It is essential to control the electronic structure of graphene in order to apply graphene films for use in electrodes. We have introduced chemical dopants that modulate the electronic properties of few-layer graphene films synthesized by chemical vapor deposition. The work function, sheet carrier density, mobility, and sheet resistance of these films were systematically modulated by the reduct...

Atmospheric doping of supported graphene was investigated by Raman scattering under different pressures. Various Raman spectra parameters were found to depend on the pressure and the substrate material. The results are interpreted in terms of atmospheric adsorption leading to a change in graphene charge carrier density and the effect of the substrate on the electronic and phonon properties of g...

The current study both synthesizes and uses four compounds of graphene oxide (GO), nitrogen doped graphene oxide (ND-GO), high nitrogen doped graphene oxide (HND-GO), and three dimensional high nitrogen doped graphene oxide (3D-HND-GO) in order to remove a model anionic dye, Congo red (CR) from wastewaters. It also compares their carbon nano-structure, with regard to removal efficiency and find...

Doping of heteroatoms such as nitrogen into the lattice structure of graphene can tune and tailor the overall electronic properties. N-doped graphene, depending on the nitrogen bonding mode and/or bonding configuration, displays subtly altered properties in comparison to pristine graphene. However, there remains a disappointing shortage of reliable methods for introducing dopants in a controlle...

The high ratio of pyridinic and pyridone N-doped graphene sheets have been synthesized by functionalizing graphene oxide (GO) with different oxygen groups on its surface. The typical N-doped graphene was determined to be ~3-5 layers by transmission electron microscopy (TEM) and atomic force microscopy (AFM), and the nitrogen content was measured as 6.8-8 at. % by X-ray photoelectron spectroscop...

Broadband graphene oxide/PVA films were used as saturable absorbers (SAs) for mode locking erbium-doped fiber laser (EDFL) and ytterbium-doped fiber laser (YDFL) at 1.06 μm and 1.55 μm. They provide modulation depths of 3.15% and 6.2% for EDFL and YDFL, respectively. Stable self-starting mode-locked pulses are obtained for both lasers, confirming that the graphene oxide is cost-effective. We ha...

We have determined the electronic bandstructure of clean and potassium-doped single layer graphene, and fitted the graphene π bands to a oneand three-near-neighbor tight binding model. We characterized the quasiparticle dynamics using angle resolved photoemission spectroscopy. The dynamics reflect the interaction between holes and collective excitations, namely plasmons, phonons, and electron-h...

Nitrogen-doped graphene decorated by iron-nickel alloy is introduced as a promising electrode material for supercapacitors. Compared to pristine and Ni-decorated graphene, in acid media, the introduced electrode revealed excellent specific capacitance as the corresponding specific capacitance was multiplied around ten times with capacity retention maintained at 94.9% for 1,000 cycles. Briefly, ...

We demonstrate that 100% light absorption can take place in a single patterned sheet of doped graphene. General analysis shows that a planar array of small particles with losses exhibits full absorption under critical-coupling conditions provided the cross section of each individual particle is comparable to the area of the lattice unit cell. Specifically, arrays of doped graphene nanodisks dis...

A specific structure of doped graphene with substituted silicon impurity is introduced and ab initio density-functional approach is applied for the energy band structure calculation of the proposed structure. Using the band structure calculation for different silicon sites in the host graphene, the effect of silicon concentration and unit cell geometry on the bandgap of the proposed structure i...