Worldwide commercial interest in carbon nanotubes (CNTs) is reflected in a production capacity that presently exceeds several thousand tons per year. Currently, bulk CNT powders are incorporated in diverse commercial products ranging from rechargeable batteries, automotive parts, and sporting goods to boat hulls and water filters. Advances in CNT synthesis, purification, and chemical modification are enabling integration of CNTs in thin-film electronics and large-area coatings. Although not yet providing compelling mechanical strength or electrical or thermal conductivities for many applications, CNT yarns and sheets already have promising performance for applications including supercapacitors, actuators, and lightweight electromagnetic shields.

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Carbon Nanotubes: Present and Future Commercial Applications

Thermal conductivity of carbon nanotubes and their polymer nanocomposites: A review

Heavy metal removal from aqueous solution by advanced carbon nanotubes: Critical review of adsorption applications

Recent research and development has been incredibly successful at advancing the capabilities for vacuum electronic device (VED) sources of powerful terahertz (THz) and near-THz coherent radiation, both CW or average and pulsed. Currently, the VED source portfolio covers over 12 orders of magnitude in power (mW-to-GW) and two orders of magnitude in frequency (from ; 10 THz). Further advances are still possible and anticipated. They will be enabled by improved understanding of fundamental beam-wave interactions, electromagnetic mode competition and mode control, along with research and development of new materials, fabrication methods, cathodes, electron beam alignment and focusing, magnet technologies, THz metrology and advanced, broadband output radiation coupling techniques.

Vacuum Electronic High Power Terahertz Sources

Dye-sensitized solar cells (DSSCs) are regarded as prospective solar cells for the next generation of photovoltaic technologies and have become research hotspots in the PV field. The counter electrode, as a crucial component of DSSCs, collects electrons from the external circuit and catalyzes the redox reduction in the electrolyte, which has a significant influence on the photovoltaic performance, long-term stability and cost of the devices. Solar cells, dye-sensitized solar cells, as well as the structure, principle, preparation and characterization of counter electrodes are mentioned in the introduction section. The next six sections discuss the counter electrodes based on transparency and flexibility, metals and alloys, carbon materials, conductive polymers, transition metal compounds, and hybrids, respectively. The special features and performance, advantages and disadvantages, preparation, characterization, mechanisms, important events and development histories of various counter electrodes are presented. In the eighth section, the development of counter electrodes is summarized with an outlook. This article panoramically reviews the counter electrodes in DSSCs, which is of great significance for enhancing the development levels of DSSCs and other photoelectrochemical devices.

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Counter electrodes in dye-sensitized solar cells

We report the controlled growth of ultralong single-wall carbon nanotube (SWNT) arrays using an improved chemical vapor deposition strategy. Using ethanol or methane as the feed gas, monodispersed Fe−Mo as the catalyst, and a superaligned carbon nanotube (CNT) film as the catalyst supporting frame, ultralong CNTs over 18.5 cm long were grown on Si substrates. The growth rate of the CNTs was more than 40 μm/s. No catalyst-related residual material was found on the substrates due to the use of a CNT film as the catalyst supporting frame, facilitating any subsequent fabrication of SWNT-based devices. Electrical transport measurements indicated that the electrical characteristics along a single ultralong SWNT were uniform. We also found that maintaining a spatially homogeneous temperature during the growth process was a critical factor for obtaining constant electrical characteristics along the length of the ultralong SWNTs.

Fabrication of Ultralong and Electrically Uniform Single-Walled Carbon Nanotubes on Clean Substrates

The thermal contact resistance is a difficult problem that has puzzled many researchers in measuring the intrinsic thermal conductivity of an individual carbon nanotube (CNT). To avoid this problem, a non-contact Raman spectra shift method is introduced, by which we have successfully measured the thermal conductivity (kappa) of an individual single-walled carbon nanotube and a multi-walled carbon nanotube. The measured kappa values are 2400 W m(-1) K(-1) and 1400 W m(-1) K(-1), respectively. The CNT was suspended over a trench and heated by electricity. The temperature difference between the middle and the two ends of the CNT indicated its intrinsic heat transfer capability. The temperature difference was determined by the temperature-induced shifts of its G band Raman spectra. This new method can eliminate the impact of the thermal contact resistance which was a Gordian knot in many previous measurements.

https://iopscience.iop.org/article/10.1088/0957-4484/20/14/145702/pdf

Measuring the thermal conductivity of individual carbon nanotubes by the Raman shift method.

Magnetron sputtering is an important method in the superconducting thin films deposition. The residual gas inside the vacuum chamber will directly affect the quality of the superconducting films. In this paper, niobium films are deposited by magnetron sputtering under different chamber residual gas conditions. The influence of baking and sputtering process on residual gas are studied as well. Surface morphology, electrical and mechanical properties of the films are analysed. The residual gas analysis result before the sputtering process could be regarded as a reference condition to achieve high quality superconducting thin films.

Effect of residual gas on structural, electrical and mechanical properties of niobium films deposited by magnetron sputtering deposition

We have fabricated single-walled carbon nanotube (SWNT) arrays, about 85% of which are semiconducting. Fe nanoparticles, which were used as a catalyst, were produced simply and cheaply from Wistar rat blood. The SWNT arrays generally grow parallel to the gas flow. Hundreds of devices with varying SWNT density in the channel were measured and we found that the on–off ratio for such devices with the quasi-parallel, semiconducting-rich SWNTs in the channel can be easily increased via an electrical breakdown method. Thus, large-scale fabrication of FET devices is possible simply by controlling the width of the channel. Finally, we determined that the mobility of the devices reached 3900 cm2 V − 1 s − 1.

http://iopscience.iop.org/article/10.1088/0957-4484/21/39/395602/pdf

Selective fabrication of quasi-parallel single-walled carbon nanotubes on silicon substrates

http://ieeexplore.ieee.org/iel7/6892250/6898219/06898499.pdf

Xueshen Wang

Papers

Fabrication of Ultralong and Electrically Uniform Single-Walled Carbon Nanotubes on Clean Substrates

Measuring the thermal conductivity of individual carbon nanotubes by the Raman shift method.

Effect of residual gas on structural, electrical and mechanical properties of niobium films deposited by magnetron sputtering deposition

Selective fabrication of quasi-parallel single-walled carbon nanotubes on silicon substrates

New design of decimal nominal value resistance based on Quantum Hall Array