Cone-like graphene nanostructures: electronic and optical properties

Autor(es)

Ulloa, Pablo ^[1] ; Latge, Andrea ^[2] ; Oliveira, Luiz E. ^[3] ; Pacheco, Monica ^[1]

Afiliação do(s) autor(es)

^[1] Univ Tecn Federico Santa Maria, Dept Fis, Valparaiso - Chile

^[2] Univ Fed Fluminense, Inst Fis, BR-24210340 Niteroi, RJ - Brazil

^[3] Univ Estadual Campinas UNICAMP, Inst Fis, BR-13083859 Campinas, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: NANOSCALE RESEARCH LETTERS; v. 8, SEP 12 2013.
• Citações Web of Science: 5

Resumo

A theoretical study of electronic and optical properties of graphene nanodisks and nanocones is presented within the framework of a tight-binding scheme. The electronic densities of states and absorption coefficients are calculated for such structures with different sizes and topologies. A discrete position approximation is used to describe the electronic states taking into account the effect of the overlap integral to first order. For small finite systems, both total and local densities of states depend sensitively on the number of atoms and characteristic geometry of the structures. Results for the local densities of charge reveal a finite charge distribution around some atoms at the apices and borders of the cone structures. For structures with more than 5,000 atoms, the contribution to the total density of states near the Fermi level essentially comes from states localized at the edges. For other energies, the average density of states exhibits similar features to the case of a graphene lattice. Results for the absorption spectra of nanocones show a peculiar dependence on the photon polarization in the infrared range for all investigated structures. (AU)

• Processo FAPESP: 12/51691-0 - A física de novos materiais e nanoestruturas semicondutoras
• Beneficiário: Luiz Eduardo Moreira Carvalho de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Temático