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Bueno Lopez, J. (author), Sberna, P.M. (author), Fiorellini Bernardis, A. (author), Zhang, H. (author), Neto, A. (author), Llombart, Nuria (author)State-of-the-art THz pulsed commercial systems operating over large bandwidth suffer from high dispersion or low radiation efficiency due to the poor coupling between the transmitter and receiver photoconductive antennas (PCAs). In this work, we present the fabrication and characterization of a leaky-lens PCA that has the potential to solve...journal article 2023
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Fiorellini Bernardis, A. (author), Sberna, P.M. (author), Bueno Lopez, J. (author), Zhang, H. (author), Llombart, Nuria (author), Neto, A. (author)Drude's description of the response of low-temperature gallium arsenide to optical pulse excitation is used to evaluate the components of a time-domain Norton equivalent circuit of a photoconductive antenna (PCA) source. The saturation of the terahertz (THz) radiated power occurring at large optical excitation levels was previously associated...journal article 2023
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Jahangiri, M. (author), Sberna, P.M. (author), Sammak, A. (author), Nihtianova, S. (author)A clear understanding of the spectral components of an irradiated beam, or captured optical emission, is essential to optimize an optical system and increase its performance. Logically, for this purpose a grating-based spectrometer could be the first choice. However, in the case of a wide range spectrum, and for radiation with one dominant...conference paper 2023
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Zhang, H. (author), Bueno Lopez, J. (author), Sberna, P.M. (author), Llombart, Nuria (author), Neto, A. (author)Photoconductive antennas (PCAs) are promising candidates for sensing and imaging systems. We have investigated their properties under pulsed laser illumination both in transmission and reception. First, a transmitting PCA has been characterized including a power measurement. Then, a Quasi-Optical (QO) link between a transmitter and a receiver...conference paper 2023
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Xu, M. (author), Shin, D. (author), Sberna, P.M. (author), van der Kolk, R.J.H. (author), Cupertino, A. (author), Bessa, M.A. (author), Norte, R.A. (author)For decades, mechanical resonators with high sensitivity have been realized using thin-film materials under high tensile loads. Although there are remarkable strides in achieving low-dissipation mechanical sensors by utilizing high tensile stress, the performance of even the best strategy is limited by the tensile fracture strength of the...journal article 2023
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Buijtendorp, Bruno T. (author), Bueno, Juan (author), Thoen, David (author), Murugesan, Vignesh (author), Sberna, P.M. (author), Baselmans, J.J.A. (author), Vollebregt, S. (author), Endo, A. (author)Superconducting circuit elements used in millimeter-submillimeter (mm-submm) astronomy would greatly benefit from deposited dielectrics with small dielectric loss and noise. This will enable the use of multilayer circuit elements and thereby increase the efficiency of mm-submm filters and allow for a miniaturization of microwave kinetic...journal article 2022
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Bueno Lopez, J. (author), Huiskes, M. (author), Zhang, H. (author), Sberna, P.M. (author), Llombart, Nuria (author), Neto, A. (author)Photoconductive antennas are devices that provide power up to THz frequencies at a relatively low cost. However, the power radiated by each antenna is typically quite low and arrays have been proposed to increase it. In this paper we present the design of a leaky enhanced array architecture that surpasses the state of the art as it operates...conference paper 2022
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Fang, Piet Xiaowen (author), Nihtianova, S. (author), Sberna, P.M. (author), de Wijs, Gilles A. (author), Fang, Changming (author)Metal-Semiconductor (M/S) heterojunctions, better known as Schottky junctions play a crucial role in modern electronics. At present, the mechanisms behind the M/S junctions are still a subject of discussion. In this work, we investigate the interfaces between semiconducting crystalline Si and amorphous metallic indium, Si{0 0 1}/a-In and Si{1...journal article 2022
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Fiorellini Bernardis, A. (author), Zhang, H. (author), Sberna, P.M. (author), Bueno Lopez, J. (author), Neto, A. (author), Llombart, Nuria (author)The time evolution of voltages and currents in a pulsed photo conductive antenna (PCA) source is evaluated resorting to a rigorous procedure that stems from semiconductor physics first, to define the phenomena involved in the generation of the photocurrent, and then relies on an equivalent circuit in time domain, providing a direct estimation...abstract 2021
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van Schelven, R.M. (author), Fiorellini Bernardis, A. (author), Sberna, P.M. (author), Neto, A. (author)Semiconductor (SC)-based bulk absorbers operating in the (sub-) THz range are discussed. The conductivities of the bulk media are described by the Drude model for electron gas where the electron density is controlled. The Drude model predicts the existence of two frequencies of interest: one associated with the scattering time of the electrons...journal article 2021
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Sberna, P.M. (author), Fang, Piet Xiaowen (author), Fang, C. (author), Nihtianova, S. (author)The discovery of the extremely shallow amorphous boron-crystalline silicon heterojunction occurred during the development of highly sensitive, hard and robust detectors for low-penetration-depth ionizing radiation, such as ultraviolet photons and low-energy electrons (below 1 keV). For many years it was believed that the junction created by...review 2021
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Protti, Michele (author), Sberna, P.M. (author), Sberna, Angelo E. (author), Ferrante, Renzo (author), Mandrioli, Roberto (author), Mercolini, Laura (author)Volumetric absorptive microsampling (VAMS) and dried urine spot (DUS) strategies were applied for the collection of dried microsamples for anti-doping testing of low-stability peptide hormones and growth factors prohibited by the World Anti-Doping Agency (WADA). Drying, storage and transport conditions, as well as pretreatment steps, were...journal article 2021
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Chen, M. (author), Shang, Ran (author), Sberna, P.M. (author), Luiten-Olieman, Mieke W.J. (author), Rietveld, L.C. (author), Heijman, Sebastiaan (author)Silicon carbide (SiC) ceramic membranes are of particular significance for wastewater treatment due to their mechanical strength, chemical stability, and antifouling ability. Currently, the membranes are prepared by SiC-particle sintering at a high temperature. The production suffers from long production time and high costs. In this paper, we...journal article 2020
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Fiorellini Bernardis, A. (author), Sberna, P.M. (author), Neto, A. (author), Llombart, Nuria (author)Pulsed terahertz time-domain systems rely on antennas printed on photoconductive substrates (PCA), which show extremely fast conductivity transients when illuminated by femto-seconds laser pulses. This work introduces a time domain representation of the PCA transmitter that accounts for time evolving voltages at the terminals of the...conference paper 2019
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Fiorellini Bernardis, A. (author), Sberna, P.M. (author), Neto, A. (author), Llombart, Nuria (author)Recently, powerful, reliable and cost-effective THz radiation photoconductive-emitters have been developed, providing up to 1mW of pulsed power in the range of frequencies between 0.1 and 0.7THz. In this paper we study the potential use of such sources for future pulsed radar systems aiming at stand-off imaging applications. Specifically, we...conference paper 2019
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Garufo, A. (author), Sberna, P.M. (author), Carluccio, G. (author), Freeman, Joshua R. (author), Bacon, David R. (author), Li, Lianhe (author), Baselmans, J.J.A. (author), Llombart, Nuria (author), Neto, A. (author)A pulsed photoconductive terahertz (THz) source is presented that is able to radiate milliwatt (mW) level average power over a large bandwidth, by exploiting both the optical and electrical properties of photoconductive sources and the ultrawideband properties of connected antenna arrays. An optical system composed of a microlenses array...journal article 2019
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Alfaro, J.A. (author), Sberna, P.M. (author), Silvestri, C. (author), Mastrangeli, Massimo (author), Ishihara, R. (author), Sarro, Pasqualina M (author)A novel, simple, low-cost method for the void-free filling of high aspect ratio (HAR) through-silicon-vias (TSVs) is presented. For the first-time pure indium, a type-I superconductor metal, is used to fill HAR vias, 300 to 500 μm in depth and 50 to 100 μm in diameter. The low electrical resistivity achieved without sintering, its...conference paper 2018
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Trifunovic, M. (author), Sberna, P.M. (author), Shimoda, T (author), Ishihara, R. (author)Printing of electronics has been gaining a lot of attention over the past decade as a low cost alternative to conventional electronic fabrication methods. A significant development in this area was the possibility to print a silicon precursor, polydihydrosilane, which can directly be transformed into polycrystalline silicon by an excimer laser...journal article 2017
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Sberna, P.M. (author), Trifunovic, M. (author), Ishihara, R. (author)Currently, research has been focusing on printing and laser crystallization of cyclosilanes, bringing to life polycrystalline silicon (poly-Si) thin-film transistors (TFTs) with outstanding properties. However, the synthesis of these Sibased inks is generally complex and expensive. Here, we prove that a polysilane ink, obtained as a byproduct of...journal article 2017
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Trifunovic, M. (author), Shimoda, T (author), Ishihara, R. (author), Sberna, P.M. (author)Printing of electronics is pursued as a low-cost alternative to conventional manufacturing processes. In addition, owing to relatively low process temperatures, flexible substrates can be used enabling novel applications. Among flexible substrates, paper was found to be a particularly interesting candidate, since it has an order of magnitude...journal article 2017