Nitrogen-containing carbon nanotube growth from Ni phthalocyanine by chemical vapor deposition

Yudasaka, Masako; Kikuchi, Rie; Ohki, Y.; Yoshimura, Susumu

doi:10.1016/s0008-6223(96)00142-x

Cited by 145 publications

(74 citation statements)

References 8 publications

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“…[16] The commonly measured mobilities of pentacene TFTs (top-contact) are around 0.6 cm 2 V ±1 s ±1 for polycrystalline thin films. [1] In addition, a recently reported bottom-contact pentacene-based TFT gave the best value of 0.48 cm 2 V ±1 s ±1 , [5] a value comparable with our results based on bottom-contact Me 4 PENT TFT (0.30 cm 2 V ±1 s ±1 ). Furthermore, all devices were measured in air, which was expected to yield lower on/off ratios due to the fact that an electron-donating-substituted pentacene is expected to react more exothermically with oxygen than pentacene.…”

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confidence: 92%

“…[1] Organic thin-film FETs have shown charge transport mobilities in the range 0.005±2.1 cm 2 V ±1 s ±1 and on/off current ratios larger than 10 8 in some cases. [1] Unlike oligothiophene-based thin-film transistors (TFTs), [2] where an impressive increase in mobility was achieved through the preparation of new semiconductors or by the introduction of new synthetic methodologies, increased performance of pentacene-based TFTs has been mainly achieved through the development of improved device fabrication techniques including: [3] optimization of the film deposition parameters, [3,4] improvement of morphology, dielectric±semiconductor interfacial properties, and purification of materials. [5] While it may be possible to continue the improvement of device performance by employing device physics and engineering techniques, new materials design and synthesis are viable alternatives for pushing pentacene-based TFTs to a new performance level.…”

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confidence: 99%

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Tetramethylpentacene: Remarkable Absence of Steric Effect on Field Effect Mobility

et al. 2003

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nanotube is observed and the lower side of the wall corresponds to the outside of the nanotube. The thickness of the wall is about 3.3 nm and it consists of many parallel graphene layers. Each layer, however, curves and wrinkles to some extent, indicating lower crystallinity of the present nanotubes than the ones prepared by other methods, such as arc discharge synthesis. It should be noted that this image does not exhibit any clear difference in crystallinity between pure carbon layers (upper half of the wall) and N-doped layers (the lower half). In the case of nanotubes from P-A CVD, their HRTEM images (not shown here) were found to be very similar to the image of Figure 4, and again there was no crystallinity difference between N-doped and undoped multiwalls.In conclusion, this study has demonstrated the fabrication of aligned carbon nanotubes with double coaxial structure of N-doped and undoped multiwalls. It can be determined whether the N-doped layer belongs to the inner or outer multiwalls by changing the sequence of the two-step CVD process. Moreover, the thickness of both the N-doped and pure carbon layers is controllable by changing each CVD period. The use of the AAO film as a template enables us for the first time to precisely control the nitrogen location in N-doped carbon nanotubes. Since nitrogen doping would enhance the electron-conducting properties of carbon nanotubes, the present carbon nanotubes may exhibit excellent performance as field electron emitters. The present technique opens up a novel route for the synthesis of heteroatom-doped carbon nanotubes with double coaxial structure and furthermore this will lead to the production of coaxial heterojunctions (pn, npn, or pnp) by stacking N-and B-doped layers. ExperimentalBy anodic oxidation of an aluminum plate, an AAO film with a channel diameter of 30 nm and a thickness of about 70 lm was prepared. Details are given elsewhere [13]. The resultant AAO film was placed on a quartz boat in a horizontal quartz reactor (inside diameter 55 mm). The reactor temperature was then increased to 800 C under N 2 flow. When the temperature reached 800 C, propylene gas (1.2 % in N 2 ) was passed through the reactor at a total flow rate of 1000 cm 3 (STP)/min. After the 2 h carbon deposition from propylene, the reactor was cooled down to room temperature and the carbon-coated AAO film taken out. In the second step, the carbon-coated film was placed in the reactor again and acetonitrile vapor (4.2 % in N 2 of 500 cm 3 (STP)/min) was allowed to flow over the film at 800 C. The vapor was generated by bubbling N 2 through acetonitrile liquid in a saturator kept at 0 C. This acetonitrile CVD was performed for 5 h. After this two-step sequential CVD process, the doubly coated AAO film was treated with 10 M NaOH solution at 150 C for 6 h to remove the alumina template, thereby liberating the nanotubes from the template AAO film.The carbon-coated AAO films and the corresponding carbon nanotubes were analyzed by X-ray photoelectron spectroscopy (XPS). The samples were...

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confidence: 99%

Tetramethylpentacene: Remarkable Absence of Steric Effect on Field Effect Mobility

et al. 2003

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“…It is suggested that the number of carbon atoms in the precursor molecule influences the SWCNT packing density in the template channels. Among other organic compounds, amino-dichloro-s-triazine, pyrolyzed on cobalt-patterned silica substrates, resulted in highly pure CNTs (Terrones et al, 1997) Almost contemporary, organometallic compounds such as metallocene (ferrocene, cobaltocene, nickelocene) (Sen et al, 1997) and nickel phthalocyanine (Yudasaka et al, 1997) were used as the carbon-cumcatalyst precursor; however, as-grown CNTs were highly metal-encapsulated and the yield was very low. Later, pyrolysis of thiophene with metallocene led to the formation of Yjunction CNTs (Satishkumar et al, 2000).…”

Section: New Cnt Precursorsmentioning

confidence: 99%

Carbon Nanotube Synthesis and Growth Mechanism

Kumar¹

2011

Carbon Nanotubes - Synthesis, Characterization, Applications

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“…The key to obtaining high yields of pure CNTs is achieving hydrocarbon decomposition on catalyst sites alone and avoiding spontaneous pyrolysis. CNTs have been successfully synthesized using organometallic compounds (nickel phthalocyanine 77 and ferrocene 78 ) as carbon-cum-catalyst precursors, though the as-grown CNTs were mostly metal encapsulated. The use of ethanol has drawn attention for synthesizing SWNTs at relatively low temperatures ( 850°C) on Fe-Co impregnated zeolite supports and Mo-Co coated quartz substrates 79,80,81 .…”

Section: Chemical Vapor Depositionmentioning

confidence: 99%

Large Scale Synthesis of Carbon Nanotubes

Karthikeyan¹,

Mahalingam²,

Karthik

2008

Journal of Chemistry

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Abstract:Since the discovery of carbon nanotubes in 1991 by Iijima, they have been of great interest both from the fundamental point of view and for future applications. The most eye catching features of this structure are their electronic, mechanical, optical and chemical characteristics, which opens a way to future applications. These properties can even be measured on single nanotubes. For commercial applications, large quantities of purified nanotubes are needed. In this paper, recent research on preparation of carbon nanotubes with special reference to low temperature synthesis of high purity is reviewed. The reported achievements in this area will open up more knowledge on carbon nanostructured materials in many areas of emerging nanoscale science and nanotechnology.

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Nitrogen-containing carbon nanotube growth from Ni phthalocyanine by chemical vapor deposition

Cited by 145 publications

References 8 publications

Tetramethylpentacene: Remarkable Absence of Steric Effect on Field Effect Mobility

Tetramethylpentacene: Remarkable Absence of Steric Effect on Field Effect Mobility

Carbon Nanotube Synthesis and Growth Mechanism

Large Scale Synthesis of Carbon Nanotubes

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