PT Unknown
AU Fedorov, G
   Gayduchenko, I
   Titova, N
   Moskotin, M
   Obraztsova, E
   Rybin, M
   Goltsman, G
TI Graphene-based lateral Schottky diodes for detecting terahertz radiation
SE Proc. Optical Sensing and Detection V
PY 2018
BP 30
EP 39
VL 10680
DI 10.1117/12.2307020
DE graphene; terahertz radiation; detectors; Schottky diodes; carbon nanotubes; plasma waves
AB 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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