• 文献标题:   A multiscale study of electronic structure and quantum transport in C6n2H6n-based graphene quantum dots
  • 文献类型:   Article
  • 作  者:   DERETZIS I, FORTE G, GRASSI A, LA MAGNA A, PICCITTO G, PUCCI R
  • 作者关键词:  
  • 出版物名称:   JOURNAL OF PHYSICSCONDENSED MATTER
  • ISSN:   0953-8984
  • 通讯作者地址:   Univ Catania
  • 被引频次:   10
  • DOI:   10.1088/0953-8984/22/9/095504
  • 出版年:   2010

▎ 摘  要

We implement a bottom-up multiscale approach for the modeling of defect localization in C6n2H6n islands, i.e. graphene quantum dots with a hexagonal symmetry, by means of density functional and semiempirical approaches. Using the ab initio calculations as a reference, we recognize the theoretical framework under which semiempirical methods adequately describe the electronic structure of the studied systems and thereon proceed to the calculation of quantum transport within the nonequilibrium Green function formalism. The computational data reveal an impurity-like behavior of vacancies in these clusters and evidence the role of parameterization even within the same semiempirical context. In terms of conduction, failure to capture the proper chemical aspects in the presence of generic local alterations of the ideal atomic structure results in an improper description of the transport features. As an example, we show wavefunction localization phenomena induced by the presence of vacancies and discuss the importance of their modeling for the conduction characteristics of the studied structures.