of CeO2/graphene nanoribbons are favor for electron-holes pairs generated by visible light, separation, and transfer, which would be important potential applications in photocatalysts, artificial photosynthesis system, nano/micro-devices, et al.

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Saraswat, Vivek, Austin J. Way, Xiaoqi Zheng, Robert M. Jacobberger, Sebastian Manzo, Nikhil Tiwale, Jonathan H. Dwyer, et al. "Bottom-up synthesis of mesoscale nanomeshes of graphene nanoribbons on germanium." APL Materials 11, no. 4 (April 1, 2023): 041123. http://dx.doi.org/10.1063/5.0134756.

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The synthesis of functional graphene nanostructures on Ge(001) provides an attractive route toward integrating graphene-based electronic devices onto complementary metal oxide semiconductor-compatible platforms. In this study, we leverage the phenomenon of the anisotropic growth of graphene nanoribbons from rationally placed graphene nanoseeds and their rotational self-alignment during chemical vapor deposition to synthesize mesoscale graphene nanomeshes over areas spanning several hundred square micrometers. Lithographically patterned nanoseeds are defined on a Ge(001) surface at pitches ranging from 50 to 100 nm, which serve as starting sites for subsequent nanoribbon growth. Rotational self-alignment of the nanoseeds followed by anisotropic growth kinetics causes the resulting nanoribbons to be oriented along each of the equivalent, orthogonal Ge⟨110⟩ directions with equal probability. As the nanoribbons grow, they fuse, creating a continuous nanomesh. In contrast to nanomesh synthesis via top-down approaches, this technique yields nanomeshes with atomically faceted edges and covalently bonded junctions, which are important for maximizing charge transport properties. Additionally, we simulate the electrical characteristics of nanomeshes synthesized from different initial nanoseed-sizes, size-polydispersities, pitches, and device channel lengths to identify a parameter-space for acceptable on/off ratios and on-conductance in semiconductor electronics. The simulations show that decreasing seed diameter and pitch are critical to increasing nanomesh on/off ratio and on-conductance, respectively. With further refinements in lithography, nanomeshes obtained via seeded synthesis and anisotropic growth are likely to have superior electronic properties with tremendous potential in a multitude of applications, such as radio frequency communications, sensing, thin-film electronics, and plasmonics.

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Li, Yinfeng, Simanta Lahkar, Qingyuan Wei, Pizhong Qiao, and Han Ye. "Strength nature of two-dimensional woven nanofabrics under biaxial tension." International Journal of Damage Mechanics 28, no. 3 (April 13, 2018): 367–79. http://dx.doi.org/10.1177/1056789518769343.

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Woven nanostructures have been acknowledged as a platform for solar cells, supercapacitors, and sensors, making them especially of interest in the fields of materials sciences, nanotechnology, and renewable energy. By employing molecular dynamics simulations, the mechanical properties of two-dimensional woven nanofabrics under biaxial tension are evaluated. Two-dimensional woven nanostructures composed of graphene and graphyne nanoribbons are examined. Dynamic failure process of both graphene woven nanofabric and graphyne woven nanofabric with the same woven unit cell initiates at the edge of interlaced ribbons accompanied by the formation of cracks near the crossover location of yarns. Further stress analysis reveals that such failure mode is attributed to the compression between two overlaced ribbons and consequently their deformation under biaxial tension, which is sensitive to the lattice structure of nanoribbon as well as the density of yarns in fabric. Systemic comparisons between nanofabrics with different yarn width and interval show that the strength of nanofabric can be effectively controlled by tuning the space interval between nanoribbons. For nanofabrics with fixed large gap spacing, the strength of fabric does not change with the ribbon width, while the strength of nanofabric with small gap spacing decreases anomalously with the increase in yarn density. Such fabric strength dependency on gap spacing is the result of the stress concentration caused by the interlace compression. The outcomes of simulation suggest that the compacted arrangement of yarns in carbon woven nanofabric structures should be avoided to achieve high strength performance.

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Journal articles on the topic 'Graphene Nanoribbons'

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