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

Hui-Juan Cui,^a Xian-Lei Sheng,^b Qing-Bo Yan,^c Qing-Rong Zheng^a and Gang Su*^a

^aSchool of Physics, University of Chinese Academy of Sciences, P. O. Box 4588, Beijing 100049, China

^bBeijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P. O. Box 4588, Beijing 100190, China

^cCollege of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, P. O. Box 4588, Beijing 100049, China

Abstract

By means of 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 found to differ remarkably from that of graphene.