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Tretyakov I, Shurakov A, Perepelitsa A, Kaurova N, Svyatodukh S, Zilberley T, et al. Room temperature silicon detector for IR range coated with Ag2S quantum dots. Phys Status Solidi RRL. 2019;13(9):1900187–(1.
Abstract: For decades, silicon has been the chief technological semiconducting material of modern microelectronics and has a strong influence on all aspects of the society. Applications of Si-based optoelectronic devices are limited to the visible and near infrared (IR) ranges. For photons with an energy less than 1.12 eV, silicon is almost transparent. The expansion of the Si absorption to shorter wavelengths of the IR range is of considerable interest for optoelectronic applications. By creating impurity states in Si, it is possible to cause sub-bandgap photon absorption. Herein, an elegant and effective technology of extending the photo-response of Si toward the IR range is presented. This approach is based on the use of Ag 2 S quantum dots (QDs) planted on the surface of Si to create impurity states in the Si bandgap. The specific sensitivity of the room temperature zero-bias Si_Ag 2 Sp detector is 10 11 cm Hz W 1 at 1.55 μm. Given the variety of available QDs and the ease of extending the photo-response of Si toward the IR range, these findings open a path toward future studies and development of Si detectors for technological applications. The current research at the interface of physics and chemistry is also of fundamental importance to the development of Si optoelectronics.
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Korneev AA, Korneeva YP, Mikhailov MY, Pershin YP, Semenov AV, Vodolazov DY, et al. Characterization of MoSi superconducting single-photon detectors in the magnetic field. IEEE Trans Appl Supercond. 2015;25(3):2200504 (1 to 4).
Abstract: We investigate the response mechanism of nanowire superconducting single-photon detectors (SSPDs) made of amorphous MoxSi1-x. We study the dependence of photon count and dark count rates on bias current in magnetic fields up to 113 mT at 1.7 K temperature. The observed behavior of photon counts is similar to the one recently observed in NbN SSPDs. Our results show that the detecting mechanism of relatively high-energy photons does not involve the vortex penetration from the edges of the film, and on the contrary, the detecting mechanism of low-energy photons probably involves the vortex penetration from the film edges.
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Korneev A, Korneeva Y, Manova N, Larionov P, Divochiy A, Semenov A, et al. Recent nanowire superconducting single-photon detector optimization for practical applications. IEEE Trans Appl Supercond. 2013;23(3):2201204 (1 to 4).
Abstract: In this paper, we present our approaches to the development of fiber-coupled superconducting single photon detectors with enhanced photon absorption. For such devices we have measured detection efficiency in wavelength range from 500 to 2000 nm. The best fiber coupled devices exhibit detection efficiency of 44.5% at 1310 nm wavelength and 35.5% at 1550 nm at 10 dark counts per second.
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Seliverstov S, Maslennikov S, Ryabchun S, Finkel M, Klapwijk TM, Kaurova N, et al. Fast and sensitive terahertz direct detector based on superconducting antenna-coupled hot electron bolometer. IEEE Trans Appl Supercond. 2015;25(3):2300304.
Abstract: We characterize superconducting antenna-coupled hot-electron bolometers for direct detection of terahertz radiation operating at a temperature of 9.0 K. The estimated value of responsivity obtained from lumped-element theory is strongly different from the measured one. A numerical calculation of the detector responsivity is developed, using the Euler method, applied to the system of heat balance equations written in recurrent form. This distributed element model takes into account the effect of nonuniform heating of the detector along its length and provides results that are in better agreement with the experiment. At a signal frequency of 2.5 THz, the measured value of the optical detector noise equivalent power is 2.0 × 10-13 W · Hz-0.5. The value of the bolometer time constant is 35 ps. The corresponding energy resolution is about 3 aJ. This detector has a sensitivity similar to that of the state-of-the-art sub-millimeter detectors operating at accessible cryogenic temperatures, but with a response time several orders of magnitude shorter.
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Zhang W, Miao W, Li SL, Zhou KM, Shi SC, Gao JR, et al. Measurement of the spectral response of spiral-antenna coupled superconducting hot electron bolometers. IEEE Trans Appl Supercond. 2013;23(3):2300804.
Abstract: Measured spectral response of spiral-antenna coupled superconducting hot electron bolometers (HEBs) often drops dramatically at frequencies that are still within the frequency range of interest (e.g., ~ 5 THz). This is inconsistent with the implied low receiver noise temperatures from the same measurements. To understand this discrepancy, we exhaustively test and calibrate the thermal sources used in Fourier transform spectrometer measurements. We first investigate the absolute emission spectrum of high-pressure Hg arc lamp, then measure the spectral response of two spiral-antenna coupled NbN HEBs with a Martin-Puplett interferometer as spectrometer and 77 K blackbody as broadband signal source. The measured absolute emission spectrum of Hg arc lamp is proportional to frequency, corresponding to an equivalent blackbody temperature of 4000 K at 1 THz, 1500 K at 3 THz, and 800 K at 5 THz, respectively. Measured spectral response of spiral-antenna coupled NbN HEBs, corrected for air absorption, is nearly flat in the frequency range of 0.5-4 THz, consistent with simulated coupling efficiency between HEB and spiral-antenna. These results explain the discrepancy, and prove that spiral-antenna coupled superconducting NbN HEBs work well in a wide frequency range. In addition, this calibration method and these results are broadly applicable to other quasi-optical THz receivers.
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Palma F, Teppe F, Fatimy AE, Green R, Xu J, Vachontin Y, et al. THz communication system based on a THz quantum cascade laser and a hot electron bolometer. In: 35th Int. Conf. Infrared, Millimeter, and Terahertz Waves.; 2010. 11623798 (1 to 2).
Abstract: We present the experimental study of the direct emission – detection system based on the THz Quantum Cascade Laser as a source and Hot Electron Bolometer (HEB) detector – in view of its application as an optical communication system. We show that the system can efficiently transmit the QCL Terahertz pulses. We estimate the maximal modulation speed of the system to be about several GHz and show that it is limited only by the QCL pulse power supply, detector amplifier and connection line/wires parameters.
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