A First-principles Investigation On The Effect Of The Divacancy Defect On The Band Structures Of Boron Nitride Nanoribbons

Graphene have been fabricated successfully, and their realization has evoked anew revolution to materials science. Particularly, as the structural analogues ofgraphene and GNRs, the two-dimensional (2D) hexagonal inorganic BN nanosheetand one-dimensional (1D) BN nanoribbons (BNNRs). The (1D) BN nanoribbons hasbeen achived, which can exhibit the high thermal and chemical stabilities, however,the BNNRs exhibit intrinsic semiconducting characteristic with a large band gap (ca.4~6eV), which somewhat inhibits the application of BNNRs in nano-electronicdevices.To address this important issue, on the basis of the comprehensive first-principlescomputations, we investigated the geometries, electronic and magnetic properties ofzigzag and armchair boron nitride nanoribbons (BNNRs) with the divacancy defect of5-8-5ring fusions formed by removing B-N pair, where the defect orientation andposition are considered. Our computed results reveal that all of the defective BNNRssystems can uniformly exhibit nonmagnetic semiconducting behavior, and theformation of the divacancy5-8-5defect can significantly impact the band structuresof BNNRs with not only the zigzag but also armchair edges, where their wide bandgaps are reduced and the defect orientation and position play an important role.Clearly, introducing divacancy defect can be a promising and effective approach toengineer the band structures of BNNRs, and the present computed results can providesome valuable insights for promoting the practical applications of excellent BN-basednanomaterials in the nanodevices.