空位缺陷对锯齿型硅纳米带电子结构和磁性的影响

基于密度泛函理论,采用广义梯度近似下的第一性原理投影缀加波赝势方法,系统的研究了单空位(双空位)缺陷对锯齿型硅纳米带电子结构和磁性的影响.结果表明:不同位置的单原子空位(双原子空位)锯齿型硅纳米带,结构弛豫后,都能得到一个九边环(八边环),同类缺陷更容易在锯齿型硅纳米带的边缘区域形成;与完整的锯齿型硅纳米带相比,中心位置含空位缺陷(单原子或双原子空位)的锯齿型硅纳米带由原有的反铁磁半导体转变为反铁磁金属;非中心位置含空位缺陷(单原子或双原子空位)的锯齿型硅纳米带则具有铁磁态金属性, 在远离缺陷的纳米带边缘硅原子上局域的分布着差分电荷密度,这使得锯齿型硅纳米带在自旋电子学领域拥有可观的应用前景.

Effect of Vacancy Defects on Electronic and Magnetic Properties of Zigzag Silicon Nanoribbons

Based on the density function theory, using the first-principles projector augmented wave potential under the generalized gradient approximation, we investigate the electronic structure and magnetism of zigzag silicon nanoribbons with a monovacancy or a divacancy.The results show that Zigzag silicon nanoribbons with a monovacancy (a divacancy) of different position will become a nine side ring (octagon ring) after structural relaxation, the same kind of defect is easier to form in edge region of Zigzag silicon nanoribbons.Either a monovacancy or a divacancy at the center of ribbon, Zigzag silicon nanoribbons change an antiferromagnetism semiconductor to an antiferromagnetism metallic.However, when a monovacancy or a divacancy deviate from the ribbon center, zigzag silicon nanoribbons become ferromagnetic metallic, the difference charge densities are localized only at one edge further to the vacancy, this brings potential applications in the field of spintronics for zigzag silicon nanoribbons.