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Autor Piqueras de Noriega, Javier |
Documentos disponibles escritos por este autor (322)
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Maestre Varea, David ; Martínez Velasco, I. ; Cremades Rodríguez, Ana Isabel ; Amati, M. ; Piqueras de Noriega, Javier | Amer Chemical Soc | 2010-07-15Mn-doped In(2)O(3) nanopyramids have been grown by a catalyst-free thermal process at 700 degrees C using InN and Mn(2)O(3) powders as precursors. Energy dispersive spectroscopy, as well as X-ray photoelectron spectroscopy, demonstrate the prese[...]![]()
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Cebriano Ramírez, Teresa ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | Elsevier Science SA | 2012-08-15Sb_2O_3 micro- and nanostructures of the face centered cubic phase, have been grown by a catalyst free evaporation deposition method with powder of metallic Sb as precursor. Nanopyramids, octahedra and nanorods are the building blocks of complex[...]![]()
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Pereira, L. ; Pereira, E. ; Gomes, H. ; Rodrigues, A. ; Rees, A. ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | Elsevier Science SA | 2000-04The properties of microelectrical conduction in microwave plasma assisted chemical vapour deposition (MPCVD) diamond films were investigated using an atomic force microscopy probe, giving a morphological map of the electrical conduction with a s[...]![]()
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Castaldini, A. ; Cavallini, A. ; Fraboni, B. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | American Physical Society | 1997-12-15We study, by cathodoluminescence and junction spectroscopy methods, the deep traps located near midgap in semiconducting and semi-insulating II-VI compounds, namely, undoped CdTe, CdTe:Cl, and Cd0.8Zn0.2Te. In order to understand the role such d[...]![]()
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Alonso Orts, Manuel ; Nogales Díaz, Emilio ; San Juan, J. M. ; Nó, M. L. ; Piqueras de Noriega, Javier ; Méndez Martín, Bianchi | Amer Physical Soc | 2018-06-07Optical microcavities are key elements in many photonic devices, and those based on distributed Bragg reflectors (DBRs) enhance dramatically the end reflectivity, allowing for higher quality factors and finesse values. Besides, they allow for wi[...]![]()
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Maestre Varea, David ; Haeussler, Dietrich ; Cremades Rodríguez, Ana Isabel ; Jaeger, Wolfgang ; Piqueras de Noriega, Javier | Amer Chemical Soc | 2011-04In_2O_3 nanorods have been grown by a catalyst free evaporation-deposition method. Transmission electron microscopy (TEM) investigations reveal that the rods contain tubular cavities, herein referred to as "nanopipes", along the total length of [...]![]()
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Urbieta Quiroga, Ana Irene ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Vasco, E. ; Zaldo, C. | natl Inst Optoelectronics | 2004-03Scanning tunnelling microscopy and spectroscopy have been used to characterize electrically active grain boundaries in pulsed laser deposited ZnO films with grain sizes in the range 216-500 nm. The p-type behaviour at the boundary is evidenced b[...]![]()
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Piqueras de Noriega, Javier ; Fernández Sánchez, Paloma ; Urbieta Quiroga, Ana Irene | Elsevier Science SA | 2012-02-15Mn doped ZnO nano- and microstructures have grown by a catalyst free evaporation-deposition method. Different morphologies such as nanowires, nanorods and stacks of nanoplates with a skewer arrangement around a central rod, have been obtained. S[...]![]()
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Dutta, P. S. ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Dieguez, E. ; Bhat, H. L. | Amer Inst Physics | 1996-07-15Diffusion of tellurium In undoped p-GaSb has been carried out. Using the cathodoluminescence and photoluminescence techniques, the luminescence centers in Te-diffused samples have been identified and compared with the Te-doped bulk GaSb. Fundame[...]![]()
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The contactless modulation spectroscopy technique of photoreflectance (PR) has been used to study the near band edge transitions in CdTe, CdTe:V and CdTe:Ge bulk crystals in the range of 14 and 400 K for the first time. The lineshape of the PR[...]![]()
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Nogales Díaz, Emilio ; Joachimsthaler, I. ; Heiderhoff, R. ; Piqueras de Noriega, Javier ; Balk, L.J. | American Institute of Physics | 2002-07-15Near-field cathodoluminescence (NFCL) has been used to characterize hydride vapor phase epitaxy grown n-GaN films. This technique can obtain high resolution luminescence images and perform local measurements of the diffusion length for minority [...]![]()
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Piqueras de Noriega, Javier ; Vila Santos, María ; Díaz-Guerra Viejo, Carlos | IOP publishing ltd | 2010-04-07CuO nanostructures with different morphologies, such as single-crystal nanowires, nanoribbons and nanorods, have been grown by thermal oxidation of copper in the 380–900?°C temperature range. Cathodoluminescence spectra of the nanostructures sho[...]![]()
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Cremades Rodríguez, Ana Isabel ; Albrecht, M. ; Ulloa, J.M. ; Piqueras de Noriega, Javier ; Strunk, H.P. ; Hanser, D. ; Davis, R. F. | Materials Research Society | 2000A series of 100 nm thick InGaN films with In content up to 14% has been grown by MOVPE on SiC substrates. Optical characterization was carried out by means of reflectance spectrometry, photoluminescence and cathodoluminescence. Optical propertie[...]![]()
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Herrera Zaldiva, M. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Sukhoveyev, W. ; Ivantsov, V. A. ; Shreter, Y. G. | Springer | 2000-07Cathodoluminescence (CL) in the scanning electron microscope has been applied to study the luminescence emission of GaN single crystals grown by LPE methods. CL spectra show the presence of near band edge and of yellow emissions. The latter has [...]![]()
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Vásquez, G. C. ; Karazhanov, S. Zh. ; Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier ; Foss, S. E. | American Physical Society | 2016-11-23The effects of doubly ionized oxygen vacancies [(V_O)ˆ(2+)]on the electronic structure and charge distribution in rutile TiO_2 are studied by combining first-principles calculations based on density functional theory and experimental results fro[...]![]()
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Panin, G. N. ; Dutta, P. S. ; Piqueras de Noriega, Javier ; Dieguez, E. | Amer Inst Physics | 1995-12-11Inversion in conductivity type of GaSb from p- to n- has been observed as a result of argon ion beam milling. Electron beam induced current (EBIC) measurements have been employed for detecting the type conversion. Enhancement in the luminescence[...]![]()
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Dutta, P. S. ; Sreedhar, A. K. ; Bhat, H. L. ; Dubey, G. C. ; Kumar, V. ; Dieguez, E. ; Pal, U. ; Piqueras de Noriega, Javier | American Institute of Physics | 1996-03-15Passivation of point and extended defects in GaSb has been observed as a result of hydrogenated amorphous silicon (a-Si:H) treatment by the glow discharge technique. Cathodoluminescence (CL) images recorded at various depths in the samples clear[...]![]()
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Monteiro, T. ; Pereira, E. ; Domínguez-Adame Acosta, Francisco ; Piqueras de Noriega, Javier | Electrochemical Soc Inc | 1993-12Time resolved photoluminescence (TRPL) of untreated and heat-treated n-type GaP:S samples has been investigated and compared with data from cathodoluminescence in a scanning electron microscope (CL-SEM). Special attention is given to broad emiss[...]![]()
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Plaza, J. L. ; Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Dieguez, E. | Elsevier Science SA | 2000-02-14In this work several changes induced by polishing, chemical etching and thermal treatment in the properties of Er- and Nd-doped GaSb substrates with different doping levels grown by the vertical Bridgman method have been studied. The analysis ha[...]![]()
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Monaico, E. ; Ursaki, V. V. ; Urbieta Quiroga, Ana Irene ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Boyd, R. W. ; Tiginyanu, I. M. | IOP publishing ltd | 2004-12Porous CdSe layers have been produced by anodic etching of crystalline substrates in a HCl solution. Anodization under in situ. UV illumination resulted in the formation of uniformly distributed parallel pores with a diameter of 30 nm, stretchin[...]![]()
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Fernández Sánchez, Paloma ; Solís, J. ; Piqueras de Noriega, Javier | natl Inst Optoelectronics | 2000-09Pulsed laser treatments in air and in vacuum have been performed in CdTe wafers. The laser induced changes have been monitored by emissive mode and cathodoluminescence (CL) in a scanning electron microscope. Remarkable differences between the ef[...]![]()
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Gonzalo, A. ; Nogales Díaz, Emilio ; Lorenz, K. ; Víllora, E. G. ; Shimamura, K: ; Piqueras de Noriega, Javier ; Méndez Martín, Bianchi | Elsevier Science BV | 2017-11The structural and luminescence properties of gallium oxide nanowires doped with chromium or manganese have been investigated. Undoped Ga?O? nanostructures have been fabricated by a thermal evaporation method, while doping was subsequently achie[...]![]()
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Iribarren, A. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | Wiley-V C H Verlag Gmbh | 2014-03Cathodoluminescence (CL) of Te doped elongated ZnO microstructures obtained by a vapour-solid (V-S) technique has been investigated. The CL intensity changes along the microstructures axis are related to the gradient of Te content, which influen[...]![]()
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Nogales Díaz, Emilio ; García, José A. ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | American Institute of Physics | 2007-02-01Red luminescence emission from chromium doped ß-Ga_2O_3 nanowires has been studied by means of photoluminescence (PL) techniques. PL excitation shows several bands in the ultraviolet-visible region. Time decay values, obtained by time resolved P[...]![]()
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Rodríguez Fernández, J. ; Carcelen, V. ; Hidalgo Alcalde, Pedro ; Vijayan, N. ; Piqueras de Noriega, Javier ; Sochinskii, N. V. ; Pérez, J. M. ; Dieguez, E. | Amer Inst Physics | 2009-08-15Cadmium zinc telluride, CdZnTe, bulk single crystals doped with 10^19 at./cm^3 of indium in the initial melt were grown by vertical Bridgman technique. The samples were investigated by energy dispersive spectroscopy, cathodoluminiscence (CL), an[...]![]()
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Remote electron beam induced current (REBIC) measurements have been carried out to investigate electrically active regions in YBa_2Cu_3O_(7-x) single crystals. Enhanced REBIC contrast, found in growth steps and other topographic features of the [...]![]()
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García, J.A. ; Plugaru, R ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Tate, T. J. | Cambridge Univ Press | 2004-07The luminescence of amorphous silicon layers either implanted with Er or co-implanted with Er and O has been studied by photoluminescence (PL) and cathodoluminescence (CL) in the scanning electron microscope. Annealing in nitrogen causes the for[...]![]()
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Cebriano Ramírez, Teresa ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | Springer | 2013-05Sb_2O_3 microrods of the orthorhombic phase have been grown by evaporation deposition with Sb powder as precursor. The rods, of rectangular cross section, are composed of weakly bonded stacks of tiny plates of few hundreds of nanometres, which s[...]![]()
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Domínguez-Adame Acosta, Francisco ; Piqueras de Noriega, Javier | American Institute of Physics | 1989-09-15Polycrystalline GaP and InP have been observed by scanning electron acoustic microscopy. While grain boundaries show a weak contrast, twinned regions are clearly revealed. Results suggest that the contrast observed is related to signal generatio[...]![]()
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Domínguez-Adame Acosta, Francisco ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | Pergamon-Elsevier Science Ltd | 1993-09The temperature dependence of scanning electron acoustic microscopy (SEAM) and cathodoluminescence signals of B_i2Sr_2CaCu_2O_x samples have been measured. The evolution of SEAM signal with temperature between 90 and 300 K indicates the capabili[...]![]()
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Some scanning electron acoustic microscopy (SEAM) applications to the characterization of electronic materials are discussed. The specific problem of the observation of dislocations and dislocation-related features in GaAs is treated as an examp[...]![]()
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Dislocation lines in {110} sections of In-doped GaAs are imaged by scanning electron acoustic microscopy (SEAM). Cathodoluminescence measurements show the presence of a high indium concentration at dislocations. It is proposed that the semi-insu[...]![]()
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Urchulutegui, M. ; Piqueras de Noriega, Javier ; LLopis, J. | American Institute of Physics | 1989-04-01The capability of scanning electron?acoustic microscopy in the characterization of MgO crystals has been studied. The conditions for the observation of different surface and subsurface features in as?grown and deformed crystals are described and[...]![]()
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Urbieta Quiroga, Ana Irene ; Piqueras de Noriega, Javier ; Muñoz, V. | Elsevier Science SA | 2000-12-15ZnSe single crystals were grown from n-type microcrystalline boules by a Solid Phase Recrystallization (SPR) method. The recrystallizations were performed under different atmospheres, Ar or Se, and pressures to investigate the influence of growt[...]![]()
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Urbieta, C. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Muñoz, V. | Elsevier Science SA | 2001-03-22ZnSe single crystals were grown from n-type microcrystalline boules by :I solid phase recrystallization (SPR) method. During. SPP,. twinned regions appear with different electronic recombination properties. The recrystallizations were performed [...]![]()
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Urbieta, S. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Vasco, E. ; Zaldo, C | Wiley-V C H Verlag Gmbh | 2003-01Highly (001) textured ZnO films grown on (100)InP by pulsed laser deposition have been studied by Scanning Tunneling Microscopy (STM). Constant current images show a well defined grain structure, which allows to perform local spectroscopic studi[...]![]()
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Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Dutta, P: S. ; Dieguez, E. | American Physical Society | 1999-10-15V- and Ru-doped GaSb crystals have been investigated by scanning tunneling spectroscopy in a combined scanning electron microscope-scanning tunneling microscope system. Local variations of surface band gap have been measured with high spatial re[...]![]()
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Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Plaza, J. L. ; Dieguez, E. | American Institute of Physics | 1999-08-01Er doped GaSb single crystals have been studied by scanning tunneling spectroscopy (STS) and cathodoluminescence (CL) in a combined scanning electron microscope-scanning tunnelling microscope system. The surface band gap in doped samples has bee[...]![]()
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Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Golubev, VG. ; Kurdyukov, D.A. ; Pevtsov, A. B. ; Zamoryanskaya, M. V. | Amer Inst Physics | 2002-11-13Scanning tunneling microscopy and scanning tunneling spectroscopy (STS) are used to investigate the local electronic behavior of Pt-Si nanostructures fabricated in an opal matrix formed by silica spheres of 250 nm diameter. Si and Pt are regular[...]![]()
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Nogales Díaz, Emilio ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Plugaru, R | IOP publishing ltd | 2001-09Scanning tunnelling microscopy (STM) has been sometimes applied in recent years to characterize porous silicon. In contrast, other forms of light emitting Si, such as nanocrystalline silicon films, prepared by different methods, have not been, o[...]![]()
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Urbieta Quiroga, Ana Irene ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Sekiguchi, T. | IOP publishing ltd | 2001-07Bulk ZnO single crystals grown by the hydrothermal and flux methods have been characterized by scanning tunnelling spectroscopy performed in the different crystalline faces. Normalized differential conductance has been found to depend on the fac[...]![]()
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Piqueras de Noriega, Javier ; Fernández Sánchez, Paloma ; Ortega Villafuerte, Yanicet | IOP publishing ltd | 2011-08Al-doped ZnO nanorod networks and other microstructures have been grown by a thermal evaporation–deposition method with a mixture of ZnS and Al_2O_3 powders as precursor. Some of the grown structures consist of star-like arrays of nanorods arran[...]![]()
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Ortega Villafuerte, Yanicet ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | Elsever Science | 2009-03-15Sintering of a ZnS-SnO(2) mixture under argon flow leads to the growth of columnar nanoplate arrays as well as arrays of nanowires, nanorods and nanoplates with six-fold symmetry. The six-fold nanoplate structures correspond to a more advanced s[...]![]()
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Chioncel, M. ; Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier | American Institute of Physics | 2008-12-15?-Fe_2O_3 (hematite) nanostructures with various morphologies have been grown by thermal oxidation of compacted iron powder at temperatures between 700 and 900 degrees C. Different thermal treatments have been found to induce the growth of singl[...]![]()
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Alonso Orts, Manuel ; Sanchez, Ana M ; Hindmarsh, Steven A ; López, Iñaki ; Nogales Díaz, Emilio ; Piqueras de Noriega, Javier ; Méndez Martín, Bianchi | Amer Chemical Soc | 2017-01-11Tailoring the shape of complex nanostructures requires control of the growth process. In this work, we report on the selective growth of nanostructured tin oxide on gallium oxide nanowires leading to the formation of SnO_2/Ga_2O_3 complex nanost[...]![]()
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MgO crystals have been studied by scanning?electron acoustic microscopy under different experimental conditions. Contrast mechanisms in imaging are discussed and compared. The experimental results obtained by earthing or nonearthing the specimen[...]![]()
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Piqueras de Noriega, Javier ; Ortega Villafuerte, Yanicet ; Urbieta Quiroga, Ana Irene ; Fernández Sánchez, Paloma | World Scientific Publ Co Pte Ltd | 2007Sintering of ZnO-SnO_2 and ZnO-MgO mixtures, with few at. % of Sn or Mg at 1280 C under argon flaw leads to the growth of microrods on the sample surface, which are formed by oriented stacks of nanoplates. Energy dispersive spectroscopy and cath[...]![]()
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Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | IOP publishing ltd | 2008-11-12Sn doped GeO_2 nanowires and microwires have been grown by an evaporation-deposition method, using a mixture of Ge and SnO_2 powders as precursors. Comparison with undoped GeO_2 nanowires grown by the same method shows that the presence of Sn pr[...]![]()
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Vicent López, José Luis ; Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Dieguez, E. | Elsevier Science B.V. | 2006-08-01Dilute Te-doped GaSb alloys have been prepared by the vertical feeding method (VFM) using both casting and feeding configurations. The structural and optical properties of the samples were characterized by etching, X-ray diffraction and cathodol[...]![]()
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Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Domínguez-Adame Acosta, Francisco ; De Diego, N. | Amer Inst Physics | 1988-11-01Cathodoluminiscence (CL) scanning electron microscopy and positron annihilation techniques have been used to investigate the distribution of defects in GaAs: Te wafers. Dislocation density and near-band-edge CL profiles along the wafer have di[...]![]()
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Pal, U. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier ; Serrano, M. D. ; Dieguez, E. | IOP publishing ltd | 1994The nature of the 1.4eV band in CdTe is studied by cathodoluminescence. Results indicate that the band is not related only to surface defects.![]()
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Piqueras de Noriega, Javier ; Domínguez-Adame Acosta, Francisco ; Monteiro, T. ; Pereira, E. | Elsevier Science SA | 1993-09Cathodoluminescence (CL) from untreated as well as heat-treated GaP:Te:Mn samples has been investigated. Spectra of untreated samples present two emission bands that peak at 585 and 730 nm. The CL image shows bright spots associated with disloca[...]![]()
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Castaldini, A. ; Calvallini, A,. ; Fraboni, B ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | Amer Inst Physics | 1994-07-15The distribution in liquid-encapsulated-Czochralski (LEC) GaAs:Te wafers of point and complex defects has been investigated together with their influence on the minority-carrier diffusion length L. Three wafers with different Te-doping concentra[...]![]()
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Cavallini, A. ; Dupasquier, A. ; Ferro, G. ; Piqueras de Noriega, Javier ; Valli, M. | Trans Tech Publications Ltd | 1997The radial vacancy distribution along a LEC-GaAs:Te wafer with an average free carrier concentration n = 1.5 x 10(18) cm(-3) was studied by means of positron lifetime spectroscopy. An M-shaped radial distribution of vacancy-like defects, most pr[...]![]()
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Domínguez-Adame Acosta, Francisco ; Piqueras de Noriega, Javier ; De Diego, N. ; LLopis, J. | American Institute of Physics | 1988-04-15Cathodoluminescencescanning electron microscopy and positron annihilation techniques have been used to investigate the distribution of defects in GaP wafers. The results show the existence of a gradient of the concentration of vacancy?type defec[...]![]()
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Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Popa, V. ; Cojocaru, A. ; Tiginyanu, M. | Amer Inst Physics | 2005-05-30The emission properties of GaN nanostructures created by photoelectrochemical etching have been investigated by cathodoluminescence (CL) in the scanning electron microscope. Columnar structures with diameters of 150-250 nm formed near the surfac[...]![]()
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Nogales Díaz, Emilio ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Plugaru, R. | Materials Research Society | 2003Electrically active regions of nanocrystalline silicon (nc-Si) films as well as of a p-type crystalline silicon (c-Si) wafer have been investigated by using a scanning electron microscope/scanning tunneling microscope (SEM/STM) combined instrume[...]![]()
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Díaz-Guerra Viejo, Carlos ; Chioncel, M. ; Piqueras de Noriega, Javier | Academic Press LTD-Elsevier Science LTD | 2009-04Nanostructures of two transition metal oxides, WO(3) and ?-Fe_2O_3, have been grown by a thermal deposition method without a catalyst and characterized by x-ray diffraction, scanning electron microscopy (SEM), high-resolution transmission electr[...]![]()
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Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier | American Institute of Physics | 2007-10-15V_2O_5 nanostructures have been grown on 4H-SiC and Si substrates by a thermal deposition method without a catalyst. High aspect ratio nanowires with rectangular cross sections were grown on 4H-SiC. High-resolution transmission electron microsco[...]![]()
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Díaz-Guerra Viejo, Carlos ; Montone, A. ; Piqueras de Noriega, Javier ; Cardellini, F. | IOP publishing ltd | 2002-01The structural and luminescent properties of nanocrystalline silicon produced by high-energy ball milling of Si single crystals have been investigated using transmission electron microscopy (TEM), x-ray diffraction (XRD) and cathodoluminescence [...]![]()
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Tomashpolskii, Y. Y. ; Sadovskaya, N. V. ; Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Opagiste, C. | Amer Inst Physics | 1997-03The structural changes and the cation and anion compositions of the surface of superconducting YBa_2Cu_3O_(7-x) and Tl_2Ba_2CuO_(6+x) ceramics after local irradiation for several seconds by an electron probe with an accelerating voltage of 25 kV[...]![]()
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Rodríguez Fernández, José ; Carcelen, V. ; Hidalgo Alcalde, Pedro ; Vijayan, N. ; Piqueras de Noriega, Javier ; Sochinskii, N. V. ; Pérez, J. M. ; Dieguez, E. | Institute of Physics | 2004-01-21The cathodoluminescence (CL) technique is used to analyse the radiative recombination properties of four distinct silicon carbide (SiC) samples: a 6H-SiC n^+ -type Lely wafer, two off-axis 4H-SiC epitaxial layers of n type and p type, and a (11 [...]![]()
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A series of 100 nm thick InGaN films with Indium content up to 14% has been grown by MOVPE on SiC substrates. Cathodoluminescence (CL) and remote electron beam induced current (REBIC) in the scanning electron microscope have been applied to inve[...]![]()
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The effect of Cl doping on the luminescence properties of CdTe is investigated by cathodoluminescence microscopy. Cl enhances the 1.4 eV emission and retards the appearance of the tellurium vacancy related emission band. The behaviour under anne[...]![]()
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Cremades Rodríguez, Ana Isabel ; Domínguez-Adame Acosta, Francisco ; Piqueras de Noriega, Javier | American Institute of Physics | 1993-11-01Cathodoluminescence (CL) in the scanning electron microscope has been used to study the upper surface and cross-sectional samples of chemical vapor deposited diamond films. The CL emission is mainly localized at the grain boundaries of the colum[...]![]()
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Zaldivar, M.H. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | American Institute of Physics | 1998-03-01Cathodoluminescence (CL) in the scanning electron microscope has been used to study cross-sectional samples on GaN epitaxial films grown on sapphire. Increased CL emission, attributed to the presence of stacking faults and decorated dislocations[...]![]()
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Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Cavallini, A. ; Fraboni, B. | Elsevier Science SA Lausanne | 1994-05Evidence for IR cathodoluminescence (CL) at 1.2 and 1.0 eV in Te-doped GaAs in the temperature range 80-300 K has been obtained. The evolution of CL intensity and half-width of emission bands after silicon implantation and annealing has been inv[...]![]()
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Díaz-Guerra Viejo, Carlos ; Chioncel, M. F. ; Vincent, J ; Bermudez, V. ; Piqueras de Noriega, Javier ; Dieguez, E. | Wiley-V C H Verlag Gmbh | 2005The homogeneity and luminescence properties of undoped and Te-doped In_xGa_(1-x)Sb crystals grown by the Bridgman and Vertical Feeding methods have been studied by cathodoluminescence (CL) and X-ray microanalysis in a scanning electron microscop[...]![]()
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Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Dutta, P: S. | Materials Research Society | 2000GaSb p-n junctions formed by Zn diffusion in Te-doped n-GaSb single crystalline wafers have been characterized by cathodoluminescence (CL) microscopy and by scanning tunneling spectroscopy. CL plane-view observations of the Zn diffused side enab[...]![]()
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Zaldivar, M.H. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | American Institute of Physics | 2001-07-15Remote electron beam induced current (REBIC) measurements have been carried out to investigate electrically active regions in Si doped GaN films. REBIC bright-dark contrast has been observed in the border of growth, round or pyramidal, hillocks,[...]![]()
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Cebriano Ramírez, Teresa ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | Springer | 2012-10Luminescence of micro-and nanotriangles of cubic antimony oxide, Sb_2O_3 has been investigated by cathodoluminescence (CL) in scanning electron microscope and by photoluminescence (PL) in a laser confocal microscope. The triangles were grown by [...]![]()
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Scanning electron acoustic microscopy (SEAM) has been used in the observation of domain walls in iron- and cobalt-based amorphous alloys ribbons. Controlled magnetic annealing experiments enabled the direct identification of domain walls in SEAM[...]![]()
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Magdas, D.A. ; Malestre, D. ; Cremades Rodríguez, Ana Isabel ; Gregorati, Luca ; Piqueras de Noriega, Javier | Academic Press Ltd- Elsevier Science Ltd | 2009-04In this work sintered thick microcrystalline films as well as micro and nanostructures of In(2)O(3) have been studied. The results obtained by XPS microscopy show that the boundary regions of the microcrystalline films present a higher amount of[...]![]()
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Herrera, M. ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier ; Stutzmann, M. ; Ambacher, O. | American Institute of Physics | 2004-11Cathodoluminescence (CL) in the scanning electron microscope and atomic force microscopy (AFM) have been used to study the formation of pinholes in tensile and compressively strained AlInGaN films grown on Al2O3 substrates by plasma-induced mole[...]![]()
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Pal, U. ; Piqueras de Noriega, Javier ; Fernández Sánchez, Paloma ; Serrano, M. D. ; Dieguez, E. | American Institute of Physics | 1994-09-15Cathodoluminescence in the scanning electron microscope has been used to investigate the relationship of point defects in CdTe and CdTe:V with luminescence bands at 1.40 and 1.13 eV. V has been found to inhibit the 1.40 eV luminescence. Annealin[...]![]()
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Garcia, J. A. ; Remon, A. ; Domínguez-Adame Acosta, Francisco ; Piqueras de Noriega, Javier | Elsevier Science SA | 1991-07The spectral emission of GaP:S in the range 1.5- 2.1eV (800-600nm) has been studied by cathodoluminescence in the scanning electron microscope and by photoluminescence. In as-grown samples the spectra show two bands centered at about 700-730 and[...]![]()
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Piqueras de Noriega, Javier ; Fernández Sánchez, Paloma ; Vicent López, José Luis | Amer Inst Physics | 1990-12-17Changes in the visible and infrared cathodoluminescence(CL)spectra of YBa2Cu3O7?x are detected during irradiation in the scanning electron microscope. Results indicate the influence of oxygen content on the appearance of a CL band at 450–600 nm.[...]![]()
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Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier ; Albrecht, M. ; Stutzmann, M. ; Strunk, H.P. | Elsevier Science SA | 2002-03-22InGaN quantum well (QW) structures with different thicknesses have been characterised by means of cathodoluminescence (CL) in the scanning electron microscope and transmission electron microscopy (TEM), in order to study the structural defects t[...]![]()
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Urbieta Quiroga, Ana Irene ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | American Institute of Physics | 2004-08-20The effect of mechanical milling on the structure and luminescent properties of CdSe powder has been investigated by means of cathodoluminescence (CL) in the scanning electron microscope, transmission electron microscopy (TEM) and x-ray diffract[...]![]()
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Plaza, J. L. ; Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Dieguez, E. | Elsevier Science SA | 2002-04-30The defect structure of Te-doped GaSb samples co-doped with Er_2O_3 and grown by the vertical Bridgman technique has been analysed. This study was carried out for different Er and Te concentrations. The defect structure of the samples has been a[...]![]()
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Maestre Varea, David ; Ramírez Castellanos, Julio ; Hidalgo Alcalde, Pedro ; Cremades Rodríguez, Ana Isabel ; Gónzalez Calbet, J.M. ; Piqueras de Noriega, Javier | Wiley-V C H Verlag Gmbh | 2007-04The defect structure of sintered SnO_2 was investigated by high-resolution transmission electron microscopy (HRTEM), cathodoluminescence (CL), and electrical measurements. HRTEM shows the presence of the SnO phase in the sintered samples as well[...]![]()
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Crocco, J. ; Bensalah, H. ; Zheng, Q. ; Dierre, F. ; Hidalgo Alcalde, Pedro ; Carrascal, J. ; Vela, O. ; Piqueras de Noriega, Javier ; Dieguez, E. | IEEE-Inst Electrical Electronics Engineers Inc | 2011-08The Vertical Gradient Freeze (VGF) method has been used to grow high resistivity Cadmium Zinc Telluride (CZT) for high energy radiation applications. In this work, the effect of lapping and polishing the lateral edges of planar detectors is stud[...]![]()
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Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | Elsevier Science B.V. | 2009-02-01A study of the variation of structural and optical properties of different SnO2 micro- and nanostructures grown by thermal treatments including a post-growth annealing under argon flow has been carried out. The samples have been characterized by[...]![]()
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López, Iñaqui ; Lorenz, K. ; Nogales Díaz, Emilio ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Alves, E. ; Garcia, J. A. | Springer | 2014-02A systematical analysis of the correlation between the crystalline quality and the luminescence of rare-earth-implanted ß-Ga_2O_3 nanostructures with potential applications in visible and ultraviolet photonics is presented. Europium ions led to [...]![]()
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Plugaru, R. ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Tate, T.J. | Institute of Physics | 2002-12-16Visible luminescence of amorphous silicon layers either implanted with Er or co-implanted with Er and O and subsequently annealed in nitrogen has been investigated by cathodoluminescence (CL) in a scanning electron microscope. Co-implanted sampl[...]![]()
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Hidalgo Alcalde, Pedro ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Dutta, P: S. | Elsevier Science SA | 2001-03-22We report here the studies carried out in zinc diffused n-type GaSb by cathodoluminescence (CL) microscopy and by scanning tunneling spectroscopy. Samples with different diffusion profiles measured by secondary ion mass spectrometry (SIMS) were [...]![]()
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Plugaru, R. ; Vasilco, R. ; Piqueras de Noriega, Javier ; Cremades Rodríguez, Ana Isabel | IEEE | 2003Polyerystalline TiO2 surface reconstruction in oxygen atmosphere has been investigated by atomic force microscopy (AFM) and cathodoluminescence in the scanning electron microscopy (SEM-CL). The reactivity to oxygen is related to the presence of [...]![]()
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Piqueras de Noriega, Javier ; Díaz-Guerra Viejo, Carlos ; Umek, Polona ; Gloter, Alexandre | American Chemical Society | 2010-05-13We report on the synthesis of Cr^3^+-doped sodium titanate nanotubes and nanoribbons by a hydrothermal method. The presence of dopant ions in these nanostructures was confirmed by high angle annular dark field scanning transmission electron micr[...]![]()
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Díaz-Guerra Viejo, Carlos ; Umek, Paloma ; Gloter, Alexandre ; Piqueras de Noriega, Javier | Elsevier Science BV | 2010-05-13We report on the synthesis of Cr^(3+)-doped sodium titanate nanotubes and nanoribbons by a hydrothermal method. The presence of dopant ions in these nanostructures was confirmed by high angle annular dark field scanning transmission electron mic[...]![]()
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Mitric, A. ; Corregidor, V. ; Alves, L. C. ; Amariei, A. ; Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier | Elsevier Science B.V. | 2005-02-15GaSb and GaInSb compounds were synthesised from the component elements using a new technique. The effect of the electro-magnetic induction on the conductor materials is used in order to heat, melt and mix the Ga, Sb and In elements. The homogene[...]![]()
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Diaz, Joquín ; López, Iñaki ; Nogales Díaz, Emilio ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | Springer | 2011-05Silicon-doped gallium oxide nanowires have been synthesized by thermal methods using either a mixture of gallium oxide and silicon powders or metallic gallium with silicon powder as precursor materials. The growth mechanism has been found to be [...]![]()
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Maestre Varea, David ; Hernandez, Elena ; Cremades Rodríguez, Ana Isabel ; Matteo, Amati ; Piqueras de Noriega, Javier | Amer Chemical Soc | 2012-05Microtubes of Er-doped SnO2, as well as nanorods and nanoparticles, have been fabricated by a thermal evaporation deposition method at temperatures between 1400 and 1500 degrees C, by using a pellet of compacted SnO2 and Er2O3 powder mixture as [...]![]()
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Méndez Martín, Bianchi ; López, I. ; Alonso Orts, Manuel ; Sanz, A. ; Nogales Díaz, Emilio ; Hidalgo Alcalde, Pedro ; Piqueras de Noriega, Javier | Spie-Int Soc Optical Engineering | 2017-05-30The synthesis of complex nanostructures that combine materials and dimensionality, promises the ability to identify novel designs and architectures with enhanced properties that could be used in new devices. One of the building blocks in nanomat[...]![]()
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Vincent López, José Luis ; Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Dieguez, E. | Amer Inst Physics | 2007In this work, the experimental set-up of the Vertical Feeding Method (VFM) which has been used for the preparation of GaSb and GaInSb materials is presented. The different elements of the set-up are detailed as well as the preparation process. T[...]![]()
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The variation of the electron acoustic signal as a function of temperature in ceramic materials has been studied. Scanning electron acoustic microscopy (SEAM) contrast in MgO single crystals and in reaction bonded SiC, between 100 and 273 K, is [...]![]()
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Peche Herrero, M. A. ; Maestre Varea, David ; Ramirez Castellanos, J. ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier ; Gonzalez Calvet, J. M. | RSC Royal Society of Chemistry | 2014SnO_2 nanoparticles doped with transition metals (V, Cr, Mn) have been synthesized by both the hydrothermal method (HDT) in a basic media and the liquid mixed method (LQM) based on the Pechini method. Nanocrystalline particles obtained via a liq[...]![]()
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Plugaru, R ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | Institute of Physics | 2004-07-21Polycrystalline samples of titanium oxide were prepared by thermal sintering, in argon and air atmospheres at temperatures ranging from 1100 to 1500 degreesC, from powders of anatase and rutile phases. The samples sintered in argon were further [...]![]()
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Castaldini, A. ; Cavallini, A. ; Fraboni, B. ; Piqueras de Noriega, Javier | American Institute of Physics | 1995-12-01We have investigated highly doped GaAs:Te at different doping concentrations (> 10(17) cm(-3)) to assess the presence of the EL2 trap. We have utilized both capacitance and current transient spectroscopy techniques. The crucial parameter for the[...]![]()
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López García, Iñaki ; Cebriano Ramírez, Teresa ; Hidalgo Alcalde, Pedro ; Nogales Díaz, Emilio ; Piqueras de Noriega, Javier ; Méndez Martín, Bianchi | American Institute of Materials Science (AIMS) | 2016A thermal evaporation method developed in the research group enables to grow and design several morphologies of semiconducting oxide nanostructures, such as Ga_2O_3, GeO_2 or Sb_2O_3, among others, and some ternary oxide compounds (ZnGa_2O_4, Zn[...]![]()
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Vanadium pentoxide (V_2O_5) nanorods and nanotips have been grown without a catalyst by a thermal deposition method using compacted V_2O_5 powder as the starting material. The tips, with diameters of about 50-100 nm, grow on the top of rods of l[...]![]()
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Alemán, B. ; Hidalgo Alcalde, Pedro ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | IOP publishing ltd | 2009-11-21Bi doped ZnO nanowires and rods have been grown by a catalyst free evaporation-deposition method with precursors containing either ZnO and Bi_2O_3 or ZnS and Bi_2O_3 powders. The use of ZnS as a precursor was found to lead to a higher density of[...]![]()
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Piqueras de Noriega, Javier ; Sotillo Buzarra, Belén ; Fernández Sánchez, Paloma | Elsevier Science B.V. | 2012-06-01ZnS nanowires and nanoribbons have been obtained by the vapor–solid (VS) method. The morphology depends mainly on the deposition temperature; nanowires are grown at temperatures between 300 °C and 650 °C while the growth of nanoribbons takes pla[...]![]()
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Maestre Varea, David ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier ; Gregorati, Luca | American Institute of Physics | 2008-05-01In-doped SnO_2 microtubes as well as Sn-doped In_2O_3 (ITO) nano- and microislands have been grown by thermal treatment of compacted SnO_2-In_2O powders under argon flow at 1350 degrees C in a catalyst-free process. The SnO_2 tubes contain about[...]![]()
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Bartolomé Vílchez, Javier ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | Royal Soc. Chemistry | 2013Indium oxide microcrystals with shapes of truncated cubes and pyramids as well as microrods with square, triangular or hexagonal cross-sections are grown by a catalyst free evaporation deposition method. Size and shape control of the crystals as[...]![]()
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Magdas, Dana A. ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | American Institute of Physics | 2006-11-01Elongated In2O3 micro- and nanostructures have been grown by two-step thermal treatments of compacted InN powder, at temperatures between 350 and 700 degrees C. Different thermal treatments have been found to induce the growth of structures with[...]![]()
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Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Castaldini, A. ; Cavallini, A. ; Polenta, L. | American Institute of Physics | 2003-08-15Time-resolved cathodoluminescence (TRCL) and photocurrent (PC) spectroscopies have been applied to the study of the yellow band of Si-doped GaN. Measurements carried out combining both techniques unambiguously reveal the complex nature of this b[...]![]()
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Díaz-Guerra Viejo, Carlos ; Piqueras de Noriega, Javier ; Cavallini, A. | Amer Inst Physics | 2003-03-31The temporal behavior of deep-level luminescence emissions in undoped hydride-vapor-phase-epitaxy GaN layers of different thicknesses has been investigated by time-resolved cathodoluminescence (TRCL). The complex nature of the yellow luminescenc[...]![]()
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García Tecedor, Miguel ; Prado Hurtado, Félix del ; Bueno, Carlos ; Vásquez, G. Cristian ; Bartolomé Vílchez, Javier ; Maestre Varea, David ; Díaz, Tomás ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | American Institute of Materials Science (AIMS) | 2016Microtubes and rods with nanopipes of transparent conductive oxides (TCO), such as SnO_2, TiO_2, ZnO and In_2O_3, have been fabricated following a vapor-solid method which avoids the use of catalyst or templates. The morphology of the as-grown t[...]![]()
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Bartolomé Vílchez, Javier ; Maestre Varea, David ; Amati, Mateo ; Cremades Rodríguez, Ana Isabel ; Piqueras de Noriega, Javier | Springer | 2013-09-27Indium-zinc oxide nanostructures, such as nanosheets, nanobelts, and wires formed by oriented stacks of nanoplates have been grown by a controlled thermal evaporation method without the use of a foreign catalyst. Surface features in the stacked [...]![]()
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The capabilities of SEAM in uniformity assessment of SI GaAs are investigated. Profiles of SEAM signals across the wafer and SEAM images of dislocation distribution are obtained. Part of the nonlinear signal shows a profile that is not related t[...]![]()
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Nogales Díaz, Emilio ; Garcia, J. A. ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Lorenz, K. ; Alves, E. | IOP publishing ltd | 2008-03-20The luminescence properties of Er doped ?-Ga_2O_3 and of the erbium gallium garnet Er_3 Ga_5O_12(ErGG) have been investigated both in the visible and in the infrared (IR) ranges by means of photoluminescence (PL). Doping of the ?-Ga_2O_3 was obt[...]![]()
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Nogales Díaz, Emilio ; Montone, A. ; Cardellin, F. ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | IOP publishing ltd | 2002-12There. has been interest in the past years in the visible luminescence properties of germanium nanocrystals. Most of the previous works refer to Ge nanocrystals embedded in an oxide matrix. In this work nanocrystalline germanium has been prepare[...]![]()
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Borini, S. ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | American Institute of Physics | 2003-12-15The luminescence of mechanically milled GaSb has been investigated by means of cathodoluminescence (CL) in the scanning electron microscope. Transmission electron microscopy reveals that the GaSb powders obtained after the milling process contai[...]![]()
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Nogales Díaz, Emilio ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier | IOP publishing ltd | 2008-01-23Erbium doped ß-Ga_2O_3 nanowires and microwires have been obtained by a vapour-solid process from an initial mixture of ß-Ga_2O_3 and Er_2O_3 powders. X-ray diffraction (XRD) analysis reveals the presence of erbium gallium garnet as well as ß-Ga[...]![]()
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Nogales Díaz, Emilio ; Méndez Martín, Bianchi ; Piqueras de Noriega, Javier ; Plugaru, R ; Coraci, A. ; Garcia, J. A. | IOP publishing ltd | 2002Visible luminescence from erbium oxide layers grown on crystalline and amorphous silicon (c-Si and a-Si) has been investigated. The results show strong red and green cathodoluminescence bands due to intraionic Er3+ radiative transitions at room [...]![]()
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Ortega Villafuerte, Yanicet ; Dieker, Ch ; Jaeger, W. ; Piqueras de Noriega, Javier ; Fernández Sánchez, Paloma | IOP publishing ltd | 2010-06-04ZnO nanorods containing different hollow structures have been grown by a thermal evaporation-deposition method with a mixture of ZnS and SnO(2) powders as precursor. Transmission electron microscopy shows rods with rows of voids as well as rods [...]![]()
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Méndez Martín, Bianchi ; Cebriano Ramírez, Teresa ; López, I. ; Nogales Díaz, Emilio ; Piqueras de Noriega, Javier | Spie-Int Soc Optical Engineering | 2013Interest on the control of light at the nano- and microscale has increased in the last years because of the incorporation of nanostructures into optical devices. In particular, semiconductor oxides microstructures emerge as important active mate[...]![]()
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Khomenkova, L. ; Fernández Sánchez, Paloma ; Piqueras de Noriega, Javier | Amer Chemical Soc | 2007-04ZnO microspheres, with surfaces covered with nanowalls, as well as nano- and microrods, have been grown by thermal treatment of ZnS powder. The structures have been grown at temperatures in the range of 750-900 ºC in a catalyst-free process. Pre[...]