Uncooled Detectors Challenges for THz/sub-THz Arrays Imaging

Terahertz (THz) technology is one of emerging technologies that will change our life. A lot of attractive applications in security, medicine, biology, astronomy, and non-destructive materials testing have been demonstrated already. However, the realization of THz emitters and receivers is a challenge because the frequencies are too high for conventional electronics and the photon energies are too small for classical optics. As a result, THz radiation is resistant to the techniques commonly employed in these well established neighbouring bands.In the paper, issues associated with the development and exploitation of THz radiation detectors and focal plane arrays are discussed. Historical impressive progress in THz detector sensitivity in a period of more than half century is analyzed. More attention is put on the basic physical phenomena and the recent progress in both direct and heterodyne detectors. After short description of general classification of THz detectors, more details concern Schottky barrier diodes, pair braking detectors, hot electron mixers and field-effect transistor detectors, where links between THz devices and modern technologies such as micromachining are underlined. Also, the operational conditions of THz detectors and their upper performance limits are reviewed. Finally, recent advances in novel nanoelectronic materials and technologies are described. It is expected that applications of nanoscale materials and devices will open the door for further performance improvement in THz detectors.

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“…The NEP value for uncooled detectors typically is from 10 -10 to 10 -9 W/Hz 1/2 (see Table 3, Ref. 36).…”

Section: Direct Detectionmentioning

confidence: 99%

Terahertz detectors and focal plane arrays

Rogalski

Сизов

2011

Opto-Electronics Review

318

225

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“…These data of S V and NEP were obtained without any special antennas incorporated (as antennas serve the contact wires). They correspond to parameters of many other un−cooled THz/sub−THz detectors [1,16] but really they are underesti− mated as no special antennas were applied.…”

Section: Sensitivity and Nep Discussionmentioning

confidence: 98%

“…FET detectors cited in these papers were manufactured according to better design rules (0.13 and 0.065 μm) than used here. Still in these cited papers there were not achieved potentially high parameters of MOSFET THz detectors themselves that can be obtained for optimized substrates and antennas design with high antenna effective area valu− es, and these parameters remain at least from 2 to 3 orders worth of the ultimate estimations (NEP ult »(2-5)×10 -15 W/Hz 1/2 ) for uncooled detector NEP's limited only by power fluctuations of the background radiation for diffrac− tion limited beams [16]. Realization for n−MOSFETs, the values of NEP < 10 -12 W/Hz 1/2 can pave the way towards focal plane arrays for passive vision but, in fact, at present n−MOSFET uncooled detectors can be used only in active vision systems.…”

Section: Sensitivity and Nep Discussionmentioning

confidence: 99%

Sub-THz radiation room temperature sensitivity of long-channel silicon field effect transistors

Сизов

Голенков

But

et al. 2012

Opto-Electronics Review

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Room temperature operating n-MOSFETs (n-type metal-oxide silicon field effect transistors) used for registration of sub-THz (sub-terahertz) radiation in the frequency range ν = 53−145 GHz are considered. n-MOSFETs were manufactured by 1-μm Si CMOS technology applied to epitaxial Si-layers (d ≈15 μm) deposited on thick Si substrates (d = 640 μm). It was shown that for transistors with the channel width to length ratio W/L = 20/3 μm without any special antennas used for radiation input, the noise equivalent power (NEP) for radiation frequency ν ≈76 GHz can reach NEP ∼6×10−10 W/Hz1/2. With estimated frequency dependent antenna effective area Sest for contact wires considered as antennas, the estimated possible noise equivalent power NEPpos for n-MOSFET structures themselves can be from ∼15 to ∼103 times better in the specral range of ν ∼55–78 GHz reaching NEPpos ≈10−12 W/Hz1/2.

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“…MCT technologies are well developed now, and today this material is one of the basic semiconductors for photon detectors from near IR (wavelength λ∼1.5 μm) to long IR (λ∼20 μm) and is used in large scale arrays with silicon CMOS readouts. However, in spite of achievable band gap Eg∼0 these semiconductors can't be used as photon detectors in THz/sub-THz region because of high thermal generation rate even at temperatures T∼1K [2]. When considering MCT-hot electron bolometers (HEB) as THz/sub-THz detectors as it was shown [2] they are sensitive at least in the range of ν≈37 GHz... 1.6. There are numerous applications for THz technology, such as for security, for environmental monitoring, medical sciences, quality and process controls.…”

Section: Introductionmentioning

confidence: 99%

MCT as sub-terahertz and infrared detector

Sizov

Zabudsky

Dvoretsky

et al. 2015

Terahertz Physics, Devices, and Systems IX: Advanced Applications in Industry and Defense

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Development of infrared and sub-terahertz radiation detectors at the same sensitive elements on the base of mercurycadmium-telluride (MCT) is reported. Two-color un-cooled and cooled to 78 K narrow-gap MCT semiconductor thin layers, grown by liquid phase epitaxy or molecular beam epitaxy method on high resistivity CdZnTe or GaAs substrates, with bow-type antennas were considered both as sub-terahertz direct detection bolometers and 3 to 10 μm infrared photoconductors. Their room temperature noise equivalent power (NEP) at frequency ~ 140 GHz and signal-to-noise ratio (S/N) in the spectral sensitivity maximum under the monochromatic (spectral resolution of ~0.1 μm) globar illumination were reached NEP ~4.5*10 -10 W/Hz 1/2 and S/N~50, respectively.

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Uncooled Detectors Challenges for THz/sub-THz Arrays Imaging

Cited by 45 publications

References 24 publications

Terahertz detectors and focal plane arrays

Terahertz detectors and focal plane arrays

Sub-THz radiation room temperature sensitivity of long-channel silicon field effect transistors

MCT as sub-terahertz and infrared detector

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