Guided Growth of Large‐Scale, Horizontally Aligned Arrays of Single‐Walled Carbon Nanotubes and Their Use in Thin‐Film Transistors

Abstract

A convenient process for generating large-scale, horizontally aligned arrays of pristine, single-walled carbon nanotubes (SWNTs) is described. The approach uses guided growth, by chemical vapor deposition (CVD), of SWNTs on miscut single-crystal quartz substrates. Studies of the growth reveal important relationships between the density and alignment of the tubes, the CVD conditions, and the morphology of the quartz. Electrodes and dielectrics patterned on top of these arrays yield thin-film transistors that use the SWNTs as effective thin-film semiconductors. The ability to build high-performance devices of this type suggests significant promise for large-scale aligned arrays of SWNTs in electronics, sensors, and other applications.

Nanobarrier-terminated growth of single-walled carbon nanotubes on quartz surfaces

“…Based on the VLS mechanism, many methods have been developed to grow SWNTs in a controlled manner. For example, the size distribution of catalyst nanoparticles can strongly influence the distribution of nanotube diameters [3,4]; special catalysts can grow SWNTs with narrow chirality distributions [5,6]; site-controlled catalyst nanoparticles determine the growth position of carbon nanotubes [7]; the carbon feeding rate during the growth can be used to control the diameter distribution of SWNTs [8]; the growth of SWNTs Nano Res (2009) 2: 768 773 Áoating in the gas phase [9,10] can afford ultra-long Á carbon nanotubes (up to centimeters in length); and on single-crystal substrates, such as sapphire [11,12] and quartz [13,14], SWNTs with extremely high alignment can be grown. However, for an individual carbon nanotube, it is difÀ cult to control its growth, À because the active growth time and growth rate depend on the activity of the catalyst, which is uncontrollable.…”

Microwave purification of large-area horizontally aligned arrays of single-walled carbon nanotubes

“…The required horizontally aligned array configurations in SWNTs are possible through chemical vapour deposition (CVD)-based growth on quartz substrates 23,24 . A long-standing challenge for use of such arrays in demanding applications arises from the need to remove all of the metallic tubes (m-SWNTs), which typically comprise B1/3 of all of the SWNTs.…”

Resonance R aman Spectroscopy

“…In addition, controlling in diameter of verticalaligned (VA-) SWNT has also been reported [23]. Not only the controls of vertical morphology structure of SWNT, but also the horizontal structure, were also realized on crystal lattice substrate [24][25][26][27].…”

“…For the horizontal direction growth, its success has been reported by many groups by using an electric field [43][44][45], a fast gas flow [46,47], and atomic steps of substrates [25,26,48,49,50,51] with other carbon sources. Furthermore, the ACCVD method has not been used for only random or VA-SWNTs, but also for horizontally-aligned SWNTs [52].…”

“…Due to their onedimensionality, many properties of SWNT are anisotropic, thus control over the orientation is highly desirable for exploiting these anisotropic properties. All of these synthesis methods coupled together with advancement in SWNT research, yielded many forms of SWNT morphology that were successfully synthesized such as, random structures [29], vertical-aligned [22], and horizontal-aligned [24][25][26][27] SWNTs as shown in Figure 3-2.…”