Aspects of the theory of graphene

Abstract

Following a brief review of the device-friendly features of graphene, recent work on its Green's functions with and without a normal magnetic field are discussed, for an infinite graphene sheet and also for a quantum dot, with analyses of the Landau-quantized energy spectra of the sheet and dot. The random phase approximation dielectric response of graphene is reviewed and discussed in connection with the van der Waals interactions of a graphene sheet with atoms/molecules and with a second graphene sheet in a double layer. Energy-loss spectroscopy for a graphene sheet subject to both parallel and perpendicular particle probes of its dynamic, non-local response properties are also treated. Furthermore, we discuss recent work on the coupling of a graphene plasmon and a surface plasmon, yielding a collective plasma mode that is linear in wavenumber. Finally, we discuss the unusual aspects of graphene conduction and recent work on diffusive charge transport in graphene, in both the DC and AC regimes.

Optimization of the Synthesis Procedures of Graphene and Graphite Oxide

“…Graphite oxide synthesized from graphite flakes can be easily soaked and dispersed in water and could be used as the precursor for different applications due to its hydrophilic character. They detected that an improved graphite oxide with fewer defect in the basal plane can be prepared using KMnO 4 as oxidation agent and a 9:1 mixture of concentrated H 2 SO 4 and H 3 PO 4. They also reported that graphite oxide synthesized with this Improved Hummers method provided a greater amount of hydrophilic-oxidized graphite, likewise having a more regular structure with a greater amount of basal plane framework retained.…”

“…No graphene nucleation was observed below this value, whereas higher hydrogen concentrations caused degradation in graphene quality [44]. Finally, several groups have shown that the growth of bilayer and few-layer graphene depends on the concentration of active carbon species [55], which was in turn related with the CH 4 /H 2 flow ratio and the total flow rate of CH 4 and H 2 used during the reaction step.…”

“…Recent studies have showed that the concentration of hydrogen, which is obviously related with the CH 4 /H 2 flow rate ratio and the total flow rate of CH 4 and H 2 during the reaction step, also plays an important role in providing quality to CVD graphene. Gao et al found for an atmospheric pressure CVD system that high hydrogen concentrations contributes to the degradation of the graphene quality as a result of the occurrence of defects and wrinkles [54].…”

“…Each atom is bonded by a covalent bond to other three carbon atoms. These carbon atoms are densely packaged in a honeycombshape crystal lattice [3] comprising, in turn, of two superimposed triangular subnets [4]. Although graphene has been known since 1960, it was not until 2004 when Andre Geim and Konstantin Novoselov achieved to obtain an isolated graphene sheet using the Scotch ® tape method [5].…”

Plasmas meet plasmonics

“…Moreover, they state that using graphene, may pave the way towards 'quantum plasmonics' [152]. The study of collective quantum effects in plasmas [153][154][155][156][157][158][159][160][161][162][163] and particularly in graphene [164][165][166] is a significant challenge that is likely to be the subject of intense research efforts in the future. Plasmas have been shown to be a very promising way to make graphenebased structures, the particular benefit is that they may be grown without the presence of a metal catalyst [148,167].…”