Strain-induced Dirac cone-like electronic structures and semiconductor-semimetal transition in graphdiyne

TL;DR

This study uses first-principles calculations to reveal how strain can induce a semiconductor to semimetal transition in graphdiyne, creating Dirac cone-like structures and significantly altering its electronic properties.

Contribution

It demonstrates strain-induced electronic structure changes in graphdiyne, including a transition to a semimetal and the formation of Dirac cones, which differ from graphene's behavior.

Findings

Biaxial strain increases the band gap from 0.47 eV to 1.39 eV.

Uniaxial strain reduces the band gap to nearly zero.

Dirac cone-like electronic structures are observed under strain.

Abstract

By means of the first-principles calculations combined with the tight-binding approximation, the strain-induced semiconductor-semimetal transition in graphdiyne is discovered. It is shown that the band gap of graphdiyne increases from 0.47 eV to 1.39 eV with increasing the biaxial tensile strain, while the band gap decreases from 0.47 eV to nearly zero with increasing the uniaxial tensile strain, and Dirac cone-like electronic structures are observed. The uniaxial strain-induced changes of the electronic structures of graphdiyne come from the breaking of geometrical symmetry that lifts the degeneracy of energy bands. The properties of graphdiyne under strains are disclosed different remarkably from that of graphene.