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nanotube arrays
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Aligned Carbon Nanotube Arrays
Aligned carbon nanotube arrays are grown on a number of substrates as custom orders. The arrays are synthesized in a chemical vapor deposition (CVD) system, using one of two types of CVD processes we have in house; Plasma Enhanced CVD, or Thermal-CVD. The output from these processes differ significantly in their properties.
Features  PECVD   Thermal CVD
Diameter, nm 30-150 1-2 (SWNT) 5-30 (MWNT)
Length, microns 1-20 5-500
Rigidity Freestanding (bed of nails) Mutually Supported
Site Density CNT/cm2 105 to 109 1010 to 1011
Substrates Si, SiO2, W, Mo, SS, C Si, SiO2, SS, Ti, mica
Adhesion Layer Ti or Cr, 100nm Al2O3
Catalyst Nickel Iron
Size up to 2" square up to 1.25" x 4"
Patterns Yes, lithographic Yes, lithographic
Uses field emission devices, sensors, electrostatically actuated devices, etc supercapacitors, electrodes, optical coatings, heat transfer, etc.

PECVD Details: For PECVD arrays, the substrate (metal, glass, silicon, etc) are first coated with an adhesion layer (titanium or chromium), and then overcoated with nickel nanoparticles, then introduced to the CVD chamber. The method of nickel nanoparticle deposition defines the nanotube site density. Standard aligned carbon nanotube forests are produced from a sputtered nickel catalyst film on the substrate, whereas low site-density carbon nanotube arrays are produced by electrodeposition of the nickel catalyst onto the substrate.
In the PECVD system, the carbon nanotubes grow vertically from the substrate surface, and are freestanding. The length is related to the process time, but the diameter depends primarily on the nickel particle size.

In structure, PECVD aligned carbon nanotubes have multilayer graphitic sidewalls and hollow core ( Fig. 1). The graphitic sidewalls contain bamboo structures (Fig. 2). All nanotube tips are capped with a single nickel nanoparticle, a result of a tip-growth mechanism of aligned carbon nanotubes (Fig. 3).

Thermal CVD Details: In TCVD forests and arrays, the nanotubes are much smaller in diameter, and can grow to extreme lengths. We can readily grow either single wall or multiwall nanotubes with this process. The nanotubes are not self-supporting, and the alignment is due to crowding of neighboring nanotubes. The growth is catalyzed by an iron catalyst, typically deposited atop an alumina adhesion layer. These forests have high surface area, and can be used as is to form sensors and detectors, or drawn to form nanotube sheets or yarns. They can also be used as optical and infrared black coatings. When you order an array, please discuss your application with the sales engineer, as we have a broad experience base to draw upon to maximize the effectiveness of the products you purchase.

NanoLab offers a wide variety of aligned carbon nanotube arrays. We can tailor a carbon nanotube array to your specifications, including complex patterning on many types of substrates using microscale and nanoscale lithography. Please allow three week delivery for most orders. Forests can also be transferred to other substrates if needed.
phone (781) 609 2722     fax(781) 609 2899     email an PECVD Array Specialist or a T-CVD Forest Specialist to ask questions.
Thermal CVD Aligned Arrays images    Check stock items
  • Carbon nanotube diameter: 1-2nm (SWNT), 5-30nm (MWNT)
• Carbon nanotube length: 5-500 microns.
• Carbon nanotube site density: 1010-1011 nanotubes/cm2.
• Substrate material: Silicon, Silica, Titanium, Stainless Steel, Mica
Plasma Enhanced CVD Aligned Arrays
  Standard PECVD Aligned Carbon Nanotube Arrays: images     Check stock items
View substrate materials and/or place an order -- HTML
Data Sheets for PECVD Aligned Carbon Nanotube Arrays -- PDF
• Nanotube length: Specify 1-20 microns, and allow a tolerance of ± 10%
• Nanotube diameter: Specify between 30 & 150 nm, and allow a tolerance of ± 30%
• CNT site density: 1~2x109nanotubes/cm2

Low Site Density Aligned PECVD CNT Arrays: images    Check stock items
View substrate materials and/or place an order -- HTML
• Nanotube length: 1-5 microns
• Nanotube diameter: 50-150 nm
• Nanotube site density: 105~107 nanotubes/cm2

Aligned Nanotube Matrix Arrays: images
• Nanotube length: 1-10 microns
• Nanotube diameter: 100 nm
• Nanotube site density: per customer specifications

Metal-Decorated Aligned CNT Arrays: images
• Various of metals available to decorate standard carbon nanotube arrays and low site density carbon nanotube arrays, such as TiW, HfC, Cu, Ti, Ag, Au, etc. For more metals, please email array specialist,zhongping@nano-lab.com

Polymer-sealed CNT Arrays:
† CNT arrays sealed with spin-on glass images
• Sealing thickness: 1-3 microns.
† CNT arrays sealed with PDMS images
• Sealing thickness 5-20 microns.

Custom Aligned Carbon Nanotube Arrays:
• Other sizes, up to 2 inches diameter
• Different substrate materials
• Complex patterns and designs. images

PECVD-MWCNT Suspensions
• Click Aligned carbon nanotube suspensions to go to our suspension page.
The page was updated on 11/01/2011