Bandgap Opening by Patterning Graphene

Abstract

Owing to its remarkable electronic and transport properties, graphene has great potential of replacing silicon for next-generation electronics and optoelectronics; but its zero bandgap associated with Dirac fermions prevents such applications. Among numerous attempts to create semiconducting graphene, periodic patterning using defects, passivation, doping, nanoscale perforation, etc., is particularly promising and has been realized experimentally. However, despite extensive theoretical investigations, the precise role of periodic modulations on electronic structures of graphene remains elusive. Here we employ both the tight-binding modeling and first-principles electronic structure calculations to show that the appearance of bandgap in patterned graphene has a geometric symmetry origin. Thus the analytic rule of gap-opening by patterning graphene is derived, which indicates that if a modified graphene is a semiconductor, its two corresponding carbon nanotubes, whose chiral vectors equal graphene's supercell lattice vectors, are both semimetals.

Boron and nitrogen doping in graphene antidot lattices

“…The properties of GALs have been studied theoretically by several groups. 12,23,[45][46][47][48][49][50][51][52] In the notation in Ref. 48, the one synthesized by Bieri et al is a rotated GAL (RGAL).…”

Tunable many-body interactions in semiconducting graphene: Giant excitonic effect and strong optical absorption

“…Other similar scaling rules for structurally modified graphene based on tight-binding or DFT have also been proposed [17][18][19]37 . We expect E g obtained from our GW calculations to also obey the same scaling law (with quantitatively more accurate parameters).…”

“…Certain patterns of defects on graphene induce long-range order that causes a nonzero scattering matrix element between Dirac points and opens a sizable band gap (E g ). The magnitude of E g in these semiconducting materials depends on defect size, type, and distribution [17][18][19][20][21][22][23] .…”

Nanoperforated graphene with alternating gap switching for optical applications

“…Extensive approaches have been used to tackle with this problem including dimensionality reduction tailoring, [6][7] surface modification, 8 heteroatom doping, 9 layered stacking, 10 and exerted to external potential. 11 In addition to those schemes, however recently, the topic about graphene superlattice with nanoholes, [12][13][14] also dubbed graphene nanomesh (GNM), [15][16][17][18][19][20][21][22][23] or graphene antidote lattice (GAL), [24][25][26][27][28][29][30][31] attracts substantial research interest since a non-vanishing gap is introduced in certain unique structures. Due to the effective tunability of intrinsic graphene bang gap, these porous graphene structures possess potential applications in spintronics, 12,14 thermoelectronics, 23,27 waveguiding devices, 29,31 and transistors.…”