Under the generalized gradient approximation (GGA), the divacancy effect on armchair (Boron Nitride) nanoribbon (with zigzag edge shape) are investigated by using the first-principles projector augmented wave (PAW) potential within the density function theory (DFT) framework. The results show that optimized geometry of BN nanoribbon with vertical divacancy generates a 14 ring. The 4—10—4 structure appears for odd width of BN nanoribbon with slope divacancy while a 5—8—5 structure exists for even width of BN nanoribbon with slope divacancy. In addition, the formation of a vacancy is an endotheric procedure and the formation energy of the BN nanoribbon to produce vertical divacancy is higher than that of slope divacancy. The formation energy decreases with ribbon width increasing. The BN nanoribbon with divacancy is still semiconductor, only the band structure near the Fermi level changes.

BN nanoribbon; divacancy defect; electronic structures; band structure; first-principles