| 1. |
- Bauer, Maris, et al.
(författare)
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Terahertz detection with graphene field-effect transistors
- 2015
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Ingår i: Graphene Week 2015.
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Konferensbidrag (refereegranskat)abstract
- Detectors for quasi-optical and guide THz waves are key elements of any THz technology. In recent years, there has been much progress in their development. Notably, field-effect transistors (FETs) have been shown to be well suited for detector implementation at room temperature exploiting (self-)mixing effects in their channels [1]. They reach a typical noise-equivalent power (NEP) of several tens of pW/Hz^1/2 at 0.6 THz in CMOS and other technologies. First focal-plane arrays and cameras have been implemented. Frequency coverage to at least 5 THz has been demonstrated. Recently, this type of detection concept has been extended successfully to graphene-based FETs [2] opening the way to freely positionable THz detectors on a wide variety of substrates (also flexible plastics). We have improved the technology (see Fig. 1) [3] and reach, for GFETs on Si, an optical NEP of 150 pW/Hz^1/2 at 0.3 THz, with considerable room for improvement. An unusually strong thermoelectric contribution has been identified [2, 3] which may help to engineer enhanced detector performance.
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| 2. |
- Bauer, Maris, et al.
(författare)
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The potential for sensitivity enhancement by the thermoelectric effect in carbon-nanotube and graphene Tera-FETs
- 2015
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Ingår i: Journal of Physics: Conference Series. - : IOP Publishing. - 1742-6588 .- 1742-6596. ; 647:1, s. UNSP 012004-
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Konferensbidrag (refereegranskat)abstract
- We report on terahertz (THz) measurements with graphene field-effect transistors with integrated antennas (Tera-FETs) lay special emphasis on thermoelectric contributions to the detected THz photoresponse. Graphene Tera-FETs with integrated broad-band bow-tie antennas were fabricated in a CVD-based growth process and were successfully applied for detection at 600 GHz with optical NEPs down to 515 pW/Hz^1/2. While rectification of THz radiation by (distributed) resistive mixing of charge-density waves induced in the gated transistor channel region is well known, significant additional contributions to the detected signal have experimentally been observed and hot-carrier thermoelectric effects have been identified as a possible origin of these signals. We also observe similar signal contributions in carbonnanotube transistors.
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| 3. |
- Stake, Jan, 1971, et al.
(författare)
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Graphene in Millimeter Wave Devices
- 2014
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Ingår i: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035. - 9781479938773 ; , s. Art. no. 6956168-
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Konferensbidrag (refereegranskat)abstract
- We present work on graphene devices and circuits for microwave and millimeter wave applications, including detectors, mixers and microwave amplifiers. Field effect transistors were fabricated from exfoliated graphene and graphene grown using chemical vapor deposition (CVD). Results from noise assessment in the microwave region, millimeter wave mixers and 0.6THz direct detectors are presented.
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| 4. |
- Vukusic, Josip, 1972, et al.
(författare)
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Heterogeneous integration of terahertz electronics
- 2015
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Ingår i: Global symposium on millimeter-waves (GSMM) 2015.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Abstract: Compact heterodyne receivers operating in the terahertz range are needed for earth observation instruments, space science missions (e.g. ESA’s “Jupiter icy moons explorer - JUICE”) and in the millimeter wave region for ground-based applications such as security scanners. Existing terahertz heterodyne receivers are usually bulky due to complex hybrid integration and there is a strong need for a terahertz monolithic integration circuit (“TMIC”) platform that allows for higher circuit functionality, ease of assembly, and low loss at terahertz frequencies. Moreover, this part of the electromagnetic spectrum, where optical and microwave techniques meet, call for an integration scheme that can support both active THz electronics & photonics. A possible solution is heterogeneous integration of THz devices (III-V, graphene) on a silicon carrier, which also allows for advanced micromaching of passive components and interconnects such as waveguides and antennas. This talk provides an overview of research on integrated diode circuits for terahertz applications. Progress on heterogeneous integration of HBV multipliers and Schottky diode mixers on silicon substrates (SOI) will be presented.
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| 5. |
- Zak, Audrey, 1990, et al.
(författare)
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20 μm gate width CVD graphene FETs for 0.6 THz detection
- 2014
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Ingår i: International Conference on Infrared, Millimeter, and Terahertz Waves, IRMMW-THz. - 2162-2027 .- 2162-2035. ; , s. Art. no. 6956250-
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Konferensbidrag (refereegranskat)abstract
- We have fabricated 20 μm gate width graphene field effect transistors (GFETs) based on graphene grown by chemical vapor deposition (CVD). These GFETs are integrated with split bow-tie antennae for room temperature, direct detection of a 0.6 THz signal. Our detectors reach a maximum optical responsivity of 3.0 V/W and a minimum noise-equivalent power (NEP) of 700 pW/Hz^0.5. The successful demonstration of THz detection using CVD graphene introduces the possibility for scalable detector production.
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| 6. |
- Zak, Audrey, 1990, et al.
(författare)
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Antenna-integrated 0.6 THz FET direct detectors based on CVD graphene
- 2014
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Ingår i: Nano Letters. - : American Chemical Society (ACS). - 1530-6992 .- 1530-6984. ; 14:10, s. 5834-5838
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Tidskriftsartikel (refereegranskat)abstract
- We present terahertz (THz) detectors based on top-gated graphene field effect transistors (GFETs) with integrated split-bow-tie antennas. The GFETs were fabricated using graphene grown by chemical vapor deposition (CVD). The THz detectors are capable of room-temperature rectification of a 0.6 THz signal and achieve a maximum optical responsivity better than 14 V/W and minimum optical noise-equivalent power (NEP) of 515 pW/Hz^0.5. Our results are a significant improvement over previous work on graphene direct detectors and are comparable to other established direct detector technologies. This is the first time room-temperature direct detection has been demonstrated using CVD graphene, which introduces the potential for scalable, wafer-level production of graphene detectors.
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