Browsing by Author "Pallarès Marzal, Josep"

Now showing items 1-17 of 17

    • A two dimensional KTiOPO4 photonic crystal grown using a macroporous silicon template 

      Peña Revellez, Alexandra; Finizio, Sergio Di; Todorov Trifonov, Trifon; Carvajal, Joan Josep; Aguiló Díaz, Magdalena; Pallarès Marzal, Josep; Rodríguez Martínez, Ángel; Alcubilla González, Ramón; Marsal Garví, Lluís Francesc; Diaz, Francesc; Martorell Pena, Jordi (2006-09)
      Article
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      2D KTiOPO4 photonic crystals are fabricated using a silicon membrane of air holes as a template. Columns of KTiOPO4 are grown by liquid-phase epitaxy from a substrate into such air holes. The crystallographic orientation ...

    • Analysis of bias stress on thin-film transistors obtained by Hot-Wire Chemical Vapour Deposition 

      Dosev, D K; Puigdollers i González, Joaquim; Orpella García, Alberto; Voz Sánchez, Cristóbal; Fonrodona, Marta; Soler Vilamitjana, David; Marsal, L F; Pallarès Marzal, Josep; Bertomeu Balaguero, Joan; Andreu Batallé, Jordi; Alcubilla González, Ramón (2001-02)
      Article
      Open Access
      The stability under gate bias stress of unpassivated thin film transistors was studied by measuring the transfer and output characteristics at different temperatures. The active layer of these devices consisted of in ...

    • Analysis of photonic band gaps in two-dimensional photonic crystals with rods covered by a thin interfacial layer 

      Todorov Trifonov, Trifon; Marsal, L F; Rodríguez Martínez, Ángel; Pallarès Marzal, Josep; Alcubilla González, Ramón (2004-11)
      Article
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      We investigate different aspects of the absolute photonic band gap (PBG) formation in two-dimensional photonic structures consisting of rods covered with a thin dielectric film. Specifically, triangular and honeycomb ...

    • Characterization and application of a-SiCx:H films for the passivation of the c-Si surface 

      Martín Campos, Ignacio Clemente; Vetter, M; Orpella García, Alberto; Puigdollers i González, Joaquim; Voz Sánchez, Cristóbal; Marsal, L F; Pallarès Marzal, Josep; Alcubilla González, Ramón (2002-01)
      Article
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      In this work we investigate the effects of typical thermal treatments on c-Si surface passivation by intrinsic a-SiCx:H films. First, a forming gas anneal (FGA), (400 °C, 30 min in H2/N2) is applied resulting in an improvement ...

    • Characterization of 2D macroporous silicon photonic crystals: improving the photonic band identification in angular-dependent reflection spectroscopy in the mid-IR 

      Král, Z; Ferré Burrull, José; Pallarès Marzal, Josep; Todorov Trifonov, Trifon; Rodríguez Martínez, Ángel; Alcubilla González, Ramón; Marsal, L F (2008-02)
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      We report the experimental characterization of two-dimensional (2D) macroporous silicon photonic crystals using angular-dependent reflectance spectroscopy in the mid-IR region. We have investigated different sample structures ...

    • Effects of symmetry reduction in two-dimensional square and triangular lattices 

      Todorov Trifonov, Trifon; Marsal, L F; Rodríguez Martínez, Ángel; Pallarès Marzal, Josep; Alcubilla González, Ramón (2004-06)
      Article
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      We investigate the absolute photonic band gap (PBG) formation in two-dimensional (2-D) photonic crystals designed using symmetry reduction approach. The lattice symmetry, shape and orientation of dielectric scatterers ...

    • Fabrication and characterization of in-situ doped a-Si0.8C0.2 emitter bipolar transistors 

      Orpella García, Alberto; Puigdollers i González, Joaquim; Bardés Llorensí, Daniel; Alcubilla González, Ramón; Marsal, L F; Pallarès Marzal, Josep (2000-09)
      Article
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      Silicon–carbon emitters were deposited by plasma enhanced chemical vapour deposition (PECVD) on a conventional silicon transistor base. The resulting transistors were annealed after the emitter had been deposited which led ...

    • Fabrication of silicon oxide microneedles from macroporous silicon 

      Rodríguez Martínez, Ángel; Molinero, D; Valera Cano, Enrique Andrés; Todorov Trifonov, Trifon; Marsal, L F; Pallarès Marzal, Josep; Alcubilla González, Ramón (2005-04)
      Article
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      This paper presents a novel technique for silicon dioxide (SiO2) microneedle fabrication. Microneedles are hollow microcapillaries with tip diameters in the range of micrometers. They can be used in the fabrication of ...

    • Fabrication of two- and three-dimensional photonic crystals by electrochemical etching of silicon 

      Todorov Trifonov, Trifon; Marsal, L F; Rodríguez Martínez, Ángel; Pallarès Marzal, Josep; Alcubilla González, Ramón (2005-05)
      Article
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      This paper reports on the fabrication of two-dimensional macropore arrays by electrochemical etching of silicon. We describe some critical effects accompanying the etching process that can generate imperfections in the ...

    • High aspect ratio silicon dioxide pillars 

      Todorov Trifonov, Trifon; Rodríguez Martínez, Ángel; Servera, F; Marsal, L F; Pallarès Marzal, Josep; Alcubilla González, Ramón (2005-06)
      Article
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      This article describes the benefits of including cross-layer information in the scheduling mechanism of a UMTS downlink channel. In particular, the information obtained from the fast power control algorithm is used to ...

    • In-situ doped amorphous Si0.8C0.2 emitter bipolar transistors 

      Orpella García, Alberto; Bardés Llorensí, Daniel; Alcubilla González, Ramón; Marsal, L F; Pallarès Marzal, Josep (1999-11)
      Article
      Open Access
      The fabrication and characterization of in situ-doped amorphous Si/sub 0.8/C/sub 0.2/ emitter transistors are presented. Emitter Gummel numbers exceeding 10/sup 14/ s/cm/sup 4/ are reported for the first time in this type ...

    • Influence of acid-base properties of calcined MgAl and CaAl layered double hydroxides on the catalytic glycerol etherification to short-chain polyglycerols 

      Perez Barrado, Elena; Cinta Pujol, Maria; Aguilo, Magdalena; Llorca Piqué, Jordi; Cesteros, Yolanda; Diaz, Francesc; Pallarès Marzal, Josep; Marsal Garví, Lluis; Salagre, Pilar (2015-03-15)
      Article
      Open Access
      Several MgAl-LDHs (HT) and CaAl-LDHs (HC) were synthesized in different conditions and later calcined at 723 K, resulting in catalysts (cHT and cHC), with different acid base properties. Calcined samples were tested in the ...

    • Investigation of the formation of silicon nanocrystals by annealing of amorphous SiCx/c-Si structures 

      Torres, I; Vetter, M; Ferré Burrull, José; Marsal, L F; Orpella García, Alberto; Alcubilla González, Ramón; Pallarès Marzal, Josep (2007-04)
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      In this work, we study the changes in the optical properties of 300-nm-thick hydrogenated amorphous silicon carbide layers after an annealing process. Both intrinsic and phosphorus-doped amorphous silicon carbide layers ...

    • New approaches for the fabrication of photonic structures of nonlinear optical materials 

      Carvajal, J J; Peña, A; Kumar, R.; Pujol, M. C.; Mateos, X.; Aguiló Díaz, Magdalena; Díaz, F; Vázquez De Aldana, J. R.; Méndez, Carlos Alberto; Moreno, P; Roso, L; Todorov Trifonov, Trifon; Rodríguez Martínez, Ángel; Alcubilla González, Ramón; Král, Z; Ferré Borrull, J.; Pallarès Marzal, Josep; Marsal, L F; Finizio, Sergio Di; Martorell Pena, Jordi; Macovez, Roberto (2009-12)
      Article
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      We revisited two different strategies to fabricate 1D photonic crystals of nonlinear optical dielectric materials based on ultrafast laser ablation of the surface of an RbTiOPO4 crystal, and selective etching of ferroelectric ...

    • Polymer microfibers obtained using porous silicon templates 

      Marsal Garví, Lluís Francesc; Formentín, P.; Palacios, R.; Todorov Trifonov, Trifon; Ferré Burrull, José; Rodríguez Martínez, Ángel; Pallarès Marzal, Josep; Alcubilla González, Ramón (2008)
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      The deposition of specific materials into ordered pores arranged in a regular lattice allows the fabrication of ordered fiber arrays. Porous silicon is an attractive candidate for use as a template because the porosity and ...

    • Space charge recombination in p-n junctions with a discrete and continous trap distribution 

      Pallarès Marzal, Josep; Marsal Garví, Lluís Francesc; Correig, Xavier; Calderer Cardona, Josep; Alcubilla González, Ramón (1997-01)
      Article
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      Space charge Shockley-Read-Hall recombination currents in the presence of discrete or continuous distributions of recombination centres are analysed. For a single level trap, depending on its position inside the forbidden ...

    • Visible light emission from macroporous Si 

      Cheylan, Stephanie; Todorov Trifonov, Trifon; Rodríguez Martínez, Ángel; Marsal Garví, Lluís Francesc; Pallarès Marzal, Josep; Alcubilla González, Ramón; Badenes, Gonçal (2006-10)
      Article
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      Macroporous silicon structures have been fabricated by electrochemical etching. Such fabrication process is known to result in the presence of a thin microporous Si layer at the walls of the macropores and at the surface. ...