Quantum-Confined Electronic States in Atomically Well-Defined Graphene Nanostructures
2011; American Physical Society; Volume: 107; Issue: 23 Linguagem: Inglês
10.1103/physrevlett.107.236803
ISSN1092-0145
AutoresSampsa K. Hämäläinen, Zhixiang Sun, Mark P. Boneschanscher, Andreas Uppstu, Mari Ijäs, Ari Harju, Daniël Vanmaekelbergh, Peter Liljeroth,
Tópico(s)Carbon Nanotubes in Composites
ResumoDespite the enormous interest in the properties of graphene and the potential of graphene nanostructures in electronic applications, the study of quantum-confined states in atomically well-defined graphene nanostructures remains an experimental challenge. Here, we study graphene quantum dots (GQDs) with well-defined edges in the zigzag direction, grown by chemical vapor deposition on an Ir(111) substrate by low-temperature scanning tunneling microscopy and spectroscopy. We measure the atomic structure and local density of states of individual GQDs as a function of their size and shape in the range from a couple of nanometers up to ca. 20 nm. The results can be quantitatively modeled by a relativistic wave equation and atomistic tight-binding calculations. The observed states are analogous to the solutions of the textbook "particle-in-a-box" problem applied to relativistic massless fermions.
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