Contact transfer of aligned carbon nanotube arrays onto conducting substrates

Kumar, Ashavani; Pushparaj, V.; Kar, Swastik; Nalamasu, Omkaram; Ajayan, Pulickel M.; Baskaran, Rajashree

doi:10.1063/1.2356899

Cited by 74 publications

(51 citation statements)

References 13 publications

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“…Recently, we have demonstrated the contact transfer of aligned CNT arrays onto conducting substrates using low-temperature soldering. [10] For many applications, it is desirable to develop a technique to obtain freestanding CNT films by direct peeling from a substrate without disturbing their aligned structure. [11][12][13] Owing to the weak Van der Waals forces stitching together the vertically aligned nanotube arrays, the direct mechanical removal of CNT films from substrates could damage the alignment of nanotubes in the films.…”

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confidence: 99%

Ultrathick Freestanding Aligned Carbon Nanotube Films

Manikoth

et al. 2007

Advanced Materials

143

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Owing to their excellent electronic, mechanical, and chemical properties, carbon nanotubes (CNTs) have been extensively investigated for various applications. [1,2] Vertically aligned CNT arrays, prepared by chemical vapor deposition (CVD) methods, are considered to be well suited for many of these applications. [3][4][5][6][7] The properties of the supporting substrates on which the nanotube films are grown often play a critical role in some of these applications. For example, nanotube arrays on conductive metallic substrates exhibit improved field emission properties, [8] whereas nanotubes on flexible polymer substrates [9] may be well suited for certain device applications. However, only a limited variety of substrate materials are compatible with nanotube CVD growth processes. Typically, the CVD growth temperature is higher than 600°C, which limits the use of many substrates. We have recently demonstrated the direct growth of aligned MWNTs on a metallic alloy using vapor-phase catalyst-delivery-assisted CVD. [8] The interaction between the catalyst and substrate is critical for nanotube growth. Si and quartz wafers are the two substrate materials most commonly used to grow CNTs by CVD. [5][6][7] Several applications require the transfer or deposition of nanotube arrays onto substrates other than the ones they are grown on. Recently, we have demonstrated the contact transfer of aligned CNT arrays onto conducting substrates using low-temperature soldering.[10] For many applications, it is desirable to develop a technique to obtain freestanding CNT films by direct peeling from a substrate without disturbing their aligned structure. [11][12][13] Owing to the weak Van der Waals forces stitching together the vertically aligned nanotube arrays, the direct mechanical removal of CNT films from substrates could damage the alignment of nanotubes in the films. CNT films grown on silica have been released from the substrate by chemical etching processes. [14] Chemical processes tend to contaminate the nanotube films thus precluding their use in certain applications. Moreover, these processes induce the formation of a foam-like structure [15] when the nanotube arrays come in contact with solvents. The detachment of nanotube films from substrates by means of the thermocapillary effect has been attempted using hot distilled water, [16] which also results in the formation of foam-like structures.Hence it is important to develop new techniques to obtain freestanding CNT films without disturbing or degrading the alignment of nanotubes. Here, we report a reliable self-releasing technique to directly prepare freestanding vertically aligned CNT films. Freestanding CNT films thus obtained from a single CVD run retain their alignment and structure and can be directly used for applications. Additionally, this novel technique facilitates the effective incorporation of CNT films into devices in various configurations for practical applications.The experimental process for the growth of freestanding nanotube films essentially involves t...

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confidence: 99%

Ultrathick Freestanding Aligned Carbon Nanotube Films

Manikoth

et al. 2007

Advanced Materials

143

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“…Compared with the results reported in Refs. [18][19][20], the lower turn-on field and the higher current density are obtained at low electrical fields. The corresponding linear function of the Fowler-Nordheim plot shown in Fig.…”

Section: Field Emission Measurementsmentioning

confidence: 99%

Simple method to rapidly fabricate chain-like carbon nanotube films and its field emission properties

Wang

2010

Int J Miner Metall Mater

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A simple process to fabricate chain-like carbon nanotube (CNT) films by microwave plasma-enhanced chemical vapor deposition (MPCVD) was developed successfully. Prior to deposition, the Ti/Al 2 O 3 substrates were ground with Fe-doped SiO 2 powder. The nano-structure of the deposited films was analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The field electron emission characteristics of the chain-like carbon nanotube films were measured under the vacuum of 10 −5 Pa. The low turn-on field of 0.80 V/μm and the emission current density of 8.5 mA/cm 2 at the electric field of 3.0 V/μm are obtained. Based on the above results, chain-like carbon nanotube films probably have important applications in cold cathode materials and electrode materials.

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“…[18] Second, carbon nanotubes can be easily patterned through a simple transfer printing process. [19][20][21] In this work, using patterned SWNT bundles as templates, we find that a broad range of technologically important organic semiconductors such as pentacene, tetracene and sexiphenylene can all be crystallized into large-area patterns. Using pentacene as a model system, we studied the dependence of the number of crystals on the amount of carbon nanotube bundles as well as the crystal nucleation and growth mechanism.…”

Section: Introductionmentioning

confidence: 99%

Selective Crystallization of Organic Semiconductors on Patterned Templates of Carbon Nanotubes

Liu

Briseño

Mannsfeld

et al. 2007

Adv Funct Materials

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A method of patterning large arrays of organic single crystals is reported. Using single‐walled carbon nanotube (SWNT) bundles as patterned templates, several organic semiconductor materials were successfully patterned, including p‐type pentacene, tetracene, sexiphenylene, and sexithiophene, as well as n‐type tetracyanoquinodimethane (TCNQ). This study suggests that the selective growth of crystals onto patterned carbon nanotubes is most likely due to the coarse topography of the SWNT bundles. Moreover, we observed that the crystals nucleated from SWNT bundles and grew onto SWNT bundles in a conformal fashion. The dependence of the number of crystals on the quantity of SWNT bundles is also discussed. The crystal growth can be directly applied onto transistor source‐drain electrodes and arrays of organic single‐crystal field effect transistors are demonstrated. The results demonstrate the potential of utilizing carbon nanotubes as nucleation templates for patterning a broad range of organic materials for applications in optoelectronics.

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Contact transfer of aligned carbon nanotube arrays onto conducting substrates

Cited by 74 publications

References 13 publications

Ultrathick Freestanding Aligned Carbon Nanotube Films

Ultrathick Freestanding Aligned Carbon Nanotube Films

Simple method to rapidly fabricate chain-like carbon nanotube films and its field emission properties

Selective Crystallization of Organic Semiconductors on Patterned Templates of Carbon Nanotubes

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