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Room-temperature, low-impedance and high-sensitivity terahertz direct detector based on bilayer graphene field-effect transistor
- Source :
- Carbon. 116:760-765
- Publication Year :
- 2017
- Publisher :
- Elsevier BV, 2017.
-
Abstract
- We report a room-temperature, low-impedance and high-sensitivity terahertz direct detector based on bilayer graphene field-effect transistor (GFET). Epitaxially grown on silicon carbide, the bilayer graphene had an as-grown carrier mobility of 3000 cm 2 /Vs. The source/drain contacts were formed on the freshly cleaned graphene sheet to minimize the contact resistance and served also as terahertz antennas. The gate and the dielectric layer underneath with a length of 145 nm and a gap of 203 nm to the source/drain antennas were formed in a self-alignment process. Although the carrier mobility in the GFET was reduced to about 405 cm 2 /Vs, the high-quality ohmic contacts and the short graphene channel delivered an overall source-drain resistance less than 203 Ω. A voltage responsivity of 30 V/W and a noise-equivalent power of 51 pW/Hz 1/2 were estimated in direct detection at 0.33 THz. By using the GFET detector as a two-terminal detector, i.e., with the gate floating, a transmission-type terahertz imaging was demonstrated. Such a low-impedance GFET detector is ready to be matched to a commercial 50-Ω low-noise radio/microwave frequency amplifier allowing for high-speed homodyne detection and heterodyne detection in a quasi-optical configuration.
- Subjects :
- 010302 applied physics
Electron mobility
Materials science
business.industry
Graphene
Terahertz radiation
Detector
02 engineering and technology
General Chemistry
021001 nanoscience & nanotechnology
01 natural sciences
law.invention
Responsivity
Homodyne detection
law
0103 physical sciences
Optoelectronics
General Materials Science
Field-effect transistor
0210 nano-technology
business
Bilayer graphene
Subjects
Details
- ISSN :
- 00086223
- Volume :
- 116
- Database :
- OpenAIRE
- Journal :
- Carbon
- Accession number :
- edsair.doi...........ca2c5a4e669cc568e900a1244a140de3