Gayduchenko, I. A., Fedorov, G. E., Ibragimov, R. A., Stepanova, T. S., Gazaliev, A. S., Vysochanskiy, N. A., et al. (2016). Synthesis of single-walled carbon nanotube networks using monodisperse metallic nanocatalysts encapsulated in reverse micelles. Chem. Ind. Belgrade, 70(1), 1–8.
Abstract: We report on a method of synthesis of single-walled carbon nanotubes percolated networks on silicon dioxide substrates using monodisperse Co and Ni catalyst. The catalytic nanoparticles were obtained by modified method of reverse micelles of bis-(2-ethylhexyl) sulfosuccinate sodium in isooctane solution that provides the nanoparticle size control in range of 1 to 5 nm. The metallic nanoparticles of Ni and Co were characterized using transmission electron microscopy (TEM) and atomic-force microscopy (AFM). Carbon nanotubes were synthesized by chemical vapor deposition of CH4/H2 composition at temperature 1000 °С on catalysts pre-deposited on silicon dioxide substrate. Before temperature treatment during the carbon nanotube synthesis most of the catalyst material agglomerates due to magnetic forces while during the nanotube growth disintegrates into the separate nanoparticles with narrow diameter distribution. The formed nanotube networks were characterized using AFM, scanning electron microscopy (SEM) and Raman spectroscopy. We find that the nanotubes are mainly single-walled carbon nanotubes with high structural perfection up to 200 μm long with diameters from 1.3 to 1.7 nm consistent with catalyst nanoparticles diameter distribution and independent of its material.
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Gayduchenko, I. A., Fedorov, G. E., Stepanova, T. S., Titova, N., Voronov, B. M., But, D., et al. (2016). Asymmetric devices based on carbon nanotubes as detectors of sub-THz radiation. In J. Phys.: Conf. Ser. (Vol. 741, 012143 (1 to 6)).
Abstract: Demand for efficient terahertz (THz) radiation detectors resulted in intensive study of the asymmetric carbon nanostructures as a possible solution for that problem. In this work, we systematically investigate the response of asymmetric carbon nanodevices to sub-terahertz radiation using different sensing elements: from dense carbon nanotube (CNT) network to individual CNT. We conclude that the detectors based on individual CNTs both semiconducting and quasi-metallic demonstrate much stronger response in sub-THz region than detectors based on disordered CNT networks at room temperature. We also demonstrate the possibility of using asymmetric detectors based on CNT for imaging in the THz range at room temperature. Further optimization of the device configuration may result in appearance of novel terahertz radiation detectors.
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Titova, N., Gayduchenko, I. A., Moskotin, M. V., Fedorov, G. F., & Goltsman, G. N. (2019). Carbon nanotube based terahertz radiation detectors. In J. Phys.: Conf. Ser. (Vol. 1410, 012208 (1 to 5)).
Abstract: In this paper, we study terahertz detectors based on single quasimetallic carbon nanotubes (CNT) with asymmetric contacts and different metal pairs. We demonstrate that, depending on the contact metallization of the device, various detection mechanisms are manifested.
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Matyushkin, Y. E., Gayduchenko, I. A., Moskotin, M. V., Goltsman, G. N., Fedorov, G. E., Rybin, M. G., et al. (2018). Graphene-layer and graphene-nanoribbon FETs as THz detectors. In J. Phys.: Conf. Ser. (Vol. 1124, 051054).
Abstract: We report on detection of sub-THz radiation (129-430 GHz) using graphene based asymmetric field-effect transistor (FET) structures with different channel geometry: monolayer graphene, graphene nanoribbons. In all devices types we observed the similar trends of response on sub-THz radiation. The response fell with increasing frequency at room temperature, but increased with increasing frequency at 77 K. Our calculations show that the change in the trend of the frequency dependence at 77 K is associated with the appearance of plasma waves in the graphene channel. Unusual properties of p-n junctions in graphene are highlighted using devices of special geometry.
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Moskotin, M. V., Gayduchenko, I. A., Goltsman, G. N., Titova, N., Voronov, B. M., Fedorov, G. F., et al. (2018). Bolometric effect for detection of sub-THz radiation with devices based on carbon nanotubes. In J. Phys.: Conf. Ser. (Vol. 1124, 051050 (1 to 5)).
Abstract: In this work we investigate the response on THz radiation of a FET device based on an individual carbon nanotube conductance channel. It was already shown, that the response of such devices can be either of diode rectification origin or of thermoelectric effect origin or of their combination. In this work we demonstrate that at 77K and 8K temperatures strong bolometric effect also makes a significant contribution to the response.
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