Cherednichenko, S., Drakinskiy, V., Baubert, J., Krieg, J. - M., Voronov, B., Gol'tsman, G., et al. (2007). Gain bandwidth of NbN hot-electron bolometer terahertz mixers on 1.5 μm Si3N4 / SiO2 membranes. J. Appl. Phys., 101(12), 124508 (1 to 6).
Abstract: The gain bandwidth of NbN hot-electron bolometer terahertz mixers on electrically thin Si3N4/SiO2 membranes was experimentally investigated and compared with that of HEB mixers on bulk substrates. A gain bandwidth of 3.5 GHz is achieved on bulk silicon, whereas the gain bandwidth is reduced down to 0.6–0.9 GHz for mixers on 1.5 μm Si3N4/SiO2 membranes. We show that application of a MgO buffer layer on the membrane extends the gain bandwidth to 3 GHz. The experimental data were analyzed using the film-substrate acoustic mismatch approach.
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Cherednichenko, S., Drakinskiy, V., Baubert, J., Lecomte, B., Dauplay, F., Krieg, J. M., et al. (2006). 2.5 THz multipixel heterodyne receiver based on NbN HEB mixers. In Proc. SPIE (Vol. 6275, 62750I (1 to 11)).
Abstract: A 16 pixel heterodyne receiver for 2.5 THz has been developed based on NbN superconducting hot-electron bolometer (HEB) mixers. The receiver uses a quasioptical RF coupling approach where HEB mixers are integrated into double dipole antennas on 1.5 µm thick Si3N4/SiO2 membranes. Spherical mirrors (one per pixel) and backshort distance from the antenna have been used to design the output mixer beam profile. The camera design allows all 16 pixel IF readout in parallel. The gain bandwidth of the HEB mixers on Si3N4/SiO2 membranes was found to be 0.7÷0.9 GHz, which is much smaller than for similar devices on silicon. Application of buffer layers and use of alternative types of membranes (e.g. silicon-on-insulator) is under investigation.
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Dickert, F. L., Haunschild, A., Kuschow, V., Reif, M., & Stathopulos, H. (1996). Mass-sensitive detection of solvent vapors. Mechanistic studies on host-guest sensor principles by FT-IR spectroscopy and BET adsorption analysis. Anal. Chem., 68(6), 1058–1061.
Abstract: Chemical sensors, based on highly mass sensitive QMB or SAW devices, coated with thin layers of calixarenes, enable the detection of organic solvent vapours, especially halogenated or aromatic hydrocarbons, down to a few ppm. Force field calculations allow the tailoring of these sensor materials seeing that the predicted interaction energies between the host molecules and a large variety of analytes are linearly correlated to the measured sensor effects. These correlations and also BET adsorption analysis prove the analyte recognition properties of these calixarene coatings to be mainly based on host/guest inclusion principles.
Keywords: supramolecular recognition, quartz crystal microbalance, QCM, surface acoustic wave, SAW, mass-sensitive sensor, detector, calixarenes, MM3 force field, Brunauer, Emmett and Teller theory, BET
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Dickert, F. L. (2007). Christoph A. Schalley (Ed.): Analytical methods in supramolecular chemistry. Anal Bioanal Chem, 389(7-8), 2039–2040.
Abstract: This is a review of book.
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Lieberzeit, P. A., & Dickert, F. L. (2009). Chemosensors in environmental monitoring: challenges in ruggedness and selectivity. Anal Bioanal Chem, 393(2), 467–472.
Abstract: Environmental analysis is a potential key application for chemical sensors owing to their inherent ability to detect analytes on-line and in real time in distributed systems. Operating a chemosensor in a natural environment poses substantial challenges in terms of ruggedness, long-term stability and calibration. This article highlights current trends of achieving both the necessary selectivity and ruggedness: one way is deploying sensor arrays consisting of robust broadband sensors and extracting information via chemometrics. If using only a single sensor is desired, molecularly imprinted polymers offer a straightforward way for designing artificial recognition materials. Molecularly imprinted polymers can be utilized in real-life environments, such as water and air, aiming at detecting analytes ranging from small molecules to entire cells.
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