中文摘要：

在广义梯度近似下,采用密度泛函理论框架下的第一性原理投影缀加波赝势方法,研究了扶手椅型氮化硼（BN）纳米带（锯齿边缘）双空位缺陷效应.结果表明：垂直双空位结构优化后形成一个14环,斜向双空位在奇数宽度纳米带中形成4—10—4环,而在偶数宽度纳米带中形成5—8—5环.这两种双空位的形成过程是吸热的,垂直双空位的形成能比斜向双空位的形成能高.随着BN纳米带宽度的增加,两种双空位的形成能均有减少.双空位的存在虽不改变BN纳米带的半导体特性,但改变了费米能级附近的能带结构.

英文摘要：

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.