Absorption in Finite-Length Chevron-Type Graphene Nanoribbons

Development of on-chip integrated carbon-based optoelectronic nanocircuits requires fast and non-invasive structural characterization of their building blocks. Recent advances in synthesis of single wall carbon nanotubes and graphene nanoribbons allow for their use as atomically precise building blocks. However, while cataloged experimental data are available for the structural characterization of carbon nanotubes, such an atlas is absent for graphene nanoribbons. Here we theoretically investigate the optical absorption resonances of armchair carbon nanotubes and zigzag graphene nanoribbons continuously spanning the tube (ribbon) transverse sizes from 0.5(0.4) nm to 8.1(12.8) nm. We show that the linear mapping is guaranteed between the tube and ribbon bulk resonance when the number of atoms in the tube unit cell is , where is the number of atoms in the ribbon unit cell. Thus, an atlas of carbon nanotubes optical transitions can be mapped to an atlas of zigzag graphene nanoribbons.

show abstract

“…4a, b that similar to ref. 62 the DFT and fitted TBM absorption spectra are in full agreement. It is also seen in Fig.…”

Section: Resultssupporting

confidence: 57%

2N+4-rule and an atlas of bulk optical resonances of zigzag graphene nanoribbons

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Therefore, revealing the effect of length is of great importance. Lately, we investigated the optical absorption [21] in finite-length self-assembled graphene nanoribbon superlattices produced in [19]. We found that in the 25…”

Section: Introductionmentioning

confidence: 99%

Edge functionalization of finite graphene nanoribbon superlattices

Abdelsalam

Saroka

Younis

2019

Superlattices and Microstructures

View full text Add to dashboard Cite

The effect of chemical functionalization on the electronic properties of graphene nanoribbon superlattices with zigzag and armchair terminations is investigated using the density functional theory. The calculated positive binding energies imply that all the considered structures are stable before and after chemical modifications. The superlattices with armchair edges are characterized by a wide energy gap while those with zigzag edges have a narrow energy gap. The energy gap in superlattices with armchair edges nearly independent of their length while it strongly decreases and almost closes in superlattices with zigzag edges. The energy gap is comparably sensitive to the width variations in both types of the superlattices. It was found that the electric dipole moment increases with increasing the width in the case of armchair while it oscillates in zigzag superlattices. The electric dipole moment can be enhanced by chemical functionalization with COOH and NH2 groups. The effect of this functionalization is moderate for the energy gap, but the adsorption of tetracyanoquinodimethane transforms the system from insulator (E g =2.66 eV) to a narrow band gap semiconductor (E g =0.25 eV). The adsorption energy of tetracyanoquinodimethane and tetrathiafulvalene molecules can be enhanced by chemical functionalization which makes graphene superlattices useful for sensor applications and wastewater treatment.

show abstract

“…Such nanoribbons are synthesized by the self-assembly of molecules on a substrate [18]. At a width of 7.5 Å, they are semiconductors with the band gap E g = 0.3 eV [19]. In the nanoribbons studied in our work, the number of carbon atoms in the supercell is less by two.…”

Section: Resultsmentioning

confidence: 96%

Study of a New Type of Crimped-Shape Nanotubes Cut from Bilayer Graphene with the Moiré Angle Θ = 27.8°

et al. 2020

Self Cite

View full text Add to dashboard Cite

New quasi-one-dimensional hollow nanostructures similar to flattened nanotubes are numerically simulated. These nanostructures can be obtained by connecting the edges of nanoribbons cut out of twisted bilayer graphene with the Moiré angle Θ = 27.8°. The resulting nanotubes are non-chiral and contain chains of topological defects at the connected edges. A detailed description of their structure is given, and their energy stability is also demonstrated. The electronic characteristics of such structures and their evolution in the course of deformation are determined using ab initio methods. All nanotubes under study are metallic, except the structure with a width of 14 Å, characterized by the band gap E g = 0.2 eV. It is shown that the electronic and elastic characteristics of such nanotubes differ significantly from those of nanoribbons forming them and of single-walled carbon nanotubes.

show abstract

Absorption in Finite-Length Chevron-Type Graphene Nanoribbons

Cited by 15 publications

References 23 publications

2N+4-rule and an atlas of bulk optical resonances of zigzag graphene nanoribbons

2N+4-rule and an atlas of bulk optical resonances of zigzag graphene nanoribbons

Edge functionalization of finite graphene nanoribbon superlattices

Study of a New Type of Crimped-Shape Nanotubes Cut from Bilayer Graphene with the Moiré Angle Θ = 27.8°

Contact Info

Product

Resources

About