Abstract-Terahertz rectennas on flexible substrates based on one-dimensional metal-insulator-graphene diodes

 

Andreas Hemmetter,  Xinxin Yang , Zhenxing Wang, Martin Otto, Burkay Uzlu , Marcel Andree , Ullrich Pfeiffer, Andrei Vorobiev, Jan Stake, Max C. Lemme, Daniel Neumaier, 

https://arxiv.org/abs/2106.11679

Flexible energy harvesting devices fabricated in scalable thin-film processes are important components in the field of wearable electronics and the Internet of Things. We present a flexible rectenna based on a one-dimensional junction metal-insulator-graphene diode, which offers low-noise power detection at terahertz (THz) frequencies. The rectennas are fabricated on a flexible polyimide film in a scalable process by photolithography using graphene grown by chemical vapor deposition. A one-dimensional junction area reduces the junction capacitance and enables operation in the D-band (110 - 170 GHz). The rectenna on polyimide shows a maximum voltage responsivity of 80 V/W at 167 GHz in free space measurements and minimum noise equivalent power of 80 pW/Hz−−−√.

Abstract-Room-temperature, low-impedance and high-sensitivity terahertz direct detector based on bilayer graphene field-effect transistor

• Hua Qin^1,, 
• Jiandong Sun¹, 
• Shixiong Liang², 
• Xiang Li^1, 3, 
• Xinxin Yang^1, †, 
• Zehao He², 
• Cui Yu²,
• Zhihong Feng^2, , 

• ¹ Key Laboratory of Nanodevices and Applications, Suzhou Institute of Nano-tech and Nano-bionics (SINANO), Chinese Academy of Sciences, 398 Ruoshui Road, Suzhou 215123, PR China
• ² National Key Laboratory of ASIC, Hebei Semiconductor Research Institute, Shijiazhuang, Hebei 050051, PR China
• ³ School of Nano Technology and Nano Bionics, University of Science and Technology of China, Suzhou 215123, PR China
• 
  

http://www.sciencedirect.com/science/article/pii/S0008622317301653

We report a room-temperature, low-impedance and high-sensitivity terahertz direct terahertz 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 cm²/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 cm²/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^1/2were 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.