Optical properties of graphene nanoflakes: Shape matters

CANDELA MANSILLA WETTSTEIN; FRANCO BONAFÉ; MARÍA BELÉN OVIEDO; CRISTIÁN G. SÁNCHEZ

JOURNAL OF CHEMICAL PHYSICS

AMER INST PHYSICS

Lugar: New York; Año: 2016 vol. 144 p. 224305 - 224305

0021-9606

n recent years there has been significant debate on whether the edge type of graphene nanoflakes (GNF) or graphene quantum dots (GQD) are relevant for their electronic structure, thermal stability and optical properties. Using computer simulations, we have proven that there is a fundamental difference in the absorption spectra between samples of the same shape, similar size but different edge type, namely, armchair or zigzag edges. These can be explained by the presence of electronic structures near the Fermi level which are localized on the edges. These features are also evident from the dependence of band gap on the GNF size, which shows three very distinct trends for different shapes and edge geometries.