Abstract-CMOS fully integrated terahertz thermal detector using metamaterial absorber and proportional-to-absolute temperature sensor Xu Wang

 

Xu Wang

https://www.spiedigitallibrary.org/journals/optical-engineering/volume-59/issue-9/097106/CMOS-fully-integrated-terahertz-thermal-detector-using-metamaterial-absorber-and/10.1117/1.OE.59.9.097106.short?SSO=1

Terahertz (THz) detectors have drawn much attention and have been widely applied in imaging, spectroscopy, and sensing fields. An uncooled monolithic resonant THz thermal detector implemented in a standard 55-nm CMOS process is presented. The integration of a frequency selective metamaterial (MM) absorber coupled with an optimized proportional-to-absolute temperature (PTAT) sensor leads to an approach toward uncooled, compact, low-cost, easy-integration, and mass-production THz detectors. The theoretical analysis, design considerations, and characteristic measurements are demonstrated in detail. The proposed thermal detector is designed to resonate at 2.58 THz for the accessible THz source and the natural atmospheric window. The MM absorber achieves near-perfect absorptivity of 98.6%, and the optimized PTAT sensor obtains a high-temperature sensitivity of 10.11  mV  /    °  C. The calculated responsivity is 49.81  V  /  W at 2.58 THz with a calculated noise-equivalent power (NEP) of 0.78  μW  /  Hz^0.5 at a modulation frequency of 3 Hz. Relatively better experimental results are obtained at 2.58 THz with a maximum responsivity of 48.3  V  /  W and a minimum NEP of 1.06  μW  /  Hz^0.5.

© 2020 Society of Photo-Optical Instrumentation Engineers (SPIE) 0091-3286/2020/$28.00 © 2020 SPIE

Abstract-Singularity-enhanced terahertz detection in high-mobility field-effect transistors

Michail Khavronin, Aleksandr S. Petrov, Aleksandr E. Kazantsev, Egor I. Nikulin, Denis A. Bandurin

https://arxiv.org/abs/2005.04739

Detectors of high-frequency radiation based on high-electron-mobility transistors benefit from low noise, room-temperature operation, and the possibility to perform radiation spectroscopy using gate-tunable plasmon resonance. Despite successful proof-of-concept demonstrations, the responsivity of transistor-based detectors of THz radiation, at present, remains fairly poor. To resolve this problem, we propose a class of devices supporting singular plasmon modes, i.e. modes with strong electric fields near keen electrodes. A large plasmon-enhanced electric field results in amplified non-linearities, and thus efficient ac-to-dc conversion. We analyze sub-terahertz detectors based on a two-dimensional electron system (2DES) in the Corbino geometry as a prototypical and exactly solvable model and show that the responsivity scales as 1/r20 with the radius of the inner contact r0. This enables responsivities exceeding 10 kV/W at sub-THz frequencies for nanometer-scale contacts readily accessible by modern nanofabrication techniques.

Abstract-A review of terahertz detectors

R A Lewis

https://iopscience.iop.org/article/10.1088/1361-6463/ab31d5/pdf

Physics is the interplay of energy and matter. Energy, in the form of light, interacting with matter, principally in the solid state, underpins this topical review. The subject is developed carefully and methodically, beginning with basic definitions pertaining to terahertz detectors and terahertz radiation, then proceeding systematically to delineate characteristics of terahertz photons and terahertz detectors in more detail. In-between, the intimate connection linking terahertz sensors and terahertz sources is highlighted—an important aspect unfortunately often overlooked or ignored when terahertz detectors are discussed in isolation. At the centre of this topical review are the various physical mechanisms by which electromagnetic radiation of terahertz frequencies interacts with matter. The logic is to present first the underlying physical principles of detection before presenting the practical implementation in a specific device, rather than the other way around. A taxonomy of terahertz detectors is then proposed based on the underlying physical principles of detection. Following on from this classification, state-of-the-art terahertz detectors are surveyed and appraised; this overview constitutes the longest section of the review. Key detector parameters which inform applications are then presented and tabulated. Finally, the present state-of-the-art is anchored within the wider scientific context of historical developments and future prospects.

Abstract-The Route to Nanoscale Terahertz Technology: Nanowire-based Terahertz Detectors and Terahertz Modulators

Jessica L Boland, Kun Peng, Sarwat Baig, Diamshid Damry, Patrick Parkinson, Lan Fu, Hark Hoe Tan,  

https://ieeexplore.ieee.org/document/8510319

In this work, we demonstrate novel THz detectors and modulators based on semiconductor nanowires. We show that single nanowire PC THz receivers exhibit excellent sensitivity, high SNR of 40, and a broad detection bandwidth up to 2 THz, comparable to the bulk InP PC receivers. We also demonstrate ultrafast THz modulation by GaAs nanowire polarisers with a less than 5ps switching time and a modulation depth of -8dB, We show an extinction of over 13% and dynamic range of -9dB, comparable to microsecond-switchable graphene- and metamaterial-based THz modulators.

Abstract-Quantum dot THz detectors and its applications for imaging

Kenji Ikushima,

https://www.spiedigitallibrary.org/conference-proceedings-of-spie/10729/1072902/Quantum-dot-THz-detectors-and-its-applications-for-imaging/10.1117/12.2319927.short?SSO=1

Single photon detection is realized by utilizing semiconductor quantum structures in a wide range of the terahertz (THz) region. In this paper, we review quantum-dot type THz photon detectors and its applications for passive THz imaging.

© (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

Abstract-Tunable Stub Plasmonic Structures for Terahertz Detectors and Sources

Michael S. Shur, Gregory R. Aizin, and J. Mikalopas

http://65.202.222.105/abstract.cfm?uri=FiO-2018-JW4A.75

Numerous applications of terahertz communication and sensing technology require powerful electronic sources and sensitive detectors. Recently proposed “plasmonic boom” terahertz devices require the electron velocity repeatedly cross the plasma velocity in periodic electronic structures. Such devices could increase the generated power and detection sensitivity by orders of magnitude. However, they require tuning boundary conditions at heterodimensional interfaces and decreasing the velocity of the plasmons. We propose using the protruding side regions attached to a plasmonic channel – “plasmonic stubs” – to control the boundary conditions and slow down plasmons in a controllable and tunable fashion. Using the transmission line modeling approach, we derive the expression for the input impedance of the device with a stub and show the input impedance could be tuned from minus to plus infinity. We derive and solve the dispersion equation for the plasmons and show the tunable plasma velocity decrease. These results are important for design, characterization, modeling, and parameter extraction of the next generation of THz electronic devices and circuits.

© 2018 The Author(s)

Abstract-Comparative study on calculated terahertz absorption spectra of different heterostructure materials with external magnetic field

Lei Cao

http://iopscience.iop.org/article/10.1088/2399-6528/aadbba

Room temperature operation and frequency tunability are attractive advantages of terahertz (THz) detectors based on the two-dimensional electron gas (2DEG) in the heterostructure material with external magnetic field. This work compared absorption spectra of four typical heterostructure materials (AlGaN/GaN, InAlN/GaN, AlGaAs/GaAs and SiGe/Si) with the nonlocal magnetoconductivity model at ambient and cryogenic temperatures in the frequency range 0-5 THz. The GaN based materials have the highest absorption amplitude, while the AlGaAs/GaAs material owns the largest frequency shift as the magnetic field increases up to 10 tesla, although superconducting magnets at cryogenic temperature are usually employed to provide that high magnetic field. The numerical results showed that the absorption properties (amplitude and frequency) could be further optimized by other parameters, such as the period and filling factor of the grating coupler, and the barrier thickness.

Abstract-High-Tc Josephson Junctions as Quasiclassical THz Detectors

 Irina Gundareva,  Valery Pavlovskiy,  Yuriy Divin,

https://ieeexplore.ieee.org/document/8331140/

[100]-tilt YBa2Cu3O7-x bicrystal Josephson junctions (JJs) with resistances Rn = (50-500) Ω and characteristic voltages IcRn(50 K) of 2.5 mV have been fabricated and their potential as classical terahertz detectors has been evaluated. The dc I-V curves of the JJs at temperatures T above 40 K have been found free of hysteresis and demonstrated high nonlinearity with the second derivatives d2V/dI2 up to 107-108 Ω/A at T = 50 K. The response ΔV(I) at the current I corresponding to the maximum of d2V/dI2 has been observed in a power range of more than four orders of magnitude, and ΔV is directly proportional to the incident power P (square-law detection) at low power, then ΔV ~ P1/2 (linear detection) at higher power. The responses ΔV(V) at low voltages V to external radiation with the frequencies from 0.05 to 3 THz have been experimentally found to be proportional to d2V/dI2 (classical detection) at low frequencies and to dV/dI (Josephson detection) at high frequencies with a crossover near the low-frequency limit fl = (0.9 ± 0.3) THz of the ac Josephson effect in our JJs. Numerical simulations of such quasiclassical detector with Rn = 300 Ω at T = 50 K predict the NEP-values of 5·10-15 W/Hz1/2 at the frequencies up to 1 THz.

Abstract-Two-color detector: Mercury-cadmium-telluride as a terahertz and infrared detector

F. Sizov¹, V. Zabudsky¹, S. Dvoretskii², V. Petryakov¹, A. Golenkov¹, K. Andreyeva¹ and Z. Tsybrii¹
 HIDE AFFILIATIONS
1 Institute of Semiconductor Physics, 03028 Kiev, Ukraine
2 Institute of Semiconductor Physics of SB RAS, 630090 Novosibirsk, Russia
http://scitation.aip.org/content/aip/journal/apl/106/8/10.1063/1.4913590
Appl. Phys. Lett. 106, 082104 (2015); http://dx.doi.org/10.1063/1.4913590

In this paper, issues associated with the development of infrared (IR) and terahertz (THz)radiation detectors based on HgCdTe are discussed. Two-color un-cooled and cooled to 78 K narrow-gap mercury-cadmium-telluride semiconductor thin layers with antennas were considered both as sub-THz (sub-THz) direct detection bolometers and 3–10 μm IRphotoconductors. The noise equivalent power (NEP) for one of the detectors studied at ν ≈ 140 GHz reaches NEP300 K ≈ 4.5 × 10⁻¹⁰ W/Hz^1/2 and NEP78 K ≈ 5 × 10⁻⁹ W/Hz^1/2. The samedetector used as an IR photoconductor showed the responsivity at temperatures T = 78 K and 300 K with signal-to-noise ratio S/N ≈ 750 and 50, respectively, under illumination by using IR monochromator and globar as a thermal source.

Terahertz Detectors: Large-area carbon-nanotube terahertz detector is broadband and polarization-sensitive

07/30/2014

By Gail Overton
Senior Editor

http://www.laserfocusworld.com/articles/print/volume-50/issue-08/world-news/terahertz-detectors-large-area-carbon-nanotube-terahertz-detector-is-broadband-and-polarization-sensitive.html

With applications in astronomy, sensing, defense and security, and communications, terahertz detectors are in high demand. To date, terahertz detectors made from antenna-coupled, bundled, and individual metallic single-walled carbon nanotubes (CNTs) or even graphene-based devices exhibit very small collection areas and typically require coupling of the terahertz radiation with antennas.

Recognizing that narrowband, cryogenic, small-area terahertz detectors serve only limited terahertz-detection applications, researchers at Rice University (Houston, TX), Tokyo Institute of Technology (Tokyo Tech; Japan), and Sandia National Laboratories (Livermore, CA) have successfully collaborated in the development of a large-area, broadband, polarization-dependent, and room-temperature-operable terahertz detector that uses an ensemble of single-wall CNTs with mixed chirality.¹

Broadband operation
Single-wall CNTs with mixed chirality can absorb radiation at essentially any wavelength in the electromagnetic spectrum via intraband (free-carrier) and interband (excitonic) absorption, a property shared with graphene.

The solid-state CNT-based terahertz detector begins with aligned ultralong CNTs grown vertically on a silicon substrate through chemical vapor deposition. They are then transferred to a Teflon substrate to form a highly flexible film of horizontally aligned CNTs. This film is strongly polarization-dependent due to the aligned nature of the nanotubes and collective antenna effects. The n-type region is made by doping the as-grown p-type CNT film with benzyl viologen; two gold electrodes complete the p-n junction detector device (see figure).

A schematic (a) shows the carbon nanotube (CNT)-based p-n junction terahertz detector. The current-voltage characteristics (b) are shown for the device when illuminated by a 2.52 THz beam (red) and when not illuminated (black). (Courtesy: Rice University)

When illuminated with terahertz light at 3.11, 2.52, and 1.39 THz, responsivity values are 2.5, 2.4, and 1.7 V/W, respectively. The noise-equivalent-power, a figure of merit for photodetectors, is 20 nW/Hz^1/2 at room temperature—a value already approaching that of existing uncooled terahertz detectors. Through a series of experiments the research team demonstrated the photothermoelectric nature of the response, which clears the path towards improving the noise-equivalent-power by correspondingly improving the device design and the thermoelectric properties of the CNT thin film.

“This work opens up a new avenue for developing terahertz detectors that are low cost and flexible,” says François Léonard, distinguished member of technical staff at Sandia. “We are looking for partners to further develop the technology and realize its full promise.”

REFERENCE
1. Xiaowei He et al., Nano Letters 14, 7, 3953–3958 (May 29, 2014).

Abstract-Noise Analysis of Photoconductive Terahertz Detectors

Ning Wang, 

Mona Jarrahi

http://link.springer.com/article/10.1007%2Fs10762-013-9995-1

The noise performance of photoconductive terahertz detectors is analyzed and the tradeoff between low-noise and high-responsivity operation of photoconductive detectors is investigated as a function of device parameters and operational settings. The analysis is conducted on two general photoconductive detector architectures, symmetrically pumped and asymmetrically pumped photoconductive detector architectures. The results indicate that the highest signal-to-noise ratios are offered by the symmetrically pumped and asymmetrically pumped detector architectures for the photoconductive detectors based on short-carrier lifetime and long-carrier lifetime semiconductors, respectively.