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  • 1.
    Afanasiev, Sergey V.
    et al.
    Joint Institute for Nuclear Research Joliot-Curie 6.
    Afonin, Alexander G.
    Institute of High Energy Physics - Moscow Region.
    Ambrosi, Giovanni
    INFN Sezione di Perugia.
    Azzarello, Philipp
    INFN Sezione di Perugia.
    Baranov, Vladimir T.
    Institute of High Energy Physics - Moscow Region.
    Baricordi, Stefano
    INFN Sezione di Ferrara.
    Battiston, Roberto
    INFN Sezione di Perugia.
    Bertucci, Bruna
    INFN Sezione di Perugia.
    Bolognini, Davide
    Università dell'Insubria.
    Burger, William J.
    INFN Sezione di Perugia.
    Carnera, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Cavoto, Gianluca
    INFN Sezione di Roma.
    Chesnokov, Yury A.
    Institute of High Energy Physics - Moscow Region.
    Dalpiaz, Pietro
    INFN Sezione di Ferrara.
    Mea, Gianantonio Della
    INFN Laboratori Nazionali di Legnaro.
    Denisov, Alexander S.
    Petersburg Nuclear Physics Institute.
    Salvador, Davide De
    INFN Laboratori Nazionali di Legnaro.
    Fiorini, Massimiliano
    INFN Sezione di Ferrara.
    Foggetta, Luca
    Università dell'Insubria.
    Gavrikov, Yury A.
    Petersburg Nuclear Physics Institute.
    Guidi, Vincenzo
    INFN Sezione di Ferrara.
    Hasan, Said
    Università dell'Insubria.
    Ionica, Maria
    INFN Sezione di Perugia.
    Ivanov, Yuri M.
    Petersburg Nuclear Physics Institute.
    Ivochkin, Vladimir G.
    Petersburg Nuclear Physics Institute.
    Vomiero, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Zuccon, Paolo
    INFN Sezione di Perugia.
    Experimental apparatus to study crystal channeling in an external SPS beamline2007In: Proceedings of SPIE, the International Society for Optical Engineering, ISSN 0277-786X, E-ISSN 1996-756X, Vol. 6634Article in journal (Refereed)
    Abstract [en]

    For the new generation of high intensity hadronic machines as, for instance, LHC, halo collimation is a necessary issue for the accelerator to operate at the highest possible luminosity and to prevent the damage of superconductor magnets.1 We propose an experiment aimed to systematic study of the channeling phenomenology and of the newly observed "volume reflection" effect. This experiment will be performed for an external SPS beamline and will make use of a primary proton beam with 400 GeV/c momentum and very small (∼ 3 μrad) divergence. The advantage of a proposed experiment is precise tracking of particles that interacted with a crystal, so that to determine the single-pass efficiency for all the processes involved. For this purpose, a telescope equipped with high-resolution silicon microstrip detectors will be used. New generation silicon crystals and an extra-precise goniometer are mandatory issues. Main goal of the experiment is to get the precise information on channeling of relativistic particles and, ultimately, on the feasibility of such technique for halo collimation at LHC. In this contribution we review the status of the setting-up of experimental apparatus and its future development in sight of the planned run in September 2006.

  • 2.
    Ahdikari, Rajesh
    et al.
    Centre for Energy, Materials and Telecommunications, Institut National de la Recherche Scientifique, 1650 Boul. Lionel-Boulet, Varennes.
    Jin, Lei
    Institut National de la Recherche Scientifique Energie Varennes.
    Pardo, Fabola Navarro
    Centre for Energy, Materials and Telecommunications, Institut National de la Recherche Scientifique, Varennes.
    Benetti, Daniele
    INRS, Quebec University, Varennes, Centre for Energy, Materials and Telecommunications, Institut National de la Recherche Scientifique, Varennes.
    Otabi, Bandar Al
    Department of Electrical and Computer Engineering, McGill University, Montreal.
    Vanka, Srinivas
    Department of Electrical and Computer Engineering, McGill University, Montreal.
    Zhao, Haiguang
    Institut National de la Recherche Scientifique Energie Varennes, INRS Centre for Energy, Materials and Telecommunications, CNR-INO SENSOR Lab, Centre for Energy, Materials and Telecommunications, Institut National de la Recherche Scientifique, 1650 Boul. Lionel-Boulet, Varennes.
    Mi, Zetian
    Department of Electrical and Computer Engineering, McGill University, Montreal.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Rosei, Frederico
    Institut National de la Recherche Scientifique Energie Varennes, Centre for Energy, Materials and Telecommunications, Institut National de la Recherche Scientifique, 1650 Boul. Lionel-Boulet, Varennes.
    High Efficiency, Pt-free Photoelectrochemical Cells for Solar Hydrogen Generation based on “Giant” Quantum Dots2016In: Nano Energy, ISSN 2211-2855, Vol. 27, p. 265-274Article in journal (Refereed)
    Abstract [en]

    Quantum dot (QD) sensitized TiO2 is considered as a highly promising photoanode material for photoelectrochemical (PEC) solar hydrogen production. However, due to its limited stability, the photoanode suffers from degradation of its long-term PEC performance. Here, we report the design and characterization of a high-efficiency and long-term stable Pt-free PEC cell. The photoanode is composed of a mesoporous TiO2 nanoparticle film sensitized with “giant” core@shell QDs for PEC solar hydrogen generation. The thick shell enhances light absorption in the visible range, increases the stability of the QDs and does not inhibit charge separation, injection and transport, needed for proper operation of the device. We prepared thin films of Cu2S nanoflakes through a simple and reproducible procedure, and used them as counter-electrodes replacing the standard Pt film, resulting in equivalent performances of the PEC cell. We obtained an unprecedented photocurrent density (~10 mA/cm2) for “giant” QDs based PEC devices (and corresponding H2 generation) and a very promising stability, indicating that the proposed cell architecture is a good candidate for long-term stable QD-based PEC solar hydrogen generation.

  • 3.
    Alvi, Sajid Ali
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ghamgosar, Pedram
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Rigoni, Federica
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Akhtar, Farid
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Adaptive nanolaminate coating by atomic layer deposition2019In: Thin Solid Films, ISSN 0040-6090, E-ISSN 1879-2731Article in journal (Refereed)
    Abstract [en]

    Atomic layer deposition (ALD) was used to deposit ZnO/Al2O3/V2O5 nanolaminate coatings to demonstrate a coating system with temperature adaptive frictional behaviour. The nanolaminate coating exhibited excellent conformity and crack-free coating of thickness 110 nm over Inconel 718 substrate. The ALD trilayer coating showed a hardness and elastic modulus of 12 GPa and 193 GPa, respectively. High-temperature tribology of the nanolaminate trilayer was tested against steel ball in dry sliding condition at 25 °C (room temperature, RT), 200 °C, 300 °C, and 400 °C. It was found that the nanolaminate coating showed a low coefficient of friction (COF) and wear rate at RT and 300 °C. The trilayer coating was found intact and stable at all temperatures during the friction tests. The adaptability of nanolaminate coating with the temperature was verified by performing the cyclic friction test at 300 °C and RT. The low COF and wear rate had been attributed to the (100) and (002) basal plane sliding of ZnO top layer, and the interlayer sliding of weakly bonded planes parallel to (001) plane in V2O5 bottom layer. Furthermore, even after the removal of ZnO coating during the tribotest, the bottom V2O5 layer coating stabilized the COF and wear rate at RT and 300 °C.

  • 4.
    Amin, Sidra
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan.Department of Chemistry, Shaheed Benazir Bhutto University, Shaheed Benazirabad, Pakistan.
    Tahira, Aneela
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Solangi, Amber
    National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan.
    Beni, Valerio
    RISE Acreo, Research Institute of Sweden, Norrköping, Sweden.
    Morante, J.R
    Catalonia Institute for Energy Research (IREC), Barcelona, Spain.
    Liu, Xianjie
    Department of Physics, Chemistry and Biology, Surface Physics and Chemistry, Linköping University, Faculty of Science & Engineering, Sweden.
    Falhman, Mats
    Department of Physics, Chemistry and Biology, Surface Physics and Chemistry, Linköping University, Faculty of Science & Engineering, Sweden.
    Mazzaro, Raffaello
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ibupoto, Zafar
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Institute of Chemistry, University of Sindh, Jamshoro, Pakistan.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    A practical non-enzymatic urea sensor based on NiCo2O4 nanoneedles2019In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 9, no 25, p. 14443-14451Article in journal (Refereed)
    Abstract [en]

    We propose a new facile electrochemical sensing platform for determination of urea, based on a glassy carbon electrode (GCE) modified with nickel cobalt oxide (NiCo2O4) nanoneedles. These nanoneedles are used for the first time for highly sensitive determination of urea with the lowest detection limit (1 μM) ever reported for the non-enzymatic approach. The nanoneedles were grown through a simple and low-temperature aqueous chemical method. We characterized the structural and morphological properties of the NiCo2O4 nanoneedles by TEM, SEM, XPS and XRD. The bimetallic nickel cobalt oxide exhibits nanoneedle morphology, which results from the self-assembly of nanoparticles. The NiCo2O4 nanoneedles are exclusively composed of Ni, Co, and O and exhibit a cubic crystalline phase. Cyclic voltammetry was used to study the enhanced electrochemical properties of a NiCo2O4 nanoneedle-modified GCE by overcoming the typical poor conductivity of bare NiO and Co3O4. The GCE-modified electrode is highly sensitive towards urea, with a linear response (R2 = 0.99) over the concentration range 0.01–5 mM and with a detection limit of 1.0 μM. The proposed non-enzymatic urea sensor is highly selective even in the presence of common interferents such as glucose, uric acid, and ascorbic acid. This new urea sensor has good viability for urea analysis in urine samples and can represent a significant advancement in the field, owing to the simple and cost-effective fabrication of electrodes, which can be used as a promising analytical tool for urea estimation.

  • 5.
    Amin, Sidra
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan. Department of Chemistry, Shaheed Benazir Bhutto University, Shaheed Benazirabad, Pakistan.
    Tahira, Aneela
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Solangi, Amber
    National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, Pakistan.
    Mazzaro, Raffaello
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ibupoto, Zafar
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Department of Chemistry, Shaheed Benazir Bhutto University, Shaheed Benazirabad, Pakistan.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    A sensitive enzyme-free lactic acid sensor based on NiO nanoparticles for practical applications2019In: Analytical Methods, ISSN 1759-9660, E-ISSN 1759-9679, Vol. 11, p. 3578-3583Article in journal (Refereed)
    Abstract [en]

    A facile and efficient electrochemical sensing platform has been successfully exploited for the first time for the determination of lactic acid using a nickel oxide (NiO) nanoparticle-modified glassy carbon electrode (GCE). Nickel oxide nanoparticles were prepared by a chemical growth method using different quantities of arginine as a soft template. The structural and morphological properties of NiO nanoparticles were characterized by Raman spectroscopy, scanning electron microscopy (SEM) and X-ray diffraction (XRD). Cyclic voltammetry (CV) was used to study the electrochemical properties of various samples. The modified electrode is highly sensitive and presents a linear response over a wide range (0.005–5 mM) of lactic acid concentrations in 0.1 M NaOH. The detection limit for the sensor was found to be 5.7 μM, and it exhibits good stability. Furthermore, the sensor shows excellent selectivity in the presence of common interfering species. The lactic acid sensor showed good viability for lactic acid analysis in real samples (milk, yogurt and red wine) and demonstrated significant advancement in sensor technology for practical applications.

  • 6.
    Baratto, Camilla
    et al.
    University of Brescia.
    Comini, Elisabetta
    University of Brescia.
    Faglia, Guido
    University of Brescia.
    Ferroni, Matteo
    University of Brescia.
    Ponzoni, Andrea
    University of Brescia.
    Vomiero, Alberto
    University of Brescia, CNR-INFM SENSOR Laboratory.
    Sberveglieri, Giorgio
    University of Brescia.
    Transparent Metal Oxide Semiconductors as Gas Sensors2010In: Transparent Electronics: From Synthesis to Applications, John Wiley and Sons , 2010, p. 417-442Chapter in book (Refereed)
  • 7. Baricordi, S.
    et al.
    Biryukov, V. M.
    Institute for High Energy Physics.
    Carnera, A.
    Chesnokov, Yu A.
    Institute for High Energy Physics.
    Mea, G. Della
    University of Trento, Department of Materials Engineering and Industrial Technologies.
    Guidi, V.
    Ivanov, Yu M.
    Petersburg Institute for Nuclear Physics.
    Martinelli, G.
    Milan, E.
    Restello, S.
    INFN.
    Sambo, A.
    Scandale, W.
    CERN.
    Vomiero, Alberto
    Department of Physics, University of Padova.
    Low-energy-channeling surface analysis on silicon crystals designed for high-energy-channeling in accelerators2005In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 87, no 9, article id 94102Article in journal (Refereed)
    Abstract [en]

    Channeling of relativistic particles in bent Si crystals is a powerful technique for use with accelerators. Its efficiency can be found to be highly dependent on the state of the surface of the crystal steering the particles. We investigated the morphology and structure of the surface of the samples that have been used with high efficiency for channeling in accelerators. Low-energy channeling of 2 MeVα particles or protons was used as a probe. We found that mechanical treatment of the samples leads to a superficial damaged layer, which is correlated to efficiency limitations of the crystal in accelerators. In contrast, chemical etching, which was used to treat the surface of the most efficient crystals, leaves a surface with superior perfection. © 2005 American Institute of Physics.

  • 8.
    Baricordi, S.
    et al.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Guidi, V.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Mazzolari, A.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Martinelli, G.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Carnera, A.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Salvador, D. De
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Sambo, A.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Mea, G. Della
    Dipartimento di Ingegneria dei Materiali, Università di Trento.
    Milan, R.
    INFN Laboratori Nazionali di Legnaro.
    Vomiero, Alberto
    INFM-CNR Sensor Lab.
    Scandale, W.
    European Organization for Nuclear Research.
    Optimal crystal surface for efficient channeling in the new generation of hadron machines2007In: Applied Physics Letters, ISSN 0003-6951, E-ISSN 1077-3118, Vol. 91, no 6, article id 61908Article in journal (Refereed)
    Abstract [en]

    The new generation of hadron machines may profitably take advantage of channeling for steering and collimation of high-energy particle beams. In that case, the requirements on the quality of the crystal surface are rather stringent in terms of both lattice perfection and roughness. Here, the authors show the structural and morphological characterizations of crystals fabricated through a method to achieve a surface that fulfills all needed specifications for application in hadron machines. © 2007 American Institute of Physics.

  • 9.
    Basu, Kaustubh
    et al.
    Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Benetti, Daniele
    Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Zhao, Haiguang
    Institut National de la Recherche Scientifique Energie Varennes, Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Jin, Lei
    Institut National de la Recherche Scientifique Energie Varennes, Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Vetrone, Fiorenzo
    Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Rosei, Frederico
    Institut National de la Recherche Scientifique Energie Varennes, Institut National de la Recherche Scientifique-Énergie, Matériaux et Télécommunications, Université du Québec, Varennes.
    Enhanced photovoltaic properties in dye sensitized solar cells by surface treatment of SnO2 photoanodes2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, article id 23312Article in journal (Refereed)
    Abstract [en]

    We report the fabrication and testing of dye sensitized solar cells (DSSC) based on tin oxide (SnO2) particles of average size ~20 nm. Fluorine-doped tin oxide (FTO) conducting glass substrates were treated with TiOx or TiCl4 precursor solutions to create a blocking layer before tape casting the SnO2 mesoporous anode. In addition, SnO2 photoelectrodes were treated with the same precursor solutions to deposit a TiO2 passivating layer covering the SnO2 particles. We found that the modification enhances the short circuit current, open-circuit voltage and fill factor, leading to nearly 2-fold increase in power conversion efficiency, from 1.48% without any treatment, to 2.85% achieved with TiCl4 treatment. The superior photovoltaic performance of the DSSCs assembled with modified photoanode is attributed to enhanced electron lifetime and suppression of electron recombination to the electrolyte, as confirmed by electrochemical impedance spectroscopy (EIS) carried out under dark condition. These results indicate that modification of the FTO and SnO2 anode by titania can play a major role in maximizing the photo conversion efficiency

  • 10.
    Bemmerer, D.
    et al.
    INFN.
    Confortola, F.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Lemut, A.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Bonetti, R.
    Istituto di Fisica Generale Applicata.
    Broggini, C.
    INFN.
    Corvisiero, P.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Costantini, H.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Cruz, J.
    Centro de Fısica Nuclear da Universidade de Lisboa.
    Formicola, A.
    Laboratori Nazionali del Gran Sasso.
    Fülöp, Zs
    Institute of Nuclear Research (ATOMKI), Debrecen.
    Gervino, G.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Guglielmetti, A.
    Istituto di Fisica Generale Applicata.
    Gustavino, C.
    Laboratori Nazionali del Gran Sasso.
    Gyürky, Gy
    Institute of Nuclear Research (ATOMKI), Debrecen.
    Imbriani, G.
    Dipartimento di Scienze Fisiche, Universitá Federico II.
    Jesus, A. P.
    Centro de Fısica Nuclear da Universidade de Lisboa.
    Junker, M.
    Laboratori Nazionali del Gran Sasso.
    Limata, B.
    Dipartimento di Scienze Fisiche, Universitá Federico II.
    Menegazzo, R.
    INFN.
    Prati, P.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Roca, V.
    Dipartimento di Scienze Fisiche, Universitá Federico II.
    Rogalla, D.
    Seconda Università di Napoli.
    Rolfs, C.
    Institut Für Experimentalphysik III.
    Romano, M.
    Dipartimento di Scienze Fisiche, Universitá Federico II.
    Alvarez, C. Rossi
    INFN.
    Vomiero, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Feasibility of low-energy radiative-capture experiments at the LUNA underground accelerator facility2005In: European Physical Journal A, ISSN 1434-6001, E-ISSN 1434-601X, Vol. 24, no 2, p. 313-319Article in journal (Refereed)
    Abstract [en]

    The LUNA (Laboratory Underground for Nuclear Astrophysics) facility has been designed to study nuclear reactions of astrophysical interest. It is located deep underground in the Gran Sasso National Laboratory, Italy. Two electrostatic accelerators, with 50 and 400 kV maximum voltage, in combination with solid and gas target setups allowed to measure the total cross-sections of the radiative-capture reactions 2H2H(p, γ) 3He3Heand 14N14N(p, γ) 15O15Owithin their relevant Gamow peaks. We report on the gamma background in the Gran Sasso laboratory measured by germanium and bismuth germanate detectors, with and without an incident proton beam. A method to localize the sources of beam-induced background using the Doppler shift of emitted gamma rays is presented. The feasibility of radiative-capture studies at energies of astrophysical interest is discussed for several experimental scenarios. © Società Italiana di Fisica/Springer-Verlag 2005.

  • 11.
    Benetti, Daniele
    et al.
    INRS Centre for Energy, Materials and Telecommunications, 1650 Boulevard Lionel-Boulet, Varennes, Québec, J3X 1S2, Canada..
    Cui, Daling
    INRS Centre for Energy, Materials and Telecommunications, 1650 Boulevard Lionel-Boulet, Varennes, Québec, J3X 1S2, Canada..
    Zhao, Haiguang
    INRS Centre for Energy, Materials and Telecommunications, 1650 Boulevard Lionel-Boulet, Varennes, Québec, J3X 1S2, Canada..
    Rosei, Federico
    INRS Centre for Energy, Materials and Telecommunications, 1650 Boulevard Lionel-Boulet, Varennes, Québec, J3X 1S2, Canada..
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Direct Measurement of Electronic Band Structure in Single Quantum Dots of Metal Chalcogenide Composites.2018In: Small (Weinheim an der Bergstrasse, Germany), ISSN 1613-6810, Vol. 14, no 51, article id 1801668Article in journal (Refereed)
    Abstract [en]

    Metal chalcogenide quantum dots (QDs) are among the most promising materials as light harvesters in all-inorganic systems for applications in solar cells and production of solar fuels. The electronic band structure of composite QDs formed by lead and cadmium chalcogenides directly grafted on highly oriented pyrolytic graphite surfaces through successive ionic layer absorption and reaction is investigated. Atomic force microscopy and Kelvin probe force microscopy (KPFM) are applied to investigate PbS, CdS, and PbS/CdS QD systems. The variation of the surface potential of individual QDs is measured, investigating the evolution of the electronic band structure as a function of QD size and composition. A shift of the Fermi level toward more negative values occurs when QD size is increased. The shift is more pronounced in CdS than in PbS, while the composite PbS/CdS exhibits an intermediate behavior. The calculated shift is in good agreement with the experiments. These results highlight the ability of KPFM to directly measure the electronic band structure in individual QDs of metal chalcogenide composites. This feature regulates charge dynamics in composite systems, thereby affecting device performance. This work provides valuable insights for applications in several fields, in which charge injection plays a major role.

  • 12.
    Benetti, Daniele
    et al.
    INRS Centre for Energy, Materials and Telecommunications.
    Dembele, Kadiatou Therese
    INRS Centre for Energy, Materials and Telecommunications.
    Benavides, Jaime
    Département de Génie Électrique, École de Technologie Supérieure, Montréal.
    Zhao, Haiguang
    INRS Centre for Energy, Materials and Telecommunications, CNR-INO SENSOR Lab.
    Cloutier, Sylvain
    Département de Génie Électrique, École de Technologie Supérieure, Montréal.
    Concina, Isabella
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Rosei, Federico
    INRS Centre for Energy, Materials and Telecommunications, Institute for Fundamental and Frontier Science University of Electronic 15 Science and Technology of China, Center for Self-Assembled Chemical Structures, McGill University.
    Functionalized multi-wall carbon nanotubes/TiO2 composites as efficient photoanodes for dye sensitized solar cells2016In: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 4, no 16, p. 3555-3562Article in journal (Refereed)
    Abstract [en]

    We report on the effects of incorporation of different concentrations of carboxyl group (COOH)-functionalized multi-wall carbon nanotubes (F-MWCNTs) into TiO2 active layers for dye-sensitized solar cells (DSSCs). Standard DSSCs with bare TiO2 exhibit a photo-conversion efficiency (PCE) of 6.05% and a short circuit current density (Jsc) of 13.3 mA cm−2. The presence of 2 wt% F-MWCNTs in the photoanodes increases the PCE up to 7.95% and Jsc up to 17.5 mA cm−2. The photoanodes were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and Raman spectroscopy. The electrochemical behaviour of the solar cells was investigated by electrochemical impedance spectroscopy (EIS). We attribute the improved performances to the combined effect of increased dye loading and reduced charge recombination (as clarified by dye loading and EIS measurements), due to the conformal coverage of F-MWCNTs, which allows fast and efficient charge collection in operating solar cells. These results can help in improving the PCE in DSSCs in an elegant and straightforward way, minimizing the need of additional steps (e.g. pre- and post-treatment with TiCl4) for photoanode preparation.

  • 13.
    Benetti, Daniele
    et al.
    INRS Centre for Energy, Materials and Telecommunications, Varennes, Québec, Canada.
    Jokar, Efat
    Department of Applied Chemistry, Institute of Molecular Science and Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu, Taiwan. Center for Emergent Functional Matter Science, National Chiao Tung University, Taiwan.
    Yu, Che-Hsun
    Department of Applied Chemistry, Institute of Molecular Science and Center for Emergent Functional Matter Science, National Chiao Tung University, Taiwan.
    Fathi, Amir
    Department of Applied Chemistry, Institute of Molecular Science and Center for Emergent Functional Matter Science, National Chiao Tung University, Taiwan.
    Zhao, Haiguang
    INRS Centre for Energy, Materials and Telecommunications, Varennes, Québec, Canada.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Wei-Guang Diau, Eric
    Department of Applied Chemistry, Institute of Molecular Science and Center for Emergent Functional Matter Science, National Chiao Tung University, Hsinchu, Taiwan. Center for Emergent Functional Matter Science, National Chiao Tung University, Taiwan.
    Rosei, Federico
    INRS Centre for Energy, Materials and Telecommunications, Varennes, Québec, Canada. Institute of Fundamental and Frontier Science, University of Electronic Science and Technology of China, Chengdu, China.
    Hole-extraction and photostability enhancement in highly efficient inverted perovskite solar cells through carbon dot-based hybrid material2019In: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 62, p. 781-790Article in journal (Refereed)
    Abstract [en]

    We report the effect of the integration of carbon dots (Cdots) in high-performance inverted planar-heterojunction (PHJ) perovskite solar cells (PSCs). We used Cdots to modify the hole-transport layer in planar PSC devices. By introducing Cdots on graphene oxide (GO) as hole-transporting layer, the efficiency of the PSC improved significantly from 14.7% in the case of bare GO to 16.2% of the best device with optimized Cdots content. When applying Cdots with an engineered absorption in the UV range as downshifting layer, the device performance was further improved, attaining a maximum PCE of 16.8% (+14%); the stability of the device was also enhanced of more than 20%. Kelvin probe force microscopy (KPFM) and cyclic voltammetry (CV) were employed to analyze the electronic band alignment at the interface between GO/Cdots and the perovskite film. Holes were extracted and transferred to the conductive substrate more efficiently in the presence of Cdots, thus delaying charge recombination. Photoluminescence (PL), transient PL decays and transient photovoltage (TPV) decays investigated the charge-transfer kinetics and proved the retardation of charge recombination. This work reveals an effective enhancement of the performance of planar PSCs by using Cdots/GO as hole transport material.

  • 14.
    Bianchi, S.
    et al.
    CNR IDASC SENSOR Lab.
    Comini, E.
    CNR IDASC SENSOR Lab.
    Ferroni, M.
    CNR IDASC SENSOR Lab.
    Faglia, G.
    CNR IDASC SENSOR Lab.
    Vomiero, Alberto
    University of Brescia, CNR-INFM SENSOR Laboratory.
    Sberveglieri, G.
    CNR IDASC SENSOR Lab.
    Indium oxide quasi-monodimensional low temperature gas sensor2006In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 118, no 1-2, p. 204-207Article in journal (Refereed)
    Abstract [en]

    We have investigated the sensing properties of indium oxide nanostructures and tailored the deposition conditions in order to obtain nano-wires of indium oxide. We have comparatively tested the gas sensing properties of nano-wires with micrometric or even nanometric size. The micro-wires feature interesting gas sensitivity at room temperature, particularly in the case of nitrogen dioxide detection. The sensing performance is improved as the lateral dimension of the wire decreases. © 2006 Elsevier B.V. All rights reserved.

  • 15.
    Borgani, Riccardo
    et al.
    Nanostructure Physics, KTH Royal Institute of Technology, Stockholm, Sweden.
    Gilzad Kohan, Mojtaba
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Haviland, David B.
    Nanostructure Physics, KTH Royal Institute of Technology, Stockholm, Sweden.
    Fast Multifrequency Measurement of Nonlinear Conductance2019In: Physical Review Applied, E-ISSN 2331-7019, Vol. 11, no 4, article id 044062Article in journal (Refereed)
    Abstract [en]

    We describe a phase-coherent multifrequency lock-in measurement technique that uses the inverse Fourier transform to reconstruct the nonlinear current-voltage characteristic of a nanoscale junction. The method provides separation of the galvanic and displacement currents in the junction and easy cancellation of the parasitic displacement current from the measurement leads. These two features allow us to overcome traditional limitations imposed by the low conductance of the junction and the high capacitance of the leads, thus providing an increase in measurement speed of several orders of magnitude. We demonstrate the method in the context of conductive atomic force microscopy, acquiring current-voltage characteristics at every pixel while scanning at standard imaging speed.

  • 16.
    Bortoluzzi, Marco
    et al.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia.
    Castro, Jesús
    Departamento de Química Inorgánica, Universidade de Vigo, Facultade de Química, Edificio de Ciencias Experimentais.
    Enrichi, Francesco
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Consorzio Interuniversitario Reattività Chimica e Catalisi (CIRCC) .
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Busato, Marta
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia.
    Huang, Weizhe
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia.
    Green-emitting manganese (II) complexes with phosphoramide and phenylphosphonic diamide ligands2018In: Inorganic Chemistry Communications, ISSN 1387-7003, E-ISSN 1879-0259, Vol. 92, p. 145-150Article in journal (Refereed)
    Abstract [en]

    Tetrahedral manganese(II) complexes having formulae [MnX2{O = PR(NMe2)2}2] (X = Br, I; R = NMe2, Ph) were isolated and characterized, and in the case of [MnBr2{O = PPh(NMe2)2}2] the structure was ascertained by means of single crystal X-ray diffraction. All the complexes showed intense green emission assigned to the Mn(II) 4T1(4G) → 6A1(6S) transition upon excitation with UV light, with photoluminescence lifetimes in the range 100–1000 μs. Bromo-complexes maintain their luminescence features once dispersed in polycaprolactone matrix.

  • 17.
    Bortoluzzi, Marco
    et al.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, Mestre, VE, Italy;Consorzio Interuniversitario Reattività Chimica e Catalisi (CIRCC), Bari, Italy.
    Castro, Jesús
    Departamento de Química Inorgánica, Universidade de Vigo, Facultade de Química, Edificio de Ciencias Experimentais, Galicia, Spain.
    Girotto, Matteo
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, Mestre, VE, Italy.
    Enrichi, Francesco
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, Mestre, VE, Italy.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca' Foscari Venezia, Mestre, VE, Italy.
    Luminescent copper(I) coordination polymer with 1-methyl-1H-benzotriazole, iodide and acetonitrile as ligands2019In: Inorganic Chemistry Communications, ISSN 1387-7003, E-ISSN 1879-0259, Vol. 102, p. 141-146Article in journal (Refereed)
    Abstract [en]

    The Cu(I) coordination polymer [Cu33-I)3(μ-btzMe)(NCCH3)]n (btzMe = 1-methyl-1H-benzotriazole) was prepared and characterized by X-Ray diffraction. The compound showed strong green emission upon excitation with wavelengths below 475 nm, with lifetime of 47 μs. The emission was attributed to 3(X,M)LCT transition on the basis of experimental data and DFT calculations.

  • 18.
    Boscarino, Diego
    et al.
    INFN Laboratori Nazionali di Legnaro.
    Vomiero, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Mattei, Giovanni
    INFM Unit̀ di Ricerca di Padova.
    Quaranta, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Mazzoldi, Paolo
    INFM Unit̀ di Ricerca di Padova.
    Mea, Gianantonio Della
    INFN Laboratori Nazionali di Legnaro.
    Deposition of silica-silver nanocomposites by magnetron cosputtering2005In: Journal of Vacuum Science & Technology B, ISSN 1071-1023, E-ISSN 1520-8567, Vol. 23, no 1, p. 11-19Article in journal (Refereed)
    Abstract [en]

    Thin films have been grown on silicon and silica substrates by cosputtering of silica and silver in Ar, Ar+2.5% O2, and Ar+5% O2 gas mixtures. Rutherford backscattering spectrometry showed that the films have Ag atomic fractions xAg in the range of ∼1 to ∼10 at. %, and, by valence considerations, that the fraction of oxidized Ag in the films deposited in presence of oxygen is limited. Transmission electron microscopy images revealed the presence of Ag nanoclusters, with a mean size diameter not larger than 5 nm. The clusters are preferentially arranged along columns. It is suggested that the columns are regions with diameter in the nanometer range in which the density of the dielectric matrix is lower, thus favoring the formation of metal clusters. In presence of O2, the clusters were observed to have a more regular spherical shape. The optical absorption spectra of films grown in presence of O2 are distinguished from those grown in Ar by specific features, which are attributed to oxidation at the cluster surface. © 2005 American Vacuum Society.

  • 19.
    Botella, Pablo
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Errandonea, D.
    Universidad de Valencia, Valencia, Spain.
    Garg, A.B.
    Bhabha Atomic Research Centre, Mumbai, India. Homi Bhabha National Institute, Mumbai, India.
    Rodriguez-Hernandez, P.
    Universidad de La Laguna, La Laguna, Spain.
    Muñoz, A.
    Departamento de Física, Instituto de Materiales y Nanotecnología, MALTA Consolider Team, Universidad de La Laguna, La Laguna, Spain.
    Achary, S.N
    Chemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai, India.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    High-pressure characterization of the optical and electronic properties of InVO4, InNbO4, and InTaO42019In: SN Applied Sciences, ISSN 2523-3963, Vol. 1, no 5, article id 389Article in journal (Refereed)
    Abstract [en]

    We have studied the electronic properties at ambient pressure and under high pressure of InVO4, InNbO4, and InTaO4 powders, three candidate materials for hydrogen production by means of photocatalytic water splitting using solar energy. A combination of optical absorption and resistivity measurements and band structure calculations have allowed us to determine that these materials are wide band-gap semiconductors with a band-gap energy of 3.62(5), 3.63(5), and 3.79(5) eV for InVO4, InNbO4, and InTaO4, respectively. The last two compounds are indirect band-gap materials, and InVO4 is a direct band-gap material. The pressure dependence of the band-gap energy and the electrical resistivity have been determined too. In the three compounds, the band gap opens under compression until reaching a critical pressure, where a phase transition occurs. The structural transition triggers a band-gap collapse larger than 1.2 eV in the three materials, being the abrupt decrease in the band-gap energy related to an increase in the pentavalent cation coordination number. The phase transitions also cause changes in the electrical resistivity, which can be correlated with changes induced by pressure in the band structure. An explanation to the reported results is provided based upon ab initio calculations. The conclusions attained are of significance for technological applications of the studied oxides.

  • 20.
    Braga, Antonio
    et al.
    Photovoltaic and Optoelectronic Devices Group.
    Giménez, Sixto
    Photovoltaic and Optoelectronic Devices Group.
    Concina, Isabella
    Department of Physics and Chemistry, INFM — University of Brescia.
    Vomiero, Alberto
    Department of Physics and Chemistry for Materials and Engineering and CNR-IDASC SENSOR Lab, Brescia University.
    Mora-Seró, Iván
    Photovoltaic and Optoelectronic Devices Group.
    Panchromatic sensitized solar cells based on metal sulfide quantum dots grown directly on nanostructured TiO2 electrodes2011In: Journal of Physical Chemistry Letters, Vol. 2, no 5, p. 454-460Article in journal (Refereed)
    Abstract [en]

    The use of narrow band gap semiconductors such as PbS may expand the light absorption range to the near-infrared region in quantum-dot-sensitized solar cells (QDSCs), increasing the generated photocurrent. However, the application of PbS as a sensitizer in QDSCs causes some problems of stability and high recombination. Here, we show that the direct growth of a CdS coating layer on previously deposited PbS by the simple method of successive ionic layer adsorption and reaction (SILAR) minimizes these problems. A remarkable short-circuit current density for PbS/CdS QDSCs is demonstrated, ∼11 mA/cm2, compared to that of PbS QDSCs, with photocurrents lower than 4 mA/cm2, using polysulfide electrolyte in both cells. The cell efficiency reached a promising 2.21% under 1 sun of simulated irradiation (AM1.5G, 100 mW/cm2). Enhancement of the solar cell performance beyond the arithmetic addition of the efficiencies of the single constituents (PbS and CdS) is demonstrated for the nanocomposite PbS/CdS configuration. PbS dramatically increases the obtained photocurrents, and the CdS coating stabilizes the solar cell behavior. © 2011 American Chemical Society.

  • 21.
    Caciolli, A.
    et al.
    Istituto Nazionale di Fisica Nucleare (INFN).
    Mazzocchi, C.
    Università Degli Studi di Milano and INFN.
    Capogrosso, V.
    Università Degli Studi di Milano and INFN.
    Bemmerer, D.
    Helmholtz-Zentrum Dresden-Rossendorf.
    Broggini, C.
    Istituto Nazionale di Fisica Nucleare (INFN).
    Corvisiero, P.
    Università di Genova.
    Costantini, H.
    Università di Genova.
    Elekes, Z.
    Institute of Nuclear Research (ATOMKI), Debrecen.
    Formicola, A.
    INFN.
    Fülöp, Zs
    Institute of Nuclear Research (ATOMKI), Debrecen.
    Gervino, G.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Guglielmetti, A.
    Università Degli Studi di Milano and INFN.
    Gustavino, C.
    INFN.
    Gyürky, Gy
    Institute of Nuclear Research (ATOMKI), Debrecen.
    Imbriani, G.
    Dipartimento di Scienze Fisiche, Universitá Federico II.
    Junker, M.
    INFN.
    Lemut, A.
    Università di Genova.
    Marta, M.
    Helmholtz-Zentrum Dresden-Rossendorf.
    Menegazzo, R.
    Istituto Nazionale di Fisica Nucleare (INFN).
    Palmerini, S.
    Dipartimento di Fisica, Università di Roma “La Sapienza”, Rome.
    Prati, P.
    Università di Genova.
    Roca, V.
    Dipartimento di Scienze Fisiche, Universitá Federico II.
    Rolfs, C.
    Institut für Experimentalphysik.
    Alvarez, C. Rossi
    Istituto Nazionale di Fisica Nucleare (INFN).
    Somorjai, E.
    Institute of Nuclear Research (ATOMKI), Debrecen.
    Vomiero, Alberto
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Revision of the 15N(p, γ)16O reaction rate and oxygen abundance in H-burning zones2011In: Astronomy and Astrophysics, ISSN 0004-6361, E-ISSN 1432-0746, Vol. 533, article id A66Article in journal (Refereed)
    Abstract [en]

    Context. The NO cycle takes place in the deepest layer of a H-burning core or shell, when the temperature exceeds T ≈ 30 × 106 K. The O depletion observed in some globular cluster giant stars, always associated with a Na enhancement, may be due to either a deep mixing during the red giant branch (RGB) phase of the star or to the pollution of the primordial gas by an early population of massive asymptotic giant branch (AGB) stars, whose chemical composition was modified by the hot bottom burning. In both cases, the NO cycle is responsible for the O depletion. Aims. The activation of this cycle depends on the rate of the 15N(p, γ)16O reaction. A precise evaluation of this reaction rate at temperatures as low as experienced in H-burning zones in stellar interiors is mandatory to understand the observed O abundances. Methods. We present a new measurement of the 15N(p, γ)16O reaction performed at LUNA covering for the first time the center of mass energy range 70-370 keV, which corresponds to stellar temperatures between 65 × 106 K and 780 × 106 K. This range includes the 15N(p, γ)16O Gamow-peak energy of explosive H-burning taking place in the external layer of a nova and the one of the hot bottom burning (HBB) nucleosynthesis occurring in massive AGB stars. Results. With the present data, we are also able to confirm the result of the previous R-matrix extrapolation. In particular, in the temperature range of astrophysical interest, the new rate is about a factor of 2 smaller than reported in the widely adopted compilation of reaction rates (NACRE or CF88) and the uncertainty is now reduced down to the 10% level. © 2011 ESO.

  • 22.
    Cailotto, Simone
    et al.
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy.
    Mazzaro, Raffaello
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Enrichi, Francesco
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Piazza del Viminale 1, 00184 Roma, Italy.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Selva, Maurizio
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy.
    Cattaruzza, Elti
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy.
    Cristofori, Davide
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy;Centro di microscopia elettronica “G. Stevanato”, Via Torino 155b, 30172 Venezia-Mestre, Italy.
    Amadio, Emanuele
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy.
    Perosa, Alvise
    Department of Molecular Sciences and Nanosystems, Università Ca’ Foscari Venezia, Via Torino 155, 30172 Venezia Mestre, Italy.
    Design of Carbon Dots for Metal-free Photoredox Catalysis2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 47, p. 40560-40567Article in journal (Refereed)
    Abstract [en]

    The photoreduction potential of a set of four different carbon dots (CDs) was investigated. The CDs were synthesized by using two different preparation methods—hydrothermal and pyrolytic—and two sets of reagents—neat citric acid and citric acid doped with diethylenetriamine. The hydrothermal syntheses yielded amorphous CDs, which were either nondoped (a-CDs) or nitrogen-doped (a-N-CDs), whereas the pyrolytic treatment afforded graphitic CDs, either non-doped (g-CDs) or nitrogen-doped (g-N-CDs). The morphology, structure, and optical properties of four different types of CDs revealed significant differences depending on the synthetic pathway. The photocatalytic activities of the CDs were investigated as such, that is, in the absence of any other redox mediators, on the model photoreduction reaction of methyl viologen. The observed photocatalytic reaction rates: a-N-CDs ≥ g-CDs > a-CDs ≥ g-N-CDs were correlated with the presence/absence of fluorophores, to the graphitic core, and to quenching interactions between the two. The results indicate that nitrogen doping reverses the photoredox reactivity between amorphous and graphitic CDs and that amorphous N-doped CDs are the most photoredox active, a yet unknown fact that demonstrates the tunable potential of CDs for ad hoc applications.

  • 23.
    Carturan, S.
    et al.
    University of Padova.
    Quaranta, A.
    University of Trento, Department of Materials Engineering and Industrial Technologies.
    Bonafini, M.
    Istituto Nazionale di Fisica Nucleare (INFN).
    Vomiero, Alberto
    Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro.
    Maggioni, G.
    University of Padova.
    Mattei, G.
    Fernández, C. De Julián
    Bersani, M.
    Mazzoldi, P.
    Mea, G. Della
    University of Trento, Department of Materials Engineering and Industrial Technologies.
    Formation of silver nanoclusters in transparent polyimides by Ag-K ion-exchange process2007In: European Physical Journal D: Atomic, Molecular and Optical Physics, ISSN 1434-6060, E-ISSN 1434-6079, Vol. 42, no 2, p. 243-251Article in journal (Refereed)
    Abstract [en]

    Silver nanoclusters embedded in two transparent fluorinated polyimides, 4,4'-hexafluoroisopropylidene diphthalic anhydride - 2,3,5,6-tetramethyl paraphenylene diamine (6FDA-DAD) and 3,3',4,4' - biphenyltetracarboxylic acid dianhydride - 1,1-bis(4-aminophenyl)-1-phenyl-2,2,2-trifluoroethane (BPDA-3F), have been produced by surface modification with KOH aqueous solution followed by K-assisted Ag doping and thermal reduction in hydrogen atmosphere. The reaction rate of the nucleophilic hydrolysis in KOH, studied by Fourier transform infrared spectroscopy (FT-IR) and Rutherford backscattering spectrometry (RBS), depends on the polyimide chemical structure. After ion-exchange in AgNO 3 solution and subsequent annealing, the polyimide structure recovery was monitored by FT-IR whereas the characteristic surface plasmon absorption band of silver nanoparticles was evidenced by optical absorption measurements. The structure of silver nanoclusters as related to size and size distribution in the different polyimide matrices was thoroughly investigated by Transmission electron microscopy (TEM) and X-ray diffraction (XRD). The collected data evidenced a uniform distribution of Ag clusters of nanometric size after thermal treatment at 300 °C in both polyimides. For the same ion-exchange treatment parameters and annealing temperature, XRD analyses evidenced the presence of crystallites with similar sizes. © EDP Sciences/Società Italiana di Fisica/Springer-Verlag 2007.

  • 24. Carturan, S.
    et al.
    Quaranta, A.
    Laboratori Nazionali di Legnaro.
    Vomiero, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Bonafini, M.
    Laboratori Nazionali di Legnaro.
    Maggioni, G.
    Mea, G. Della
    Laboratori Nazionali di Legnaro.
    Polyimide-based scintillators studied by ion beam induced luminescence2004In: IEEE Nuclear Science Symposium Conference Record, ISSN 1095-7863, Vol. 2, p. 869-873Article in journal (Refereed)
    Abstract [en]

    New organic scintillators for ionizing radiation sensors are synthesized by dispersing dye molecules into chemically imidized polyimide hosts in order to obtain detection systems with improved radiation resistance with respect to the traditional polyvinyltoluene based materials. Nile Red and Rhodamine B are dispersed at different concentrations in polyimides derived from the following monomers 6FDA-DAD, 6FDA-DAB and BPDA-3F. Scintillating thin films are produced by the spin coating technique. Scintillation tests are performed both on pure polyimides and on binary systems by means of Ion Beam Induced Luminescence (IBIL), in which the emission spectrum is collected during the irradiation of the films with a 4He+ beam. From the intensity and the degradation rate of the IBIL signal during irradiation, the scintillation efficiency with respect to NE102 and the radiation hardness of the produced films are calculated. © 2004 IEEE.

  • 25. Carturan, S.
    et al.
    Quaranta, A.
    Laboratori Nazionali di Legnaro.
    Vomiero, Alberto
    Department of Physics, University of Padova.
    Bonafini, M.
    Department of Engineering Materials, Department of Mechanical Engineering, Linköping University.
    Maggioni, G.
    Mea, G. Della
    Laboratori Nazionali di Legnaro.
    Polyimide-based scintillators studied by ion beam induced luminescence2005In: IEEE Transactions on Nuclear Science, ISSN 0018-9499, E-ISSN 1558-1578, Vol. 52, no 3 II, p. 748-751Article in journal (Refereed)
    Abstract [en]

    New organic scintillators for ionizing radiation sensors are synthesized by dispersing dye molecules into chemically imidized polyimide hosts in order to obtain detection systems with improved radiation resistance with respect to the traditional polyvinyltoluene-based materials. Nile red (NR) and rhodamine B (RB) are dispersed at different concentrations in polyimides derived from the following monomers: 6FDA-DAD, 6FDA-DAB, and BPDA-3F. Scintillating thin films are produced by the spin coating technique. Scintillation tests are performed both on pure polyimides and on binary systems by means of ion beam induced luminescence (IBIL), in which the emission spectrum is collected during the irradiation of the films with a 4He+ beam. From the intensity and the degradation rate of the IBIL signal during irradiation, the scintillation efficiency with respect to NE102 and the radiation hardness of the produced films are calculated. © 2005 IEEE.

  • 26.
    Comini, E.
    et al.
    CNR IDASC SENSOR Lab.
    Baratto, C.
    CNR IDASC SENSOR Lab.
    Faglia, G.
    CNR IDASC SENSOR Lab.
    Ferroni, M.
    CNR IDASC SENSOR Lab.
    Vomiero, Alberto
    CNR-INFM SENSOR Laboratory.
    Sberveglieri, G.
    CNR IDASC SENSOR Lab.
    Quasi-one dimensional metal oxide semiconductors: Preparation, characterization and application as chemical sensors2009In: Progress in Materials Science, ISSN 0079-6425, E-ISSN 1873-2208, Vol. 54, no 1, p. 1-67Article in journal (Refereed)
    Abstract [en]

    The continuous evolution of nanotechnology in these years led to the production of quasi-one dimensional (Q1D) structures in a variety of morphologies such as nanowires, core-shell nanowires, nanotubes, nanobelts, hierarchical structures, nanorods, nanorings. In particular, metal oxides (MOX) are attracting an increasing interest for both fundamental and applied science. MOX Q1D are crystalline structures with well-defined chemical composition, surface terminations, free from dislocation and other extended defects. In addition, nanowires may exhibit physical properties which are significantly different from their coarse-grained polycrystalline counterpart because of their nanosized dimensions. Surface effects dominate due to the increase of their specific surface, which leads to the enhancement of the surface related properties, such as catalytic activity or surface adsorption: key properties for superior chemical sensors production. High degree of crystallinity and atomic sharp terminations make nanowires very promising for the development of a new generation of gas sensors reducing instabilities, typical in polycrystalline systems, associated with grain coalescence and drift in electrical properties. These sensitive nanocrystals may be used as resistors, and in FET based or optical based gas sensors. This article presents an up-to-date review of Q1D metal oxide materials research for gas sensors application, due to the great research effort in the field it could not cover all the interesting works reported, the ones that, according to the authors, are going to contribute to this field's further development were selected and described. © 2008 Elsevier Ltd. All rights reserved.

  • 27.
    Comini, E.
    et al.
    INFM-CNR Sensor Lab.
    Bianchi, S.
    INFM-CNR Sensor Lab.
    Faglia, G.
    INFM-CNR Sensor Lab.
    Ferroni, M.
    INFM-CNR Sensor Lab.
    Vomiero, Alberto
    INFM-CNR Sensor Lab.
    Sberveglieri, G.
    INFM-CNR Sensor Lab.
    Functional nanowires of tin oxide2007In: Applied Physics A: Materials Science & Processing, ISSN 0947-8396, E-ISSN 1432-0630, Vol. 89, no 1, p. 73-76Article in journal (Refereed)
    Abstract [en]

    Quasi-one-dimensional nanostructures of tin oxide were produced in controlled conditions through condensation from the vapor phase. The preparation was assisted by noble metal catalysts and uniform single-crystalline nanowires were produced. The nucleation of nanowires was achieved at 470 °C, owing to the vapor-liquid-solid growth mechanism activated by the catalytic Pt clusters. The peculiar microstructural properties of these semiconducting metal oxide nanostructures will be summarized. The high aspect ratio and the high degree of crystallinity achieved for the nanowires foresee their functional exploitation. © 2007 Springer-Verlag.

  • 28.
    Comini, E.
    et al.
    CNR IDASC SENSOR Lab.
    Vomiero, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Faglia, G.
    CNR IDASC SENSOR Lab.
    Mea, G. Della
    INFN.
    Sberveglieri, G.
    CNR IDASC SENSOR Lab.
    Influence of iron addition on ethanol and CO sensing properties of tin oxide prepared with the RGTO technique2006In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 115, no 2, p. 561-566Article in journal (Refereed)
    Abstract [en]

    Effects of iron introduction in RGTO prepared tin oxide gas sensors are presented. The films were deposited by sputtering from a tin target with the introduction of an adjustable number or iron inset. Iron content was varied in the range 0-7%. The thin films are investigated by the volt-amperometric technique for electrical and gas-sensing properties. The layers are capable of sensing CO and ethanol, no evidence of surface poisoning is detected, and recovery of the resistance is complete. The response of the sensors is stable and reproducible at all operating temperatures tested (200-500 °C) during 3 months of operation. © 2005 Elsevier B.V. All rights reserved.

  • 29.
    Comini, Elisabetta
    et al.
    CNR IDASC SENSOR Lab.
    Baratto, Camilla
    CNR IDASC SENSOR Lab.
    Concina, Isabella
    CNR IDASC SENSOR Lab.
    Faglia, Guido
    CNR IDASC SENSOR Lab.
    Falasconi, Matteo
    CNR IDASC SENSOR Lab.
    Ferroni, Matteo
    CNR IDASC SENSOR Lab.
    Galstyan, Vardan
    CNR IDASC SENSOR Lab.
    Gobbi, Emanuela
    CNR IDASC SENSOR Lab.
    Ponzoni, Andrea
    CNR IDASC SENSOR Lab.
    Vomiero, Alberto
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Zappa, Dario
    CNR IDASC SENSOR Lab.
    Sberveglieri, Veronica
    CNR IDASC SENSOR Lab.
    Sberveglieri, Giorgio
    CNR IDASC SENSOR Lab.
    Metal oxide nanoscience and nanotechnology for chemical sensors2013In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 179, p. 3-20Article in journal (Refereed)
    Abstract [en]

    This paper focuses on the capabilities and development prospects of nanostructured metal oxides (MOX) representing the most versatile and richest class of materials in terms of electronic structure and structural, chemical, and physical properties. MOX nano-materials with controlled composition, surface terminations, and crystalline structures to be used as chemical sensors as a new area in analytical chemistry and instrument engineering are discussed. Their principles of operation, and basic characteristics are outlined and main applications of MOX sensor technology are presented. © 2012 Elsevier B.V. All rights reserved.

  • 30.
    Comini, Elisabetta
    et al.
    INFM-CNR Sensor Lab.
    Baratto, Camilla
    INFM-CNR Sensor Lab.
    Faglia, Guido
    INFM-CNR Sensor Lab.
    Ferroni, Matteo
    INFM-CNR Sensor Lab.
    Vomiero, Alberto
    University of Brescia, CNR-INFM SENSOR Laboratory.
    Sberveglieri, Giorgio
    INFM-CNR Sensor Lab.
    Highly sensitive single crystalline metal oxide nanowires gas sensors2006In: Proceedings of the 2006 Conference on Optoelectronic and Microelectronic Materials and Devices: 6-8 December 2006, Perth, Australia., Piscataway, NJ: IEEE Communications Society, 2006, p. 315-320, article id 4429946Conference paper (Refereed)
    Abstract [en]

    Interest in nanowires of metal oxide oxides has been exponentially growing in the last years, due to the attracting potential of application in electronic, optical and sensor field. We have focused our attention on the sensing properties of semiconducting nanowires as conductometric and optical gas sensors. Single crystal nanostructures In2O3, SnO 2, and ZnO were synthesized to explore and study their capability in form of multi-nanowires sensors. © 2006 IEEE.

  • 31.
    Comini, Elisabetta
    et al.
    CNR IDASC SENSOR Lab.
    Faglia, Guido
    CNR IDASC SENSOR Lab.
    Ferroni, Matteo
    CNR IDASC SENSOR Lab.
    Ponzoni, Andrea
    CNR IDASC SENSOR Lab.
    Vomiero, Alberto
    INFM-CNR Sensor Lab.
    Sberveglieri, Giorgio
    CNR IDASC SENSOR Lab.
    Metal oxide nanowires: Preparation and application in gas sensing2009In: Journal of Molecular Catalysis A: Chemical, ISSN 1381-1169, E-ISSN 1873-314X, Vol. 305, no 1-2, p. 170-177Article in journal (Refereed)
    Abstract [en]

    Quasi one-dimensional nanowires of metal oxides are promising for the development of nano-devices. Sn, In, and Zn oxides were produced in form of single-crystalline nanowires through condensation from vapor phase. Furthermore longitudinal and radial heterostructures have been prepared. Nanowires growth occurs in controlled condition and allows the exploitation of size reduction effects on the electrical response to gases. Preparation, microstructural, morphological and electrical characterizations of nanowires are presented and the peculiarities of these innovative structures are highlighted. © 2009 Elsevier B.V. All rights reserved.

  • 32.
    Comini, Elisabetta
    et al.
    INFM-CNR Sensor Lab.
    Ferroni, Matteo
    INFM-CNR Sensor Lab.
    Guidi, Vincenzo
    INFM-CNR Sensor Lab.
    Vomiero, Alberto
    INFN - Legnaro National Laboratories.
    Merli, Pier Giorgio
    CNR.
    Morandi, Vittorio
    CNR.
    Sacerdoti, Michele
    Dipartimento di Scienze della Terra, via Laterina 8, 53100 Siena.
    Mea, Gianantonio Della
    INFN - Legnaro National Laboratories.
    Sberveglieri, Giorgio
    INFM-CNR Sensor Lab.
    Effects of Ta/Nb-doping on titania-based thin films for gas-sensing2005In: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 108, no 1-2 SPEC. ISS., p. 21-28Article in journal (Refereed)
    Abstract [en]

    Thin films of titania with the addition of niobium and tantalum have been achieved by reactive sputtering process. Structural and morphological studies have been carried out by means of XRD, RBS, TEM and AFM in order to correlate the microstructural features to the sensing performance of the layers. The films proved sensitive to ethanol and carbon monoxide and ammonia. In the case of niobium addition, it was shown that annealing temperature and niobium content strongly influence the gas response of the films converting a n-type response, which is typical of pure TiO2 and of most of metal-oxide sensors, to a p-type response; this peculiarity is crucial for the discrimination of different gases. In the case of tantalum addition, the annealing treatment at 800 °C led only to a phase transformation that reduced the sensing performance of the layer. High sensitivity to CO is achieved with anatase or mixed anatase and rutile phases, while the rutile phase only exhibit a low gas sensitivity. © 2005 Elsevier B.V. All rights reserved.

  • 33.
    Concina, Isabella
    et al.
    CNR IDASC SENSOR Lab.
    Frison, Enrico
    Dipartimento di Scienze Chimiche, Università di Catania.
    Braga, Antonio
    CNR IDASC SENSOR Lab.
    Silvestrini, Simone
    Dipartimento di Scienze Chimiche, Università di Catania.
    Maggini, Michele
    Dipartimento di Scienze Chimiche, Università di Catania.
    Sberveglieri, Giorgio
    CNR IDASC SENSOR Lab.
    Vomiero, Alberto
    SENSOR Lab, Department of Chemistry and Physics, Brescia University and CNR-IDASC.
    Carofiglio, Tommaso
    Dipartimento di Scienze Chimiche, Università di Catania.
    On-line monitoring and active control of dye uptake in dye-sensitised solar cells2011In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 47, no 42, p. 11656-11658Article in journal (Refereed)
    Abstract [en]

    Real-time monitoring of dye loading (N3 and N719) under continuous flow conditions on TiO2 photoanodes for dye-sensitized solar cells has been applied to quantitatively investigate dye uptake kinetics, demonstrating that static impregnation provides in all cases higher dye loading and, as a consequence, better working devices. © 2011 The Royal Society of Chemistry.

  • 34.
    Concina, Isabella
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Ibupoto, Zafar Hussain
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science. Dr. M. A. Kazi Institute of Chemistry University of Sindh Jamshoro, Sindh, Pakistan.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Semiconducting metal oxide nanostructures for water splitting and photovoltaics2017In: Advanced Energy Materials, ISSN 1614-6832, Vol. 7, no 23Article in journal (Refereed)
    Abstract [en]

    Metal oxide (MOx) semiconducting nanostructures hold the potential for playing a critical role in the development of a new platform for renewable energies, including energy conversion and storage through photovoltaic effect, solar fuels, and water splitting. Earth-abundant MOx nanostructures can be prepared through simple and scalable routes and integrated in operating devices, which enable exploitation of their outstanding optical, electronic, and catalytic properties. In this review, the latest research results in this field are illustrated, highlighting the versatility of MOx nanostructures in meeting the stringent requirements to boost the efficiency of different systems. The functional properties inherently correlate to the morphology and the crystalline habit of MOx, which in most of the cases are organized in complex heterostructures. Tailoring the assembly of heterojunctions and their electronic band structure, the catalytic surface properties and the charge transport through complex networks represent the main challenge for the transition of MOx from the research to the real-life in the field of energy conversion and storage.

  • 35.
    Concina, Isabella
    et al.
    Dipartimento di Ingegneria dell’Informazione, Università di Brescia.
    Manzoni, Cristian
    Istituto di Fotonica e Nanotecnologie (IFN)-CNR, Politecnico di Milano.
    Granchini, Giulia
    Center for Nano Science and Technology@Polimi, Istituto Italiano di Tecnologia.
    Celikin, Mert
    INRS Centre for Energy, Materials and Telecommunications.
    Soudi, Afsoon
    INRS Centre for Energy, Materials and Telecommunications.
    Rosei, Federico
    INRS Centre for Energy, Materials and Telecommunications.
    Zavelani-Rossi, Margherita
    Dipartimento di Fisica, Politecnico di Milano, Istituto di Fotonica e Nanotecnologie (IFN)-CNR.
    Cerullo, Giulio
    Dipartimento di Fisica, Politecnico di Milano, Istituto di Fotonica e Nanotecnologie (IFN)-CNR.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Modulating Exciton Dynamics in Composite Nanocrystals for Excitonic Solar Cells2015In: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 6, no 13, p. 2489-2495Article in journal (Refereed)
    Abstract [en]

    Quantum dots (QDs) represent one of the most promising materials for third-generation solar cells due to their potential to boost the photoconversion efficiency beyond the Shockley-Queisser limit. Composite nanocrystals can challenge the current scenario by combining broad spectral response and tailored energy levels to favor charge extraction and reduce energy and charge recombination. We synthesized PbS/CdS QDs with different compositions at the surface of TiO2 nanoparticles assembled in a mesoporous film. The ultrafast photoinduced dynamics and the charge injection processes were investigated by pump-probe spectroscopy. We demonstrated good injection of photogenerated electrons from QDs to TiO2 in the PbS/CdS blend and used the QIN to fabricate solar cells. The fine-tuning of chemical composition and size of lead and cadmium chalcogenide QDs led to highly efficient PV devices (3% maximum photoconversion efficiency). This combined study paves the way to the full exploitation of QDs in next-generation photovoltaic (PV) devices.

  • 36.
    Concina, Isabella
    et al.
    Department of Information Engineering, University of Brescia and SENSOR Laboratory, CNR-INO.
    Memarian, N.
    Department of Information Engineering, University of Brescia and SENSOR Laboratory, CNR-INO.
    Selopal, G. S.
    Department of Information Engineering, University of Brescia and SENSOR Laboratory, CNR-INO.
    Natile, M. M.
    CNR-ISTM.
    Sberveglieri, G.
    Department of Information Engineering, University of Brescia and SENSOR Laboratory, CNR-INO.
    Vomiero, Alberto
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Spray-assisted silar deposition of cadmium sulphide quantum dots on metal oxide films for excitonic solar cells2013In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 240, p. 736-744Article in journal (Refereed)
    Abstract [en]

    The proof of principle of the successful application of spray deposition to the SILAR (successive ionic layer absorption and reaction) technique, one of the most effective strategies to sensitized TiO2 scaffold with QDs, is demonstrated. Systematically improved optical features of the materials (higher optical density together with reduced nanocrystal sizes) as well as of the functional performances of QD solar cells (photoconversion efficiency, fill factor, short circuit current, open circuit voltage) sensitized via SD-SILAR, with respect to traditional SILAR sensitization based on impregnation, are demonstrated. © 2013 Elsevier B.V. All rights reserved.

  • 37.
    Concina, Isabella
    et al.
    CNR IDASC SENSOR Lab.
    Natile, M.
    Department of Chemical Sciences and INSTM Padova, Padova University.
    Braga, A.
    CNR IDASC SENSOR Lab.
    Vomiero, Alberto
    Department of Physics and Chemistry for Materials and Engineering and CNR-IDASC SENSOR Lab, Brescia University.
    Morandi, V.
    CNR-IMM Sezione di Bologna.
    Ortolani, L.
    CNR-IMM Sezione di Bologna.
    Ferroni, M.
    CNR IDASC SENSOR Lab.
    Sberveglieri, G.
    CNR IDASC SENSOR Lab.
    One pot synthesis of bi-linker stabilised CdSe quantum dots2010In: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 244, article id 12067Article in journal (Refereed)
    Abstract [en]

    In this study we exploited the classic Murray's synthesis for generating a hydrophilic CdSe quantum dot system in a single step procedure, with the aim of directly obtaining a material responding to the characteristic of polarity required in many end applications. 6-phosphonohexanoic acid was used as both ligand for generating the active monomer during the synthesis of the quantum dots and final stabiliser. Diffraction measurements identified the cubic phase of cadmium selenide. Energy dispersive spectroscopy analysis revealed non-stoichiometric quantum dots, being the Cd/Se ratio 60/40. This feature suggests a configuration in which Cd2+ ions are present on the nanocrystal surface. Diffuse reflectance infrared Fourier transform analysis was applied in order to investigate the structure of the quantum dot system: the results indicate a configuration in which the carboxylic function of 6-phosphonohexanoic acid establishes only a partial interaction with the quantum dot surface, being set in a pseudo-ester configuration. © 2010 IOP Publishing Ltd.

  • 38.
    Concina, Isabella
    et al.
    CNR IDASC SENSOR Lab.
    Natile, M. M.
    Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing.
    Ferroni, M.
    CNR IDASC SENSOR Lab.
    Migliori, A.
    CNR-IMM Sezione di Bologna.
    Morandi, V.
    CNR-IMM Sezione di Bologna.
    Ortolani, L.
    CNR-IMM Sezione di Bologna.
    Vomiero, Alberto
    CNR IDASC SENSOR Lab.
    Sberveglieri, G.
    CNR IDASC SENSOR Lab.
    CdSe spherical quantum dots stabilised by thiomalic acid: Biphasic wet synthesis and characterisation2011In: ChemPhysChem, ISSN 1439-4235, E-ISSN 1439-7641, Vol. 12, no 4, p. 863-870Article in journal (Refereed)
    Abstract [en]

    CdSe quantum dots stabilised by thiomalic acid have been synthesised by an aqueous biphasic ligand exchange reaction in air. The materials are completely water-soluble and were found to be stable over a long time. X-ray diffraction and transmission electron microscopy reveal the formation of CdSe nanocrystals with cubic structure (a=0.6077 nm; spatial group: F-43m). The average particle size is about 5 nm. Energy dispersive X-ray analysis shows that the nanocrystals are nonstoichiometric, with a Cd/Se ratio varying between 60/40 and 70/30, and indicates the presence of Cd2+ ions at the nanocrystal surface. Diffuse reflectance infrared Fourier transform measurements suggest that thiomalic acid chelates CdSe through the thiol group and one carboxylic function, while the second COOH group is semi-free. A complex-like structure is proposed, in which thiomalic acid forms a five-membered chelate ring with the Cd2+ ions present on the nanocrystal surface. Chelate effect accounts for the easiness of ligand exchange and is expected to additionally stabilise the nanosystem. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  • 39.
    Concina, Isabella
    et al.
    Department of Information Engineering, University of Brescia and SENSOR Laboratory, CNR-INO.
    Selopal, Gurpreet S.
    Department of Information Engineering, University of Brescia and SENSOR Laboratory, CNR-INO.
    Milan, Riccardo
    Department of Information Engineering, University of Brescia and SENSOR Laboratory, CNR-INO.
    Sberveglieri, Giorgio
    Department of Information Engineering, University of Brescia and SENSOR Laboratory, CNR-INO.
    Vomiero, Alberto
    Department of Information Engineering, University of Brescia and SENSOR Laboratory, CNR-INO.
    Light harvester band gap engineering in excitonic solar cells: A case study on semiconducting quantum dots sensitized rainbow solar cells2014In: Pure and Applied Chemistry, ISSN 0033-4545, E-ISSN 1365-3075, Vol. 86, no 5, p. 575-584Article in journal (Refereed)
    Abstract [en]

    A systematic study on the fabrication of quantum dots sensitized solar cells (QDSSCs) exploiting hybrid networks of semiconducting light harvesters is presented, which shows how the engineering of band gaps of the device components by a very simple technique allows improving the solar energy conversion performances. Panchromatic devices are fabricated and tested, and correspondent functional parameters analyzed in order to highlight both advantages and drawbacks of the most common (CdS, CdSe, PbS) quantum dots applied for light collection in QDSSCs. Judicious engineering of the light harvester layer is demonstrated as a simple and powerful strategy for boosting device performances, through the management of light collection in a rather broad range of solar spectrum and photogenerated charges injection and collection. © 2014 IUPAC & De Gruyter.

  • 40.
    Concina, Isabella
    et al.
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Selopal, Gurpreet S.
    Department of Information Engineering, University of Brescia, CNR-INO SENSOR Lab.
    Milan, Riccardo
    Department of Information Engineering, University of Brescia, CNR-INO SENSOR Lab.
    Vomiero, Alberto
    Department of Information Engineering, University of Brescia and SENSOR Laboratory, CNR-INO.
    Sberveglieri, Giorgio
    Department of Information Engineering, University of Brescia, CNR-INO SENSOR Lab.
    Engineering metal oxide structures for efficient photovoltaic devices2014In: Oxide-based materials and devices V: 2 - 5 February 2014, San Francisco, California, United States ; [proceedings of the Fifth Annual Oxide Based Materials and Devices Conference ... held at SPIE photonics west] / [ed] Ferechteh Hosseini Teherani, Bellingham, Wash.: SPIE - International Society for Optical Engineering, 2014, article id 89872EConference paper (Refereed)
    Abstract [en]

    Metal oxide-based photoanodes are critical components of dye sensitized solar cells (DSSCs), which are photoelectrochemical cells for the conversion of solar energy, promising to have several benefits as compared with their traditional counterparts. A careful engineering of the wide band gap metal oxide composing the photoanode, as well as their process design, is strategic for improving device performances and for planning a near future production scale up, especially devoted to reducing the environmental impact of the device fabrication. Herein, we present the application of ZnO hierarchical structures as efficient materials to be applied as photoanodes in DSSC, in the perspective of looking for alternative to TiO2 nanoparticles, currently the most exploited metal oxide in these devices. © 2014 SPIE.

  • 41.
    Concina, Isabella
    et al.
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Fluid and Experimental Mechanics. Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Metal Oxide Semiconductors for Dye- and Quantum-Dot-Sensitized Solar Cells2015In: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 11, no 15, p. 1744-1774Article in journal (Refereed)
    Abstract [en]

    This Review provides a brief summary of the most recent research developments in the synthesis and application of nanostructured metal oxide semiconductors for dye sensitized and quantum dot sensitized solar cells. In these devices, the wide bandgap semiconducting oxide acts as the photoanode, which provides the scaffold for light harvesters (either dye molecules or quantum dots) and electron collection. For this reason, proper tailoring of the optical and electronic properties of the photoanode can significantly boost the functionalities of the operating device. Optimization of the functional properties relies with modulation of the shape and structure of the photoanode, as well as on application of different materials (TiO2, ZnO, SnO2) and/or composite systems, which allow fine tuning of electronic band structure. This aspect is critical because it determines exciton and charge dynamics in the photoelectrochemical system and is strictly connected to the photoconversion efficiency of the solar cell. The different strategies for increasing light harvesting and charge collection, inhibiting charge losses due to recombination phenomena, are reviewed thoroughly, highlighting the benefits of proper photoanode preparation, and its crucial role in the development of high efficiency dye sensitized and quantum dot sensitized solar cells.

  • 42.
    Concina, Isabella
    et al.
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Solar Cells: Metal Oxide Semiconductors for Dye- and Quantum-Dot-Sensitized Solar Cells2015In: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 11, no 15, p. 1743-Article in journal (Refereed)
    Abstract [en]

    Metal oxide semiconductors are an appealing class of material, extensively used as photoanodes in excitonic solar cells such as dye- and quantum dot-sensitized solar cells. On page 1744, I. Concina and A. Vomiero describe how proper tailoring of the shape, composition, and crystalline structure of these materials can significantly boost the performances of these solar energy converting devices by ameliorating the processes of exciton separation, charge transport, and collection, while reducing charge losses due to recombination and back reactions.

  • 43.
    Corradini, M.
    et al.
    Dipartimento di Ingegneria dell’Informazione, Università di Padova.
    Hayano, R.
    Department of Physics, University of Tokyo.
    Hori, M.
    Department of Physics, University of Tokyo.
    Leali, M.
    Dipartimento di Ingegneria dell’Informazione, Università di Padova.
    Rizzini, E. Lodi
    Dipartimento di Ingegneria dell’Informazione, Università di Padova.
    Mascagna, V.
    Dipartimento di Ingegneria dell’Informazione, Università di Padova.
    Mozzanica, A.
    Dipartimento di Ingegneria dell’Informazione, Università di Padova.
    Prest, M.
    Istituto Nazionale di Fisica Nucleare, Sezione di Cagliari.
    Todoroki, K.
    Department of Physics, University of Tokyo.
    Vallazza, E.
    Istituto Nazionale di Fisica Nucleare, Sezione di Cagliari.
    Venturelli, L.
    Dipartimento di Ingegneria dell’Informazione, Università di Padova.
    Zurlo, N.
    Dipartimento di Ingegneria dell’Informazione, Università di Padova.
    Baratto, C.
    Dipartimento di Ingegneria dell’Informazione, Università di Padova.
    Ferroni, M.
    Dipartimento di Ingegneria dell’Informazione, Università di Padova.
    Vomiero, Alberto
    CNR IDASC SENSOR Lab.
    Experimental apparatus for annihilation cross-section measurements of low energy antiprotons2013In: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 711, p. 12-20Article in journal (Refereed)
    Abstract [en]

    The nuclear physics program of the ASACUSA experiment at the Antiproton Decelerator (AD) at CERN is concerned with the measurements of antiproton-nuclei cross-sections at low energies (from 5.3 MeV down to the 100 keV region). These measurements are expected to contribute to understand the dynamics of the annihilation process. We give here a full description of the experimental apparatus used for the measurements at 5.3 MeV. © 2013 Elsevier B.V.

  • 44.
    Costantini, H.
    et al.
    Università di Genova.
    Angulo, C.
    Centre de Recherches du Cyclotron, Universit¶e Catholique de Louvain, Louvain-la-Neuve.
    Bemmerer, D.
    Institut für Atomare Physik und Fachdidaktik, Technische Universität Berlin.
    Bonetti, R.
    Università Degli Studi di Milano and INFN.
    Broggini, C.
    INFN.
    Confortola, F.
    Università di Genova.
    Corvisiero, P.
    Università di Genova.
    Cruz, J.
    Centro de Fısica Nuclear da Universidade de Lisboa.
    Descouvemont, P.
    Physique Nucléaire Théorique et Physique Mathématique, Université Libre de Bruxelles.
    Formicola, A.
    Laboratori Nazionali del Gran Sasso.
    Fülop, Z.
    Institute of Nuclear Research (ATOMKI), Debrecen.
    Gervino, G.
    Dipertemento di Fisica Teoria, Universita di Torino and INFS.
    Guglielmetti, A.
    Università Degli Studi di Milano and INFN.
    Gustavino, C.
    Laboratori Nazionali del Gran Sasso.
    Gyürky, G.
    Institute of Nuclear Research (ATOMKI), Debrecen.
    Imbriani, G.
    Osservatorio Astronomico di Collurania Vincenzo Cerulli.
    Jesus, A. P.
    Centro de Fısica Nuclear da Universidade de Lisboa.
    Junker, M.
    Laboratori Nazionali del Gran Sasso.
    Lemut, A.
    Università di Genova.
    Menegazzo, R.
    INFN.
    Prati, P.
    Università di Genova.
    Roca, V.
    Seconda Università di Napoli.
    Rolfs, C.
    Institut Für Experimentalphysik III.
    Romano, M.
    Seconda Università di Napoli.
    Alvarez, C. Rossi
    INFN.
    Vomiero, Alberto
    Dipartimento di Fisica, Università di Padova.
    Zavatarelli, S.
    Università di Genova.
    Recent results of the 14N(p,γ)15O measurement at LUNA2005In: Nuclear Physics A, ISSN 0375-9474, E-ISSN 1873-1554, Vol. 758, no 1-4 SPEC. ISS., p. 383C-386CArticle in journal (Refereed)
    Abstract [en]

    The 14N(p, γ)15O reaction has been investigated by LUNA at the National Laboratory of Gran Sasso (LNGS) using two different techniques. The first study has been performed using a solid target and detecting the γ-rays coming from the single transitions with a HPGe detector in very close geometry to the target. In a second phase a windowless gas target sorrounded by a nearly 4π BGO summing crystal has been used and the total S-factor has been measured down to Eb = 80 keV. © 2005 Elsevier B.V. All rights reserved.

  • 45.
    De Melo, C.
    et al.
    Université de Lorraine, CNRS, IJL, Nancy, France. Department of Materials Science and Engineering, Saarland University, Saarbrücken, Germany.
    Jullien, M.
    Université de Lorraine, CNRS, IJL, Nancy, France.
    Ghanbaja, J.
    Université de Lorraine, CNRS, IJL, Nancy, France.
    Montaigne, F.
    Université de Lorraine, CNRS, IJL, Nancy, France.
    Pierson, J.-F.
    Université de Lorraine, CNRS, IJL, Nancy, France.
    Soldera, F.
    Department of Materials Science and Engineering, Saarland University, Saarbrücken, Germany.
    Rigoni, Federica
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Almqvist, Nils
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Mücklich, F.
    Department of Materials Science and Engineering, Saarland University, Saarbrücken, Germany.
    Horwat, D.
    Université de Lorraine, CNRS, IJL, Nancy, France.
    Local Structure and Point-Defect-Dependent Area-Selective Atomic Layer Deposition Approach for Facile Synthesis of p-Cu2O/n-ZnO Segmented Nanojunctions2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 43, p. 37671-37678Article in journal (Refereed)
    Abstract [en]

    Area-selective atomic layer deposition (AS-ALD) has attracted much attention in recent years due to the possibility of achieving accurate patterns in nanoscale features, which render this technique compatible with the continuous downscaling in nanoelectronic devices. The growth selectivity is achieved by starting from different materials and results (ideally) in localized growth of a single material. We propose here a new concept, more subtle and general, in which a property of the substrate is modulated to achieve localized growth of different materials. This concept is demonstrated by selective growth of high-quality metallic Cu and semiconducting Cu2O thin films, achieved by changing the type of majority point defects in the ZnO underneath film exposed to the reactive species using a patterned bilayer structure composed of highly conductive and highly resistive areas, as confirmed by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). The selective growth of these materials in a patterned ZnO/Al-doped ZnO substrate allows the fabrication of p-Cu2O/n-ZnO nanojunctions showing a nonlinear rectifying behavior typical of a p-n junction, as confirmed by conductive atomic force microscopy (C-AFM). This process expands the spectra of materials that can be grown in a selective manner by ALD and opens up the possibility of fabricating different architectures, taking advantage of the area-selective deposition. This offers a variety of opportunities in the field of transparent electronics, catalysis, and photovoltaics.

  • 46.
    de Melo, Claudia
    et al.
    Université de Lorraine, CNRS, IJL, F-54000 Nancy, France. Department of Materials Science and Engineering, Saarland University, Saarbrücken, Germany.
    Jullien, Maud
    Université de Lorraine, CNRS, IJL, Nancy, France.
    Battie, Yann
    LCP-A2MC, Institut Jean Barriol, Université de Lorraine, Metz, France.
    En Naciri, Aotmane
    LCP-A2MC, Institut Jean Barriol, Université de Lorraine, Metz, France.
    Ghanbaja, Jaafar
    Université de Lorraine, CNRS, IJL, Nancy, France.
    Montaigne, François
    Université de Lorraine, CNRS, IJL, Nancy, France.
    Pierson, Jean-François
    Université de Lorraine, CNRS, IJL, Nancy, France.
    Rigoni, Federica
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Almqvist, Nils
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Migot, Sylvie
    Department of Materials Science and Engineering, Saarland University, D-66123 Saarbrücken, Germany.
    Mücklich, Frank
    Department of Materials Science and Engineering, Saarland University, Saarbrücken, Germany.
    Horwat, David
    Université de Lorraine, CNRS, IJL, Nancy, France.
    Tunable Localized Surface Plasmon Resonance and Broadband Visible Photoresponse of Cu Nanoparticles/ZnO Surfaces2018In: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, no 47, p. 40958-40965Article in journal (Refereed)
    Abstract [en]

    Plasmonic Cu nanoparticles (NP) were successfully deposited on ZnO substrates by atomic layer deposition (ALD) owing to the Volmer–Weber island growth mode. An evolution from Cu NP to continuous Cu films was observed with an increasing number of ALD cycles. Real and imaginary parts of the NP dielectric functions, determined by spectroscopic ellipsometry using an effective medium approach, evidence a localized surface plasmon resonance that can be tuned between the visible and near-infrared ranges by controlling the interparticle spacing and size of the NP. The resulting Cu NP/ZnO device shows an enhanced photoresponse under white light illumination with good responsivity values, fast response times, and stability under dark/light cycles. The significant photocurrent detected for this device is related to the hot-electron generation at the NP surface and injection into the conduction band of ZnO. The possibility of tuning the plasmon resonance together with the photoresponsivity of the device is promising in many applications related to photodetection, photonics, and photovoltaics.

  • 47.
    de Melo, Claudia
    et al.
    Universitéde Lorraine, CNRS, IJL, Nancy, France.
    Jullien, Maud
    Universitéde Lorraine, CNRS, IJL, Nancy, France.
    Battie, Yann
    LCP-A2MC, Institut Jean Barriol, Universitéde Lorraine, Metz, France.
    Naciri, Aotmane En
    LCP-A2MC, Institut Jean Barriol, Universitéde Lorraine, Metz, France.
    Ghanbaja, Jaafar
    Universitéde Lorraine, CNRS, IJL, Nancy, France.
    Montaigne, Francois
    Universitéde Lorraine, CNRS, IJL, Nancy, France.
    Pierson, Jean-Francois
    Universitéde Lorraine, CNRS, IJL, Nancy, France.
    Rigoni, Federica
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Almqvist, Nils
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Migot, Sylvie
    Department of Materials Science and Engineering, Saarland University, Saarbrücken, Germany.
    Mücklich, Frank
    Department of Materials Science and Engineering, Saarland University, Saarbrücken, Germany.
    Horwat, David
    Universitéde Lorraine, CNRS, IJL, Nancy, France.
    Semi-Transparent p‑Cu2O/n-ZnO Nanoscale-Film Heterojunctions for Photodetection and Photovoltaic Applications2019In: ACS Applied Nano Materials, ISSN 2574-0970, Vol. 2, no 7, p. 4358-4366Article in journal (Refereed)
    Abstract [en]

    Transparent nanoscale-film heterojunctions based on Cu2O and ZnO were fabricated by atomic layer deposition and reactive magnetron sputtering. The constitutive layers exhibit high crystalline quality and a local epitaxial relation between Cu2O and ZnO was achieved with [110] Cu2O || [001] ZnO and [001] Cu2O || [010] ZnO as evidenced by high resolution transmission electron microscopy and. Cu2O films show very low resistivity and high mobility values of 9–150 Ω cm and 19 cm2/V s, respectively. The Cu2O/ZnO heterojunctions exhibit a nonlinear rectifying behavior characteristic of a p–n junction, self-powered photoresponse under 1 Sun illumination and an average transmittance of 73% in the visible region of the electromagnetic spectrum. These results are promising for all-oxide transparent electronics, photodetection and photovoltaic applications.

  • 48.
    Dembele, K. T.
    et al.
    Institut National de la Recherche Scientifique.
    Nechache, R.
    Institut National de la Recherche Scientifique.
    Nikolova, L.
    Institut National de la Recherche Scientifique.
    Vomiero, Alberto
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Santato, C.
    Département de Génie Physique, École Polytechnique de Montréal.
    Licoccia, S.
    Department of Chemical Sciences and INSTM Padova, Padova University.
    Rosei, F.
    Institut National de la Recherche Scientifique.
    Effect of multi-walled carbon nanotubes on the stability of dye sensitized solar cells2013In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 233, p. 93-97Article in journal (Refereed)
    Abstract [en]

    We report the improvement of the operational stability of dye-sensitized solar cells (DSSCs) by incorporating multi-wall carbon nanotubes (MWCNTs) in conventional nanostructured semiconducting TiO2 photoanodes. DSSCs were prepared by adding various concentrations of MWCNTs (up to 1.0% wt.) to TiO2 anatase nanoparticles. Optimization of MWCNT concentration leads to photoconversion efficiency as high as 4.1% as opposed to 3.7% for pure TiO2 photoanodes. The performance of the solar cells was measured for 10 consecutive days of continuous ambient light exposure. MWCNT addition results in the decrease of efficiency from 4.1% to 3.7%, while a decrease from 3.7% to 2.4% was recorded in pure TiO2 photoanodes. These results are encouraging toward the commercial exploitation of DSSCs.© 2013 Elsevier B.V. All rights reserved.

  • 49.
    Dembele, Kadiatou Therese
    et al.
    INRS-EMT.
    Selopal, Gurpreet Singh
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Milan, Riccardo
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Trudeau, Charles
    Département de Génie Électrique, École de Technologie Supérieure, Montréal.
    Benetti, Daniele
    INRS-EMT.
    Soudi, Afsoon
    INRS-EMT.
    Natile, Marta Maria
    CNR-IENI.
    Sberveglieri, Giorgio
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Cloutier, Sylvain
    Département de Génie Électrique, École de Technologie Supérieure, Montréal.
    Concina, Isabella
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Rosei, Federico
    INRS-EMT.
    Vomiero, Alberto
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Graphene below the percolation threshold in TiO2 for dye-sensitized solar cells2015In: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 3, no 6, p. 2580-2588Article in journal (Refereed)
    Abstract [en]

    We demonstrate a fast and large area-scalable methodology for the fabrication of efficient dye sensitized solar cells (DSSCs) by simple addition of graphene micro-platelets to TiO2 nanoparticulate paste (graphene concentration in the range of 0 to 1.5 wt%). Two dimensional (2D) Raman spectroscopy, scanning electron microscopy (SEM) and atomic force microscopy (AFM) confirm the presence of graphene after 500°C annealing for 30 minutes. Graphene addition increases the photocurrent density from 12.4 mA cm-2 in bare TiO2 to 17.1 mA cm-2 in an optimized photoanode (0.01 wt% graphene, much lower than those reported in previous studies), boosting the photoconversion efficiency (PCE) from 6.3 up to 8.8%. The investigation of the 2D graphene distribution showed that an optimized concentration is far below the percolation threshold, indicating that the increased PCE does not rely on the formation of an interconnected network, as inferred by prior investigations, but rather, on increased charge injection from TiO2 to the front electrode. These results give insights into the role of graphene in improving the functional properties of DSSCs and identifying a straightforward methodology for the synthesis of new photoanodes.

  • 50.
    Dembele, Kadiatou Therese
    et al.
    Institut National de la Recherche Scientifique.
    Selopal, Gurpreet Singh
    CNR IDASC SENSOR Lab.
    Soldano, Caterina
    CNR IDASC SENSOR Lab.
    Nechache, Riad
    Institut National de la Recherche Scientifique.
    Rimada, Julio Cesar
    Solar Cells Laboratory, Institute of Materials Science and Technology (IMRE), University of Havana.
    Concina, Isabella
    CNR IDASC SENSOR Lab.
    Sberveglieri, Giorgio
    CNR IDASC SENSOR Lab.
    Rosei, Federico
    Institut National de la Recherche Scientifique.
    Vomiero, Alberto
    CNR IDASC SENSOR Lab.
    Hybrid carbon nanotubes-TiO2 photoanodes for high efficiency dye-sensitized solar cells2013In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 117, no 28, p. 14510-14517Article in journal (Refereed)
    Abstract [en]

    We describe a fast and effective procedure for the preparation of high efficiency hybrid photoanodes for dye-sensitized solar cells (DSCs), based on nanocrystalline TiO2 with limited addition of multiwall carbon nanotubes (CNTs). The mixing process between CNTs and TiO2 nanoparticles is almost instantaneous, which makes it feasible for large-scale fabrication. Enhanced electron lifetime and reduced charge recombination lead to highly increased short circuit current density and overall photoconversion efficiency (from 13.6 mA cm-2 to 16.0 mA cm-2 and from 7.0% to 9.0%, respectively, considering the bare TiO2 and the optimum CNTs concentration, which is 0.010 wt %), while the small reduction in open circuit photovoltage does not significantly affect cell performances. This result is remarkable since a standard dye molecule (N719) was used and no chemical treatments of the photoanodes prior to cell fabrication were applied (i.e., soaking in TiCl4 to boost open circuit photovoltage). © 2013 American Chemical Society.

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