Predicting a graphene-like WB4nanosheet with a double Dirac cone, an ultra-high Fermi velocity and significant gap opening by spin-orbit coupling.
The zero-band gap nature of graphene prevents it from performing as a semi-conductor in modern electronics. Although various graphene modification strategies have been developed to address this limitation, the very small band gap of these materials and the suppressed charge carrier mobility of the devices developed still significantly hinder graphene's applications. In this work, a two dimensional (2D) WB4monolayer, which exhibits a double Dirac cone, was conceived and assessed using density functional theory (DFT) methods, which would provide a sizable band gap while maintaining higher charge mobility with a Fermi velocity of 1.099 × 106m s-1. Strong spin-orbit-coupling can generate an observable band gap of up to 0.27 eV that primarily originates from the d-orbit of the heavy metal atom W; therefore a 2D WB4nanosheet would be operable at room temperature (T = 300 K) and would be a promising candidate to fabricate nanoelectronics in the upcoming post-silicon era. The phonon-spectrum and ab initio molecular dynamics calculations further demonstrate the dynamic and thermal stability of such nanosheets, thus, suggesting a potentially synthesizable Dirac material.
School of Chemistry, Physics and Mechanical Engineering Faculty, Queensland University of Technology, Garden Point Campus, Brisbane, QLD 4001, Australia. aijun.du@qut.edu.au.
Chunmei
C
Zhang
School of Chemistry, Physics and Mechanical Engineering Faculty, Queensland University of Technology, Garden Point Campus, Brisbane, QLD 4001, Australia. aijun.du@qut.edu.au.
Yalong
Y
Jiao
School of Chemistry, Physics and Mechanical Engineering Faculty, Queensland University of Technology, Garden Point Campus, Brisbane, QLD 4001, Australia. aijun.du@qut.edu.au.
Fengxian
F
Ma
School of Chemistry, Physics and Mechanical Engineering Faculty, Queensland University of Technology, Garden Point Campus, Brisbane, QLD 4001, Australia. aijun.du@qut.edu.au.
Steven
S
Bottle
School of Physics and State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China.
Mingwen
M
Zhao
Department of Chemistry, University of Puerto Rico, Rio Piedras Campus, San Juan, Puerto Rico 00931, USA.
Zhongfang
Z
Chen
School of Chemistry, Physics and Mechanical Engineering Faculty, Queensland University of Technology, Garden Point Campus, Brisbane, QLD 4001, Australia. aijun.du@qut.edu.au.
Aijun
http://orcid.org/0000-0002-3369-3283
A
Du