A Linear-Array of 300-GHz Antenna Integrated GFET Detectors on a Flexible Substrate

Abstract

Terahertz imaging has potential in a variety of applications, such as noninvasive inspection, medical examination, and security. Many of these applications call for flexible focal-plane arrays with large fields of view. Here, we demonstrate the implementation of a flexible, 300 GHz, 1 × 6 linear detector array based on graphene field-effect transistors and integrated bow-tie antennas. Conservative estimates based on room temperature measurements at 300 GHz show element voltage responsivities in the range from 20 to 70 V/W, and noise equivalent powers in the range from 0.06 to 0.2 nW/ √ Hz. Measured radiation patterns, showing good agreement with simulations, reveal half-power beamwidths of 45 • and 60 • for Hand E-planes, respectively. Characterization of the antenna array in a curved configuration shows that the voltage response is reduced up to 3 dB compared to the flat configuration due to a decrease of the antenna directivity. We believe that our preliminary results could serve as an enabling platform for the future development of flexible antenna arrays based on graphene field-effect transistors for curved focal plane imaging, important for wearable sensors and many other applications.

Tailorable Electronic and Electric Properties of Graphene with Selective Decoration of Silver Nanoparticles by Laser-Assisted Photoreduction

“…Although the laser conditions should have been optimized for growing the AgNPs efficiently, these results imply that, via controlling the laser parameters for the PR process, the growth kinetics of the AgNPs on graphene were delicately adjustable, leading to the detailed tunability of the electronic and electric properties of the AgNP-decorated graphene as well as the device characteristics of the GFETs. Due to the excellent electronic [ 2 ] and mechanical properties [ 3 , 4 ] of graphene, the GEET can be embedded into high-performance electronics [ 47 ], opto-electronics [ 26 ], sensors [ 48 ], as well as wearable devices [ 49 ].…”

Two-Dimensional Field-Effect Transistor Sensors: The Road toward Commercialization

“…Terahertz (THz) light covers a frequency range from 0.1 to 10 THz with a typical wavelength larger than 30 μm. , THz detection is challenging but significant for medical imaging, radio astronomy, noninvasive inspection, 5G wireless communication, , etc.…”

“…As a supplement to infrared imaging, THz bands exhibit higher penetrability to most nonmetallic blocks that are opaque in the SWIR rigon . Thus, THz imaging by 2D phototransistors is extremely attractive for noninvasive inspection and security. , Xu et al created a planar metal–PtTe 2 –metal structure for the direct generation of THz bands at room temperature using a PtTe 2 -graphene heterostructure phototransistor. The reported platform demonstrated the advantages of THz photodetectors by mapping a metal nut with a scan speed of 0.2 mm s –1 (Figure h).…”

Numerical Evaluation of the Effect of Geometric Tolerances on the High-Frequency Performance of Graphene Field-Effect Transistors

“…This feature is extremely interesting, for example, for the aerospace field, particularly because it is accompanied by graphene's inherent tolerance to radiation [30][31][32]. For these reasons, several examples of graphene-based RF devices have been proposed in recent years, including antennas [33,34], transmitters and receivers [35][36][37], modulators and demodulators [38][39][40][41][42][43], shields [44], power and signal amplifiers [45][46][47][48], mixers [49][50][51], and oscillators [52][53][54]. Important milestones were recently reached towards the large-scale fabrication of graphene electronic devices [55] and their integration into traditional semiconductor fabrication lines [56].…”