The grain boundary effect on mechanical and electronic transport properties of a striped borophene

The grain boundary (GB) effect on the mechanical and electronic transport properties of a striped borophene are investigated based on first principles calculations. Three GBs, (1,2)|(1,2), (2,1)|(2,1) and (3,1)|(3,1), constructed using the translation vector method are verified to possess low formation energy and stability at room temperature. The presence of GBs does not destroy the metallic nature of borophene, but results in the accumulation of charge densities. The mechanical strength of borophene is decreased due to the introduction of GBs. Their fracture behaviors are more complex, accompanied by reconstructions in the GB region. The transport current is also degraded, which is mainly caused by GBs in the borophene giving rise to backscattering. The degree of these reductions rely on the specific structure of GBs.