ACTA

Octagonal Defects as the Source of Gap States in Graphene Semiconducting Structures

M. Pelc^a, W. Jaskólski^a, A. Ayuela^b and L. Chico^c
^aInstitute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, Grudziądzka 5, 87-100 Toruń, Poland
^bCentro de Física de Materiales CSIC-UPV/EHU, Donostia International Physics Center, 20018 San Sebastián, Spain
^cInstituto de Ciencia de Materiales de Madrid, CSIC, C/Sor Juana Inés de la Cruz 3, 28049 Madrid, Spain

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We study graphene nanoribbons and carbon nanotubes with divacancies, i.e., local defects composed of one octagon and a pair of pentagons. We show that the presence of divacancies leads to the appearance of gap states, which may act as acceptor or donor states. We explain the origin of those defect-localized states and prove that they are directly related to the zero-energy states of carbon ring forming the octagonal topological defect.

DOI: 10.12693/APhysPolA.124.777
PACS numbers: 73.22.Pr, 61.72.Qq