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  • 51.
    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 tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Modulating Exciton Dynamics in Composite Nanocrystals for Excitonic Solar Cells2015Ingår i: Journal of Physical Chemistry Letters, ISSN 1948-7185, E-ISSN 1948-7185, Vol. 6, nr 13, s. 2489-2495Artikel i tidskrift (Refereegranskat)
    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.

  • 52.
    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 cells2013Ingår i: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 240, s. 736-744Artikel i tidskrift (Refereegranskat)
    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.

  • 53.
    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 dots2010Ingår i: Journal of Physics, Conference Series, ISSN 1742-6588, E-ISSN 1742-6596, Vol. 244, artikel-id 12067Artikel i tidskrift (Refereegranskat)
    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.

  • 54.
    Concina, Isabella
    et al.
    CNR-IDASC SENSOR Laboratory, Brescia University, 25133 Brescia, via Valotti 9, Italy.
    Natile, M. M.
    Department of Chemical Science, INSTM Padova, University of Padova, 35131 Padova, via Marzolo 1, Italy.
    Ferroni, M.
    CNR-IDASC SENSOR Laboratory, Brescia University, 25133 Brescia, via Valotti 9, Italy.
    Migliori, A.
    CNR-IMM Sezione di Bologna, 40129 Bologna, via Gobetti 101, Italy.
    Morandi, V.
    CNR-IMM Sezione di Bologna, 40129 Bologna, via Gobetti 101, Italy.
    Ortolani, L.
    CNR-IMM Sezione di Bologna, 40129 Bologna, via Gobetti 101, Italy.
    Vomiero, Alberto
    CNR-IDASC SENSOR Laboratory, Brescia University, 25133 Brescia, via Valotti 9, Italy.
    Sberveglieri, G.
    CNR-IDASC SENSOR Laboratory, Brescia University, 25133 Brescia, via Valotti 9, Italy.
    CdSe spherical quantum dots stabilised by thiomalic acid: Biphasic wet synthesis and characterisation2011Ingår i: ChemPhysChem, ISSN 1439-4235, E-ISSN 1439-7641, Vol. 12, nr 4, s. 863-870Artikel i tidskrift (Refereegranskat)
  • 55.
    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 cells2014Ingår i: Pure and Applied Chemistry, ISSN 0033-4545, E-ISSN 1365-3075, Vol. 86, nr 5, s. 575-584Artikel i tidskrift (Refereegranskat)
    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.

  • 56.
    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 devices2014Ingår i: 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, artikel-id 89872EKonferensbidrag (Refereegranskat)
    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.

  • 57.
    Concina, Isabella
    et al.
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik. Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Metal Oxide Semiconductors for Dye- and Quantum-Dot-Sensitized Solar Cells2015Ingår i: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 11, nr 15, s. 1744-1774Artikel i tidskrift (Refereegranskat)
    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.

  • 58.
    Concina, Isabella
    et al.
    SENSOR Lab, Department of Information Engineering, University of Brescia.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Solar Cells: Metal Oxide Semiconductors for Dye- and Quantum-Dot-Sensitized Solar Cells2015Ingår i: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 11, nr 15, s. 1743-Artikel i tidskrift (Refereegranskat)
    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.

  • 59.
    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 antiprotons2013Ingår i: Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, ISSN 0168-9002, E-ISSN 1872-9576, Vol. 711, s. 12-20Artikel i tidskrift (Refereegranskat)
    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.

  • 60.
    Costantini, H.
    et al.
    Università di Genova, Dipartimento di Fisica and INFN Genova, Italy.
    Angulo, C.
    Centre de Recherches du Cyclotron, Chemin du cyclotron 2, Louvain-la-Neuve, Belgium.
    Bemmerer, D.
    Institut für Atomare Physik und Fachdidaktik, Technische-Univ. Berlin, Germany.
    Bonetti, R.
    Università di Milano, Istituto di Fisica and INFN Milano, Italy.
    Broggini, C.
    INFN Padova, Italy.
    Confortola, F.
    Università di Genova, Dipartimento di Fisica and INFN Genova, Italy.
    Corvisiero, P.
    Università di Genova, Dipartimento di Fisica and INFN Genova, Italy.
    Cruz, J.
    Centro de Fisica Nuclear da Universidade de Lisboa, Lisboa, Portugal.
    Descouvemont, P.
    Physique Nuc. Theor. et Physique Math., Univ. Libre de Bruxelles, Brussels, Belgium.
    Formicola, A.
    INFN Laboratori Nazionali del Gran Sasso, Assergi, Italy.
    Fülop, Z.
    ATOMKI, Debrecen, Hungary.
    Gervino, G.
    Università di Torino, Dipartimento di Fisica Sperimentale and INFN Torino, Italy.
    Guglielmetti, A.
    Università di Milano, Istituto di Fisica and INFN Milano, Italy.
    Gustavino, C.
    INFN Laboratori Nazionali del Gran Sasso, Assergi, Italy.
    Gyürky, G.
    ATOMKI, Debrecen, Hungary.
    Imbriani, G.
    Osservatorio Astronomico di Collurania, Teramo and INFN Napoli, Italy.
    Jesus, A. P.
    Centro de Fisica Nuclear da Universidade de Lisboa, Lisboa, Portugal.
    Junker, M.
    INFN Laboratori Nazionali del Gran Sasso, Assergi, Italy.
    Lemut, A.
    Università di Genova, Dipartimento di Fisica and INFN Genova, Italy.
    Menegazzo, R.
    INFN Padova, Italy.
    Prati, P.
    Università di Genova, Dipartimento di Fisica and INFN Genova, Italy.
    Roca, V.
    Università di Napoli and INFN Napoli, Italy.
    Rolfs, C.
    Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany.
    Romano, M.
    Università di Napoli and INFN Napoli, Italy.
    Rossi Alvarez, C.
    INFN Padova, Italy.
    Schümann, F.
    Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany.
    Somorjai, E.
    ATOMKI, Debrecen, Hungary.
    Straniero, O.
    Osservatorio Astronomico di Collurania, Teramo and INFN Napoli, Italy.
    Strieder, F.
    Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany.
    Terrasi, F.
    Seconda Università di Napoli, Dipartimento di Scienze Ambientali, Caserta, Italy.
    Trautvetter, H.P.
    Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany.
    Vomiero, Alberto
    Dipartimento di Fisica, Università di Padova.
    Zavatarelli, S.
    Università di Genova.
    Recent results of the 14N(p,γ)15O measurement at LUNA2005Ingår i: Nuclear Physics A, ISSN 0375-9474, E-ISSN 1873-1554, Vol. 758, nr 1-4 SPEC. ISS., s. 383C-386CArtikel i tidskrift (Refereegranskat)
    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.

  • 61.
    De Julián Fernández, C.
    et al.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Manera, M. G.
    CNR-IMM Sezione di Bologna.
    Spadavecchia, J.
    CNR-IMM Sezione di Bologna.
    Maggioni, G.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Quaranta, A.
    Laboratori Nazionali di Legnaro.
    Mattei, G.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Bazzan, M.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Cattaruzza, E.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Bonafini, M.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Negro, E.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Vomiero, Alberto
    Dipartimento di Fisica, Università di Padova.
    Carturan, S.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Scian, C.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Della Mea, G.
    Laboratori Nazionali di Legnaro.
    Rella, R.
    CNR-IMM Sezione di Bologna.
    Vasanelli, L.
    CNR-IMM Sezione di Bologna.
    Mazzoldi, P.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Study of the gas optical sensing properties of Au-polyimide nanocomposite films prepared by ion implantation2005Ingår i: Sensors and actuators. B, Chemical, ISSN 0925-4005, E-ISSN 1873-3077, Vol. 111-112, nr SUPPL., s. 225-229Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Au-polyimide nanocomposites have been synthesized by implanting Au + ions in pyromellitic dianhydride-4,4′ oxydianiline polyimide films prepared by glow discharge vapor deposition polymerisation (GDVDP). A structural and optical characterization shows that Au clusters grow only implanting 5 × 1016 Au+/cm2. This sample class shows interesting dynamic optical absorption sensing responses towards methanol and ethanol vapors in the spectral range corresponding to the surface plasmon resonance (SPR) peak of the gold nanoparticles. Traditional surface plasmon resonance measurements performed onto virgin polyimide thin films in controlled atmosphere show a sensing activity due to a variation of the film thickness and of the real part of refractive index. The comparison of the results obtained onto virgin films and implanted ones suggests that the sensing mechanisms can be attributed both to the modification of polymer optical properties and to the chemical activity of gold nanoparticles. © 2005 Elsevier B.V. All rights reserved.

  • 62.
    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 tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Almqvist, Nils
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    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 Nanojunctions2018Ingår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, nr 43, s. 37671-37678Artikel i tidskrift (Refereegranskat)
    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.

  • 63.
    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 tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Almqvist, Nils
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    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 Surfaces2018Ingår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 10, nr 47, s. 40958-40965Artikel i tidskrift (Refereegranskat)
    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.

  • 64.
    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 tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Almqvist, Nils
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    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 Applications2019Ingår i: ACS Applied Nano Materials, ISSN 2574-0970, Vol. 2, nr 7, s. 4358-4366Artikel i tidskrift (Refereegranskat)
    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.

  • 65.
    Della Mea, G.
    et al.
    INFN Laboratori Nazionali di Legnaro.
    Patelli, A.
    INFN Laboratori Nazionali di Legnaro.
    Restello, S.
    INFN Laboratori Nazionali di Legnaro.
    Rigato, V.
    INFN Laboratori Nazionali di Legnaro.
    Vomiero, Alberto
    INFN Laboratori Nazionali di Legnaro.
    14N(α,p)17O nuclear reaction cross-section at 4.9-6.1 MeV2005Ingår i: Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, ISSN 0168-583X, E-ISSN 1872-9584, Vol. 240, nr 4, s. 803-809Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The 14N(α,p)17O nuclear reaction cross-section was measured in the energy range 4.9-6.1 MeV at the laboratory angle θ = 172° in order to apply ion beam analysis to the detection of N in metal oxynitride layers. Comparison between the new calculation and data in literature was performed, highlighting important discrepancies between the new results and old cross-section data. Application of the new calculations to a standard TiN film suggests improved accuracy for the data in the present work. © 2005 Elsevier B.V. All rights reserved.

  • 66.
    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 cells2013Ingår i: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 233, s. 93-97Artikel i tidskrift (Refereegranskat)
    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.

  • 67.
    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 tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Graphene below the percolation threshold in TiO2 for dye-sensitized solar cells2015Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 3, nr 6, s. 2580-2588Artikel i tidskrift (Refereegranskat)
    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.

  • 68.
    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 cells2013Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 117, nr 28, s. 14510-14517Artikel i tidskrift (Refereegranskat)
    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.

  • 69.
    Dobryden, Illia
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Division of Surface and Corrosion Science, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm, Sweden; .
    Borgani, Riccardo
    Nanostructure Physics, KTH Royal Institute of Technology, Stockholm, Sweden.
    Rigoni, Federica
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Venezia Mestre, Italy.
    Ghamgosar, Pedram
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Concina, Isabella
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Almqvist, Nils
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Venezia Mestre, Italy.
    Nanoscale characterization of an all-oxide core-shell nanorod heterojunction using intermodulation atomic force microscopy (AFM) methods2021Ingår i: Nanoscale Advances, E-ISSN 2516-0230, Vol. 3, nr 15, s. 4388-4394Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The electrical properties of an all-oxide core–shell ZnO–Co3O4 nanorod heterojunction were studied in the dark and under UV-vis illumination. The contact potential difference and current distribution maps were obtained utilizing new methods in dynamic multifrequency atomic force microscopy (AFM) such as electrostatic and conductive intermodulation AFM. Light irradiation modified the electrical properties of the nanorod heterojunction. The new techniques are able to follow the instantaneous local variation of the photocurrent, giving a two-dimensional (2D) map of the current–voltage curves and correlating the electrical and morphological features of the heterostructured core–shell nanorods.

  • 70.
    Dobryden, Illia
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Chemistry, Division of Surface and Corrosion Science, KTH Royal Institute of Technology, Stockholm, SE-100 44, Sweden.
    Touati, Baligh
    Physics Condensed Matter Laboratory, Faculty of Science of Tunis, University of Tunis El-Manar.
    Gassoumi, Abdelaziz
    Physics Condensed Matter Laboratory, Faculty of Science of Tunis, University of Tunis El-Manar.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Kamoun, Najoua
    Physics Condensed Matter Laboratory, Faculty of Science of Tunis, University of Tunis El-Manar.
    Almqvist, Nils
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Morphological and electrical characterization of Cu-doped PbS thin films with AFM2017Ingår i: Advanced Materials Letters, ISSN 0976-3961, E-ISSN 0976-397X, Vol. 8, nr 11, s. 1029-1037Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lead sulphide (PbS) is a direct band gap IV–VI intrinsic p-type semiconductor with good potential for application in solar cells, sensors, etc. Doping the films with Cu2+ ions may improve the electrical properties. Here, Cu-doped PbS films were deposited on conducting glass substrates. The morphology, topography and thickness of the doped PbS films were examined using atomic force microscopy (AFM) and high-resolution SEM. AFM analysis showed decreasing surface roughness and grain size with the increase of Cu2+ concentration from 0.5 to 2.0 at%. Local surface electrical measurements using conducting AFM and Kelvin probe force microscopy showed the possibility to probe semi-quantitatively the changes in surface potential, work function, and Fermi level upon doping of the films. The estimated apparent work function for the un-doped PbS grains in the film was slightly above 4.5 eV, while it decreased to a minimum value of 4.43-4.45 eV at 1–1.5 at% Cu-doping. Conducting AFM measurements showed that local resistance of the doped samples is lower than on pure PbS films. These results indicate Cu doping as an effective strategy to tune the electrical properties of PbS thin films toward the development of suitable optically active materials for application in photovoltaics.

  • 71.
    Enrichi, Francesco
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Armellini, Cristina
    CSMFO Lab., Istituto di Fotonica e Nanotecnologie CNR.
    Belmokhtar, Saloua
    Laboratoire des Technologies Innovantes, LTI, Université Abdelmalek Essâadi, Tanger.
    Bouajaj, Adel
    Laboratoire des Technologies Innovantes, LTI, Université Abdelmalek Essâadi, Tanger.
    Chiappini, Andrea
    CSMFO Lab., Istituto di Fotonica e Nanotecnologie CNR.
    Ferrari, M.
    Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Piazza del Viminale .
    Quandt, Alexander
    Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi.
    Righini, Giancarlo C.
    Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Zur, Lidia Z.
    Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi.
    Visible to NIR downconversion process in Tb3+-Yb3+ codoped silica-hafnia glass and glass-ceramic sol-gel waveguides for solar cells2018Ingår i: Journal of Luminescence, ISSN 0022-2313, E-ISSN 1872-7883, Vol. 193, s. 44-50Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The efficiency of photovoltaic solar cells is strongly related to the spectral absorption and photo-conversion properties of the cell's active material, which does not exploit the whole broadband solar spectrum. This mismatch between the spectrum of the solar light and the wavelength dependent cell's response can be partially overcome by using luminescent conversion layers in front or in the back of the solar cell. In this paper, the investigation of Tb3+-Yb3+ co-doped SiO2-HfO2 glass and glass-ceramic waveguides is presented. Due to a down-conversion process based on cooperative energy transfer between one Tb3+ ion and two Yb3+ ions, a blue photon at 488 nm can be divided in two NIR photons at 980 nm. Films with different molar concentrations of rare earths, up to a total amount of [Tb+Yb] = 15%, were prepared by a sol-gel route, using dip-coating deposition on SiO2 substrates. For all the films, the molar ratio [Yb]/[Tb] was taken equal to 4. The comparison of the energy-transfer efficiency between Tb3+ and Yb3+ ions in the glass and in the glass-ceramic materials demonstrated the higher performance of the glass-ceramic, with a maximum quantum transfer efficiency of 179% for the highest rare earth doping concentration. Moreover, experimental results and comparison with proper rate equations modelling showed a linear dependence of the photoluminescence emission intensity for the Yb3+ ions 2F5/22F7/2 transition at 980 nm on the excitation power, indicating a direct transfer process from Tb3+ to Yb3+ ions. The reported waveguides could find applications not only as downconverting filters in transmission but also as efficient solar concentrators in the near-IR spectral region

  • 72.
    Enrichi, Francesco
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma.
    Belmokhtar, Saloua
    Laboratoire des Technologies Innovantes, LTI, Université Abdelmalek Essâadi, Tanger.
    Benedetti, Alvise
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Mestre, Venezia.
    Bouajaj, Adel
    Laboratoire des Technologies Innovantes, LTI, Université Abdelmalek Essâadi, Tanger.
    Cattaruzza, E.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia.
    Coccetti, F.
    Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma.
    Colusso, Elena
    Dipartimento di Ingegneria Industriale (DII), Università degli Studi di Padova.
    Ferrari, M.
    Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma.
    Ghamgosar, Pedram
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Gonella, Francesco
    Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma.
    Karlsson, Maths
    Department of Chemistry and Chemical Engineering, Chalmers University of Technology.
    Martucci, Alessandro
    Dipartimento di Ingegneria Industriale (DII), Università degli Studi di Padova.
    Ottini, Riccardo
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Mestre, Venezia.
    Riello, Pietro
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Mestre, Venezia.
    Righini, Giancarlo C.
    Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma.
    Trave, Enrico
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Mestre, Venezia.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    You, Shujie
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Zur, Lidia Z.
    Museo Storico della Fisica e Centro Studi e Ricerche Enrico Fermi, Roma.
    Ag nanoaggregates as efficient broadband sensitizers for Tb3+ ions in silica-zirconia ion-exchanged sol-gel glasses and glass-ceramics2018Ingår i: Optical materials (Amsterdam), ISSN 0925-3467, E-ISSN 1873-1252, Vol. 84, s. 668-674Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper we report the study of down-shifting silica-zirconia glass and glass-ceramic films doped by Tb3+ ions and Ag nanoaggregates, which combine the typical spectral properties of the rare-earth-ions with the broadband sensitizing effect of the metal nanostructures. Na-Tb co-doped silica-zirconia samples were obtained by a modified sol-gel route. Dip-coating deposition followed by annealing for solvent evaporation and matrix densification were repeated several times, obtaining a homogeneous crack-free film. A final treatment at 700 °C or 1000 °C was performed to control the nanoscale structural properties of the samples, resulting respectively in a glass (G) or a glass-ceramic (GC), where tetragonal zirconia nanocrystals are surrounded by an amorphous silica matrix. Ag introduction was then achieved by ion-exchange in a molten salt bath, followed by annealing in air to control the migration and aggregation of the metal ions. The comparison of the structural, compositional and optical properties are presented for G and GC samples, providing evidence of highly efficient photoluminescence enhancement in both systems, slightly better in G than in GC samples, with a remarkable increase of the green Tb3+ PL emission at 330 nm excitation: 12 times for G and 8 times for GC samples. Furthermore, after Ag-exchange, the shape of Tb3+ excitation resembles the one of Ag ions/nanoaggregates, with a broad significant absorption in the whole UV-blue spectral region. This broadband enhanced downshifting could find potential applications in lighting devices and in PV solar cells.

  • 73.
    Enrichi, Francesco
    et al.
    Department of Computer Science, University of Verona, Ca' Vignal 2, Strada Le Grazie 15, 37134 Verona, Italy; CNR-ISP Institute of Polar Sciences, Via Torino 155, 30172 Mestre, Venezia, Italy.
    Cassetta, Michele
    Department of Computer Science, University of Verona, Ca' Vignal 2, Strada Le Grazie 15, 37134 Verona, Italy.
    Daldosso, Nicola
    Department of Computer Science, University of Verona, Ca' Vignal 2, Strada Le Grazie 15, 37134 Verona, Italy.
    Cattaruzza, Elti
    Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, 30172, Venezia-Mestre, Italy.
    Riello, Pietro
    Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, 30172, Venezia-Mestre, Italy.
    Zairov, Rustem
    Aleksander Butlerov Institute of Chemistry, Kazan Federal University, Kazan, 420008, 1/29 Lobachevskogo str., Russian Federation.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, 30172, Venezia-Mestre, Italy.
    Righini, Giancarlo C.
    CNR-IFAC Nello Carrara Institute of Applied Physics, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy.
    Effect of the crystal structure on the optical properties and Ag sensitization of Tb3+/Yb3+ ions in silica-zirconia glasses and glass-ceramics2022Ingår i: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 49, nr 24 Part BArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    The role of the material structure in the energy transfer between Ag and Tb3+/Yb3+ ions is studied in silica-soda-zirconia sol-gel glasses and glass-ceramics. The preparation of Tb3+ and Yb3+ doped silica-soda-zirconia layers was carried out by sol-gel and dip-coating, followed by thermal annealing. The precipitation of zirconia nanocrystals was obtained by controlling the annealing temperature: from a full amorphous glass at 700 °C into a glass-ceramic at 1000 °C. A different crystalline structure of zirconia nanocrystals, tetragonal or cubic, was controlled by the rare-earth doping and investigated in relation to the Tb3+/Yb3+ optical properties. Moreover, Ag codoping was introduced by ion-exchange, obtaining a significant photoluminescence enhancement, both in the intensity and in the broadness of the excitation band, covering the whole UV region and part of the violet-blue region. Ag-sensitized Tb3+/Yb3+ doped silica-soda-zirconia glass-ceramics were attested to be potential candidates for energy-related applications, such as spectral conversion layers for solar cells, lasers and light-emitting devices (LEDs) in the visible and NIR spectral regions.

  • 74.
    Enrichi, Francesco
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, 00184 Roma, Italy; Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, 30172 Mestre, Venezia, Italy.
    Cattaruzza, E.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, 30172 Mestre, Venezia, Italy.
    Ferrari, M.
    IFN-CNR CSMFO Lab. and FBK Photonics Unit, 38123 Povo, Trento, Italy; Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, 00184 Roma, Italy.
    Gonella, F.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, 30172 Mestre, Venezia, Italy; Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, 00184 Roma, Italy .
    Martucci, A.
    Dipartimento di Ingegneria Industriale (DII), Università degli Studi di Padova, 35131 Padova, Italy.
    Ottini, R.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, 30172 Mestre, Venezia, Italy.
    Riello, P.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, 30172 Mestre, Venezia, Italy.
    Righini, G. C.
    Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, 00184 Roma, Italy; Istituto di Fisica Applicata Nello Carrara, CNR-IFAC, 50019 Sesto Fiorentino, Firenze, Italy.
    Trave, E.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, 30172 Mestre, Venezia, Italy.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Zur, L.
    Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, 00184 Roma, Italy; IFN-CNR CSMFO Lab. and FBK Photonics Unit, 38123 Povo, Trento, Italy.
    Investigation of the role of Ag multimers as broadband sensitizers in Tb3+/Yb3+ doped glasses and glass ceramics2018Ingår i: Fiber Lasers and Glass Photonics: Materials through Applications / [ed] Stefano Taccheo; Jacob I. Mackenzie; Maurizio Ferrari, SPIE - International Society for Optical Engineering, 2018, artikel-id 106830TKonferensbidrag (Refereegranskat)
    Abstract [en]

    Rare earth ions (RE3+) have typical photoluminescence emissions due to internal 4f orbital transitions. These emissions are narrow, with long excited state lifetimes and have the capability of spectral manipulation like wavelength shifting, down-conversion or up-conversion processes. Therefore, RE-doped materials are widely used for optical applications. However, the narrow absorption bandwidths and the small excitation cross sections for their optical transitions are major limiting factors for the full exploitation of their potentials. In this work, we show that the addition of metal nanoaggregates as broadband and efficient sensitizers can be a viable strategy to overcome these limits. Silica-zirconia (70% SiO2 – 30% ZrO2) glass-ceramic films doped by Tb3+/Yb3+ ions and an additional 5 mol.% of Na2O were prepared by sol-gel synthesis followed by a thermal annealing at 1000°C. Ag introduction was then obtained by ion-exchange in a molten salt bath and the samples were subsequently annealed in air at 380°C or 430°C to induce the migration and aggregation of the metal. The structural, compositional and optical properties of the materials were investigated, providing evidence for efficient broadband sensitization of the rare earth ions by energy transfer from Ag-dimers or multimers, which could have applications for increasing the efficiency of silicon solar cells.

  • 75.
    Enrichi, Francesco
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Roma, Italy. Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Venezia, Italy.
    Cattaruzza, Elti
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Venezia, Italy.
    Ferrari, Maurizio
    Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Roma, Italy. Istituto di Fotonica e Nanotecnologie del Consiglio Nazionale delle Ricerche (IFN-CNR), Laboratorio CSMFO and Fondazione Bruno Kessler (FBK) Photonics Unit, Trento, Italy.
    Gonella, Francesco
    Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Roma, Italy. Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Venezia, Italy.
    Ottini, Riccardo
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Venezia, Italy.
    Riello, Pietro
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Venezia, Italy.
    Righini, Giancarlo C.
    Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Roma, Italy. Istituto di Fisica Applicata Nello Carrara del Consiglio Nazionale delle Ricerche (IFAC-CNR), Firenze, Italy.
    Enrico, Trave
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Venezia, Italy.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Zur, Lidia
    Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Roma, Italy. Istituto di Fotonica e Nanotecnologie del Consiglio Nazionale delle Ricerche (IFN-CNR), Laboratorio CSMFO and Fondazione Bruno Kessler (FBK) Photonics Unit, Trento, Italy.
    Ag-Sensitized Yb3+ Emission in Glass-Ceramics2018Ingår i: Micromachines, E-ISSN 2072-666X, Vol. 9, nr 8, artikel-id 380Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Rare earth doped materials play a very important role in the development of many photonic devices, such as optical amplifiers and lasers, frequency converters, solar concentrators, up to quantum information storage devices. Among the rare earth ions, ytterbium is certainly one of the most frequently investigated and employed. The absorption and emission properties of Yb3+ ions are related to transitions between the two energy levels 2F7/2 (ground state) and 2F5/2 (excited state), involving photon energies around 1.26 eV (980 nm). Therefore, Yb3+ cannot directly absorb UV or visible light, and it is often used in combination with other rare earth ions like Pr3+, Tm3+, and Tb3+, which act as energy transfer centres. Nevertheless, even in those co-doped materials, the absorption bandwidth can be limited, and the cross section is small. In this paper, we report a broadband and efficient energy transfer process between Ag dimers/multimers and Yb3+ ions, which results in a strong PL emission around 980 nm under UV light excitation. Silica-zirconia (70% SiO2-30% ZrO2) glass-ceramic films doped by 4 mol.% Yb3+ ions and an additional 5 mol.% of Na2O were prepared by sol-gel synthesis followed by a thermal annealing at 1000 °C. Ag introduction was then obtained by ion-exchange in a molten salt bath and the samples were subsequently annealed in air at 430 °C to induce the migration and aggregation of the metal. The structural, compositional, and optical properties were investigated, providing evidence for efficient broadband sensitization of the rare earth ions by energy transfer from Ag dimers/multimers, which could have important applications in different fields, such as PV solar cells and light-emitting near-infrared (NIR) devices.

  • 76.
    Enrichi, Francesco
    et al.
    CNR-ISP Istituto di Scienze Polari, c/o campus scientifico Università Ca’ Foscari Venezia, via Torino 155, 30172 Mestre-Venezia, Italy. Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, via Torino 155, 30172 Mestre-Venezia, Italy.
    Cattaruzza, Elti
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, via Torino 155, 30172 Mestre-Venezia, Italy.
    Finotto, Tiziano
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, via Torino 155, 30172 Mestre-Venezia, Italy.
    Riello, Pietro
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, via Torino 155, 30172 Mestre-Venezia, Italy.
    Righini, Giancarlo C.
    Museo Storico della Fisica e Centro Studi e Ricerche “Enrico Fermi”, Piazza del Viminale 1, 00184 Roma, Italy. CNR-IFAC Istituto di Fisica Applicata Nello Carrara, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy.
    Trave, Enrico
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, via Torino 155, 30172 Mestre-Venezia, Italy.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, via Torino 155, 30172 Mestre-Venezia, Italy.
    Ag-Sensitized NIR-Emitting Yb3+-Doped Glass-Ceramics2020Ingår i: Applied Sciences, E-ISSN 2076-3417, Vol. 10, nr 6, artikel-id 2184Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The optical photoluminescent (PL) emission of Yb3+ ions in the near infrared (NIR) spectral region at about 950–1100 nm has many potential applications, from photovoltaics to lasers and visual devices. However, due to their simple energy-level structure, Yb3+ ions cannot directly absorb UV or visible light, putting serious limits on their use as light emitters. In this paper we describe a broadband and efficient strategy for sensitizing Yb3+ ions by Ag codoping, resulting in a strong 980 nm PL emission under UV and violet-blue light excitation. Yb-doped silica–zirconia–soda glass–ceramic films were synthesized by sol-gel and dip-coating, followed by annealing at 1000 °C. Ag was then introduced by ion-exchange in a molten salt bath for 1 h at 350 °C. Different post-exchange annealing temperatures for 1 h in air at 380 °C and 430 °C were compared to investigate the possibility of migration/aggregation of the metal ions. Studies of composition showed about 1–2 wt% Ag in the exchanged samples, not modified by annealing. Structural analysis reported the stabilization of cubic zirconia by Yb-doping. Optical measurements showed that, in particular for the highest annealing temperature of 430 °C, the potential improvement of the material’s quality, which would increase the PL emission, is less relevant than Ag-aggregation, which decreases the sensitizers number, resulting in a net reduction of the PL intensity. However, all the Ag-exchanged samples showed a broadband Yb3+ sensitization by energy transfer from Ag aggregates, clearly attested by a broad photoluminescence excitation spectra after Ag-exchange, paving the way for applications in various fields, such as solar cells and NIR-emitting devices.

  • 77.
    Enrichi, Francesco
    et al.
    CNR-ISP, Institute of Polar Sciences, National Research Council, Via Torino 155, 30172 Mestre-Venezia, Italy. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, 30172 Mestre-Venezia, Italy.
    Cattaruzza, Elti
    Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, 30172 Mestre-Venezia, Italy.
    Riello, Pietro
    Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, 30172 Mestre-Venezia, Italy.
    Righini, Giancarlo C.
    CNR-IFAC, Nello Carrara Institute of Applied Physics, National Research Council, Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, 30172 Mestre-Venezia, Italy.
    Ag-sensitized Tb3+/Yb3+ codoped silica-zirconia glasses and glass-ceramics: systematic and detailed investigation of the broadband energy-transfer and downconversion processes2021Ingår i: Ceramics International, ISSN 0272-8842, E-ISSN 1873-3956, Vol. 47, nr 13, s. 17939-17949Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Various studies report that Tb3+/Yb3+ co-doped materials can split one UV or 488 nm (visible) photon in two near infrared (NIR) photons at 980 nm by an energy-transfer process involving one Tb3+ and two Yb3+ ions. Additionally, it was demonstrated that Ag multimers can provide an efficient optical sensitizing effect for rare earth ions (RE3+ ions), resulting in a broadband enhanced excitation, which could have a significant technological impact, overcoming their limited spectral absorptions and small excitation cross sections. However, a systematic and detailed investigation of the down-conversion process enhanced by Ag nanoaggregates is still lacking, which is the focus of this paper. Specifically, a step by step analysis of the energy-transfer quantum-cutting chain in Ag-exchanged Tb3+/Yb3+ co-doped glasses and glass-ceramics is presented. Moreover, the direct Ag-Yb3+ energy-transfer is also considered. Results of structural, compositional, and optical characterizations are given, providing quantitative data for the efficient broadband Ag-sensitization of Tb3+/Yb3+ quantum cutting. A deeper understanding of the physical processes beneath the optical properties of the developed materials will allow a wiser realization of more efficient energy-related devices, such as spectral converters for silicon solar cells and light-emitting devices (LEDs) in the visible and NIR spectral regions.

  • 78.
    Fanchini, G.
    et al.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Mandracci, P.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Tagliaferro, A.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Rodil, S. E.
    Instituto de Ciencia de Materiales de Madrid, Consejo Superior de Investigaciones.
    Vomiero, Alberto
    Laboratori Nazionali di Legnaro.
    Della Mea, G.
    Laboratori Nazionali di Legnaro.
    Growth and characterisation of polymeric amorphous carbon and carbon nitride films from propane2005Ingår i: Diamond and related materials, ISSN 0925-9635, E-ISSN 1879-0062, Vol. 14, nr 3-7, s. 928-933Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, we report about the deposition of a-C(N):H films by electron-cyclotron-resonance using propane as a carbon precursor. The films generally present high H contents (up to 61 at.%) and large optical gaps. The maximum N content we obtained is 13 at.%. In nitrogenated films, we observed a strong decrease of the stretching intensity of the infrared spectra of the hydrocarbon (CHn) vibrations, even at very low nitrogen content, the H content being still comparable to that of pure a-C:H. The various phenomena that can lead to such an effect are discussed: (i) different type of hydrogen bonding (CHn and NHn) in presence and in absence of nitrogenation; (ii) weakening of the cross-section of the CHn groups in presence of nitrogen; (iii) large presence of non-bonded hydrogen meaning, with this, either the presence of molecular H2 or unbounded hydrogen. In addition, the residual amount of IR absorption due to C-H vibrations shows that, in a-CN:H, C-H bonded and non-bonded hydrogen does coexist. © 2005 Elsevier B.V. All rights reserved.

  • 79.
    Fanizza, Elisabetta
    et al.
    Dipartimento di Chimica, Università degli Studi di Bari, Via Orabona 4, 70126 Bari, Italy. CNR-IPCF, SSO Bari, Via Orabona 4, 70126 Bari, Italy.
    Zhao, Haiguang
    State Key Laboratory of Bio-Fibers and Eco-Textiles, College of Physics, Qingdao University, No. 308 Ningxia Road, Qingdao 266071, China.
    De Zio, Simona
    Dipartimento di Chimica, Università degli Studi di Bari, Via Orabona 4, 70126 Bari, Italy. Dipartimento di Chimica “Giacomo Ciamician”, Università degli Studi di Bologna, Via Selmi 2, Bologna, Italy.
    Depalo, Nicoletta
    CNR-IPCF, SSO Bari, Via Orabona 4, 70126 Bari, Italy.
    Rosei, Federico
    Centre Énergie, Matériaux et Télécommunications, Institut National de la Recherche Scientifique, 1650 Boul. Lionel Boulet, Varennes, QC J3X 1S2, Canada.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, 30172 Venezia Mestre, Italy.
    Curri, M. Lucia
    Dipartimento di Chimica, Università degli Studi di Bari, Via Orabona 4, 70126 Bari, Italy. CNR-IPCF, SSO Bari, Via Orabona 4, 70126 Bari, Italy.
    Striccoli, Marinella
    CNR-IPCF, SSO Bari, Via Orabona 4, 70126 Bari, Italy.
    Encapsulation of Dual Emitting Giant Quantum Dots in Silica Nanoparticles for Optical Ratiometric Temperature Nanosensors2020Ingår i: Applied Sciences, E-ISSN 2076-3417, Vol. 10, nr 8, artikel-id 2767Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Accurate temperature measurements with a high spatial resolution for application in the biomedical fields demand novel nanosized thermometers with new advanced properties. Here, a water dispersible ratiometric temperature sensor is fabricated by encapsulating in silica nanoparticles, organic capped PbS@CdS@CdS “giant” quantum dots (GQDs), characterized by dual emission in the visible and near infrared spectral range, already assessed as efficient fluorescent nanothermometers. The chemical stability, easy surface functionalization, limited toxicity and transparency of the silica coating represent advantageous features for the realization of a nanoscale heterostructure suitable for temperature sensing. However, the strong dependence of the optical properties on the morphology of the final core–shell nanoparticle requires an accurate control of the encapsulation process. We carried out a systematic investigation of the synthetic conditions to achieve, by the microemulsion method, uniform and single core silica coated GQD (GQD@SiO2) nanoparticles and subsequently recorded temperature-dependent fluorescent spectra in the 281-313 K temperature range, suited for biological systems. The ratiometric response—the ratio between the two integrated PbS and CdS emission bands—is found to monotonically decrease with the temperature, showing a sensitivity comparable to bare GQDs, and thus confirming the effectiveness of the functionalization strategy and the potential of GQD@SiO2 in future biomedical applications.

  • 80.
    Fedorenko, Svetlana V.
    et al.
    A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Jilkin, Michail E.
    Kazan (Volga Region) Federal University.
    Gryaznova, Tatyana V.
    A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Iurko, Elizaveta O.
    A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Bochkova, Olga D.
    A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Mukhametshina, Alsu R.
    A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Nizameev, Irek R.
    A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Kholin, Kirill V.
    A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Mazzaro, Raffaello
    CNR-IMM, Bologna Section.
    Morandi, Vittorio
    CNR-IMM, Bologna Section.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Mustafina, Asiya R.
    A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Budnikova, Yulia H.
    A.E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Scientific Center of Russian Academy of Sciences.
    Silica Nanospheres Coated by Ultrasmall Ag0 Nanoparticles for Oxidative Catalytic Application2017Ingår i: Colloid and Interface Science Communications, ISSN 2215-0382, Vol. 21, s. 1-5Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The present work introduces optimal modifiсation of core-shell composite nanomaterial, where small (2–8 nm) Ag0 nanoparticles are deposited onto large (about 140 nm) silica spheres for application in oxidative catalysis. The size of Ag0 and density of its deposition onto silica spheres was modified by the post treatment of initially deposited Ag0 (about 30 nm) by hydrogen peroxide in specific conditions. The comparison of catalytic effect of the post-treated and initial SN-Ag0 in electrochemical phosphonation of benzo(thia)oxazoles by diethyl phosphite in oxidative conditions revealed the difference between the composite nanoparticles. In particular, the post-treated SNs-Ag0 nanoparticles exhibit efficient catalytic effect in oxidative conditions resulting in facile and green method for synthesis of phosphonated benzooxa(thia)zoles, while no catalytic effect is observed under the use of larger Ag0 nanoparticles deposited onto silica spheres. The use of Ag0-based nanomaterial in oxidative catalysis had been never demonstrated before

  • 81.
    Ferraro, Valentina
    et al.
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Via Torino 155, I-30170 Mestre, VE, Italy. Consorzio Interuniversitario Reattività Chimica e Catalisi (CIRCC), via Celso Ulpiani 27, 70126 Bari, Italy.
    Bortoluzzi, Marco
    Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Via Torino 155, I-30170 Mestre, VE, Italy. Consorzio Interuniversitario Reattività Chimica e Catalisi (CIRCC), via Celso Ulpiani 27, 70126 Bari, Italy.
    Castro, Jesús
    Departamento de Química Inorgánica, Universidade de Vigo, Facultade de Química, Edificio de Ciencias Experimentais, 36310 Vigo, Galicia, Spain.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Dipartimento di Scienze Molecolari e Nanosistemi, Università Ca’ Foscari Venezia, Via Torino 155, I-30170 Mestre, VE, Italy.
    You, Shujie
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Luminescent Cu(I) complex with bis(indazol-1-yl)phenylmethane as chelating ligand2020Ingår i: Inorganic Chemistry Communications, ISSN 1387-7003, E-ISSN 1879-0259, Vol. 116, artikel-id 107894Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The cationic Cu(I) complex [Cu(N^N)2]+, where N^N is bis(indazol-1-yl)phenylmethane, was synthesized as chloride or tetrafluoroborate salt by reacting CuCl or [Cu(NCCH3)4][BF4] with bis(indazol-1-yl)phenylmethane under mild conditions. The structure of [Cu(N^N)2]Cl was ascertained by single-crystal X-ray diffraction. The complex exhibited bright yellow emission upon excitation with near UV and violet light, attributed to triplet LLCT/MLCT transitions on the basis of experimental data and computational outcomes.

  • 82.
    Fiorini, M.
    et al.
    Ferrara University, INFN.
    Dalpiaz, P.
    Ferrara University, INFN.
    Guidi, V.
    Ferrara University, INFN.
    Assmann, R.
    CERN.
    Efthymiopoulos, I.
    CERN.
    Gatignon, L.
    CERN.
    Scandale, W.
    CERN.
    Taratin, A.
    JINR Dubna.
    Chesnokov, Y.
    IHEP Protvino.
    Ivanov, Y.
    PNPI Gatchina.
    Vomiero, Alberto
    INFN Laboratori Nazionali di Legnaro.
    Biino, C.
    INFN Sezione di Ferrara.
    Ambrosi, G.
    INFN Sezione di Ferrara.
    Santacesaria, R.
    INFN Sezione di Ferrara.
    Experimental study of crystal channeling at CERN-SPS for beam-HALO cleaning2006Ingår i: EPAC 2006: 10th European Particle Accelerator Conference EPAC 2006 ; a Europhysics conference ; Edinburgh, Scotland, International Conference Centre (EICC), 26 - 30 June 2006, Edinburgh: European Physical Society Accelerator Group (EPS-AG) , 2006, s. 1538-1540Konferensbidrag (Refereegranskat)
    Abstract [en]

    An efficient and robust collimation system is mandatory for any superconducting hadron collider, in particular for the LHC, which will store a beam of unprecedented high intensity and energy. The usage of highly efficient and short primary bent-crystal collimators might be a possibility for reaching nominal and ultimate LHC intensity. Over the last years, groups in Italy (Ferrara) and Russia (St. Petersburg) have developed crystal production methods, that considerably improve the crystal quality. These developments led, in turn, to a surprising increase in the channeling efficiency and to the recent observation of the "volume reflection" mechanism. The aim of the proposed experiment is the setup of a beam test facility, directing primary protons from the SPS onto a bent silicon crystal, and the quantitative study of single-pass efficiency for all involved processes. Final goal will be the extrapolation of important information on the feasibility of a crystal collimator for halo cleaning in the LHC. The experiment will be performed in the H8 beamline at the CERN SPS where a beam with very small divergence can be provided thus representing a unique facility for tests and characterization of crystals to be used for particle channeling studies.

  • 83.
    Fomekong, Roussin Lontio
    et al.
    Department of High-Temperature and Functional Coatings, Institute of Materials Research, German Aerospace Center, Cologne, Germany.
    You, Shujie
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Enrichi, Francesco
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Italy.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Italy.
    Saruhan, Bilge
    Department of High-Temperature and Functional Coatings, Institute of Materials Research, German Aerospace Center, Cologne, Germany.
    Impact of Oxalate Ligand in Co-Precipitation Route on Morphological Properties and Phase Constitution of Undoped and Rh-Doped BaTiO3 Nanoparticles2019Ingår i: Nanomaterials, E-ISSN 2079-4991, Vol. 9, nr 12, artikel-id 1697Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In order to design and tailor materials for a specific application like gas sensors, the synthesis route is of great importance. Undoped and rhodium-doped barium titanate powders were successfully synthesized by two routes; oxalate route and classic route (a modified conventional route where solid-state reactions and thermal evaporation induced precipitation takes place). Both powders were calcined at different temperatures. X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX) and Brunauer-Emmet-Teller (BET) analyses are employed to identify the phases and polymorphs, to determine the morphology, the chemical composition and the specific surface area of the synthesized materials, respectively. The so-called oxalate route yields pure BaTiO3 phase for undoped samples at 700 °C and 900 °C (containing both cubic and tetragonal structures), while the classic route-synthesized powder contains additional phases such as BaCO3, TiO2 and BaTi2O5. Samples of both synthesis routes prepared by the addition of Rh contain no metallic or oxide phase of rhodium. Instead, it was observed that Ti was substituted by Rh at temperatures 700 °C and 900 °C and there was some change in the composition of BaTiO3 polymorph (increase of tetragonal structure). Heat-treatments above these temperatures show that rhodium saturates out of the perovskite lattice at 1000 °C, yielding other secondary phases such as Ba3RhTi2O9 behind. Well-defined and less agglomerated spherical nanoparticles are obtained by the oxalic route, while the classic route yields particles with an undefined morphology forming very large block-like agglomerates. The surface area of the synthesized materials is higher with the oxalate route than with the classic route (4 times at 900 °C). The presence of the oxalate ligand with its steric hindrance that promotes the uniform distribution and the homogeneity of reactants could be responsible for the great difference observed between the powders prepared by two preparation routes.

  • 84.
    Formicola, A
    et al.
    Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany.
    Imbriani, G
    Osservatorio Astronomico di Collurania, Teramo and INFN, Napoli, Italy.
    Costantini, H
    Dipartimento di Fisica, Università di Genova, and INFN, Genova, Italy.
    Angulo, C
    Centre de Recherches du Cyclotron, Université catholique de Louvain, Belgium.
    Bemmerer, D
    Institut für Atomare Physik und Fachdidaktik, Technische-Universität Berlin, Germany.
    Bonetti, R
    Istituto di Fisica, Università di Milano, and INFN, Milano, Italy.
    Broggini, C
    INFN, Padova, Italy.
    Corvisiero, P
    Dipartimento di Fisica, Università di Genova, and INFN, Genova, Italy.
    Cruz, J
    Centro de Fisica Nuclear da Universidade de Lisboa, Lisboa, Portugal.
    Descouvemont, P
    Physique Nucléaire Théorique and Physique Mathématique, CP229 Université Libre de Bruxelles, Brussels, Belgium.
    Fülöp, Z
    ATOMKI, Debrecen, Hungary.
    Gervino, G
    Dipartimento di Fisica Sperimentale, Università di Torino, and INFN, Torino, Italy.
    Guglielmetti, A
    Istituto di Fisica, Università di Milano, and INFN, Milano, Italy.
    Gustavino, C
    INFN, Laboratori Nazionali del Gran Sasso, Assergi, Italy.
    Gyürky, G
    ATOMKI, Debrecen, Hungary.
    Jesus, A P
    Centro de Fisica Nuclear da Universidade de Lisboa, Lisboa, Portugal.
    Junker, M
    INFN, Laboratori Nazionali del Gran Sasso, Assergi, Italy.
    Lemut, A
    Dipartimento di Fisica, Università di Genova, and INFN, Genova, Italy.
    Menegazzo, R
    INFN, Padova, Italy.
    Prati, P
    Dipartimento di Fisica, Università di Genova, and INFN, Genova, Italy.
    Roca, V
    Dipartimento di Fisica, Università di Napoli, and INFN, Napoli, Italy.
    Rolfs, C
    Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany.
    Romano, M
    Dipartimento di Fisica, Università di Napoli, and INFN, Napoli, Italy.
    Rossi Alvarez, C
    INFN, Padova, Italy.
    Schümann, F
    Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany.
    Somorjai, E
    ATOMKI, Debrecen, Hungary.
    Straniero, O
    Osservatorio Astronomico di Collurania, Teramo and INFN, Napoli, Italy.
    Strieder, F
    Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany.
    Terrasi, F
    Dipartimento di Scienze Ambientali, Seconda Università di Napoli, Caserta, and INFN, Napoli, Italy.
    Trautvetter, H.P
    Institut für Experimentalphysik III, Ruhr-Universität Bochum, Bochum, Germany.
    Vomiero, Alberto
    Dipartimento di Fisica, Università di Padova.
    Zavatarelli, S
    Dipartimento di Fisica, Università di Genova, and INFN, Genova, Italy.
    Astrophysical S-factor of 14N(p,γ)15O2004Ingår i: Physics Letters B, ISSN 0370-2693, E-ISSN 1873-2445, Vol. 591, nr 1-2, s. 61-68Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We report on a new measurement of the 14N(p,γ) 15O capture cross section at Ep=140 to 400 keV using the 400 kV LUNA accelerator facility at the Laboratori Nazionali del Gran Sasso (LNGS). The uncertainties have been reduced with respect to previous measurements and their analysis. We have analyzed the data using the R-matrix method and we find that the ground state transition accounts for about 15% of the total S-factor. The main contribution to the S-factor is given by the transition to the 6.79 MeV state. We find a total S(0)=1.7±0.2 keVb, in agreement with recent extrapolations. The result has important consequences for the solar neutrino spectrum as well as for the age of globular clusters. © 2004 Elsevier B.V. All rights reserved.

  • 85.
    Galstyan, V.
    et al.
    CNR IDASC SENSOR Lab.
    Comini, E.
    CNR IDASC SENSOR Lab.
    Faglia, G.
    CNR IDASC SENSOR Lab.
    Vomiero, Alberto
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Brisotto, M.
    INSTM and Chemistry for Technologies Laboratory.
    Bontempi, E.
    INSTM and Chemistry for Technologies Laboratory.
    Sberveglieri, G.
    CNR IDASC SENSOR Lab.
    Fabrication of TiO 2 and TiO 2 nanotubular arrays and their gas sensing properties2011Ingår i: Procedia Engineering, ISSN 1877-7058, E-ISSN 1877-7058, Vol. 25, s. 757-760Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Pure TiO 2 and TiO 2 nanotubular arrays were successfully sensitized. Nanotubular arrays were prepared by electrochemical anodization of thin films of Ti and of Ti-Nb deposited on alumina substrates with two different roughness. Morphological characterization and functional properties are presented. The gas sensing properties of TiO 2 and TiO 2 nanotubes with different gases have been tested in a wide range of operating temperatures. © 2011 Published by Elsevier Ltd.

  • 86.
    Galstyan, V.
    et al.
    Department of Physics, Chemistry and Biology (IFM), Linköping University.
    Comini, E.
    Department of Physics, Chemistry and Biology (IFM), Linköping University.
    Vomiero, Alberto
    SENSOR Lab, Department of Chemistry and Physics, Brescia University and CNR-IDASC.
    Ponzoni, A.
    Department of Physics, Chemistry and Biology (IFM), Linköping University.
    Concina, Isabella
    Department of Physics, Chemistry and Biology (IFM), Linköping University.
    Brisotto, M.
    INSTM and Chemistry for Technologies Laboratory.
    Bontempi, E.
    INSTM and Chemistry for Technologies Laboratory.
    Faglia, G.
    Department of Physics, Chemistry and Biology (IFM), Linköping University.
    Sberveglieri, G.
    Department of Physics, Chemistry and Biology (IFM), Linköping University.
    Fabrication of pure and Nb-TiO 2 nanotubes and their functional properties2012Ingår i: Journal of Alloys and Compounds, ISSN 0925-8388, E-ISSN 1873-4669, Vol. 536, nr SUPPL.1, s. S488-S490Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    TiO 2 and Nb-doped TiO 2 nanotubes were obtained on flexible polymeric substrates (Kapton HN) and alumina with high roughness (alumina substrate with granular surface). Nanotubes were prepared by electrochemical anodization of a Ti thick film. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to investigate the morphology of the structures and the roughness of the substrates. The functional properties of tubular arrays obtained on flexible and rough substrates were investigated towards two applications, namely, chemoresistive gas sensors and flexible dye sensitized solar cells. © 2011 Elsevier B.V. All rights reserved.

  • 87.
    Galstyan, V.
    et al.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Vomiero, Alberto
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Comini, E.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Faglia, G.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Sberveglieri, G.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    TiO 2 nanotubular and nanoporous arrays by electrochemical anodization on different substrates2011Ingår i: RSC Advances, E-ISSN 2046-2069, Vol. 1, nr 6, s. 1038-1044Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The preparation of nanotubular arrays on different substrates and nanoporous structures on titanium foil by means of electrochemical anodization of titanium layer has been investigated. Highly aligned nanotubes of TiO 2 on flexible, rough and flat substrates are reported. Modification of anodization conditions of titanium on specific substrates such as polyethylene terephthalate (PET), conducting glass and granular alumina was found to affect the morphology of TiO 2 nanotubes. Two different kinds of aqueous electrolytes have been applied, containing either glycerol or H 2SO 4, in order to investigate the effect of ion mobility on anodization process. Galvanostatic and potentiostatic anodization modes have been investigated: transition from nanotubes to nanoporous structures has been highlighted in galvanostatic mode, depending on the intensity of anodization current density. These results pave the way for massive production of TiO 2 nanotubes over, in principle, whatever substrate, enabling exploitation of new functional properties derived from the combination of tubes and substrates. This journal is © The Royal Society of Chemistry 2011.

  • 88.
    Galstyan, Vardan
    et al.
    CNR IDASC SENSOR Lab.
    Comini, Elisabetta
    CNR IDASC SENSOR Lab.
    Faglia, Guido
    CNR IDASC SENSOR Lab.
    Vomiero, Alberto
    CNR IDASC SENSOR Lab.
    Borgese, Laura
    INSTM and Chemistry for Technologies Laboratory.
    Bontempi, Elza
    INSTM and Chemistry for Technologies Laboratory.
    Sberveglieri, Giorgio
    CNR IDASC SENSOR Lab.
    Fabrication and investigation of gas sensing properties of Nb-doped TiO 2 nanotubular arrays2012Ingår i: Nanotechnology, ISSN 0957-4484, E-ISSN 1361-6528, Vol. 23, nr 23, artikel-id 235706Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Synthesis of Nb-containing titania nanotubular arrays at room temperature by electrochemical anodization is reported. Crystallization of pure and Nb-doped TiO 2 nanotubes was carried out by post-growth annealing at 400°C. The morphology of the tubes obtained was characterized by scanning electron microscopy (SEM). Crystal structure and composition of tubes were investigated by glancing incidence x-ray diffraction (GIXRD) and total reflection x-ray fluorescence (TXRF). For the first time gas sensing characteristics of Nb-doped TiO 2 nanotubes were investigated and compared to those of undoped nanotubes. The functional properties of nanotubular arrays towards CO, H 2, NO 2, ethanol and acetone were tested in a wide range of operating temperature. The introduction of Nb largely improves conductivity and enhances gas sensing performances of TiO 2 nanotubes. © 2012 IOP Publishing Ltd.

  • 89.
    Galstyan, Vardan
    et al.
    CNR IDASC SENSOR Lab, Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali, University of Brescia, 25133 Brescia, Via Valotti 9, Italy.
    Vomiero, Alberto
    CNR IDASC SENSOR Lab, Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali, University of Brescia, 25133 Brescia, Via Valotti 9, Italy.
    Concina, Isabella
    CNR IDASC SENSOR Lab, Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali, University of Brescia, 25133 Brescia, Via Valotti 9, Italy.
    Braga, Antonio
    CNR IDASC SENSOR Lab, Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali, University of Brescia, 25133 Brescia, Via Valotti 9, Italy.
    Brisotto, Mariangela
    INSTM and Chemistry for Technologies Laboratory, University of Brescia, 25133 Brescia, Via Branze 28, Italy.
    Bontempi, Elza
    INSTM and Chemistry for Technologies Laboratory, University of Brescia, 25133 Brescia, Via Branze 28, Italy.
    Faglia, Guido
    CNR IDASC SENSOR Lab, Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali, University of Brescia, 25133 Brescia, Via Valotti 9, Italy.
    Sberveglieri, Giorgio
    CNR IDASC SENSOR Lab, Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali, University of Brescia, 25133 Brescia, Via Valotti 9, Italy.
    Vertically aligned TiO 2 nanotubes on plastic substrates for flexible solar cells2011Ingår i: Small, ISSN 1613-6810, E-ISSN 1613-6829, Vol. 7, nr 17, s. 2437-2442Artikel i tidskrift (Refereegranskat)
  • 90.
    Gatti, Teresa
    et al.
    Center for Materials Research, Justus Liebig University Giessen, Heinrich Buff Ring 17, 35392 Giessen, Germany.
    Lamberti, Francesco
    Department of Chemical Sciences, University of Padova, via Marzolo 1, Padova, 35131 Italy; Interdepartmental Centre Giorgio Levi Cases for Energy Economics and Technology, University of Padova, via Marzolo 9, Padova, 35131 Italy.
    Mazzaro, Raffaello
    Institute for Microelectronics and Microsystems, Italian National Research Council, Section of Bologna, Bologna, 40129 Italy.
    Kriegel, Ilka
    Functional Nanosystems, Italian Institute of Technology, via Morego 30, Genova, 16163 Italy.
    Schlettwein, Derck
    Center for Materials Research, Justus Liebig University Giessen, Heinrich Buff Ring 17, 35392 Giessen, Germany.
    Enrichi, Francesco
    CNR-ISP, Institute of Polar Sciences, National Research Council, Via Torino 155, Mestre-Venezia, 30172 Italy; Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, via Torino 155, Venezia, 30172 Italy.
    Lago, Nicolò
    Department of Information Engineering, University of Padova, Via Gradenigo 6/B, Padova, 35131 Italy.
    Di Maria, Eleonora
    Interdepartmental Centre Giorgio Levi Cases for Energy Economics and Technology, University of Padova, via Marzolo 9, Padova, 35131 Italy; Department of Economics and Management “Marco Fanno”, University of Padova, Via del Santo 33, Padova, 35123 Italy.
    Meneghesso, Gaudenzio
    Interdepartmental Centre Giorgio Levi Cases for Energy Economics and Technology, University of Padova, via Marzolo 9, Padova, 35131 Italy; Department of Information Engineering, University of Padova, Via Gradenigo 6/B, Padova, 35131 Italy.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, via Torino 155, Venezia, 30172 Italy.
    Gross, Silvia
    Department of Chemical Sciences, University of Padova, via Marzolo 1, Padova, 35131 Italy; Interdepartmental Centre Giorgio Levi Cases for Energy Economics and Technology, University of Padova, via Marzolo 9, Padova, 35131 Italy; Karlsruher Institut für Technologie (KIT), Institut für Technische Chemie und Polymerchemie (ITCP), Engesserstr. 20, 76131 Karlsruhe, Germany.
    Opportunities from Doping of Non-Critical Metal Oxides in Last Generation Light-Conversion Devices2021Ingår i: Advanced Energy Materials, ISSN 1614-6832, E-ISSN 1614-6840, Vol. 11, nr 31, artikel-id 2101041Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    The need to develop sustainable energy solutions is an urgent requirement for society, with the additional requirement to limit dependence on critical raw materials, within a virtuous circular economy model. In this framework, it is essential to identify new avenues for light-conversion into clean energy and fuels exploiting largely available materials and green production methods. Metal oxide semiconductors (MOSs) emerge among other species for their remarkable environmental stability, chemical tunability, and optoelectronic properties. MOSs are often key constituents in next generation energy devices, mainly in the role of charge selective layers. Their use as light harvesters is hitherto rather limited, but progressively emerging. One of the key strategies to boost their properties involves doping, that can improve charge mobility, light absorption and tune band structures to maximize charge separation at heterojunctions. In this review, effective methods to dope MOSs and to exploit the derived benefits in relation to performance enhancement in different types of devices are identified and critically compared. The work is focused specifically on the best opportunities coming from the use of non-critical raw materials, so as to contribute in defining an economically feasible roadmap for light conversion technologies based on these highly stable and widely available compounds. 

  • 91.
    Ghamgosar, Pedram
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Rigoni, Federica
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Gilzad Kohan, Mojtaba
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    You, Shujie
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Morales, Edgar Abarca
    Luleå tekniska universitet.
    Mazzaro, Raffaello
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Morandi, Vittorio
    Institute for Microelectronics and Microsystems Section of Bologna , National Research Council , Bologna , Italy..
    Almqvist, Nils
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Concina, Isabella
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Self-Powered Photodetectors Based on Core-Shell ZnO-Co3O4 Nanowire Heterojunctions2019Ingår i: ACS Applied Materials and Interfaces, ISSN 1944-8244, E-ISSN 1944-8252, Vol. 11, nr 26, s. 23454-23462Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Self-powered photodetectors operating in the UV–visible–NIR window made of environmentally friendly, earth abundant, and cheap materials are appealing systems to exploit natural solar radiation without external power sources. In this study, we propose a new p–n junction nanostructure, based on a ZnO–Co3O4 core–shell nanowire (NW) system, with a suitable electronic band structure and improved light absorption, charge transport, and charge collection, to build an efficient UV–visible–NIR p–n heterojunction photodetector. Ultrathin Co3O4 films (in the range 1–15 nm) were sputter-deposited on hydrothermally grown ZnO NW arrays. The effect of a thin layer of the Al2O3 buffer layer between ZnO and Co3O4 was investigated, which may inhibit charge recombination, boosting device performance. The photoresponse of the ZnO–Al2O3–Co3O4 system at zero bias is 6 times higher compared to that of ZnO–Co3O4. The responsivity (R) and specific detectivity (D*) of the best device were 21.80 mA W–1and 4.12 × 1012 Jones, respectively. These results suggest a novel p–n junction structure to develop all-oxide UV–vis photodetectors based on stable, nontoxic, low-cost materials.

  • 92.
    Ghamgosar, Pedram
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Rigoni, Federica
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    You, Shujie
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Dobryden, Iliya
    Division of Surface and Corrosion Science, KTH Royal Institute of Technolog.
    Gilzad Kohan, Mojtaba
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Pellegrino, Anna Lucia
    Dipartimento Scienze Chimiche, Università degli Studi di Catania, INSTM UdR-Catania.
    Concina, Isabella
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Almqvist, Nils
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Malandrino, Graziella
    Dipartimento Scienze Chimiche, Università degli Studi di Catania, INSTM UdR-Catania.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    ZnO-Cu2O core-shell nanowires as stable and fast response photodetectors2018Ingår i: Nano Energy, ISSN 2211-2855, E-ISSN 2211-3282, Vol. 51, s. 308-316Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, we present all-oxide p-n junction core-shell nanowires (NWs) as fast and stable self-powered photodetectors. Hydrothermally grown n-type ZnO NWs were conformal covered by different thicknesses (up to 420 nm) of p-type copper oxide layers through metalorganic chemical vapor deposition (MOCVD). The ZnO NWs exhibit a single crystalline Wurtzite structure, preferentially grown along the [002] direction, and energy gap Eg=3.24 eV. Depending on the deposition temperature, the copper oxide shell exhibits either a crystalline cubic structure of pure Cu2O phase (MOCVD at 250 °C) or a cubic structure of Cu2O with the presence of CuO phase impurities (MOCVD at 300 °C), with energy gap of 2.48 eV. The electrical measurements indicate the formation of a p-n junction after the deposition of the copper oxide layer. The core-shell photodetectors present a photoresponsivity at 0 V bias voltage up to 7.7 µA/W and time response ≤0.09 s, the fastest ever reported for oxide photodetectors in the visible range, and among the fastest including photodetectors with response limited to the UV region. The bare ZnO NWs have slow photoresponsivity, without recovery after the end of photo-stimulation. The fast time response for the core-shell structures is due to the presence of the p-n junctions, which enables fast exciton separation and charge extraction. Additionally, the suitable electronic structure of the ZnO-Cu2O heterojunction enables self-powering of the device at 0 V bias voltage. These results represent a significant advancement in the development of low-cost, high efficiency and self-powered photodetectors, highlighting the need of fine tuning the morphology, composition and electronic properties of p-n junctions to maximize device performances.

  • 93.
    Gilzad Kohan, Mojtaba
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Concina, Isabella
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Italy.
    All-oxide solar cells2020Ingår i: Solar Cells and Light Management: Materials, Strategies and Sustainability / [ed] Francesco Enrichi and Giancarlo C. Righini, Elsevier, 2020, s. 229-246Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    One of the most intensively investigated directions in the field of photovoltaics is the development of technologies able to provide vacuum-free and low-cost solar cells with decent efficiency, based on earth-abundant and environmentally friendly materials. Solar cells based on oxide materials are a promising candidate for the purpose, being most of the investigated oxides comparatively more stable than most of solar cell technologies alternative to silicon, and composed of harmless materials. While oxides can exhibit high extinction coefficient in the visible and near-infrared spectral region, guaranteeing full absorption of sunlight, the main factor limiting efficiency in such kind of p–n junction devices is the low hole mobility in the p-type oxide, which represents the main challenge to be overcome to make this technology competitive. This chapter illustrates the latest results in the field, including integration of nanowire geometries as viable solution toward fast charge transport and collection.

  • 94.
    Gilzad Kohan, Mojtaba
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Dobryden, Illia
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Division of Surface and Corrosion Science, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm, Sweden.
    Forchheimer, Daniel
    Nanostructure Physics, KTH Royal Institute of Technology, 114 19 Stockholm, Sweden; Intermodulation Products AB, 823 93 Segersta, Sweden.
    Concina, Isabella
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino 155, 30172 Venezia Mestre, Italy.
    In-depth Carrier Transport in a Barrier Variable Iron-oxide and Vertically Aligned Reduced-Graphene Oxide Composite.Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    A key requirement for semiconductors operating in light harvesting devices, is to efficiently convert the absorbed photons to electronic excitations while accommodating low loss pathways for the photogenerated carrier’s transport. The quality of this process corresponds to different relaxation phenomena, yet primarily it corresponds to minimized thermalization of photoexcited carriers and maximum transfer of electron-hole pairs in the bulk of semiconductor through carrier-carrier scattering process. However, several semiconductors, while providing a suitable platform for light harvesting applications, pose intrinsic low carrier diffusion length of photoexcited carriers. Here we report a system based on a vertical network of reduced graphene oxide (rGO) embedded in a thin-film structure of iron oxide semiconductor, intended to employ carrier-carrier scattering properties of rGO to increase the photoexcited carrier transfer in the bulk of the semiconductor. Using intermodulation conductive force microscopy, we locally monitored the fluctuation of current output, which is the prime indication of the prevailing carrier-carrier scattering mechanism in the system. We reveal the fundamental properties of vertical rGO and semiconductor junction in light harvesting systems that enable the design of new promising materials with broad-band optical applications. 

  • 95.
    Gilzad Kohan, Mojtaba
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Dobryden, Illia
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Division of Surface and Corrosion Science, Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Stockholm, Sweden.
    Forchheimer, Daniel
    Nanostructure Physics, KTH Royal Institute of Technology, 114 19, Stockholm, Sweden; Intermodulation Products AB, 823 93, Segersta, Sweden.
    Concina, Isabella
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca’ Foscari University of Venice, Via Torino 155, 30172, Venezia, Mestre, Italy.
    In-depth photocarrier dynamics in a barrier variable iron-oxide and vertically aligned reduced-graphene oxide composite2022Ingår i: NPJ 2D MATERIALS AND APPLICATIONS, E-ISSN 2397-7132, Vol. 6, nr 1, artikel-id 57Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A key requirement for semiconductors operating in light-harvesting devices, is to efficiently convert the absorbed photons to electronic excitations while accommodating low loss pathways for the photogenerated carrier’s transport. The quality of this process corresponds to different relaxation phenomena, yet primarily it corresponds to minimized thermalization of photoexcited carriers and maximum transfer of electron-hole pairs in the bulk of semiconductor. However, several semiconductors, while providing a suitable platform for light-harvesting applications, pose intrinsic low carrier diffusion length of photoexcited carriers. Here we report a system based on a vertical network of reduced graphene oxide (rGO) embedded in a thin-film structure of iron oxide semiconductor, intended to exploit fast electron transport in rGO to increase the photoexcited carrier transfer from the bulk of the semiconductor to rGO and then to the external circuit. Using intermodulation conductive force microscopy, we locally monitored the fluctuation of current output, which is the prime indication of successful charge transfer from photoexcited semiconductor to rGO and efficient charge collection from the bulk of the semiconductor. We reveal the fundamental properties of vertical rGO and semiconductor junction in light-harvesting systems that enable the design of new promising materials for broad-band optical applications.

  • 96.
    Gilzad Kohan, Mojtaba
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Mazzaro, Raffaello
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. CNR-IMM, Area della Ricerca di Bologna, Bologna, Italy.
    Morandi, Vittorio
    CNR-IMM, Area della Ricerca di Bologna, Bologna, Italy.
    You, Shujie
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Concina, Isabella
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Plasma assisted vapor solid deposition of Co3O4 tapered nanorods for energy applications2019Ingår i: Journal of Materials Chemistry A, ISSN 2050-7488, Vol. 7, nr 46, s. 26302-26310Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Self-standing, 1-dimensional (1D) structures of p-type metal oxide (MOx) have been the focus of considerable attention, due to their unique properties in energy storage and solar light conversion. However, the practical performance of p-type MOx is intrinsically limited by their interfacial defects and strong charge recombination losses. Single crystalline assembly can significantly reduce recombination at interface and grain boundaries. Here, we present a one-step route based on plasma assisted physical vapor deposition (PVD), for the rational and scalable synthesis of single crystalline 1D vertically aligned Co3O4 tapered nanorods (NRs). The effect of PVD parameters (deposition pressure, temperature and duration) in tuning the morphology, composition and crystalline structure of resultant NRs is investigated. Crystallographic data obtained from X-ray diffraction and high-resolution transmission electron microscopy (TEM) indicated the single crystalline nature of NRs with [111] facet preferred orientation. The NRs present two optical band gaps at about 1.48 eV and 2.1 eV. Current–voltage (I–V) characteristic of the Co3O4 NRs electrodes, 400 nm long, present two times higher current density at −1 V forward bias, compared to the benchmarking thin film counterpart. These array structures exhibit good electrochemical performance in lithium-ion adsorption–desorption processes. Among all, the longest Co3O4 NRs electrodes delivers a 1438.4 F g−1 at current density of 0.5 mA cm−2 and presents 98% capacitance retention after 200 charge–discharge cycles. The very low values of charge transfer resistance (Rct = 5.2 Ω for 400 nm long NRs) of the NRs testifies their high conductivity. Plasma assisted PVD is demonstrated as a facile technique for synthesizing high quality 1D structures of Co3O4, which can be of interest for further development of different desirable 1D systems based on transition MOx.

  • 97.
    Gilzad Kohan, Mojtaba
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Solomon, Getachew
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    You, Shujie
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Yusupov, Khabib
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Concina, Isabella
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino 155, Venezia, Mestre, 30172 Italy.
    Vertically aligned Co3O4 nanorods as a platform for inverted all‐oxide heterojunctions2021Ingår i: Nano Select, E-ISSN 2688-4011, Vol. 2, nr 5, s. 967-978Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Direct stacking of n‐type and p‐type metal oxide (MOx) semiconductors is one of the appealing directions toward low cost and environmentally friendly photovoltaics (PVs). However, the main shortcoming, hindering the PV performance of MOx heterojunction devices is attributed to the tradeoff between light absorption and maximized carrier extraction in p‐type MOx. In this work, we demonstrate that the nanorod (NR) geometry of Co3O4 light absorber with a nearly ideal bandgap of ∼1.48 eV, can remove this hurdle through strong internal light trapping of adjacent one‐dimensional (1D) structure and enhanced carrier mobility. The inverted n‐on‐p configuration of the core‐shell 1D heterojunction, obtained by depositing a thin TiO2 n‐type layer, resulted in enlarged charge generation compared to the typical p‐on‐n counterpart device. Fine‐tuning of Co3O4 NRs length, permits PV investigation of the heterojunctions with respect to absorber layers thickness. The optimized Co3O4 NRs/TiO2 heterojunction (30 nm Co3O4 NR length) presented a record high open circuit photovoltage (Voc) of (0.52 ± 0.03) V under 1 sun irradiation. Impedance analysis of the heterojunctions, indicates formation of the p+‐p depletion. The presented work can highlight some vital venues to enhance photoconversion efficiency of the all‐oxide heterojunctions while introducing a pioneer contender as inverted (n‐on‐p) MOx heterojunction.

  • 98.
    Gilzad Kohan, Mojtaba
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    You, Shujie
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Camellini, Andrea
    Dipartimento di Energia, Politecnico di Milano, Via G. Ponzio 34/3, Milano I-20133, Italy .
    Concina, Isabella
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Rossi, Margherita Zavelani
    Dipartimento di Energia, Politecnico di Milano, Via G. Ponzio 34/3, Milano I-20133, Italy; IFN-CNR, piazza L. Da Vinci 32, 20133 Milano, Italy .
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino 155, 30172 Venezia Mestre, Italy .
    Optical field coupling in ZnO nanorods decorated with silver plasmonic nanoparticles2021Ingår i: Journal of Materials Chemistry C, ISSN 2050-7526, E-ISSN 2050-7534, Vol. 9, nr 43, s. 15452-15462Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Characterizing carrier redistribution due to optical field modulation in a plasmonic hot-electron/semiconductor junction can be used to raise the framework for harnessing the carrier decay of plasmonic metals in more efficient conversion systems. In this work we comprehensively studied the carrier redistribution mechanisms of a 1-dimensional (1D) metal-semiconductor Schottky architecture, holding the dual feature of a hot-electron plasmonic system and a simple metal/semiconductor junction. We obtained a strongly enhanced external quantum efficiency (EQE) of the plasmonic Ag decorated ZnO semiconductor in both the band-edge region of ZnO and the corresponding plasmonic absorption profile of the Ag NPs (visible region). Simultaneously, the insertion of an insulating Al2O3 intermediate layer between Ag NPs and ZnO resulted in a parallel distinction of the two main non-radiative carrier transfer mechanisms of plasmonic NPs, i.e. direct electron transfer (DET) and plasmonic induced resonance energy transfer (PIRET). The multi-wavelength transient pump-probe spectroscopy indicated the very fast plasmonic radiative transfer dynamics of the system in <500 fs below 389 nm. We demonstrate a 13% increase of photogenerated current in ZnO upon visible irradiation as a result of non-radiative plasmonic hot-electron injection from Ag NPs. Overall, our device encompasses several effective solutions for designing a plasmonic system featuring non-radiative electron-electron plasmonic dephasing and high photoconversion efficiencies.

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  • 99.
    Gonella, F.
    et al.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Canton, P.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Cattaruzza, E.
    CNR-IDASC SENSOR Lab and Dipartimento di Chimica e Fisica per l'Ingegneria e per i Materiali.
    Quaranta, A.
    Dipartimento di Ingegneria dei Materiali e delle Tecnologie Industriali, Università di Trento.
    Sada, C.
    Dipartimento di Fisica Sperimentale, Università di Torino.
    Vomiero, Alberto
    CNR-INFM SENSOR Laboratory.
    Field-assisted ion diffusion of transition metals for the synthesis of nanocomposite silicate glasses2006Ingår i: Materials science & engineering. C, biomimetic materials, sensors and systems, ISSN 0928-4931, E-ISSN 1873-0191, Vol. 26, nr 5-7, s. 1087-1091Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Field-assisted ion diffusion of metals was realized for the controlled doping of silicate glasses. Metallic films deposited onto the substrates by the rf-sputtering technique were used as the metal ions source. In particular, cobalt was, for the first time, introduced into a soda-lime glass by field-assisted ion exchange, giving rise to diffusion profiles that were observed to depend on the preparation parameters, namely, temperature and electric field intensity across the samples. This technique, which allowed to dope the glass matrix with high metal concentration values, can be used as the first step in combined methodologies for the preparation of nanostructured glass composites. The shape of the measured Co diffusion profiles indicates that the migration process depends not only on the experimental parameters but also on the behavior of alkali ions within the glass. Chemical phenomena occurring at the metal/glass interface also play a significant role in the penetration of the Co ions. The possibility of doping the glass with two different metal species was also investigated, with the aim to create the condition for the formation of core-shell or alloy nanoclusters. In particular, preliminary results on Co + Au field-assisted co-diffusion are presented. © 2005 Elsevier B.V. All rights reserved.

  • 100.
    Gong, Xiao
    et al.
    State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
    Jiang, Hang
    State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
    Cao, Mengyan
    State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
    Rao, Zhihui
    State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
    Zhao, Xiujian
    State Key Laboratory of Silicate Materials for Architectures, Wuhan University of Technology, Wuhan 430070, China.
    Vomiero, Alberto
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap. Department of Molecular Sciences and Nano Systems, Ca' Foscari University of Venice Via Torino 155, 30172 Venezia Mestre, Italy.
    Eu-doped ZnO quantum dots with solid-state fluorescence and dual emission for high-performance luminescent solar concentrators2021Ingår i: Materials Chemistry Frontiers, E-ISSN 2052-1537, Vol. 5, nr 12, s. 4746-4755Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Heavy-metal-free quantum dots (QDs) are promising luminophores for luminescent solar concentrators (LSCs) because of environmental friendliness, which is essential for industrial applications. In order to keep high optical quality and inhibit aggregation-induced quenching, usually QDs can only be loaded at low concentration in a polymer optical waveguide material for LSCs, which significantly impairs the power conversion efficiency (PCE). Thus, it is a challenge to fabricate high-performance LSCs with high QD loading. Here, dual emission Eu-doped ZnO QDs with strong solid-state fluorescence are synthesized via a simple sol–gel method, which enables two characteristic photoluminescence peaks at 551 nm and 614 nm. Furthermore, Eu-doped ZnO QDs with dual fluorescence emission are for the first time reported to be applied in LSCs. The performance of LSCs can be influenced by the loading concentration of Eu-doped ZnO QDs in polyvinyl pyrrolidone (PVP) films. The obtained external optical efficiency (ηopt) of the LSCs based on Eu-doped ZnO QDs can be relatively high (4.37%) compared to the reported LSCs with a similar area when the loading concentration of Eu-doped ZnO QDs is up to 13.2% because of both their high photoluminescence intensity and dual fluorescence emission. Our results demonstrate that dual emission Eu-doped ZnO QDs with strong solid-state fluorescence are promising candidates as luminophores for LSCs.

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