Transparent, Conductive Carbon Nanotube Films

Wu, Zhuangchun; Chen, Zhihong; Du, Xu; Logan, Jonathan; Sippel, Jennifer; Nikolou, Maria; Kamarás, Katalin; Reynolds, John R.; Tanner, D. B.; Hebard, A. F.; Rinzler, Andrew G.

doi:10.1126/science.1101243

Cited by 2,862 publications

(2,219 citation statements)

References 12 publications

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“…Conducting polymers [197][198][199] can exhibit rather high optical transparency [200]. Meanwhile, thin-films of carbon nanotubes have been created which are both conducting and highly transparent [201,202]. Such alternatives to TCOs may find application in particular within flexible electronic devices.…”

Section: Discussionmentioning

confidence: 99%

Conductivity in transparent oxide semiconductors

King

Veal

2011

J. Phys.: Condens. Matter

224

180

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Abstract. Despite an extensive research effort for over 60 years, an understanding of the origins of conductivity in wide band-gap transparent conducting oxide (TCO) semiconductors remains elusive. While TCOs have already found widespread use in device applications requiring a transparent contact, there are currently enormous efforts to (i) increase the conductivity of existing materials, (ii) identify suitable alternatives, and (iii) attempt to gain semiconductor-engineering levels of control over their carrier density, essential for the incorporation of TCOs into a new generation of multifunctional transparent electronic devices. These efforts, however, are dependent on a microscopic identification of the defects and impurities leading to the high unintentional carrier densities present in these materials. Here, we review recent developments towards such an understanding. While oxygen vacancies are commonly assumed to be the source of the conductivity, there is increasing evidence that this is not a sufficient mechanism to explain the total measured carrier concentrations. In fact, many studies suggest that oxygen vacancies are deep, rather than shallow, donors, and their abundance in as-grown material is also debated. We discuss other potential contributions to the conductivity in TCOs, including other native defects, their complexes, and in particular hydrogen impurities. Convincing theoretical and experimental evidence is presented for the donor nature of hydrogen across a range of TCO materials, and while its stability and the presence of interstitial and substitutional species are still somewhat open questions, it is one of the leading contenders for unintentional conductivity in TCOs. We also review recent work indicating that the surfaces of TCOs can support very high carrier densities, opposite to the case of conventional semiconductors. In thin-film materials/devices and, in particular, nanostructures, the surface can have a large impact on the total conductivity in TCOs. We discuss models that attempt to explain both the bulk and surface conductivity based on features of the bulk band structure common across the TCOs, and compare these materials to other semiconductors. Finally, we briefly consider transparency in these materials, and its interplay with conductivity. Understanding this interplay, as well as the microscopic contenders for the conductivity of these materials, will prove essential to the future design and control of TCO semiconductors, and their implementation into novel multifunctional devices.

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Section: Discussionmentioning

confidence: 99%

Conductivity in transparent oxide semiconductors

King

Veal

2011

J. Phys.: Condens. Matter

224

180

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“…These films were cut into 0.5×2 cm strips and subsequently transferred onto a glass slide using the transfer method of Wu et al 72 . Electrical conductivity values were calculated from resistivity measurement using a four-point probe technique with a Keithley 2400 source meter (Keithley Instruments, Inc.).…”

Section: Film Formation Electrical and Mechanical Measurementsmentioning

confidence: 99%

Electrical, Mechanical, and Capacity Percolation Leads to High-Performance MoS₂/Nanotube Composite Lithium Ion Battery Electrodes

et al. 2016

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Advances in lithium ion batteries would facilitate technological developments inareas from electrical vehicles to mobile communications. While 2-dimensional systems like MoS2 are promising electrode materials due to their potentially high capacity, their poor ratecapability and low cycle-stability are severe handicaps. Here we study the electrical, mechanical and lithium storage properties of solution-processed MoS2/carbon nanotube anodes.Nanotube addition gives up to ×10 10 and ×40 increases in electrical conductivity and mechanical toughness respectively. The increased conductivity results in up to a ×100 capacity enhancement to ~1200 mAh/g (~3000 mAh/cm 3 ) at 0.1 A/g, while the improved toughness significantly boosts cycle stability. Composites with 20 wt% nanotubes combined high reversible capacity with excellent cycling stability (e.g. ~950 mAh/g after 500 cycles at 2 A/g) and high-rate capability (~600 mAh/g at 20 A/g). The conductivity, toughness and capacity scaled with nanotube content according to percolation theory while the stability increased sharply at the mechanical percolation threshold. We believe the improvements in conductivity and toughness obtained after addition of nanotubes can be transferred to other electrode materials such as silicon nanoparticles.Keywords: percolating, network, anode, mechanical 2 In recent years, lithium ion batteries (LIBs) have become the most common rechargeable power sources for portable electronic devices and electric vehicles. 1, 2 Nevertheless, they still suffer from several problems; their energy and especially power densities have not fulfilled their ultimate potential while their safety record is not unblemished. 3 A significant problem is that graphite, the dominant anode material used in LIBs, is limited by a relatively low theoretical capacity of 372 mAh/g. 4 As such, the development of the next-generation of LIBs, is expected to see the replacement of graphite-based anodes with alternative materials having higher capacity at similarly low cost. While a range of materials, including silicon, have been envisaged as future LIB anode materials, 4 of particular interest are 2-dimensional (2D) nanomaterials 5 such as graphene 6 and MoS2. 7 Over the last decade, 2D nano-materials have generated much excitement in the nanomaterials science community. [8][9][10] They come in many types including graphene, transition metal dichalcogenides (TMDs) and transition metal oxides (TMOs). These materials consist of covalently bonded monolayers which can stack via van der Waals interactions to form layered crystals. 8,9 Such 2D nanomaterials are often found as nanosheets with lateral size ranging from 10s of nm to microns and thickness of ~nm. 9 These materials have shown potential for applications 5 in both energy generation 11 and storage. 12 In the context of LIBs, exfoliated TMDs have received significant attention as prospective anode materials. 13,14 While bulk MoS2 was proposed 15 as a Li ion battery electrode material as early as 1980 due to its hi...

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“…[1][2][3] CNTs have the potential to revolutionize numerous applications where nano-sized metallic and/or semiconducting components are required along with high strength, [4,5] large flexibility [6] and superb chemical stability. [7,8] In particular, metallic (met-) nanotubes are highly suited for nanoscale circuits, [9] ultrathin, flexible, and transparent conductors, [10] supercapacitors, [11] field emitters, [12] actuators, [13] and nanosized electrochemical probes. [14] Semiconducting (sem-) CNTs on the other hand, are applicable for nanoscale sensors, [15,16] transistors, [17,18] and photovoltaic devices.…”

Section: Introductionmentioning

confidence: 99%

Carbon Nanotubes for Electronic and Electrochemical Detection of Biomolecules

2007

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The unique electronic and optical properties of carbon nanotubes, in conjunction with their size and mechanically robust nature, make these nanomaterials crucial to the development of next-generation biosensing platforms. In this Review, we present recent innovations in carbon nanotube-assisted biosensing technologies, such as DNA-hybridization, protein-binding, antibody-antigen and aptamers. Following a brief introduction on the diameter-and chirality-derived electronic characteristics of single-walled carbon nanotubes, the discussion is focused on the two major schemes for electronic biodetection, namely biotransistor-and electrochemistry-based sensors. Key fabrication methodologies are contrasted in light of device operation and performance, along with strategies for amplifying the signal while minimizing nonspecific binding. This Review is concluded with a perspective on future optimization based on array integration as well as exercising a better control in nanotube structure and biomolecular integration.

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Transparent, Conductive Carbon Nanotube Films

Cited by 2,862 publications

References 12 publications

Conductivity in transparent oxide semiconductors

Conductivity in transparent oxide semiconductors

Electrical, Mechanical, and Capacity Percolation Leads to High-Performance MoS₂/Nanotube Composite Lithium Ion Battery Electrodes

Carbon Nanotubes for Electronic and Electrochemical Detection of Biomolecules

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Transparent, Conductive Carbon Nanotube Films

Cited by 2,862 publications

References 12 publications

Conductivity in transparent oxide semiconductors

Conductivity in transparent oxide semiconductors

Electrical, Mechanical, and Capacity Percolation Leads to High-Performance MoS2/Nanotube Composite Lithium Ion Battery Electrodes

Carbon Nanotubes for Electronic and Electrochemical Detection of Biomolecules

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Product

Resources

About

Electrical, Mechanical, and Capacity Percolation Leads to High-Performance MoS₂/Nanotube Composite Lithium Ion Battery Electrodes