Nanoperforated graphene with alternating gap switching for optical applications

Abstract

In this paper, a framework of {w 1 , w 2 , R} classification for constructing the graphene nanomesh (GNM) of zigzag-edged hexagonal nanohole is systematically built. The three integer indexes w 1 , w 2 , and R indicate the distances between two neighboring sides of nanoholes in two directions and the nanohole size respectively, which leading to a straightforward gap opening criteria, i.e., 1 2 3 1, w w R n n + − = + ∈ , steered via DFT band structure calculations. The guiding rule indicates that the semimetallic and semiconducting variation is consistent with a peculiar sequence "010" and "100" ("0"/"1" represent gap closure/opening) with a period of 3 for odd and even w 1 respectively. The periodic nanoperforation induced gap sizes agreewith a linear fitting with a smaller � � ratio, while deviates from that when 1 2 ( ) 1 w w R + < + . Particularly, the {p, 1, p} and {1, q, q} structures demonstrate each unique scaling rule pertaining to the nanohole size only when n is set to zero. Furthermore, the coexistence of Dirac and flat bands is observed for {1, q, q} and {1, 1, m} structures, which is sensitive to the atomic patters.

Recent Advances in 2D Lateral Heterostructures

“…Bai et al [ 51 ] fabricated a novel graphene nanostructure called graphene nanomesh (GNM), which can open up a bandgap in monolayer 2D graphene using block copolymer lithography methods. This work intrigued a set of investigations about GNM, especially on the electronic properties of graphene nanomesh [ 52 , 53 ]. The nanohole on monolayer 2D materials is an effective way to tune the materials’ properties and form heterojunctions.…”

Prediction of two-dimensional nodal-line semimetals in a carbon nitride covalent network

“…39,40 which are all insulating. The nodal-line in C 9 N 4 forms an ideal single loop centered at  point without overlapping with any other bands in the momentum space.…”

Nanolasers Based on 2D Materials

“…[57] Initially, the studies regarding graphene were primarily focused on fundamental physical and electrical properties, while now optical properties for nanophotonics are drawing extensive attention. [58][59][60][61][62] For instance, graphene has been validated to show high optical transparency and strong light-matter interaction. [63][64][65] Also, graphene exhibited a broad optical absorption of 2.3% from the visible to infrared region, which can be effectively tuned by shifting the Fermi level through electrical gating, [46] strain engineering [66,67] and defects engineering.…”