Berlin 2012 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 13: Transport: Poster Session

TT 13.9: Poster

Montag, 26. März 2012, 15:00–19:00, Poster B

CVD growth of carbon nanotubes on ultra-flat hexagonal boron nitride — •Lidia Saptsova^1,2, Stephan Engels^1,2, K. Watanabe³, T. Taniguchi³, Carola Meyer², and Christoph Stampfer^1,2 — ¹JARA-FIT and II. Institute of Physics B, RWTH Aachen, 52074 Aachen, Germany — ²Peter Grünberg Institut, Forschungszentrum Jülich, 52425 Jülich, Germany — ³Advanced Materials Laboratory, National Institute for Materials Science, 1-1 Namiki, Tsukuba, 305-0044, Japan

Single-walled carbon nanotubes (SWNTs) are promising candidates for hosting high-quality quantum dots (QDs). However, at the present time it is difficult to achieve ultra-clean SWNT QDs on substrates, since the substrate, in particular SiO₂ introduce a significant disorder potential. For graphene devices it was recently shown that placing graphene on hexagonal boron nitride (hBN) significantly improves the device performance. Since hBN is a wide-bandgap insulator, has the graphene-like planar layer structure and is free of dangling bonds and charge traps at the surface, it might be used as a perfect substrate for CNT devices. Here, we present the fabrication technology for making SWNT quantum dots on hBN. We use a Ferritin-based Fe catalyst CVD growth method for obtaining uniformly distributed SWNTs with diameters of about 1.5-2 nm. To study the effect of the substrate material on the disorder in nanotubes, SWNTs lying on both hBN and SiO₂ were chosen using scanning force microscopy. Finally, SWNT QDs on hBN and SiO₂ were obtained by contacting individual 300 nm nanotube sections by metal electrodes.