Release Time:2019-03-11  Hits:

Indexed by: Journal Article

Date of Publication: 2017-09-07

Journal: JOURNAL OF APPLIED PHYSICS

Included Journals: EI、SCIE、Scopus

Volume: 122

Issue: 9

ISSN: 0021-8979

Abstract: Employing density functional theory calculations, mechanical and electronic properties of stable penta-B2N4 and penta-B3N3 monolayers are investigated. The different mechanical parameters obtained along different tensile directions suggest both the penta-B2N4 and penta-B3N3 demonstrate mechanical anisotropy. Moreover, due to the lower space group symmetry of penta-B3N3, its anisotropy is more prominent than that of the penta-B2N4. It was found that both the penta-B2N4 and penta-B3N3 are fast to fracture along the direction R-1 due to the small fracture strain, but hard to be stretched because of the large Young's modulus. Generally, penta-B2N4 shows better mechanical properties than those of penta-B3N3 in terms of Young's modulus and intrinsic strength. Besides, under the tensile strain, penta-B2N4 keeps its metallicity, but the band gap of penta-B3N3 can be effectively tailored, even inducing a transition from the direct to indirect band gap or transition from the semiconductor to metal. Further analysis of partial charge densities indicates breaking of B-N bonds is the main cause for the band gap enlargement, and similarly, formation of B-N bonds is the reason for the semiconductor-to-metal transition of penta-B3N3. Published by AIP Publishing.