The effect of different hydrogen terminations on the structural and electronic properties in the triangular array graphene nanomeshes

Tang, Guangze; Zhang, Z. H.; Deng, X.Q.; Fan, Zhi‐Qiang; Zhang, H. L.; Sun, Lina

doi:10.1039/c6ra27465j

Cited by 4 publications

(3 citation statements)

References 40 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…So far, the simple tight-binding model has been employed in our analysis. In order to confirm its validity, we also perform DFT calculations, where the perimeters of holes are terminated by hydrogen atoms [46], and band structures are evaluated after structural optimization. For a direct comparison, the band structures obtained by the tight-binding model and DFT calculations are displayed on the left and right column of Fig.…”

Section: Characterization Of the Bulk Bandsmentioning

confidence: 99%

Counterpropagating topological interface states in graphene patchwork structures with regular arrays of nanoholes

et al. 2018

View full text Add to dashboard Cite

Triangular and honeycomb lattices are dual to each other -if we puncture holes into a featureless plane in a regular triangular alignment, the remaining body looks like a honeycomb lattice, and vice versa, if the holes are in a regular honeycomb alignment, the remaining body has a feature of triangular lattice. In this work, we reveal that the electronic states in graphene sheets with nanosized holes in triangular and honeycomb alignments are also dual to each other in a topological sense. Namely, a regular hole array perforated in graphene can open a band gap in the energymomentum dispersion of relativistic electrons in the pristine graphene, and the insulating states induced by triangular and honeycomb hole arrays are distinct in topology. In a graphene patchwork with regions of these two hole arrays put side by side counterpropagating topological currents emerge at the domain wall. This observation indicates that the cerebrated atomically thin sheet is where topological physics and nanotechnology meet.Electrons behave as waves in microscopic world, and a regular array of scattering centers causes quantum interference, i.e., Bragg reflection, which governs the electron propagation in terms of energy and momentum. This explains band gaps and band insulators in crystals where ions are regularly aligned. The same principle is effective even if we zoom out a little bit: starting from Bloch waves, with which angstrom-scale structures of the underlying crystal are already taken into account, superstructures in micro-or meso-scopic scales can induce new band gaps and modify the electron propagation. The first example is the superlattice invented by Leo Esaki in order to control properties of semiconductors [1].In this regard, graphene -mono atomic sheet of carbon atoms in honeycomb structure [2] -is a promising playground. First, the honeycomb array of scattering centers is responsible for the most striking feature of graphene, emergent relativistic fermion [3,4] appearing as an isolated gap closing point associated with linear dispersion (Dirac cone) in the band structure. Secondly, graphene is amiable to nano structuring [5][6][7]. One idea is to introduce a regular array of holes, also known as antidot lattice, into graphene, with the remaining body dubbed as graphene nanomesh [8][9][10][11][12][13][14][15][16]. Depending on the hole alignment, the band structure of superstructured graphene can be either gapless or gapped, and in gapped cases the gap size is tunable [8,9,[17][18][19][20][21][22][23][24][25].Historically, gap introduction in a honeycomb lattice model, or mass attachment to emergent relativistic electrons, has been cornerstones in discovering new topological phases of matter. For instance, with an appropriate time reversal symmetry (TRS) breaking term, the honeycomb lattice model can derive the quantum anomalous Hall state [26], which is a typical topological state characterized by the Chern number [27]. When the spinorbit coupling (SOC) is considered in a honeycomb lattice model, one obtains the qua...

show abstract

Section: Characterization Of the Bulk Bandsmentioning

confidence: 99%

Counterpropagating topological interface states in graphene patchwork structures with regular arrays of nanoholes

et al. 2018

View full text Add to dashboard Cite

show abstract

“…A few techniques have been used to fabricate GNMs, including nanosphere lithography [35], nanoimprint lithography [36], block copolymer lithography [13,37], irradiation etching [38,39], atomic force microscopy etching [40], and oxygen reactive ion etching [41,42]. GNMs fabricated with these methods will most likely have structural defects, such as variations in the size and shape of the pores, as well as the pore lattice structure and symmetry.…”

Section: Introductionmentioning

confidence: 99%

Effect of pore-size disorder on the electronic properties of semiconducting graphene nanomeshes

Gamal¹,

Fadlallah²,

Salah³

et al. 2020

Preprint

View full text Add to dashboard Cite

Graphene nanomeshes (GNMs) are novel materials that recently raised a lot of interest. They are fabricated by forming a lattice of pores in graphene. Depending on the pore size and pore lattice constant, GNMs can be either semimetallic or semiconducting with a gap large enough (∼ 0.5 eV) to be considered for transistor applications. The fabrication process is bound to produce some structural disorder due to variations in pore sizes. Recent electronic transport measurements in GNM devices (ACS Appl. Mater. Interfaces 10, 10362, 2018) show a degradation of their bandgap in devices having pore-size disorder. It is therefore important to understand the effect of such variability on the electronic properties of semiconducting GNMs. In this work we use the density functional-based tight binding formalism to calculate the electronic properties of GNM structures with different pore sizes, pore densities, and with hydrogen and oxygen pore edge passivations. We find that structural disorder reduces the electronic gap and the carrier group velocity, which may interpret recent transport measurements in GNM devices. Furthermore the trend of the bandgap with structural disorder is not significantly affected by the change in pore edge passivation. Our results show that even with structural disorder, GNMs are still attractive from a transistor device perspective.

show abstract

“…A few techniques have been used to fabricate GNMs, including nanosphere lithography [34], nanoimprint lithography [35], block copolymer lithography [13,36], irradiation etching [37,38], atomic force microscopy etching [39], and oxygen reactive ion etching [40,41]. GNMs fabricated with these methods will most likely have structural defects, such as variations in the size and shape of the pores, as well as the pore lattice structure and symmetry.…”

Section: Introductionmentioning

confidence: 99%

Effect of pore-size disorder on the electronic properties of semiconducting graphene nanomeshes

Gamal¹,

Fadlallah²,

Salah³

et al. 2020

Nanotechnology

View full text Add to dashboard Cite

Graphene nanomeshes (GNMs) are novel materials that recently raised a lot of interest. They are fabricated by forming a lattice of pores in graphene. Depending on the pore size and pore lattice constant, GNMs can be either semimetallic or semiconducting with a gap large enough (0 .5 eV) to be considered for transistor applications. The fabrication process is bound to produce some structural disorder due to variations in pore size. Recent electronic transport measurements in GNM devices (ACS Appl. Mater. Interfaces 10, 10 362, 2018) show a degradation of their bandgap in devices having pore-size disorder. It is therefore important to understand the effect of such variability on the electronic properties of semiconducting GNMs.In this work we use the density functional-based tight binding formalism to calculate the electronic properties of GNM structures with different pore sizes, pore densities, and with hydrogen and oxygen pore edge passivations. We find that structural disorder reduces the electronic gap and the carrier group velocity, which may interpret recent transport measurements in GNM devices. Furthermore, the trend of the bandgap with structural disorder is not significantly affected by the change in pore edge passivation. Our results show that even with structural disorder, GNMs are still attractive from a transistor device perspective.

show abstract

The effect of different hydrogen terminations on the structural and electronic properties in the triangular array graphene nanomeshes

Abstract: Constructing periodic nanoscale holes on graphene to form graphene nanomeshes (GNMs) is an effective way for opening band gaps. The GNMs terminated by di-hydrogenation could open a sizable band gap due to the stronger on-site potential between holes.

Cited by 4 publications

References 40 publications

Counterpropagating topological interface states in graphene patchwork structures with regular arrays of nanoholes

Counterpropagating topological interface states in graphene patchwork structures with regular arrays of nanoholes

Effect of pore-size disorder on the electronic properties of semiconducting graphene nanomeshes

Effect of pore-size disorder on the electronic properties of semiconducting graphene nanomeshes

Contact Info

Product

Resources

About