Query: Planar metallic carbon allotrope from graphene-like nanoribbons

Candidate papers:

abstract: Abstract The net Y, a novel two dimensional carbon allotrope with four six and eight membered rings, is investigated by performing first principles calculations. The calculations on structural stability unambiguously prove that net Y is an energetically metastable, dynamically and thermally stable phase, and it can also be buckled about 0.4 A. We find that the net Y exhibits strong mechanical anisotropy, and the in plane Young's modulus of net Y along a and b directions is found smaller than graphene but comparable with that of ps graphene and penta graphene. Meanwhile, the net Y possesses intrinsic metallicity with high carrier velocities comparable to that of graphene ~106 m/s) Excitedly, a possible synthetic route towards net Y from graphene like nanoribbons embedded four and eight membered rings is achieved by first principles molecular dynamics simulations, indicating that the realization of net Y is not impossible. Moreover, two three dimensional (3D) stable close packed net Y carbon allotropes are also proposed. Unlike the metallic 3D planar net Y, the 3D buckled net Y is a superhard indirect bandgap semiconductor, which further broadens the application potential of net Y.
author_names: Ju Rong

Huicong Dong

Jing Feng

Xiao Fei Wang

Yannan Zhang

Xiaohua Yu

Zhao-lin Zhan
title: Planar metallic carbon allotrope from graphene like nanoribbons
year: 2018

abstract: Recently, a new type of quasi 1D graphene like nanoribbons periodically embedded four and eight membered rings have been successfully fabricated, and based on this structure, a novel planar 2D carbon allotrope, so called the net Y, has been proposed. Here, we study various nanoribbons derived from such a 2D monolayer focusing on the structure stability, electronic and transport properties, especially on the physical field coupling effects of electronic behaviors. The very high stability is predicted for various types of nanoribbons by the calculated binding energy and molecular dynamics simulation. Different edge shape and widths have a significant influence on their electronic properties. Armchair nanoribbons are always semiconductors, and possess a high carrier mobility. After hydrogen termination, some metallic nanoribbons can become semiconductors or quasi metals with massless Dirac fermion behavior. In particular, the electronic properties of ribbons can be effectively modulated by applying strain and electric field. The band gap size and the transition from indirect to direct band gap can be realized upon strain or electric field. These flexibly tunable electronic properties for nanoribbons expand their applications in nanoelectronics and optoelectronics.
author_names: Jing Min Hu

Zhenhua Zhang

Z Q Fan

R L Zhou
title: Electronic and transport properties and physical field coupling effects for net Y nanoribbons.
venue: Nanotechnology
year: 2019

abstract: A two dimensional carbon allotrope, H net, is proposed using first principle calculations. H net incorporates C4 distorted squares, C6 hexagons, and C8 octagons. Unlike previously reported planar graphene and other theoretical carbon sheets, H net is a two atom thick polymorph with identical C6 C4 C6 components cross facing and covalently buckled to feature a handshake like model. The feasibility of H net is evident from its dynamic stability as confirmed by phonon mode analysis and its lower total energy. H net is energetically more favorable than synthesized graphdiyne and theoretical graphyne, BPC, S graphene, polycyclic net, a squarographite, and lithographite. We explored a possible route for the synthesis of H net from graphene nanoribbons. Electronic band structure calculations indicated that H net is a semiconductor with an indirect band gap of 2.11 eV, whereas graphene and many other two dimensional carbon sheets are metallic. We also explored the electronic structure of one dimensional nanoribbons derived from H net. The narrowest H net nanoribbon showed metallic behavior, whereas the other nanoribbons are semiconductors with band gaps that increase as the nanoribbons widen. H net and its tailored nanoribbons are expected to possess more electronic properties than graphene because of their exceptional crystal structure and different energy band gaps.
author_names: Meng Hu

Yu Shu

Lin Cui

Bo Xu

Dongli Yu

Julong He
title: Theoretical two atom thick semiconducting carbon sheet.
venue: Physical chemistry chemical physics PCCP
year: 2014

abstract: Abstract A new two dimensional carbon allotrope TPDH graphene (Tetra Penta Deca Hexagonal graphene) belonging to the tetragonal pentagonal carbon ring family is proposed in this work using density functional method. The allotrope satisfies all the conditions of structural stability. This allotrope has lower cohesive energy than many existing planar carbon allotropes. It can withstand temperature as high as 1000 K without loosing its structural integrity. However, its electronic structure reflects metallic character due to delocalised pz orbital near the Fermi level. Further, this mechanically stable elastically anisotropic structure shows directional variation of In plane Young's modulus and Poisson's ratio. It is stronger than graphene in a particular direction. Moreover, The material can be identified by four characteristic peaks in the electron energy loss spectra within 10 eV energy. It has optical reflectance peaks in the visible range at ~600 nm yellow colour. Interestingly, some nanoribbons of this material show semimetallic, semiconducting and metallic behaviour. Non equilibrium Green's function method along with density functional theory is employed to study the nanodevices made of these nanoribbons. Strong current regulation property and robust negative differential resistance effect with a peak to valley ratio 3.3 are observed in two nanodevices making TPDH graphene an attractive material for use in nanoelectronics.
author_names: Debaprem Bhattacharya

Debnarayan Jana
title: TPDH graphene: A new two dimensional metallic carbon with NDR behaviour of its one dimensional derivatives
year: 2021

abstract: Elemental phosphorus nanostructures are notorious for a large number of allotropes, which limits their usefulness as semiconductors. To limit this structural diversity, we synthesize selectively quasi 1D phosphorus nanostructures inside carbon nanotubes (CNTs) that act both as stable templates and nanoreactors. Whereas zigzag phosphorus nanoribbons form preferably in CNTs with an inner diameter exceeding 1.4 nm, a previously unknown square columnar structure of phosphorus is observed to form inside narrower nanotubes. Our findings are supported by electron microscopy and Raman spectroscopy observations as well as ab initio density functional theory calculations. Our computational results suggest that square columnar structures form preferably in CNTs with inner diameter around 1.0 nm, whereas black phosphorus nanoribbons form preferably inside CNTs with 4.1 nm inner diameter, with zigzag nanoribbons energetically favored over armchair nanoribbons. Our theoretical predictions agree with the experimental findings.
author_names: Jinying Zhang

Chengcheng Fu

Shixin Song

Hongchu Du

Dan Zhao

Hongyang Huang

Lihui Zhang

Jie Guan

Yifan Zhang

Xinluo Zhao

Chuansheng Ma

Chun-Lin Jia

David Tomanek
title: Changing the Phosphorus Allotrope from a Square Columnar Structure to a Planar Zigzag Nanoribbon by Increasing the Diameter of Carbon Nanotube Nanoreactors.
venue: Nano letters
year: 2020

abstract: A novel two dimensional carbon allotrope, rectangular graphyne (R graphyne) with tetra rings and acetylenic linkages, is proposed by first principles calculations. Although the bulk R graphyne exhibits metallic property, the nanoribbons of R graphyne show distinct electronic structures from the bulk. The most intriguing feature is that band gaps of R graphene nanoribbons oscillate between semiconductor and metal as a function of width. Particularly, the zigzag edge nanoribbons with half integer repeating unit cell exhibits unexpected Dirac like fermions in the band structures. The Dirac like fermions of the R graphyne nanoribbons originate from the central symmetry and two sub lattices. The extraordinary properties of R graphene nanoribbons greatly expand our understanding on the origin of Dirac like point. Such findings uncover a novel fascinating property of nanoribbons, which may have broad potential applications for carbon based nano size electronic devices.
author_names: Wen-Jin Yin

Yuee Xie

Li-Min Liu

Ruzhi Wang

Leo W M Lau

Jianxin Zhong

Yuan-Ping Chen
title: R graphyne: a new two dimension carbon allotrope with versatile Dirac like point in nanoribbons
year: 2013

abstract: Abstract By means of the first principles calculations, we have theoretically investigated the structural stability and electronic properties of a two dimensional planar metallic carbon allotrope named C 57 carbon which possesses the P 6 2 m D 3 h 3 symmetry. This carbon allotrope is an all sp 2 hybridized bonding network consisting of 5 7 rings of carbon atoms. The stability of C 57 carbon is confirmed through phonon mode analysis, total energy and elastic constants calculations, as well as first principles molecular dynamics simulations. We conceived that the metallicity of C 57 carbon is attributed to the large states across Fermi level contributed by p y orbital due to the bond distortion, which is much different from that of graphite. This new carbon sheet can also serve as a precursor for stable one dimensional nanotubes with metallic character. These results broaden our understanding of two dimensional carbon allotropes and will attract more researchers to focus the research on the field of two dimensional carbon materials. Besides, the C 57 carbon may be useful for designing of nano electronic devices.
author_names: Chunxiang Zhao

Yi-Qi Yang

Chunyao Niu

Jia-Qi Wang

Yu Jia
title: C 57 carbon: A two dimensional metallic carbon allotrope with pentagonal and heptagonal rings
venue: Computational Materials Science
year: 2019

abstract: Two dimensional (2D) carbon allotropes have attracted great attention in both science and engineering fields. Their extraordinary and/or unique properties make them promising for engineering applications, ranging from metal ion batteries to biosensors. Herein, by employing first principles calculations, we propose a new 2D planar carbon allotrope, popgraphene, which is composed of 5 8 5 carbon rings. Using a bottom up approach, popgraphene could be constructed via the formation of atomically precise 5 8 5 line defects in graphene by simultaneous electron irradiation. Popgraphene is intrinsically metallic. It has low energy and possesses great dynamic, thermal and mechanical stability. Our calculations also show that it has a high theoretical capacity for Li atoms (Li4C6: 1487 mA h g 1) a low Li diffusion barrier <0.55 eV) and a low average open circuit voltage (0.45 V) Such excellent characteristics suggest that programmable metallic popgraphene is a promising anode material for use in Li ion batteries (LIBs) with fast charge/discharge rates. Our simulation results also indicate that van der Waals corrections play little role in the structural parameters of popgraphene, whereas they play a central role in the adsorption and diffusion abilities as well as the electrochemical performance of popgraphene. This study provides fundamental insight into the design of new materials with extraordinary properties for their excellent applications, including for the next generation of LIBs, and may open up a cutting edge field in programming experimentally realized low dimensional materials.
author_names: Shuaiwei Wang

Bao-cheng Yang

Houyang Chen

Eli Ruckenstein
title: Popgraphene: a new 2D planar carbon allotrope composed of 5 8 5 carbon rings for high performance lithium ion battery anodes from bottom up programming
year: 2018

abstract: Carbon materials based on different hybridization of carbon atoms have drawn great attention because of their unique configurations and physical and chemical properties. Here, a previously unknown 2D carbon allotrope named L 2Gy, graphene like carbon matryoshka graphynes (Gy) with two alkynyls (C[triple bond, length as m dash]C) inserted into the three fold carbon atoms of graphene, has been constructed with considerable thermal, dynamical, and mechanical stability by using ab initio density functional theory. With the increasing number of alkynyls between the three fold carbon atoms of graphene, the stability of Gy will seriously decrease. L 2Gy has a fascinating chemical bond environment consisting of sp and sp2 hybridized carbon atoms, and delocalized p electrons derived from the 27 three center two electron p bonds. This particular electronic structure plays a vital role in chemically stabilizing L 2Gy. The electronic band structure reveals the semi metallic features of L 2Gy mainly contributed by the px/z orbitals of carbon atoms. Furthermore, compared with the acknowledged catalysts for the hydrogen evolution reaction (HER) L 2Gy, as a 2D carbon allotrope, shows excellent catalytic activity for the HER.
author_names: Yaoxiao Zhao

Zhibin Gao

Kun Yuan

Xiang Zhao
title: Theoretically modelling graphene like carbon matryoshka with strong stability and particular three center two electron p bonds.
venue: Physical chemistry chemical physics PCCP
year: 2021

abstract: Abstract A two dimensional (2D) metallic carbon allotrope is proposed, which consists of linearly aligned bipentagon octagon and hexagon rings in a planar sheet. The relatively high percentage of hexagon and the regular arrangement of the polygons make it energetically more favorable than most of other predicted 2D carbon allotropes. Phonon dispersions without negative frequencies also indicate its stability. Electronic structure calculations show that its metallic nature is mainly due to the atoms shared by the pentagon, hexagon and octagon. Its lattice thermal conductivity is only about one fifth of that of graphene. Armchair and zigzag edged nanoribbons of this structure are also studied. The former is metallic while the latter has a small band gap due to the spin polarized edge states. The appropriate band gap and the significantly reduced thermal conductivity suggest potential applications in thermoelectricity.
author_names: Guo-hui Zheng

Yalei Jia

Song Gao

San-huang Ke
title: A planar carbon allotrope with linear bipentagon octagon and hexagon arrangement
year: 2017