IFEG   20353
INSTITUTO DE FISICA ENRIQUE GAVIOLA
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Arrays of uniformly shaped blocks of stacked graphene sheets
Autor/es:
BAJALES, NOELIA; ARTUR BÖTTCHER; DANIEL LÖFFLER; MANFRED KAPPES; PATRICE BRENNER; SHARALI MALIK
Lugar:
La Falda, Córdoba
Reunión:
Encuentro; Encuentro de Superficies y Materiales Nanoestructurados; 2012
Institución organizadora:
IFEG-FaMAF
Resumen:
The nanographene sheets, nG, exhibit numerous attractive properties which motivated their applications as the active elements in electronic devices. Some pioneering nanodevices based on nG exhibit very encouraging performances (nanoresonator [ ], field transistor [ ]).Numerous methods have been exploited for fabrication and exfoliation of nG sheets yet. In the research the most established method was the exfoliation of graphene sheets by micromechanical cleavage of bulk graphite. However, because of the rather random nature of the process (low reproducibility, broad size and shape distribution, purely controlled quality) this method remains of low relevance for wide technological application. In this work, oxygen-based etching of HOPG surfaces patterned by focused ion beam technique, EFIB, has been exploited to fabricate large-area 2D arrays of uniformly sized 3D grapheme blocks. Each block created is considered here as reservoir of nm-sized stacked graphene sheets, nG. As evidenced by AFM and SEM imaging rectangular graphene blocks with easily adjustable lateral sizes down to ~100 nm and heights up to ~55 nm can be fabricated routinely. This method provides well defined nG sheets in the quantity up to 1016 m-2 reached with technologically acceptable mean fabrication rates of ~1011 nG/m2s. The lateral size of the graphene blocks can be tuned by widening of the separating trenches. However, as evidenced by Raman and photoionization spectroscopies, the quality of the outermost nG sheets terminating the blocks decreases with the oxidation time. SEM images taken after applying electron exposures reveal large surface areas covered by bunches of uniformly shaped nG blocks. 1-Bunch JS, van der Zande AM, Verbridge SS, Frank IW, Tanenbaum DM, Parpia JM, Craighead HG, McEuen PL, Science 315, 2007, 490. 2-Novoselov KS, Geim AK, Morozov SV, Jiang D, Zhang Y, Dubonos SV, Grigorieva IV, Firsov AA, Science 306, 2004, 666