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We report the observation of an intense anomalous peak at 1608 cm$^{-1}$ in the Raman spectrum of graphene associated to the presence of chromium nanoparticles in contact with graphene. Bombardment with an electron beam demonstrates that…

Hexagonal boron nitride (hBN), having an in-plane hexagonal structure in the sp2 arrangement of atoms, proclaims structural similarity with graphene with only a small lattice mismatch. Despite having nearly identical atomic arrangements and…

Materials Science · Physics 2023-06-09 Vidyotma Yadav , Tanuja mohanty

In neutral graphene, two prominent cusps known as Kohn anomalies are found in the phonon dispersion of the highest optical phonon at $q=\Gamma$ (LO branch) and $q=K$ (TO branch), reflecting a significant electron-phonon coupling to undoped…

Mesoscale and Nanoscale Physics · Physics 2015-08-18 Antonio Politano , Fernando de Juan , Gennaro Chiarello , Herbert A. Fertig

Raman spectroscopy plays a key role in studies of graphene and related carbon systems. Graphene is perhaps the most promising material of recent times for many novel applications, including electronics. In this paper, the traditional and…

Materials Science · Physics 2015-12-07 Eric J. Heller , Yuan Yang , Lucas Kocia , Wei Chen , Shiang Fang , Mario Borunda , Efthimios Kaxiras

In this work we report for the first time, to the best of our concern, the tunable electronic properties of Beta-Borophene (BB) on the polar substrate (ZrO_2). We provide an analytical prescription for the calculation of ground state energy…

Mesoscale and Nanoscale Physics · Physics 2022-04-13 Defne Akay , Santanu. K. Maiti

The adsorption of boron and oxygen atoms onto mono- and multi-layer graphene leads to the formation of a buckled graphene layer (BO-graphane) and a 2D diamond-like structure (BO-diamane) sandwiched between boron monoxide layers per DFT…

Materials Science · Physics 2025-06-09 Babu Ram , Rohit Anand , Arun S. Nissimagoudar , Geunsik Lee , Rodney S Ruoff

We study the optical conductivity of a doped graphene when a sublattice symmetry breaking is occurred in the presence of the electron-phonon interaction. Our study is based on the Kubo formula that is established upon the retarded…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Kh. Jahanbani , Reza Asgari

In this work, we study the in-plane optical phonon modes of current-carrying single-layer graphene whose coupling to the $\pi$ electron gas is strong. Such modes are expected to undergo a frequency shift compared to the non-current-carrying…

Mesoscale and Nanoscale Physics · Physics 2022-06-07 Mohsen Sabbaghi , Tobias Stauber , Hyun-Woo Lee , J. Sebastian Gomez-Diaz , George W. Hanson

In this work we study the behavior of the optical phonon modes in bilayer graphene devices by applying top gate voltage, using Raman scattering. We observe the splitting of the Raman G band as we tune the Fermi level of the sample, which is…

Mesoscale and Nanoscale Physics · Physics 2012-06-07 D. L. Mafra , P. Gava , L. M. Malard , R. S. Borges , G. G. Silva , J. A. Leon , F. Plentz , F. Mauri , M. A. Pimenta

A Raman study of a back gated bilayer graphene sample is presented. The changes in the Fermi level induced by charge transfer splits the Raman G-band, hardening its higher component and softening the lower one. These two components are…

Mesoscale and Nanoscale Physics · Physics 2008-12-16 L. M. Malard , D. C. Elias , E. S. Alves , M. A. Pimenta

The Raman peak position and linewidth provide insight into phonon anharmonicity and electron-phonon interactions (EPI) in materials. For monolayer graphene, prior first-principles calculations have yielded decreasing linewidth with…

Materials Science · Physics 2022-01-27 Zherui Han , Xiaolong Yang , Sean E. Sullivan , Tianli Feng , Li Shi , Wu Li , Xiulin Ruan

We compute, from first-principles, the frequency of the E2g, Gamma phonon (Raman G-band) of graphene, as a function of the charge doping. Calculations are done using i) the adiabatic Born-Oppenheimer approximation and ii) time-dependent…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Michele Lazzeri , Francesco Mauri

Effect of doping of graphene either by Boron (B), Nitrogen (N) or co-doped by B and N is studied using density functional theory. Our extensive band structure and density of states calculations indicate that upon doping by N (electron…

Mesoscale and Nanoscale Physics · Physics 2012-07-31 Sugata Mukherjee , T. P. Kaloni

Graphene grown on metal surface, Cu(111), with a boron nitride(BN) buffer layer is studied for the first time. Our first-principles calculations reveal that charge is transferred from the copper substrate to graphene through the BN buffer…

Materials Science · Physics 2007-12-27 Y. H. Lu , P. M. He , Y. P. Feng

We derive the frequency shifts and the broadening of $\Gamma$ point longitudinal optical (LO) and transverse optical (TO) phonon modes, due to electron-phonon interaction, in graphene under uniaxial strain as a function of the electron…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 Mohamed Assili , Sonia Haddad

The 8-Pmmn borophene, a boron analogue of graphene, hosts tilted and anisotropic massless Dirac fermion quasiparticles owing to the presence of the distorted graphene-like sublattice. First-principles calculations show that the stacked…

Most popular atomically thin carbon material, called graphene, has got no band gap and this particular property of graphene makes it less useful from the aspect of nanoscale transistor devices. The band gap can be introduced in the graphene…

Applied Physics · Physics 2019-11-15 Pankaj Kumar

Excitation of electron-hole pairs in the vicinity of the Dirac cone by the Coulomb interaction gives rise to an asymmetric Breit-Wigner-Fano lineshape in the phonon Raman spectra in graphene. This asymmetric lineshape appears due to the…

Mesoscale and Nanoscale Physics · Physics 2015-06-22 Eddwi H. Hasdeo , Ahmad R. T. Nugraha , Mildred S. Dresselhaus , Riichiro Saito

Electron-phonon interaction (EPI) is presumably detrimental for thermoelectric performance in semiconductors because it limits carrier mobility. Here we show that enhanced EPI with strong energy dependence offers an intrinsic pathway to…

Materials Science · Physics 2019-11-06 Yi Xia , Junsoo Park , Vidvuds Ozoliņš , Chris Wolverton

Due to its ultra-thin nature, the study of graphene quantum optoelectronics, like gate-dependent graphene Raman properties, is obscured by interactions with substrates and surroundings. For instance, the use of doped silicon with a capping…

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