• 文献标题:   Single-particle energy - and optical absorption - spectra of multilayer graphene quantum dots
  • 文献类型:   Article
  • 作  者:   WIMMENAUER C, SCHELLER J, FASBENDER S, HEINZEL T
  • 作者关键词:   quantum dot, tight binding model, energy spectra, carbon nanodot, multilayer graphene, absorption spectra
  • 出版物名称:   SUPERLATTICES MICROSTRUCTURES
  • ISSN:   0749-6036
  • 通讯作者地址:   Heinrich Heine Univ
  • 被引频次:   0
  • DOI:   10.1016/j.spmi.2019.106171
  • 出版年:   2019

▎ 摘  要

The energy spectra of quantum dots formed by stacked disks of graphene are calculated as a function of the disk shape and size, the number of disk layers and the edge type (zigzag/armchair) within a tight-binding approach in the single-particle picture. Stacks formed by up to seven disks of hexagonal, rhombic and triangular shape are considered. For both edge types, we find a monotonously decreasing energy gap as the number of stacked disks or the disk size is increased, with the exception of triangular dots with zigzag edges, which have a metallic character. In some cases, simple scaling relations for the energy gaps can be formulated. Furthermore, the optical absorption spectra within the dipole approximation are calculated. The results are interpreted with the help of selected HOMO wave functions that form inside the stacks.