Site-dependent doping effects on quantum transport in zigzag graphene nanoribbons

Pi, Shu-Ting; Dou, Kunpeng; Tang, Chi-Shung; Kaun, Chao-Cheng

doi:10.1016/j.carbon.2015.06.069

Cited by 15 publications

(6 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Additionally, it has been shown that the N atoms at the edge of a triangle doping defect can increase the thermal conductivity of graphene nanoribbons, but with increasing N-doping concentrations the thermal conductivity decreases sharply [32]. The site-dependent effects of a substitutional N or B atom on quantum transport have been investigated and shown that Coulomb interaction drops the transmission features [33]. Furthermore, the power factor has been found to be high in various B and N codoped graphene nanostructures which makes them appropriate for energy conversion [34].…”

Section: Introductionmentioning

confidence: 99%

Effects of bonded and non-bonded B/N codoping of graphene on its stability, interaction energy, electronic structure, and power factor

et al. 2020

Self Cite

View full text Add to dashboard Cite

We model boron and nitrogen doped/codoped monolayer graphene to study its stability, interaction energy, electronic and thermal properties using density functional theory. It is found that a doped graphene sheet with non-bonded B or N atoms induces an attractive interaction and thus opens up the bandgap. Consequently, the power factor is enhanced. Additionally, bonded B or N atoms in doped graphene generate a repulsive interaction leading to a diminished bandgap, and thus a decreased power factor. We emphasis that enhancement of the power factor is not very sensitive to the concentration of the boron and nitrogen atoms, but it is more sensitive to the positions of the B or N atoms in ortho, meta, and para positions of the hexagonal structure of graphene. In the B and N codoped graphene, the non-bonded dopant atoms have a weak attractive interaction and interaction leading to a small bandgap, while bonded doping atoms cause a strong attractive interaction and a large bandgap. As a result, the power factor of the graphene with non-bonded doping atoms is reduced while it is enhanced for graphene with bonded doping atoms.

show abstract

Section: Introductionmentioning

confidence: 99%

Effects of bonded and non-bonded B/N codoping of graphene on its stability, interaction energy, electronic structure, and power factor

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…As a result of the interaction, a gap opens in zigzag ribbons, which implies magnetically ordered edge states as it has been demonstrated in an indirect way recently with the contribution of one of us. 3 The above facts motivated the exploration of the interaction effects with the use of several methods, like density-functional theory (DFT), 7,[9][10][11][12] mean-field approximation, [13][14][15][16][17][18][19][20] quantum Monte Carlo (QMC) [21][22][23] and density-matrix renormalization group algorithm (DMRG). [24][25][26] The DFT and DMRG in Ref.…”

Section: Introductionmentioning

confidence: 99%

Entanglement, excitations, and correlation effects in narrow zigzag graphene nanoribbons

Hagymási

Legeza

2016

Phys. Rev. B

View full text Add to dashboard Cite

We investigate the low-lying excitation spectrum and ground-state properties of narrow graphene nanoribbons with zigzag edge configurations. Nanoribbons of comparable widths have been synthesized very recently [P. Ruffieux, et al. Nature 531, 489 (2016)], and their descriptions require more sophisticated methods since in this regime conventional methods, like mean-field or densityfunctional theory with local density approximation, fail to capture the enhanced quantum fluctuations. Using the unbiased density-matrix renormalization group algorithm we calculate the charge gaps with high accuracy for different widths and interaction strengths and compare them with mean-field results. It turns out that the gaps are much smaller in the former case due to the proper treatment of quantum fluctuations. Applying the elements of quantum information theory we also reveal the entanglement structure inside a ribbon and examine the spectrum of subsystem density matrices to understand the origin of entanglement. We examine the possibility of magnetic ordering and the effect of magnetic field. Our findings are relevant for understanding the gap values in different recent experiments and the deviations between them.

show abstract

“…LDOS at E f , shown in the insets, possess significant weight only on the outmost edges of the molecule and the edges of the ZGNR electrodes across the whole junction, indicating that the transmission peak at E f originates from the electrode edge states rather than the molecular one. In first-principles studies , and tight-binding approach including second-nearest-neighbor interaction, transmission peaks are observed at E f , where the flat bands at E f are slightly bent and more than one band across E f contribute to different conducting channels. Here, the scaling rule of G 2 ≈ 2 G 1 is the evaluation of decaying behavior of the electrode edge states across the junction rather than the intrinsic conduction nature of PA molecules.…”

Section: Resultsmentioning

confidence: 99%

Conductance Superposition Rule in Carbon Nanowire Junctions with Parallel Paths

Dou

Kaun

2016

J. Phys. Chem. C

Self Cite

View full text Add to dashboard Cite

Using first-principles calculations, we investigate conductance of molecular junctions consisted of single and double polyacene (PA) molecules bridging different carbon nanowire electrodes, including armchair carbon nanotubes (CNT) and zigzag graphene nanoribbons (GNR). Doubling the PA molecule enhances the junction conductance, except in the junction where a molecule contacts armchair CNT with nonvertical edges. Elongating the PA molecules change junction conductance. The different conductance scaling behaviors among various junctions are governed by the interface between the molecule and the electrode, the molecular length, and the edge states of zigzag GNR.

show abstract

Site-dependent doping effects on quantum transport in zigzag graphene nanoribbons

Cited by 15 publications

References 30 publications

Effects of bonded and non-bonded B/N codoping of graphene on its stability, interaction energy, electronic structure, and power factor

Effects of bonded and non-bonded B/N codoping of graphene on its stability, interaction energy, electronic structure, and power factor

Entanglement, excitations, and correlation effects in narrow zigzag graphene nanoribbons

Conductance Superposition Rule in Carbon Nanowire Junctions with Parallel Paths

Contact Info

Product

Resources

About