Fedorov, G., Gayduchenko, I., Titova, N., Moskotin, M., Obraztsova, E., Rybin, M., et al. (2018). Graphene-based lateral Schottky diodes for detecting terahertz radiation. In F. Berghmans, & A. G. Mignani (Eds.), Proc. Optical Sensing and Detection V (Vol. 10680, pp. 30–39). Spie.
Abstract: Demand for efficient terahertz radiation detectors resulted in intensive study of the carbon nanostructures as possible solution for that problem. In this work we investigate the response to sub-terahertz radiation of graphene field effect transistors of two configurations. The devices of the first type are based on single layer CVD graphene with asymmetric source and drain (vanadium and gold) contacts and operate as lateral Schottky diodes (LSD). The devices of the second type are made in so-called Dyakonov-Shur configuration in which the radiation is coupled through a spiral antenna to source and top electrodes. We show that at 300 K the LSD detector exhibit the room-temperature responsivity from R = 15 V/W at f= 129 GHz to R = 3 V/W at f = 450 GHz. The DS detector responsivity is markedly lower (2 V/W) and practically frequency independent in the investigated range. We find that at low temperatures (77K) the graphene lateral Schottky diodes responsivity rises with the increasing frequency of the incident sub-THz radiation. We interpret this result as a manifestation of a plasmonic effect in the devices with the relatively long plasmonic wavelengths. The obtained data allows for determination of the most promising directions of development of the technology of nanocarbon structures for the detection of THz radiation.
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Titova, N. A., Baeva, E. M., Kardakova, A. I., & Goltsman, G. N. (2020). Fabrication of NbN/SiNx:H/SiO2 membrane structures for study of heat conduction at low temperatures. In J. Phys.: Conf. Ser. (Vol. 1695, 012190).
Abstract: Here we report on the development of NbN/SiNx:H/SiO2-membrane structures for investigation of the thermal transport at low temperatures. Thin NbN films are known to be in the regime of a strong electron-phonon coupling, and one can assume that the phononic and electronic baths in the NbN are in local equilibrium. In such case, the cooling of the NbN-based devices strongly depends on acoustic matching to the substrate and substrate thermal characteristics. For the insulating membrane much thicker than the NbN film, our preliminary results demonstrate that the membrane serves as an additional channel for the thermal relaxation of the NbN sample. That implies a negligible role of thermal boundary resistance of the NbN-SiNx:H interface in comparison with the internal thermal resistance of the insulating membrane.
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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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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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Gayduchenko, I., Fedorov, G., Titova, N., Moskotin, M., Obraztsova, E., Rybin, M., et al. (2018). Towards to the development of THz detectors based on carbon nanostructures. In J. Phys.: Conf. Ser. (Vol. 1092, 012039 (1 to 4)).
Abstract: Demand for efficient terahertz radiation detectors resulted in intensive study of the carbon nanostructures as possible solution for that problem. In this work we investigate the response to sub-terahertz radiation of detectors with sensor elements based on CVD graphene as well as its derivatives – carbon nanotubes (CNTs). The devices are made in configuration of field effect transistors (FET) with asymmetric source and drain (vanadium and gold) contacts and operate as lateral Schottky diodes. We show that at 300K semiconducting CNTs show better performance up to 300GHz with responsivity up to 100V/W, while quasi-metallic CNTs are shown to operate up to 2.5THz. At 300 K graphene detector exhibit the room-temperature responsivity from R = 15 V/W at f = 129 GHz to R = 3 V/W at f = 450 GHz. We find that at low temperatures (77K) the graphene lateral Schottky diodes responsivity rises with the increasing frequency of the incident sub-THz radiation. We interpret this result as a manifestation of a plasmonic effect in the devices with the relatively long plasmonic wavelengths. The obtained data allows for determination of the most promising directions of development of the technology of nanocarbon structures for the detection of THz radiation.
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