Adsorption of the water molecule on monolayer graphene surface has effect on its optical properties

In this paper, the structural, electronic, magnetic and optical properties of alkaline earth metal (AEM) atom-doped monolayer graphene are investigated using first-principles calculations.

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Electronic and optical properties of monolayer and bilayer graphene

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2010.0209 ◽

2010 ◽

Vol 368 (1932) ◽

pp. 5445-5458 ◽

Cited By ~ 17

Author(s):

Y. H. Ho ◽

J. Y. Wu ◽

Y. H. Chiu ◽

J. Wang ◽

M. F. Lin

Keyword(s):

Optical Properties ◽

Bilayer Graphene ◽

Landau Levels ◽

Optical Measurements ◽

Monolayer Graphene ◽

Zero Field ◽

Electronic And Optical Properties ◽

Graphene Layers ◽

Lower Pair ◽

Dependent Absorption

The electronic and optical properties of monolayer and bilayer graphene are investigated to verify the effects of interlayer interactions and external magnetic field. Monolayer graphene exhibits linear bands in the low-energy region. Then the interlayer interactions in bilayers change these bands into two pairs of parabolic bands, where the lower pair is slightly overlapped and the occupied states are asymmetric with respect to the unoccupied ones. The characteristics of zero-field electronic structures are directly reflected in the Landau levels. In monolayer and bilayer graphene, these levels can be classified into one and two groups, respectively. With respect to the optical transitions between the Landau levels, bilayer graphene possesses much richer spectral features in comparison with monolayers, such as four kinds of absorption channels and double-peaked absorption lines. The explicit wave functions can further elucidate the frequency-dependent absorption rates and the complex optical selection rules. These numerical calculations would be useful in identifying the optical measurements on graphene layers.

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An Effort Towards Full Graphene Photodetectors

Photonic Sensors ◽

10.1007/s13320-020-0600-7 ◽

2020 ◽

Author(s):

Farhad Larki ◽

Yaser Abdi ◽

Parviz Kameli ◽

Hadi Salamati

Keyword(s):

Optical Properties ◽

Absorption Spectrum ◽

Device Fabrication ◽

Monolayer Graphene ◽

High Quality ◽

Promising Candidate ◽

2D System ◽

Proper Design ◽

Pros And Cons ◽

Electro Magnetic

AbstractGraphene as a truly 2-dimensional (2D) system is a promising candidate material for various optoelectronic applications. Implementing graphene as the main building material in ultra-broadband photodetectors has been the center of extensive research due to its unique absorption spectrum which covers most of the electro-magnetic spectra. However, one of the main challenges facing the wide application of pure graphene photodetectors has been the small optical absorption of monolayer graphene. Although novel designs were proposed to overcome this drawback, they often need complicated fabrication processes in order to integrate with the graphene photodetector. In this regard, fabrication of purely graphene photodetectors is a promising approach towards the manufacturing of simple, inexpensive, and high photosensitive devices. The fabrication of full graphene photodetectors (FGPDs) is mainly based on obtaining an optimal technique for the growth of high quality graphene, modification of electronic and optical properties of the graphene, appropriate techniques for transfer of graphene from the grown substrate to the desire position, and a proper design for photodetection. Therefore, the available states of the art techniques for each step of device fabrication, along with their pros and cons, are reviewed and the possible approaches for optimization of FGPDs have been proposed.

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An Analytical Model for Adsorption and Diffusion of Atoms/Ions on Graphene Surface

Journal of Nanomaterials ◽

10.1155/2015/382474 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

Yan-Zi Yu ◽

Jian-Gang Guo ◽

Yi-Lan Kang

Keyword(s):

Interaction Energy ◽

Minimum Energy ◽

Gold Atom ◽

Lithium Ion ◽

Continuous Model ◽

Atomic Scale ◽

Monolayer Graphene ◽

Graphene Surface ◽

Adsorption Sites ◽

And Diffusion

Theoretical investigations are made on adsorption and diffusion of atoms/ions on graphene surface based on an analytical continuous model. An atom/ion interacts with every carbon atom of graphene through a pairwise potential which can be approximated by the Lennard-Jones (L-J) potential. Using the Fourier expansion of the interaction potential, the total interaction energy between the adsorption atom/ion and a monolayer graphene is derived. The energy-distance relationships in the normal and lateral directions for varied atoms/ions, including gold atom (Au), platinum atom (Pt), manganese ion (Mn2+), sodium ion (Na1+), and lithium-ion (Li1+), on monolayer graphene surface are analyzed. The equilibrium position and binding energy of the atoms/ions at three particular adsorption sites (hollow, bridge, and top) are calculated, and the adsorption stability is discussed. The results show that H-site is the most stable adsorption site, which is in agreement with the results of other literatures. What is more, the periodic interaction energy and interaction forces of lithium-ion diffusing along specific paths on graphene surface are also obtained and analyzed. The minimum energy barrier for diffusion is calculated. The possible applications of present study include drug delivery system (DDS), atomic scale friction, rechargeable lithium-ion graphene battery, and energy storage in carbon materials.

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Improved quasiballistic electron emission from a nanocrystalline Si cold cathode with a monolayer-graphene surface electrode

Applied Physics Letters ◽

10.1063/1.5017770 ◽

2018 ◽

Vol 112 (13) ◽

pp. 133102 ◽

Cited By ~ 14

Author(s):

Akira Kojima ◽

Ryutaro Suda ◽

Nobuyoshi Koshida

Keyword(s):

Electron Emission ◽

Monolayer Graphene ◽

Surface Electrode ◽

Cold Cathode ◽

Graphene Surface ◽

Nanocrystalline Si

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Patterning and tuning of electrical and optical properties of graphene by laser induced two-photon oxidation

Nanoscale ◽

10.1039/c4nr05207b ◽

2015 ◽

Vol 7 (7) ◽

pp. 2851-2855 ◽

Cited By ~ 28

Author(s):

Jukka Aumanen ◽

Andreas Johansson ◽

Juha Koivistoinen ◽

Pasi Myllyperkiö ◽

Mika Pettersson

Keyword(s):

Optical Properties ◽

Monolayer Graphene ◽

Optical Fabrication ◽

Electrical And Optical Properties ◽

Two Photon ◽

Graphene Devices

Laser-induced two-photon oxidation modifies locally the electrical and optical properties of monolayer graphene allowing optical fabrication of all-graphene devices.

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Tuning Graphene Surface Resistance for a 52 GHz Nano-Antenna

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.754-755.1151 ◽

2015 ◽

Vol 754-755 ◽

pp. 1151-1155

Author(s):

A.A.M. Ezanuddin ◽

A.H. Ismail

Keyword(s):

Sheet Resistance ◽

Graphene Sheet ◽

Millimeter Wave ◽

Surface Resistance ◽

Graphene Film ◽

Monolayer Graphene ◽

60 Ghz ◽

Graphene Surface ◽

Commercial Potential ◽

Key Variables

The commercial potential of the 60 GHz band, in combination with the scaling growth of graphene nanotechnology, has resulted in a lot of digital graphene circuits for millimeter-wave application. This work presents a 0.345 nm monolayer graphene film on substrates SiO2/Teflon/Copper as a new nanoantenna. The nanoantenna achieves 2.003 of maximum gain (Abs) with particularly the graphene sheet resistance and reactance as the key variables. The presented nanoantenna targets 52 GHz communication where beamforming is required.

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Imaging Conductivity Changes in Monolayer Graphene Using Electrical Impedance Tomography

Micromachines ◽

10.3390/mi11121074 ◽

2020 ◽

Vol 11 (12) ◽

pp. 1074

Author(s):

Anil Kumar Khambampati ◽

Sheik Abdur Rahman ◽

Sunam Kumar Sharma ◽

Woo Young Kim ◽

Kyung Youn Kim

Keyword(s):

Electrical Impedance Tomography ◽

Electrical Impedance ◽

Monolayer Graphene ◽

Impedance Tomography ◽

Graphene Surface ◽

Conductivity Distribution ◽

Conductivity Change ◽

Modeling Errors ◽

Imaging Approach ◽

Difference Imaging

Recently, graphene has gained a lot of attention in the electronic industry due to its unique properties and has paved the way for realizing novel devices in the field of electronics. For the development of new device applications, it is necessary to grow large wafer-sized monolayer graphene samples. Among the methods to synthesize large graphene films, chemical vapor deposition (CVD) is one of the promising and common techniques. However, during the growth and transfer of the CVD graphene monolayer, defects such as wrinkles, cracks, and holes appear on the graphene surface. These defects can influence the electrical properties and it is of interest to know the quality of graphene samples non-destructively. Electrical impedance tomography (EIT) can be applied as an alternate method to determine conductivity distribution non-destructively. The EIT inverse problem of reconstructing conductivity is highly non-linear and is heavily dependent on measurement accuracy and modeling errors related to an accurate knowledge of electrode location, contact resistances, the exact outer boundary of the graphene wafer, etc. In practical situations, it is difficult to eliminate these modeling errors as complete knowledge of the electrode contact impedance and outer domain boundary is not fully available, and this leads to an undesirable solution. In this paper, a difference imaging approach is proposed to estimate the conductivity change of graphene with respect to the reference distribution from the data sets collected before and after the change. The estimated conductivity change can be used to locate the defects on the graphene surface caused due to the CVD transfer process or environment interaction. Numerical and experimental results with graphene sample of size 2.5 × 2.5 cm are performed to determine the change in conductivity distribution and the results show that the proposed difference imaging approach handles the modeling errors and estimates the conductivity distribution with good accuracy.

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Electrically defined topological interface states of graphene surface plasmons based on a gate-tunable quantum Bragg grating

Nanophotonics ◽

10.1515/nanoph-2019-0108 ◽

2019 ◽

Vol 8 (8) ◽

pp. 1417-1431 ◽

Cited By ~ 3

Author(s):

Zhiyuan Fan ◽

Shourya Dutta-Gupta ◽

Ran Gladstone ◽

Simeon Trendafilov ◽

Melissa Bosch ◽

...

Keyword(s):

Surface Plasmons ◽

Dipole Moments ◽

Edge State ◽

Monolayer Graphene ◽

Graphene Surface ◽

Phase Switching ◽

Metal Gates ◽

Potential Applications ◽

Electrostatic Gating ◽

Plasmon Polaritons

AbstractA periodic metagate is designed on top of a boron nitride-graphene heterostructure to modulate the local carrier density distribution on the monolayer graphene. This causes the bandgaps of graphene surface plasmon polaritons to emerge because of either the interaction between the plasmon modes, which are mediated by the varying local carrier densities, or their interaction with the metal gates. Using the example of a double-gate graphene device, we discuss the tunable band properties of graphene plasmons due to the competition between these two mechanisms. Because of this, a bandgap inversion, which results in a Zak phase switching, can be realized through electrostatic gating. Here we also show that an anisotropic plasmonic topological edge state exists at the interface between two graphene gratings of different Zak phases. While the orientation of the dipole moments can differentiate the band topologies of each graphene grating, the angle of radiation remains a tunable property. This may serve as a stepping stone toward active control of the band structures of surface plasmons for potential applications in optical communication, wave steering, or sensing.

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