X-ray photoelectron spectroscopy study on Fe and Co catalysts during the first stages of ethanol chemical vapor deposition for single-walled carbon nanotube growth

Journal Article · Tue Mar 15 00:00:00 EDT 2011 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.3552306· OSTI ID:21538177

Oida, Satoshi; McFeely, Fenton R; Bol, Ageeth A ^[1]

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1. IBM TJ Watson Research Center, 1101 Kitchawan Road, Yorktown Heights, New York 10598 (United States)

Optimized chemical vapor deposition processes for single-walled carbon nanotube (SWCNT) can lead to the growth of dense, vertically aligned, mm-long forests of SWCNTs. Precise control of the growth process is however still difficult, mainly because of poor understanding of the interplay between catalyst, substrate and reaction gas. In this paper we use x-ray photoelectron spectroscopy (XPS) to study the interplay between Fe or Co catalysts, SiO{sub 2} and Al{sub 2}O{sub 3} substrates and ethanol during the first stages of SWCNT forest growth. With XPS we observe that ethanol oxidizes Fe catalysts at carbon nanotube (CNT) growth temperatures, which leads to reduced carbon nanotube growth. Ethanol needs to be decomposed by a hot filament or other technique to create a reducing atmosphere and reactive carbon species in order to grow vertically aligned single-walled carbon nanotubes from Fe catalysts. Furthermore, we show that Al{sub 2}O{sub 3}, unlike SiO{sub 2}, plays an active role in CNT growth using ethanol CVD. From our study we conclude that metallic Fe on Al{sub 2}O{sub 3} is the most optimal catalyst/substrate combination for high-yield SWCNT forest growth, using hot filament CVD with ethanol as the carbon containing gas.

• OSTI ID: 21538177
• Journal Information: Journal of Applied Physics, Vol. 109, Issue 6; Other Information: DOI: 10.1063/1.3552306; (c) 2011 American Institute of Physics; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

77 NANOSCIENCE AND NANOTECHNOLOGY
ALUMINIUM OXIDES
CARBON
CATALYSTS
CHEMICAL VAPOR DEPOSITION
COBALT
ETHANOL
FABRICATION
FILAMENTS
IRON
MOLECULES
NANOTUBES
PRECURSOR
PROCESSING
SCREENING
SCREENS
SILICON OXIDES
SUBSTRATES
X-RAY PHOTOELECTRON SPECTROSCOPY
ALCOHOLS
ALUMINIUM COMPOUNDS
CHALCOGENIDES
CHEMICAL COATING
DEPOSITION
ELECTRON SPECTROSCOPY
ELEMENTS
HYDROXY COMPOUNDS
METALS
NANOSTRUCTURES
NONMETALS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
SILICON COMPOUNDS
SPECTROSCOPY
SURFACE COATING
TRANSITION ELEMENTS