Patterned Growth of Well-Aligned Carbon Nanotubes:  A Soft-Lithographic Approach

Abstract

Using microcontact printing (µCP) and micromolding techniques, we have prepared micropatterns of carbon nanotubes aligned in a direction normal to the substrate surface. While the µCP process involves the regionspecific transfer of self-assembling monolayers (SAMs) of alkylsiloxane onto a quartz substrate and subsequent adsorption of polymer chains in the SAM-free regions, the micromolding method allows the formation of polymer patterns through solvent evaporation from a precoated thin layer of polymer solution confined between a quartz plate and a poly(dimethylsiloxane) (PDMS) elastomer mold. The polymer patterns formed in both cases were then carbonized into carbon black for region-specific growth of the aligned nanotubes in the polymer-free regions by pyrolysis of iron(II) phthalocyanine (FePc) under Ar/H 2 atmosphere at 800-1100 °C. Micropatterns of aligned nanotubes thus prepared have resolutions down to 0.8 µm, suitable for fabrication of various electronic and photonic devices. † CSIRO Molecular Science.

Carbon nanostructures and graphite-coated metal nanostructures obtained by pyrolysis of ruthenocene and ruthenocene-ferrocene mixtures

“…Pyrolysis of organometallic precursors has been employed to prepare novel carbon structures by several workers (Andrews et al 1999;Huang et al 1999Huang et al , 2000Rao et al 2001;Govindaraj and Rao 2002). Thus, pyrolysis of metallocenes such as ferrocene, cobaltocene and nickelocene in the presence or absence of other hydrocarbons gives carbon nanotubes without any external metal catalyst (Rao et al 1998).…”

Self‐Assembly of Large‐Scale Micropatterns on Aligned Carbon Nanotube Films

“…Most patterned carbon nanotubes are formed on prepatterned substrates or prepatterned catalysts during the fabrication process. [7][8][9] Herein we report the first use of a long-range force (capillary force) in the self-assembly of three-dimensional (3D) micropatterns on aligned carbon nanotube films through a water-spreading method after the growth of the carbon nanotube. It is considered that low-density regions or vacancies of carbon nanotube films play an important role in the formation of the pattern.…”

The Selective Growth of Silicon Nanowires and Their Optical Activation

“…In addition, the dense of nanowires could be controlled by the amount of gold nanoparticles, and the thickness of the gel film could also be adjusted through changing the ASB concentration. Moreover, other techniques such as soft lithography (Kind et al, 2000;Huang et al, 2000) and direct printing (Cassell et al, 2001) could also be used to print the gold-containing solution to a desired position on the substrate surface, which might facilitate the integration of Si nanowires into devices. Figure 2.12 is the XRD pattern of the Er -doped aluminous sol-gel materials sintered at 900°C.…”