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PHYSICS (538 journals)            First | 1 2 3 4 5 6 | Last

Physica B: Condensed Matter     Hybrid Journal   (Followers: 5)
physica status solidi (a)     Hybrid Journal   (Followers: 1)
physica status solidi (b)     Hybrid Journal   (Followers: 1)
physica status solidi (c)     Hybrid Journal   (Followers: 1)
Physica Status Solidi - Rapid Research Letters     Hybrid Journal   (Followers: 1)
Physical Communication     Hybrid Journal  
Physical Review C     Full-text available via subscription   (Followers: 17)
Physical Review Special Topics - Physics Education Research     Open Access   (Followers: 6)
Physical Review X     Open Access   (Followers: 4)
Physical Sciences Data     Full-text available via subscription   (Followers: 1)
Physics - spotlighting exceptional research     Full-text available via subscription   (Followers: 1)
Physics and Chemistry of Glasses - European Journal of Glass Science and Technology Part B     Full-text available via subscription   (Followers: 2)
Physics and Chemistry of Liquids: An International Journal     Hybrid Journal  
Physics and Chemistry of the Earth, Parts A/B/C     Hybrid Journal   (Followers: 3)
Physics Essays     Full-text available via subscription  
Physics in Medicine & Biology     Full-text available via subscription   (Followers: 7)
Physics in Perspective     Hybrid Journal   (Followers: 1)
Physics International     Open Access   (Followers: 2)
Physics Letters A     Hybrid Journal   (Followers: 10)
Physics Letters B     Open Access   (Followers: 2)
Physics of Fluids     Hybrid Journal   (Followers: 23)
Physics of Life Reviews     Hybrid Journal   (Followers: 1)
Physics of Plasmas     Hybrid Journal   (Followers: 6)
Physics of the Dark Universe     Open Access  
Physics of the Solid State     Hybrid Journal   (Followers: 3)
Physics of Wave Phenomena     Hybrid Journal   (Followers: 1)
Physics Procedia     Partially Free   (Followers: 1)
Physics Reports     Full-text available via subscription   (Followers: 1)
Physics Research International     Open Access   (Followers: 1)
Physics Today     Hybrid Journal   (Followers: 16)
Physics World     Full-text available via subscription   (Followers: 3)
Physics-Uspekhi     Full-text available via subscription  
Physik in unserer Zeit     Hybrid Journal  
Physik Journal     Hybrid Journal  
Plasma Physics and Controlled Fusion     Hybrid Journal   (Followers: 2)
Plasma Physics Reports     Hybrid Journal   (Followers: 2)
Pramana     Open Access   (Followers: 8)
Preview     Hybrid Journal  
Proceedings of the National Academy of Sciences     Full-text available via subscription   (Followers: 402)
Proceedings of the National Academy of Sciences, India Section A     Hybrid Journal   (Followers: 3)
Progress in Materials Science     Hybrid Journal   (Followers: 18)
Progress in Planning     Hybrid Journal   (Followers: 1)
Progress of Theoretical and Experimental Physics     Open Access  
Quantum Electronics     Full-text available via subscription   (Followers: 2)
Quantum Measurements and Quantum Metrology     Open Access  
Quarterly Journal of Mechanics and Applied Mathematics     Hybrid Journal   (Followers: 3)
Radiation Effects and Defects in Solids     Hybrid Journal   (Followers: 1)
Radiation Measurements     Hybrid Journal   (Followers: 2)
Radiation Physics and Chemistry     Hybrid Journal   (Followers: 1)
Radiation Protection Dosimetry     Hybrid Journal   (Followers: 2)
Radiation Research     Full-text available via subscription   (Followers: 2)
Radio Science     Full-text available via subscription   (Followers: 2)
Radiological Physics and Technology     Hybrid Journal   (Followers: 1)
Reflets de la physique     Full-text available via subscription  
Reports on Mathematical Physics     Full-text available via subscription  
Reports on Progress in Physics     Full-text available via subscription   (Followers: 2)
Research & Reviews : Journal of Physics     Full-text available via subscription  
Research in Drama Education     Hybrid Journal   (Followers: 9)
Research Journal of Physics     Open Access  
Results in Physics     Open Access   (Followers: 1)
Reviews in Mathematical Physics     Hybrid Journal  
Reviews of Accelerator Science and Technology     Hybrid Journal  
Reviews of Geophysics     Full-text available via subscription   (Followers: 19)
Reviews of Modern Physics     Full-text available via subscription   (Followers: 16)
Revista Colombiana de Física     Open Access  
Revista Mexicana de Astronomía y Astrofísica     Open Access  
Revista Mexicana de Física     Open Access  
Revista mexicana de física E     Open Access  
Rheologica Acta     Hybrid Journal   (Followers: 3)
Russian Journal of Mathematical Physics     Hybrid Journal  
Russian Journal of Nondestructive Testing     Hybrid Journal  
Russian Physics Journal     Hybrid Journal  
Samuel Beckett Today/Aujourd'hui     Full-text available via subscription   (Followers: 2)
Science and Technology of Nuclear Installations     Open Access   (Followers: 1)
Science China Physics, Mechanics and Astronomy     Hybrid Journal   (Followers: 1)
Science Foundation in China     Full-text available via subscription   (Followers: 2)
Scientific Journal of Physical Science     Open Access  
Scientific Reports     Open Access   (Followers: 10)
Selected Topics in Applied Earth Observations and Remote Sensing, IEEE Journal of     Hybrid Journal   (Followers: 15)
Sensor Letters     Full-text available via subscription   (Followers: 1)
Sensors and Actuators A: Physical     Hybrid Journal   (Followers: 20)
Services Computing, IEEE Transactions on     Hybrid Journal   (Followers: 3)
Shock and Vibration     Hybrid Journal   (Followers: 7)
Shock Waves     Hybrid Journal   (Followers: 4)
Small     Hybrid Journal   (Followers: 8)
Software Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 21)
Solid State Physics     Full-text available via subscription  
Solid-State Circuits Magazine, IEEE     Hybrid Journal   (Followers: 1)
South African Journal for Research in Sport, Physical Education and Recreation     Full-text available via subscription   (Followers: 3)
Space Research Journal     Open Access   (Followers: 2)
Space Weather     Full-text available via subscription   (Followers: 3)
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy     Hybrid Journal   (Followers: 7)
Spectrochimica Acta Part B: Atomic Spectroscopy     Hybrid Journal   (Followers: 4)
Spectroscopy     Hybrid Journal   (Followers: 3)
Spectroscopy Letters: An International Journal for Rapid Communication     Hybrid Journal   (Followers: 3)
Sri Lankan Journal of Physics     Open Access  
Strain     Hybrid Journal   (Followers: 2)
Strength of Materials     Hybrid Journal   (Followers: 4)
Strength, Fracture and Complexity     Hybrid Journal   (Followers: 1)
Structural Dynamics     Open Access  

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Journal Cover physica status solidi (c)
   Journal TOC RSS feeds Export to Zotero [3 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1862-6351 - ISSN (Online) 1610-1642
     Published by John Wiley and Sons Homepage  [1603 journals]   [SJR: 0.397]   [H-I: 27]
  • Silicon nanowires: synthesis, optical properties and applications
    • Authors: Cristiano D'Andrea; Maria José Lo Faro, Paolo Musumeci, Barbara Fazio, Fabio Iacona, Giorgia Franzò, Pietro Gucciardi, Cirino Vasi, Francesco Priolo, Alessia Irrera
      Pages: n/a - n/a
      Abstract: Group‐IV semiconductor nanowires (NWs) are attracting the interest of a wide scientific community as building blocks for a wide range of future nanoscaled devices. We used metal‐assisted chemical etching of Si substrates to synthesize Si NWs with different length and nanometer‐size diameter. NWs obtained by this technique have exactly the same structure and doping of the substrate and present quantum confinement effects. Photoluminescence (PL) emission at room temperature from Si NWs is reported. We observed an increasing behaviour of the PL intensity as a function of the NWs length. The fabrication of light emitting devices based on Si NWs, showing electroluminescence emission at room temperature under low voltage excitation, is also reported. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-09-12T05:10:13.275103-05:
      DOI: 10.1002/pssc.201400052
  • Ion beam analysis of Heusler alloy Fe3Si epitaxially grown on Si(111)
    • Authors: Yoshihito Maeda; Yuki Kawakubo, Yuya Noguchi, Kazumasa Narumi, Seiji Sakai
      Pages: n/a - n/a
      Abstract: We have investigated atomic ordering of Heusler alloy Fe3Si(111) epitaxially grown on Si(111) by using ion beam analysis. The total atomic displacement along Si directions was deduced from the minimum yield χmin and the critical angle Ψ1/2 for channeling. The total displacement consists of both one‐dimensional thermal vibrations computed by the Debye theory and static displacements due to imperfections, lattice mismatch, thermal expansion etc. The atomic displacement increased as the annealing temperature increased from 373 to 573 K. We found that this static displacement came from a difference in thermal expansion between the Fe3Si film and Si substrates at the anneal temperature and was quenched into room temperature as a remnant displacement. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-09-12T05:10:12.417819-05:
      DOI: 10.1002/pssc.201400027
  • First principles analysis of atomic configurations of group IV elements in
           Ge crystal for solar cells
    • Authors: Ryo Matsutani; Koji Sueoka, Eiji Kamiyama
      Pages: n/a - n/a
      Abstract: We focused on group IV semiconductors, i.e., Ge (Si), containing C, Si (C, Ge), and/or Sn atoms as alternative candidates for poly‐Si crystals to achieve higher engineering efficiency in solar cells in this research. The main target of this study was to obtain basic data on atomic configurations, such as bond strain and stable sites for substituted C, Si, and Sn atoms in Ge and for C, Ge, and Sn atoms in Si crystals through first principles analysis. We found that ((C, Si)/C) atoms with smaller covalent radii than (Ge/Si) formed tensile local strain along zigzag bonds in the direction while (Sn/(Ge, Sn)) atoms with larger covalent radii than (Ge/Si) formed compressive local strain. Another important result was that local strains except for zigzag bonds had opposite signs to strains along zigzag bonds. The main results to summarize stable configurations of substitutional IV elements were: (1) C and Sn (Si) atoms were stable at positions next to one another, while Si and Sn atoms were stable at mostly separated positions in Ge crystals. (2) C (Ge) and Sn atoms were stable at positions next to one another, while C and Ge atoms were stable at mostly separated positions in Si crystals. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-09-12T05:10:11.555634-05:
      DOI: 10.1002/pssc.201400029
  • Influence of copper contamination on the illuminated forward and dark
           reverse current‐voltage characteristics of multicrystalline
           p‐type silicon solar cells
    • Authors: Tleuzhan Turmagambetov; Sébastien Dubois, Jean‐Paul Garandet, Benoit Martel, Nicolas Enjalbert, Jordi Veirman, Etienne Pihan
      Pages: n/a - n/a
      Abstract: We studied the influence of copper (Cu) on the performances of conventional photovoltaic (PV) solar cells by growing two multicrystalline (mc) boron‐doped silicon (Si) ingots from ultra‐pure feedstocks, one of these feedstocks being deliberately contaminated with 90 ppm wt of Cu. Industrial‐like solar cells were fabricated and the associated external gettering and hydrogenation effects were studied. An originality of our approach consisted in evaluating the forward but also reverse current‐voltage (I‐V) characteristics of the fabricated cells. Furthermore we assessed the stability under illumination of the PV parameters as Cu is known to be responsible for light‐induced degradations (LID) of the carrier lifetime. On the one hand we unexpectedly showed that the PV conversion efficiency (η) was not affected by the initially large Cu concentrations. We demonstrated that it was due to the complementary actions of the external gettering effect developed by the phosphorus‐diffusion and the bulk hydrogenation. The Cu‐addition slightly enhanced the pn junction hard breakdown, however the extracted junction breakdown voltages fulfilled the common industrial requirements for this parameter. On the other hand we highlighted significant decreases under illumination of the PV performances for the Cu‐contaminated solar cells fabricated from wafers coming from the upper part of the ingot (i.e., samples with the highest Cu concentration). These decreases could be explained by the previously proposed mechanisms in the literature, which argue that the excess charge carriers could reduce the electrostatic repulsion between interstitial Cu ions and Cu precipitates, this effect enhancing the Cu precipitation. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-09-12T05:10:10.418578-05:
      DOI: 10.1002/pssc.201400036
  • Quantitative analysis of carbon impurity concentration in silicon
           epitaxial layers by luminescence activation using carbon ion implantation
           and electron irradiation
    • Authors: Satoko Nakagawa; Kazuhiko Kashima
      Pages: n/a - n/a
      Abstract: The calibration curve for the carbon concentration in silicon epitaxial layers was obtained by photo‐luminescence spectroscopy after carbon ion implantation and electron irradiation. Low carbon concentrations on the order of 1014 atoms/cm3 affected properties such as the on‐resistance and carrier lifetime of insulated gate bipolar transistors (IGBTs). We focused on carbon impurities because interstitial carbon can form complexes, such as complexes of interstitial and substitutional carbon (Ci‐Cs) and of interstitial carbon and oxygen (Ci‐Oi), which produce deep levels in the energy band gap. To verify the effects of carbon impurities separately from those of oxygen impurities, oxygen‐free silicon epitaxial layers were studied. The carbon concentration in silicon epitaxial wafers was evaluated quantitatively by using our calibration curve. Carbon ion implantation and photoluminescence spectrum measurements were performed to obtain the slope of the calibration curve. In addition, secondary ion mass spectrometry measurement gave absolute carbon concentration against photo‐luminescence intensity for fixing the calibration curve. The calibration curve was used to determine the carbon concentration for each IGBT. Carbon impurity concentrations as low as 1014 atoms/cm3 in silicon epitaxial layers lowered device performance. Therefore, decreasing the carbon impurity concentration is essential for improving the performance of advanced IGBTs. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-09-12T05:10:09.410256-05:
      DOI: 10.1002/pssc.201400046
  • Outdoor characterization of amorphous silicon based photovoltaic modules
           with different structures
    • Authors: Thomas Mambrini; Anne Migan‐Dubois, Christophe Longeaud, Mustapha Elyaakoubi
      Pages: n/a - n/a
      Abstract: Three different amorphous silicon structures of PV modules were analyzed in outdoor condition during one month. The Staebler‐Wronski effect (or light induced degradation effect) is well known for the amorphous technology and depends strongly on the manufacturing process and its structure. Due to this effect, the amorphous PV modules loose performances compared to their initial characteristics. The behaviour, during and after the aging of different amorphous silicon PV module, is investigated and a new amorphous structure, less sensitive to the Staebler‐Wronski effect and with a better response under real conditions of use is exposed. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-09-12T05:10:08.507824-05:
      DOI: 10.1002/pssc.201400048
  • Cover Picture: Phys. Status Solidi C 9–10/2014
    • Pages: n/a - n/a
      Abstract: Extended X‐ray absorption fine structure (EXAFS) can provide perhaps the most extensive information on the local atomic structure, as well as on the lattice dynamics, for a broad class of materials. However, conventional methods of EXAFS data treatment are often limited to the nearest coordination shells of the absorbing atom due to the difficulties in accurate accounting for multiple‐scattering effects. Besides, it is often difficult to resolve non‐equivalent groups of atoms in a single coordination shell due to strong correlation between struc‐tural parameters. In the study of the EXAFS data for wurtzite‐type bulk ZnO by J. Timoshenko, A. Anspoks, A. Kalinko, and A. Kuzmin (see pp. 1472–1475), these problems are overcome by applying two different simulation‐based methods: classical Molecular Dynamics (MD) and a novel Evolutionary Algorithm (EA) approach. The important part of the EA method is the employment of Morlet wavelet transform to represent the available EXAFS data in real and reciprocal space simultaneously, and hence to benefit from much more information being available for the analysis (wavelet image of the Zn K‐edge EXAFS spectrum and a part of ZnO structure are shown on the cover). Such combined approach allowed to separate the contributions of thermal disorder and the effect of noncentrosymmetric zinc oxide structure, being responsible for its piezoelectrical and pyroelectrical properties, and also to test the accuracy of several available force–field models, which are commonly used in MD simulations of bulk and nanosized ZnO.
      PubDate: 2014-09-10T09:52:16.776932-05:
      DOI: 10.1002/pssc.201470057
  • Issue Information: Phys. Status Solidi C 9–10/2014
    • Pages: n/a - n/a
      PubDate: 2014-09-10T09:52:12.043946-05:
      DOI: 10.1002/pssc.201470058
  • Multi‐frequency electron spin resonance study of inherent Si
           dangling bond defects at the thermal (211)Si/SiO2 interface
    • Authors: S. Iacovo; A. Stesmans
      Pages: n/a - n/a
      Abstract: Multifrequency low temperature electron spin resonance (ESR) studies were carried out to atomically assess inherent point defects at the thermal ‘higher index' (211)Si/SiO2 interface. This reveals, as dominant imperfections, Pb‐type centers (generic entity Si3≡Si•, the dot representing an unpaired sp3‐like hybrid) occurring in densities of ∼1 × 1013 cm–2 for oxidation temperatures ∼400 °C. On the basis of the pertinent ESR characteristics, the inherent basic defect is typified as the Pb0(211) variant, resembling closely the Pb0 center in standard (100)Si/SiO2. At the higher index (211)Si/SiO2 interface, these defects predominantly pertain to defected Si atoms located at (111)‐face terraces. Combination of angular and frequency (ν) dependent studies show the Pb0(211) peak‐to‐peak line width ΔBpp to be composed of a residual width (ν→0) of 2.2 ± 0.1 G, to which dipolar broadening contributes an essential part, and a substantial inhomogeneous broadening component due to g distribution, predominantly in g⊥, induced by non‐uniform interface strain –also similar to the Pb0(100) properties. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-08-08T04:40:13.233383-05:
      DOI: 10.1002/pssc.201400071
  • Sol–gel deposited phosphorus and boron doped thin silica films for
           diffused n+p and n+pp+ structures
    • Authors: Armel Duvalier Pene; Bouchaib Hartiti, Laurent Bitjoka, Phillippe Thevenin, Cesar Kapseu
      Pages: n/a - n/a
      Abstract: The realization of a silicon solar cell emitter is a critical and very important step in photovoltaic technology. Indeed, the surface concentration of boron (B) or phosphorus (P) and junction depth determines the photovoltaic conversion efficiency of silicon solar cells. Several techniques are used for the realization of emitters n+p and n+pp+ among which the vapor diffusion, ionic implantation and diffusion from solid sources are the most common. This work will be devoted to the realization of emitters made by diffusion of P or B from solid doping sources developed by the sol–gel method associated to spin coating on monocrystalline and polycrystalline silicon wafers. The doping solutions were prepared by sol–gel method using methyltriethoxysilane “MTEOS” or tetramethoxysilane “TEOS” and H4PO3 or H3BO3 as precursors. The n+ junction was realized by emulsion of phosphoric acid in isopropanol while the p+ junction was obtained by emulsion of boric acid H3BO3 in isopropanol or by diffusion of aluminium at high temperatures. Our samples were annealed at temperatures ranging from 850 to 1000 °C in a classical furnace under Nitrogen atmosphere. The four point technique has been used to study the electrical properties of n+p and n+pp++ structures. The results of measurements showed values of the sheet resistance Rs comparable to those of literature and confirm the diffusion of phosphorus and boron from liquid and solid sources prepared by sol–gel method. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-08-08T04:40:12.172213-05:
      DOI: 10.1002/pssc.201400060
  • Temperature dependent switching behaviour of nickel silicided undoped
           silicon nanowire devices
    • Authors: Jürgen Beister; Andre Wachowiak, André Heinzig, Jens Trommer, Thomas Mikolajick, Walter M. Weber
      Pages: n/a - n/a
      Abstract: In this work, we investigate the temperature dependence of electrical switching properties of back‐gated, undoped Si‐nanowire field‐effect transistors with Ni‐silicided source/drain contacts. A simple, phenomenological model illustrates the leading order temperature dependence of the source‐drain current, which originates predominantly from charge carrier injection by tunneling through the Schottky junction. Drain current versus gate voltage measurements have been performed for various temperatures and several drain voltages on a single nanowire device. The temperature dependence of the drain‐source current for specific gate and drain voltages is analysed within the framework of voltage dependent effective barrier heights. As a result, the temperature dependence of the tunnelling current is not only important for the sub‐threshold region, but also plays a significant role in the transistor “on‐state”. In addition, the effective barrier heights for electrons and holes tend towards the natural Schottky barriers of the NiSi2‐Si interface, if the applied external fields generate the case of flat band condition at the injection Schottky barrier, i.e. in the deep “off‐state” region. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-08-08T04:40:10.98697-05:0
      DOI: 10.1002/pssc.201400055
  • Band engineering and absorption spectra in compressively strained
           Ge0.92Sn0.08/Ge (001) double quantum well for infrared photodetection
    • Authors: N. Yahyaoui; N. Sfina, J.‐L. Lazzari, A. Bournel, M. Said
      Pages: n/a - n/a
      Abstract: We report a theoretical investigation of strained Ge1−xSnx/Ge (001)‐oriented quantum wells as a bulding block in active region of infrared photodetector. The electronic band parameters, gaps, discontinuities and effective masses for heterointerfaces between compressively strained Ge1−xSnx and relaxed Ge have beencomputed at room temperature. From this preliminary and mendatory work, we conclude that pseudomorphic Ge1−xSnx alloys become direct band gap semiconductors at a Sn‐fraction of 15.3%, e.g. a lattice mismatch as high as 2.3%. Due to achievable critical layer thickness and mainly solid solubility limit, a type‐I compressively strained Ge/Ge0.92Sn0.08/Ge (double) quantum well is studied by solving Schrödinger equation without and applied bias voltage. A strong absorption coefficient (> 1×104 cm−1) and a Stark shift of the direct transition between 2.01 μm and 2.25 μm at large external fields (40kV/cm) are attractive characteristics for the design of infrared photodetectors (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-08-08T04:40:09.615156-05:
      DOI: 10.1002/pssc.201400054
  • Electrically detected magnetic resonance study on defects in Si
           pn‐junctions created by proton implantation
    • Authors: Gernot Gruber; Stefan Kirnstoetter, Peter Hadley, Markus Koch, Thomas Aichinger, Holger Schulze, Werner Schustereder
      Pages: n/a - n/a
      Abstract: The present study focuses on electrically detected magnetic resonance (EDMR) investigations of proton implanted silicon. The samples were prepared on n‐type silicon wafers highly doped diffused boron (B) p‐region, forming a pn‐junction. A large additional n‐type doping was introduced by proton (H+) implantation. We compare samples with implantation doses up to 1015 H+/cm–2 and investigate the effects of anneals at 350 °C. We observe different types of defects in the differently prepared samples. One doublet with 118.5 G HF splitting and a g ‐value of 2.0095(4) is only observed in the samples implanted with the highest dose and is assigned to hydrogen. The structure of the other observed defects remains unidentified and can only tentatively be assigned to hydrogen. More extensive measurements would have to be performed to get a better picture. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-08-08T04:40:08.136114-05:
      DOI: 10.1002/pssc.201400053
  • High dose proton implantations into silicon: a combined EBIC, SRP and TEM
    • Authors: Stefan Kirnstoetter; Martin Faccinelli, Christian Gspan, Werner Grogger, Moriz Jelinek, Werner Schustereder, Johannes G. Laven, Hans‐Joachim Schulze, Peter Hadley
      Pages: n/a - n/a
      Abstract: Proton (H+) implantations are used in power semiconductor devices to introduce recombination centers (Hazdra et al., Microelectron. J. 32(5), 449–456 (2001)) or to form hydrogen related donor complexes (Zohta et al., Jpn. J. Appl. Phys. 10, 532–533 (1991)). Proton implantations are also used in the 'smart cut' process to generate defects that can be used to cleave thin wafers (Romani and Evans, Nucl. Instrum. Methods Phys. Res. B 44, 313–317 (1990)). However, the implantation damage resulting from H+implantations is not completely understood. In this study, protons with energies from 400 keV up to 4 MeV and doses up to 1016 H+/cm² were implanted into highly ohmic boron doped m:Cz silicon (100). Electron Beam Induced Current (EBIC) measurements were performed to locally determine the minority charge carrier diffusion length. The diffusion length decreases with increasing implantation dose and incorporated damage. Spreading Resistance Profiling (SRP) measurements were performed to analyze the charge carrier concentration profiles for different annealing procedures. The electrical activation and growth of the defect complexes varies strongly with the annealing parameters. Transmission Electron Microscopy measurements were made to investigate the microscopic structures formed by the high dose implantation processes. Due to the high local damage density resulting from low energy and high dose H+ implants, platelet structures are formed. During high‐energy high‐dose H+implantations, the implanted hydrogen generates strain in the crystal lattice resulting in changes in the distances between atomic planes. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-08-08T04:40:06.968116-05:
      DOI: 10.1002/pssc.201400051
  • Depletion of superjunction power MOSFETs visualized by electron beam
           induced current and voltage contrast measurements
    • Authors: Stefan Kirnstoetter; Martin Faccinelli, Moriz Jelinek, Werner Schustereder, Johannes G. Laven, Hans‐Joachim Schulze, Peter Hadley
      Pages: n/a - n/a
      Abstract: Electron Beam Induced Current (EBIC) measurements were used to produce cross sectional images of superjunction power transistors. These images show how the depletion width expands under reverse bias. Superjunctions are alternating p‐ and n‐type doped vertical columns placed between drain and source in a power transistor (Deboy et al., in: Proc. IEDM, 983–685 (1998); Lorenz et al., in: Proc. PCIM Europe, 250–258 (1998)). These columns allow a higher substrate doping of the drift region, resulting in a lower on‐state resistance while still maintaining a high breakdown voltage. When the device is reverse biased, the space charge region of the superjunction should expand symmetrically due to the homogeneous doping (in the n and p region) until the complete device depletes. The depletion process was also visualized using voltage contrast (VC) measurements. Here the secondary electron signal was detected when the device was reverse biased. We show that EBIC and VC measurements can provide valuable input for process tuning and process simulations, enabling the use of smaller dimensions and higher doping levels
      PubDate: 2014-08-08T04:30:06.467238-05:
      DOI: 10.1002/pssc.201400050
  • An EBIC and SRP study on thermal donors in proton implanted p‐type
           magnetic Czochralski silicon
    • Authors: Martin Faccinelli; Stefan Kirnstoetter, Werner Schustereder, Johannes G. Laven, Peter Hadley
      Pages: n/a - n/a
      Abstract: The concentration of defects in silicon can be changed by ion implantations and thermal annealing steps. Some of the defects incorporated during these processes form complexes which can act as donors or acceptors and their concentration can even overcome the initial doping concentration of the material, and hence, cause an inversion of the doping type. One way to introduce defects and also to catalyse the formation of defect complexes is by proton implantation. For our project, a high resistivity p‐type magnetic Czochralski (m:Cz) grown silicon wafer was implanted with 4 MeV protons at an implantation dose of 2 ×1014 cm–2. The wafer was broken into pieces and these pieces were annealed at different temperatures resulting in different concentrations of defect complexes. The defects were investigated in the proton implanted region and in the substrate region beyond the penetration depth of the protons (where only the heat treatment caused a change in the defect concentrations). The local doping type and the relative change of the minority carrier diffusion length were measured using Electron Beam Induced Current (EBIC). Furthermore, resistivity profiles were measured using Spreading Resistance Profiling (SRP). The results show several changes of the doping type, the minority carrier diffusion length and the resistivity profile. In addition to donor complexes already reported in the literature, the formation of additional high temperature donor complexes has been observed. The data shows that the presence of hydrogen in silicon has a far higher influence on the changes of the electrical properties of the material at annealing temperatures between 400 °C and 510 °C than at higher annealing temperatures. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-08-08T04:30:05.270823-05:
      DOI: 10.1002/pssc.201400045
  • Electron beam silicon purification
    • Authors: Anatoly Kravtsov; Alexey Kravtsov
      Pages: n/a - n/a
      Abstract: Purification of heavily doped electronic grade silicon by evaporation of N‐type impurities with electron beam heating was investigated in process with a batch weight up to 50 kilos. Effective temperature of the melt, an indicative parameter suitable for purification process characterization was calculated and appeared to be stable for different load weight processes. Purified material was successfully approbated in standard CZ processes of three different companies. Each company used its standard process and obtained CZ monocrystals applicable for photovoltaic application. These facts enable process to be successfully scaled up to commercial volumes (150‐300 kg) and yield solar grade silicon. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-08-08T04:23:33.625363-05:
      DOI: 10.1002/pssc.201400031
  • Determination of the single crystal Ge Young’s modulus between room
           temperature and melting temperature using the impulse excitation technique
    • Authors: Akhilesh K. Swarnakar; Omer Van der Biest, Jan Van Humbeeck, Jan Vanhellemont
      Pages: n/a - n/a
      Abstract: In the present study, the vibrational properties of single crystal Ge samples are studied between room and melt‐ing temperature using the impulse excitation technique (IET). From the IET measurements, the temperature dependent Young's moduli Eijk of single crystal Ge are extracted in the (100), (110) and (111) crystallographic directions in inert atmosphere. The results show an anomalous softening of an elastic constant around 890 °C temperature during the measure‐ment. The Young's moduli values between 88 to 132 GPa are obtained close to the melting temperature, depending on the crystallographic direction. Empiric expressions are derived for the temperature dependence of E(100), E(110) and E(111). (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-08-08T04:20:05.544496-05:
      DOI: 10.1002/pssc.201400011
  • Photoluminescence properties of Ce3+ ions in Ce‐doped SiO1.5 thin
           films containing Si nanocrystals
    • Authors: J. Weimmerskirch‐Aubatin; M. Stoffel, X. Devaux, A. Bouché, M. Vergnat, H. Rinnert
      Pages: n/a - n/a
      Abstract: We investigate the luminescence properties of Ce3+ ions in Ce‐doped SiO1.5 thin films containing Si nanocrystals (Si‐ncs) by means of steady‐state photoluminescence (PL), time‐resolved PL and PL excitation spectroscopy. Strong Ce‐related blue luminescence is observed with the naked eye at room temperature. The Ce‐related lumines‐cence is found to ncrease with the Ce content in the films while simultaneously, the Si‐nc‐related luminescence decreases. Moreover, the decay time of the Si‐nc related luminescence decreases for increasing Ce concentrations thus suggesting a possible indirect excitation of the Ce3+ ions via Si‐ncs. However, PL excitation measurements show that Ce3+ ions are mainly directly excited with only a negligible influence of the Si‐ncs. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-07-25T05:10:14.445674-05:
      DOI: 10.1002/pssc.201400042
  • Tuning optical a‐SiC/a‐Si active filters by UV bias light in
           the visible and infrared spectral ranges
    • Authors: M. Vieira; M. A. Vieira, I. Rodrigues, V. Silva, P. Louro
      Pages: n/a - n/a
      Abstract: Visible range to telecom band spectral translation is accomplished using an amorphous SiC pi'n/pin wavelength selector under appropriate front and back optical light bias. Results show that background intensity works as selectors in the infrared region, shifting the sensor sensitivity. Low intensities select the near‐infrared range while high intensities select the visible part according to its wavelength. Here, the optical gain is very high in the infrared/red range, decreases in the green range, stays close to one in the blue region and strongly decreases in the near‐UV range. The transfer characteristics effects due to changes in steady state light intensity and wavelength backgrounds are presented. The relationship between the optical inputs and the output signal is established. A capacitive optoelectronic model is presented and tested using the experimental results. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-07-25T05:10:13.125023-05:
      DOI: 10.1002/pssc.201400020
  • Comparison between experimental and simulated strain profiles in Ge
           channels with embedded source/drain stressors
    • Authors: R. Bühler; G. Eneman, P. Favia, H. Bender, B. Vincent, A. Hikavyy, R. Loo, J. A. Martino, C. Claeys, E. Simoen, N. Collaert, A. Thean
      Pages: n/a - n/a
      Abstract: Two planar Ge‐based MOSFET structures were analysed for n‐ and p‐type transistors with tensile and compressive strain implemented in the channel direction using source/drain stressors. Strain profiles measured by nano‐beam diffraction (NBD) have been compared with Sentaurus process simulations. The TCAD simulations were tuned with the actual process using NBD measurements, resulting in a more realistic simulation and, therefore, a more reliable interpretation is now possible. dark‐field scanning transmission electron microscopy images added to the strain profiles returned interesting results about the Ge virtual substrate condition and how it disturbs the NBD readings due to the presence of extended defects in strain relaxed Ge buffer layers. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-07-25T05:10:12.035703-05:
      DOI: 10.1002/pssc.201400021
  • Mediation effect of sub‐monolayer carbon on interfacial mixing in Ge
           growth on Si(100)
    • Authors: Yuhki Itoh; Ryo Hayase, Shinji Hatakeyama, Tomoyuki Kawashima, Katsuyoshi Washio
      Pages: n/a - n/a
      Abstract: The mediation effect of carbon (C) on interfacial mixing in Ge growth was studied using C‐covered Si surface (Ge/C/Si) and C over thin Ge buffer layer (Ge/C/Ge/Si) systems. The samples were prepared by solid‐source molecular beam epitaxy system with electron beam gun for C sublimation and K‐cell for Ge evaporation. The interdiffusion at the interface and deterioration in crystallinity of Ge layer was evaluated by Raman spectroscopy and X‐ray diffraction, respectively. In the case of Ge/C/Si system, the interdiffusion of Si and Ge atoms was suppressed by more than 0.3 monolayer (ML)‐C depositions while crystallinity of Ge layer was deteriorates by the formation of Si‐C at the Si surface and the incorporation of C atoms in Ge layer. In the case of Ge/C/Ge/Si system, the crystallinity of Ge layer was maintained even at C coverage of a few MLs, however, the amount of C to suppress the Ge/Si interdiffusion was more than 3 ML. From the correlation between Ge crystallinity and surface roughness, Ge/C/Ge/Si structure is considered to be more effective to take advantage of C mediation. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-07-25T05:10:11.101235-05:
      DOI: 10.1002/pssc.201400032
  • Viability of the use of an a‐SiC:H multilayer device in a domestic
           VLC application
    • Authors: P. Louro; V. Silva, M. A. Vieira, M. Vieira
      Pages: n/a - n/a
      Abstract: In this paper the viability of an integrated wavelength optical filter and photodetector for visible light communication (VLC) is discussed. The proposed application uses indoor warm light lamps lighting accomplished by ultra‐bright light‐emitting diodes (LEDs) pulsed at frequencies higher than the ones perceived by the human eye. The system was analyzed at two different wavelengths in the visible spectrum (430 nm and 626 nm) with variable optical intensities. The signals were transmitted into free space and measured using a multilayered photodetector based on a‐SiC:H/a‐Si:H. The detector works as an optical filter with controlled wavelength sensitivity through the use of optical bias. The output photocurrent was measured for different optical intensities of the transmitted optical signal and the extent of each signal was tested. The influence of environmental fluorescent lighting was also analysed in order to test the strength of the system. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-07-25T05:10:10.256382-05:
      DOI: 10.1002/pssc.201400035
  • Enhancement of IR photoluminescence of β‐FeSi2 nanocrystals by
           Cu‐doping and study of its mechanism
    • Authors: Yoshihito Maeda; Takahide Tatsumi, Yuki Kawakubo, Yuya Noguchi, Hiroyuki Kobayashi, Kazumasa Narumi, Seiji Sakai
      Pages: n/a - n/a
      Abstract: We have investigated the IR photoluminescence (PL) behavior of Cu‐doped β‐FeSi2 nanocrystals (β‐NCs) embedded in Si layers. The diffusion rate of Cu atom was controlled by annealing. The most appropriate condition brought the largest intensities of both the intrinsic A band emission at 0.803 eV by 214% and the acceptor related C band emission at ∼0.75 eV by 582% in comparison with those of non‐doped β‐NCs. Rutherford backscattering spectrometry (RBS) revealed increase of Cu atoms in the Si layer with β‐NCs with increasing the anneal duration. The C band enhancement surely is originated from increase of a density of state at acceptor levels relating to increase of Cu in β‐lattice. Photocarrier injection PL measurements (PCI‐PL) reveal that the enhancement of the A band emission may be attributed to a controlled migration process of holes with a repeated trap process due to Cu‐doping into the Si phase. This dynamic condition leads to an increase of valence band offset at the β‐NCs/Si heterointerfaces where the migration of holes from the β‐NCs to Si is prevented, so that a radiative recombination rate can be enhanced. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-07-25T05:10:09.416628-05:
      DOI: 10.1002/pssc.201400039
  • Raman analysis of gold catalyst vapor liquid solid germanium nanowires
    • Authors: M. Israel; A. Moreac, R. Rogel, J. P. Landesman, L. Pichon
      Pages: n/a - n/a
      Abstract: Germanium nanowires (GeNWs) were synthesized in a low pressure chemical vapor deposition reactor (LPCVD) using a vapor‐liquid‐solid process (VLS). In this work, the focus is put on the characterization of these GeNWs using scanning electron microscopy (SEM) combined with Raman spectroscopy. In particular, NWs with conical shape grown at a moderate temperature (320 °C) were investigated in terms of the intensity measured for the Ge‐related Raman line. The two main observations, discussed in this paper, are the anomalous magnitude of this line, as compared to measurements under the same conditions on a Ge(100) substrate, and the oscillations observed when the Raman line intensity is measured while scanning the laser beam along the axis of the conical shaped NWs, from the tip to the bottom. These effects are discussed involving the fact that optical modes appear in such NWs (both for the incident and Raman scattered light) when conditions on the diameter, the laser excitation wavelength, and substrate (on which the NWs are transferred after growth) are fulfilled. Taking into account these specific optical modes, the effects observed can be explained. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-07-25T05:10:08.278128-05:
      DOI: 10.1002/pssc.201400041
  • Electronic structureof amorphous ZnO films
    • Authors: Dieter Schmeißer; Jörg Haeberle, Pedro Barquinha, Diana Gaspar, Luís Pereira, Rodrigo Martins, Elvira Fortunato
      Pages: n/a - n/a
      Abstract: We use resonant photoemission spectroscopy (resPES) to study the electronic properties of amorphous ZnO (a‐ZnO) layers. We report on the core levels, the valence band (VB) PES data, and the X‐ray absorption (XAS) data which we use for the conduction band (CB) density of states. From these results we are able to derive the partial density of states (pDOS) of O2p and Zn4s4p states in the VB and CB, respectively as well as a band scheme. At the O1s resonance we observe a band of localized defect states which is located between the Fermi energy and the CBM. At the Zn2p edge the XAS data indicate that localized Zn4s4p states are involved in the DOS starting already at the Fermi energy. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-07-24T06:10:08.545943-05:
      DOI: 10.1002/pssc.201400010
  • High temperature electrical conductivity in hydrothermally grown ZnO
    • Authors: K. Lott; T. Nirk, L. Türn, S. Shinkarenko, A. Öpik, E. Kortunova, P. Shvanskiy, E. Gorokhova, A. Vishnjakov
      Pages: n/a - n/a
      Abstract: Results of measurements of high temperature electrical conductivity (HTEC) in undoped hydrothermally grown ZnO single crystal are presented. HTEC measurements were made under the Zn component vapor pressure (up to 1 atm) and in the temperature range from 873 K to 1273 K. Reliable thermodynamic equilibrium in the ZnO crystal for HTEC measurements of isotherms and isobars was obtained at the temperatures higher than 873 K. Surprisingly slow chemical diffusion prolonged the high temperature measurement cycles continuously for several weeks. In our experiments the absolute value of HTEC in undoped hydrothermally grown ZnO was several orders of magnitude higher than HTEC in undoped ZnS. Slopes of HTEC isotherms varied with component vapor pressure and changed in the range from 0.2 to 0.4. For HTEC isobar in the temperature range from 1173 K to 1273 K it was found activation energy value 0.3‐0.4 eV at zinc vapour pressure 0.092 atm. Defect model for explanation of this high temperature experiment is discussed in connection with impurities. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-07-24T06:10:07.34355-05:0
      DOI: 10.1002/pssc.201400009
  • Effect of iron on the dielectric properties of silicate glasses prepared
           by sol‐gel
    • Authors: S. A. Salehizadeh; M. P. F. Graça, M. A. Valente
      Pages: n/a - n/a
      Abstract: The sol‐gel method is a very flexible route for producing sieving matrix such as SiO2 with pore radii in nanoscale region to embed oxide particles like Fe2O3. In this work, iron oxide nanoparticles embedded in a SiO2 glassy matrix prepared by the sol‐gel method have been investigated as a function of Fe/Si ratio. Different composition of dried gels with 1, 2, 10 and 20 mol% of Fe2O3 in the SiO2 matrix were heat‐treated (HT) in air, at temperatures from 400 ºC up to 1400 °C. The structure and morphology of the obtained glasses and glass‐ceramics were studied by X‐ray powder diffraction (XRD), Raman spectroscopy and scanning electron microscopy (SEM). Impedance spectroscopy measurements and magnetic characterization were performed as function of temperature and the results are related with the microstructure. The X‐ray diffraction patterns showed that increasing the amount of Fe2O3 oxide promotes the formation of crystalline phases, in particular silicate phases. The increase of the heat‐treatment temperature has a similar behavior. The electrical and dielectric properties were related with these structural modifications and with the sample morphology. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-26T06:10:21.942599-05:
      DOI: 10.1002/pssc.201400015
  • Annealing related changes in near‐edge absorption and structural
           properties of Al‐doped ZnO thin films
    • Authors: S. Schönau; F. Ruske, S. Neubert, B. Rech
      Pages: n/a - n/a
      Abstract: In order to clarify the origin of the previously reported reduction of sub‐band gap absorption of sputtered ZnO:Al films upon thermal annealing and raising deposition temperature, structural characterization using Ra‐man spectroscopy was carried out on various films. Correlation of the Urbach energy to the FWHM of the E(high)2 mode was found. Oxygen addition to the film growth did not result in changes of the Urbach energy, despite pronounced changes of the electrical properties. The results suggest that extended defects, rather than intrinsic point defects, give rise to the sub‐band gap absorption. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-26T06:10:21.028944-05:
      DOI: 10.1002/pssc.201400002
  • Kinetic parameters of Cd1‐x‐yMnxZnyTe alloys melting and
           crystallization processes
    • Authors: V. Kopach; O. Kopach, P. Fochuk, L. Shcherbak, A. Bolotnikov, R. B. James
      Pages: n/a - n/a
      Abstract: The knowledge about parameters of melting and crystallization processes is required for controlled growth of ternary or quaternary single crystals from the melts. The differential thermal analysis method was used for investigation of the melting and crystallization kinetic parameters of Cd1‐x‐yMnxZnyTe alloys (x = 0.05–0.25, y = 0.05, 0.10). Two different ways of sample thermal processing allow us to study the supercooling‐superheating dependencies and the volume fraction of quasi‐solid phase (clusters) depending on the melt holding temperature and time. “Negative” supercooling of Cd1‐x‐yMnxZnyTe melts was observed when superheating of the melts don't exceed 20 K after their melting start. The su‐ percooling values of Cd1‐x‐yMnxZnyTe melts decreased with increasing x (i.e. Mn content). The change of the melts holding time from 10 to 60 min has no effect on the supercooling values. Volume fraction of Cd1‐x‐yMnxZnyTe alloys clusters existing in the melt decreased with the holding temperature increasing. Full homogenization occurred only after of Cd0.95‐xMnxZn0.05Te melts superheating higher than 1385 K, below this temperature melts exist in semiliquid state. The volume fraction of the quasi‐solid phase is smaller if the melt was heated at 10 K/min than after heating at 5 K/min to the same temperature. Melting temperature of Cd0.95‐xMnxZn0.05Te alloys decreased with Mn content increasing. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-26T06:10:20.120683-05:
      DOI: 10.1002/pssc.201300660
  • Modeling and multifractal analysis of radiation defect evolution in solids
    • Authors: Kazbek Baktybekov; Aliya Baratova
      Pages: n/a - n/a
      Abstract: The results of modeling of radiation defects formation and evolution on the surface and in the volume of a crystal are presented in this paper. Statistical properties are calculated for the investigated system. It is revealed that defect structure is a multifractal and system entropy decreases, while observing self‐organization of the physical system. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-20T07:23:11.964285-05:
      DOI: 10.1002/pssc.201400005
  • Influence of annealing on the properties of (Cd,Mn)Te crystals
    • Authors: M. Witkowska‐Baran; D. M. Kochanowska, A. Mycielski, R. Jakieła, A. Wittlin, W. Knoff, A. Suchocki, P. Nowakowski, K. Korona
      Pages: n/a - n/a
      Abstract: Semi‐insulating (Cd,Mn)Te crystals are believed to be suitable to successfully replace the commonly used (Cd,Zn)Te and CdTe crystals as a material for manufacturing large‐area X‐ and γ‐ray detectors. The purpose of the studies was to elaborate the technology of the (Cd,Mn)Te crystal plates with high resistivity, uniform in the whole volume of the plate. The article presents a method of annealing of the monocrystalline (Cd,Mn)Te crystal plates, giving the desired, repeatable results. The semi‐insulating (Cd,Mn)Te crystals, doped (for compensation) mainly by vanadium, but sometimes by Cl, In, or Cl and V, were grown by the Bridgman method, and the monocrystalline plates were cut. Subsequently the plates were annealed in Cd vapour. The resistivity of the plates was around 109 Ωcm, and the μτ‐product was about 10‐4 ‐10‐3 cm2/V. Mapping of the resistivity was performed on both the as‐grown crystals and the annealed crystal plates. The resistivity of the as‐grown crystals was in the range of 105‐106 Ωcm and inhomogeneous. After annealing the resistivity increased up to 109 Ωcm and better homogeneity could be seen. Annealing in the saturated Cd vapour influenced tellurium inclusions/precipitates. It was studied by IR transmission microscopy. For the as‐grown samples the density of Te inclusions (>1 µm) was ≈ 4×105 cm‐3, but for the annealed samples it was ≈ 104 cm‐3. The low‐temperature photoluminescence (PL) measurements indicated significantly lowered concentrations of acceptors after annealing. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-14T05:20:08.412358-05:
      DOI: 10.1002/pssc.201300746
  • Photoluminescence study of γ‐irradiation effect on the defect
           structure in Ge‐doped CdTe single crystals
    • Authors: Iu. Nasieka; L. Rashkovetskyi, M. Boyko, V. Strelchuk, Z. Tsybrii, B. Danilchenko, L. Shcherbak
      Pages: n/a - n/a
      Abstract: An effect of γ‐irradiation in the dose range 10‐500 kGy on the defect structure of Ge‐doped CdTe single crystals (CdTe:Ge) was investigated via the method of low‐temperature photoluminescence. It was obtained that γ‐irradiation in mentioned above dose range leads to the substantial decreasing of intensities of excitonic emission bands – D0X, A0X, VDX and increase in the intensities of impurity‐related emission bands – eA1,eA2, DA. It was shown that such changes in the luminescence can be explained by radiation‐stimulated redistribution of luminescence centers between recombination channels. The latter includes vacancy‐type defects filling by Ge dopant atoms which leads to the improving of the crystalline perfection of irradiated CdTe:Ge crystals. Mentioned material quality increasing was confirmed analysing the electron‐LO‐phonon coupling in irradiated crystals which was characterized via the Huang‐Rhys factor for corresponding luminescence bands. For the verification of the assumption about radiation‐stimulated compensation of native defects the resonant Raman measurements also were carried out. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-14T05:10:19.789265-05:
      DOI: 10.1002/pssc.201300571
  • Raman investigation on thin and thick CdTe films obtained by close spaced
           vacuum sublimation technique
    • Authors: D. Nam; H. Cheong, A. S. Opanasyuk, P. V. Koval, V. V. Kosyak, P. M. Fochuk
      Pages: n/a - n/a
      Abstract: The CdTe thin and thick films were obtained by the close spaced vacuum sublimation technique on a glass substrate under the following growth conditions: the evaporator temperature was 620 °C; and the substrate temperature was varied in the range from 250 °C to 550 °C. High purity CdTe powder was used as a charge for evaporation. The Raman spectra were measured using TRIAX 320 and TRIAX 550 spectrometers at room temperature. The 488‐nm line and 514.5‐nm line of an Ar+ laser and a 785‐nm diode laser were used as excitation sources. The signal was collected by the liquid nitrogen cooled charge‐coupled‐device (CCD) detector. A number of intense Raman peaks at 140, 167, 190, 271, 332 and 493 cm‐1 were observed and were interpreted as TO (140 cm‐1), 1LO (167 cm‐1), 2LO (332 cm‐1), 3LO (493 cm‐1) phonon modes and plasmon‐phonon mode (190 cm‐1). The presence of several phonon replicas in the Raman spectra confirms high crystal quality of the samples. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-14T05:10:18.985556-05:
      DOI: 10.1002/pssc.201300577
  • Self‐compensation limited conductivity of Cl‐doped CdTe
    • Authors: O. L. Maslyanchuk; L. A. Kosyachenko, S. V. Melnychuk, P. M. Fochuk, T. Aoki
      Pages: n/a - n/a
      Abstract: The conductivity of semi‐insulating Cl‐doped CdTe crystals produced by Acrorad Co. Ltd. with a resistivity ρ = (3‐6)×109 Ω·cm (300 K) was investigated. It is shown that the Fermi level in the band gap is located below the Fermi level in intrinsic CdTe which indicates the hole conductivity of the material. The concentration of holes in the studied crystals is determined to be 2‐3 orders of magnitude higher than the concentration of electrons. The statistics of electrons and holes in a semi‐insulating semiconductor containing self‐compensation complexes (centers) is considered bearing in mind that the effect of background impurities and defects in heavily Cl‐doped CdTe crystal is strongly reduced. A method for determining the ionization energy and the compensation degree of deep donors contained in the complexes was applied. It is shown that virtually intrinsic conductivity of the studied CdTe crystals is provided by the donors with ionization energy 0.68‐0.69 eV, whose level is located at 0.05‐0.06 eV above the middle of the band gap. Due to strong compensation, the Fermi level turns out below the middle of the band gap. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-14T05:10:18.072856-05:
      DOI: 10.1002/pssc.201300694
  • Studies of the surface regions of (Cd,Mn)Te crystals
    • Authors: Dominika Kochanowska; Marcin Rasiński, Marta Witkowska‐Baran, Małgorzata Lewandowska, Andrzej Mycielski
      Pages: n/a - n/a
      Abstract: The growth process conditions affect quality of the crys­tal. Structural defects such as grains, twin boundaries and precipitates are formed during the crystal growth. The defects (especially‐inclusions) at the surface can be investigated in a microscale by the scanning electron microscopy (SEM). It is shown in the article that a well known etchant, usually used for visual inspection of the quality of the CdTe‐related crystals, can be applied to the preparation of the (Cd,Mn)Te surface for SEM investigations. Samples, cut from different parts of a (Cd,Mn)Te crystal, were ground, mechano‐chemically polished, and treated by the special etchant (to indicate polarity and to reveal twinning). After that treatment the defects (grain and twin boundaries, tellurium inclusions) at the surface became much more accessible for both SEM and visual investigations. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-14T05:10:17.056833-05:
      DOI: 10.1002/pssc.201300711
  • LEDs based on p‐type ZnO nanowires synthesized by electrochemical
           deposition method
    • Authors: V. Kapustianyk; B. Turko, I. Luzinov, V. Rudyk, V. Tsybulskyi, S. Malynych, Yu. Rudyk, M. Savchak
      Pages: n/a - n/a
      Abstract: The data concerning the light‐emitting diodes based on ZnO homojunction with ITO/n ‐ZnO/p ‐ZnO+photoresist/Au/Ti and ITO/n ‐ZnO/p ‐ZnO+pho‐toresist+PEDOT:PSS/Au/Ti structures are reported. The p ‐ZnO nanowires were grown by electrochemical deposition method. It is suggested that the p ‐type conductivity first of all is connected with the zinc vacancies VZn. The clear rectifying behavior was observed on the current‐voltage curve of the ZnO p ‐n homojunction. The broad electroluminescence (EL) emission bands in the blue, green and red regions lead to observation of the white light by a naked eye under forward bias. The intrinsic defects such as Zni, VZn, Vo and Oi would be responsible for occurrence of these bands. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-07T06:30:10.579816-05:
      DOI: 10.1002/pssc.201300671
  • Structural, electrical and optical properties of zinc‐iridium oxide
           thin films deposited by DC reactive magnetron sputtering
    • Authors: Martins Zubkins; Roberts Kalendarev, Jevgenijs Gabrusenoks, Kaspars Vilnis, Andris Azens, Juris Purans
      Pages: n/a - n/a
      Abstract: ZnO‐IrO2 thin films were deposited on glass by DC reactive magnetron sputtering at room tem‐perature. Structural, electrical and optical properties were investigated as a function of iridium atomic concentra‐tion in the films. XRD data shows that ZnO‐IrO2 thin films are X‐ray amorphous and Raman spectrum resembles the spectrum of IrO2, without any distinct features of wurtzite ZnO structure. The lowest film resistivity and the highest transmittance achieved in the present study were 1.4 × 10‐3 Ωcm and 33% at 550 nm, respectively. However, resistivity and transmittance are inversely related to the iridium concentration in the films.
      PubDate: 2014-05-07T06:23:11.504355-05:
      DOI: 10.1002/pssc.201300653
  • Influence of annealing in Zn vapor on the luminescence of MgZnO ceramics
    • Authors: I. Markevich; T. Stara, O. Kolomys, A. S. Romanyuk, V. Strelchuk
      Pages: n/a - n/a
      Abstract: ZnO‐based compounds that exhibit a number of strongly overlapping emission bands in visible spectral region are promising materials for white‐light emitters with continuous emission spectrum. Defect‐related emission in doped with different impurities ZnO, however, spreads from green to red spectral region, so its shift toward shorter wavelengths is required. We supposed that this problem can be solved due to broadening of ZnO band gap by alloying ZnO with MgO. The enhancement of visible emission brightness is also an important problem. In this work, MgxZn1‐xO ceramics with x =0 and x=0.2 were sintered both in air and Zn vapor at 950 oC. Emission and Raman scattering spectra were measured at 300 K using 325 nm line of He‐Cd laser as excitation source. In samples sintered in air, bright UV emission and weak visible one took place, adding MgO to ZnO resulting in blue‐shift of the latter. Sintering in Zn vapor was found to weaken UV emission and to increase drastically the brightness of visible one especially in blue‐green spectral region. As a result, bright blue radiation was observed from MgZnO ceramics under excitation by considerably week UV light. Obtained effects were accounted for by the shift of “green” centers energetic level with respect to involved band edge as a result of band‐gap broadening and by the increase of this center density due to annealing in Zn vapor. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-07T06:23:10.54456-05:0
      DOI: 10.1002/pssc.201300647
  • Influence of doping precursor on band gap and morphologies of
           sol‐gel deposited ZnMgO thin films
    • Authors: Amanpal Singh; Sonia Saini, Dinesh Kumar, P. K. Khanna, Mukesh Kumar, B. Prasad
      Pages: n/a - n/a
      Abstract: Zn1–xMgxO thin films were deposited by sol–gel route on p–type Si (100) and quartz substrates. It is ob‐served that the incorporation of Mg and morphological features of the sol–gel derived Zn1–xMgxO thin films extremely depend upon the selection of doping (Mg) precursor salts. Investigation of different doping precursors such as magnesium acetate, magne‐sium chloride and magnesium nitrate have been carried out. Zn1–xMgxO (x = 0.15) thin films deposited us‐ing each doping source were annealed at 300, 500, 700 and 900 °C in the presence of oxygen for one hour. The results showed that the magnesium nitrate required lower annealing temperature and provided good quality of films, However traces of N were observed in the films. The surface morphology and microstructure of the depos‐ited thin films were analyzed by atomic force microscopy. The crystallite dimension, shape and the growth rate were found to be significantly affected by dopant precursors. The chemical compositions were determined by elemen‐tal dispersive spectra. The band gap modulation is stud‐ied by varying the magnesium content from x = 0.00 to 0.40 for each type of salt for Mg doping. The Zn1–xMgxO films deposited using magnesium chloride exhib‐ited poor band gap modulation and lower quality of mi‐crostructure. The films deposited using magnesium ace‐tate exhibited minimum defects, good crystallinity and higher band gap modulation. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-07T06:20:21.788418-05:
      DOI: 10.1002/pssc.201300593
  • Optical and structural properties of Al2O3/ZnO nanolaminates deposited by
           ALD method
    • Authors: Adib Abou Chaaya; Roman Viter, Ieva Baleviciute, Mikhael Bechelany, Arunas Ramanavicius, Donats Erts, Valentyn Smyntyna, Philipe Miele
      Pages: n/a - n/a
      Abstract: We report on the investigation of optical and structural properties of Al2O3/ZnO nanolaminates. The nanolaminates were deposited on Si and glass substrates by Atomic layer deposition method. Structural properties of nanolaminates were studied by SEM, GIXRD, and AFM. Optical characterization was performed by transmittance and photoluminescence spectroscopy. Complex analysis of monolayer properties was done by ellipsometry. Optical constants for Al2O3 and ZnO monolayer were calculated.
      PubDate: 2014-05-07T06:20:20.87946-05:0
      DOI: 10.1002/pssc.201300607
  • Local structure and dynamics of wurtzite‐type ZnO from
           simulation‐based EXAFS analysis
    • Authors: Janis Timoshenko; Andris Anspoks, Aleksandr Kalinko, Alexei Kuzmin
      Pages: n/a - n/a
      Abstract: Conventional methods of EXAFS data analysis are often limited to the nearest coordination shells of the absorbing atom due to the difficulties in accurate accounting for the so‐called multiple‐scattering effects. Besides, it is often difficult to resolve the non‐equivalent groups of atoms in a single coordination shell due to strong correlation between structural parameters. In this study we overcome these problems by applying two different simulation‐based methods, i.e., classical molecular dynamics (MD) and reverse Monte with evolutionary algorithm (EA), to the analysis of the Zn K‐edge EXAFS data for wurtzite‐type bulk ZnO. The RMC/EA‐EXAFS method allowed us to separate the contributions of thermal disorder and the effect of noncentrosymmetric zinc oxide structure, being responsible for its piezoelectrical and pyroelectrical properties. The MD‐EXAFS method allowed us to test the accuracy of several available force‐field models, which are commonly used in the MD simulations of ZnO nanostructures.
      PubDate: 2014-05-07T06:20:20.0518-05:00
      DOI: 10.1002/pssc.201300615
  • Optical and electrical studies of transparent conductive AZO and ITO
           sputtered thin films for CIGS photovoltaics
    • Authors: R. A. Mereu; S. Marchionna, A. Le Donne, L. Ciontea, S. Binetti, M. Acciarri
      Pages: n/a - n/a
      Abstract: Due to the many advantages of aluminum doped zinc oxide (AZO) as an alternative to indium tin oxide (ITO), the optical and electrical properties of AZO thin films deposited on large substrates by D.C. pulsed magnetron sputtering have been investigated in view of future industrial applications. In order to evaluate the effectiveness of AZO thin films as transparent conductive oxide (TCO), their properties have been compared with those of standard ITO grown with the same technique. The effect of the thickness on the optical properties revealed higher transmittance values for AZO (T>86 %) than for ITO (T>83 %) films. The best resistivity values obtained for AZO were about 9.7×10–4 Ωcm versus 5.09×10–4 Ωcm measured for ITO films. Moreover, it was observed that the film resistivity is significantly influenced by the working pressure in the case of AZO films while the ITO resistivity appears almost unaffected. Finally, since both the optical and electrical properties are influenced by the film thickness, it was crucial to determine the proper AZO thickness in order to obtain the optimum of electrical and optical properties for the photovoltaic applications. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-07T06:20:19.187917-05:
      DOI: 10.1002/pssc.201300631
  • Concentration determination and activation of rare earth dopants in zinc
           oxide thin films
    • Authors: A. Ziani; A. Tempez, C. Frilay, C. Davesnne, C. Labbé, Ph. Marie, S. Legendre, X. Portier
      Pages: n/a - n/a
      Abstract: In this paper, we will present the development of rare‐earth (RE) doped zinc oxide (ZnO) films for white light emitting diodes (LED). We will present the structural changes of these films as well as their optical properties and associated photoluminescence before and after rapid thermal treatments. We will report depth profile results from plasma profiling time of flight mass spectrometry (PP‐TOFMS) giving the distributions and concentrations of the different elements in the films. We will correlate depth profile and luminescence data to understand the RE emission mechanisms in ZnO matrix. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-07T06:20:18.382059-05:
      DOI: 10.1002/pssc.201300636
  • Influence of deposition parameters on ZnO and ZnO:Al thin films
    • Authors: Nilufer Evcimen Duygulu; Alp Osman Kodolbas, Ahmet Ekerim
      Pages: n/a - n/a
      Abstract: Zinc oxide (ZnO) and 2% aluminium doped ZnO (ZnO:Al) thin films were deposited on glass by using r.f. magnetron sputtering without intentional heating. The r.f. power was varied in the range of 150 W to 175 W and process gas (argon) pressure was changed from 0.20 Pa to 0.60 Pa in small variation ranges to identify the influence of sputtering parameters. Achieved results were analysed with the help of XRD, AFM, SEM, HRTEM, four point probe, optical transmittance measurement techniques. According to the results, 165 W was selected as optimum r.f. power value, while 0.20 Pa for ZnO and 0.30 Pa for ZnO:Al thin films were determined as argon gas pressure values. All the thin films were oriented with the crystallographic c‐(002) axis perpendicular to the substrate surface. Moreover, at this deposition values; the resistivity was measured as around 10‐3Ω.cm, while the deposition rate showed variations. The optical transmittance of ZnO:Al was obtained (85%) higher than ZnO (75%) thin film. The optical band gap was changed from 3.45 eV to 4.2 eV. Surface roughness (RMS) values were obtained as 5.44 nm for ZnO and as 2.36 nm for ZnO:Al. (© WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-07T06:20:17.60807-05:0
      DOI: 10.1002/pssc.201300640
  • UV detector based on zinc oxide nanorods obtained by the hydrothermal
    • Authors: Bartlomiej S. Witkowski; Lukasz Wachnicki, Sylwia Gieraltowska, Piotr Sybilski, Krzysztof Kopalko, Marcin Stachowicz, Marek Godlewski
      Pages: n/a - n/a
      Abstract: Properties of UV detector based on ZnO nanorods, grown by a hydrothermal method, are discussed. The innovative growth technology was used to produce ZnO nanorods. It is characterized by a much higher growth rate, than reported (till now) in the literature, and a very low costs (both of technology and materials). Importantly, ZnO nanorods grown by this method are free from oxygen vacancies. Despite the fact that detector proposed by us is not based on a single nanorod, but on a whole array of nanorods, it is very sensitive. The detector shows sensitivity of 20 mW/m2 (2 µW/cm2) upon UV illumination. Due to a high energy band gap of zinc oxide and a high purity of the obtained nanorods visible light is not detected. The resistivity/current changes are proportional to illumination intensity, i.e., detector response scales with the intensity of UV light. The observed changes of the detector resistivity relate to surface reactions generated upon an illumination. Importantly, detector does not need annealing or cleaning to reset to an initial state.(© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-02T06:10:15.381857-05:
      DOI: 10.1002/pssc.201300761
  • Electrical characterization of organic (amorphous) electronic materials
    • Authors: Peter Stallinga
      Pages: n/a - n/a
      Abstract: Organic electronic materials, or amorphous electronic materials in general, have relatively low conductivity and this limits their application to the low‐frequency electronics market. To describe electronic conduction in these materials it is common to use percolation [1] or (variable range) hopping theory [2] (the two being equivalent). This is an inheritance from the earlier research in organic materials that were invariably insulators, where conduction was a perturbation – movement of charge was a rare event. Summarizing in this paper our work on organic electronic materials, it is shown that for electronic materials, instead, it is better to revert to classical semiconductor theories, like band theory [3]. If we include a large density of traps in the energy system, all observed phenomena are easily explained. This includes 1. strong temperature dependent charge‐carrier mobility, 2. field‐dependent mobility, 3. anomalous transient behavior. Moreover, it is consistent with observations in many types of devices, ranging from two‐terminal devices such as diodes to three‐terminal devices such as thin‐film transistors [4]. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-02T06:10:14.237667-05:
      DOI: 10.1002/pssc.201300508
  • Formation of ordered array of core/shell ZnS/Ge/ZnS nanostructures by
           thermal evaporation method
    • Authors: A. Beltiukov; R. Valeev, E. Romanov, V. Mukhgalin
      Pages: n/a - n/a
      Abstract: This paper reports the results of studies of ZnS/Ge/ZnS nanostructures, obtained by high vacuum thermal deposition of ZnS and Ge powders into porous anodic aluminium oxide (AAO) with different diameters of pores. Scanning electron microscopy (SEM) investigations reveal two types of nanostructures having the form of rings (sample with diameter of pores 70 nm) and rods (samples with diameter of pores 80 and 110 nm). It is also shown that the other porosity parameters such as interporous distances affect the formation of a particular type of nanostructures. X‐ray and electron diffraction study show two phases, ZnS and Ge. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-02T06:10:13.138862-05:
      DOI: 10.1002/pssc.201300623
  • Seasonal variation of performance in concentrator photovoltaic system
    • Authors: Kei Nomura; Yasuyuki Ota, Takashi Minemoto, Kensuke Nishioka
      Pages: n/a - n/a
      Abstract: Concentrator Photovoltaic (CPV) system was installed in the University of Miyazaki, Japan. The system's output parameters and meteorological condition experienced by the system i.e. incident irradiance, incident spectrum distribution, and cell temperature were recorded. A statistical analysis method was proposed so that the influences of spectrum distribution variations and cell temperature on the output performance of the system can be observed separately. It was found that the performance of the CPV system significantly depended on the variation of the incident solar spectrum distribution rather than cell temperature. Using this method, the performance of CPV system was analysed throughout the seasons. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-02T06:10:11.940701-05:
      DOI: 10.1002/pssc.201300629
  • The study of large semiconducting boron doped single crystal diamond
           sectorial structure
    • Authors: A. Chepugov; S. Ivakhnenko, V. Garashchenko
      Pages: n/a - n/a
      Abstract: The sectorial structure of semiconductor single‐crystal diamond grown at high pressure and temperature was considered. Influence of crystal structure on shape of IR‐absorption maps and photoluminescence glow were studied. The distribution of boron impurity and its concentration in the areas which belonging to different growth sectors were measured. The analysis of the effect of the conditions of type IIb crystal growth at HPHT on their structure was performed, conditions for getting the most homogeneous samples were defined. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-02T06:10:10.973538-05:
      DOI: 10.1002/pssc.201300633
  • Swift Xe ion irradiation effect on structure and vibrational properties of
           undoped and Cd‐doped ZnO films
    • Authors: Denys Myroniuk; Ivan Shtepliuk, George Lashkarev, Vasyl Lazorenko, Vladimir Skuratov, Izabella Timofeeva, Artem Romaniuk, Viktor Strelchuk, Oleksandr Kolomys
      Pages: n/a - n/a
      Abstract: The undoped and Cd‐doped (0.4, 0.5 at. %) ZnO films deposited by radiofrequency magnetron sputtering have been irradiated by 167 MeV Xe26+ ions with energy to a fluence 3×1012 ions/cm2. The structure and vibrational properties of as‐grown and irradiated samples were studied using X‐ray diffraction and Raman spectroscopy techniques. It was found that Cd‐doped ZnO films in comparison with undoped films demonstrate an improvement of crystal structure due to increased size of X‐ray coherent scattering regions, relaxation of strain between grains in the films and reduction of modes which relates to defects in ZnO crystal lattice. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-02T06:10:10.08855-05:0
      DOI: 10.1002/pssc.201300641
  • Towards X‐ray in‐situ visualization of ammonothermal crystal
           growth of nitrides
    • Authors: Saskia Schimmel; Ulrike Künecke, Hasan Baser, Thomas G. Steigerwald, Benjamin Hertweck, Nicolas S. A. Alt, Eberhard Schlücker, Wilhelm Schwieger, Peter Wellmann
      Pages: n/a - n/a
      Abstract: In‐situ X‐ray visualization of hydrothermal growth of silicalite‐1 is applied as an intermediate step for developing X‐ray in‐situ visualization techniques for ammonothermal growth of nitride materials. In‐situ X‐ray imaging of silicalite‐1 crystals grown by the bulk material dissolution technique (Shimizu and Hamada, Angew. Chem., Int. Ed. 38, 2725 (1999) [1]) is demonstrated using a stainless steel autoclave equipped with ceramic aluminium oxide windows. Processes in the reaction medium such as local density changes are also visualized. The transferability of the technique to ammonothermal growth of nitrides is evaluated. Furthermore, the applicability of windowless autoclaves for X‐ray in‐situ monitoring of ammonothermal crystal growth of nitrides is investigated. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-02T06:10:09.220193-05:
      DOI: 10.1002/pssc.201300656
  • Structural, electrical and optical properties of CuGaTe2 absorber for
           thin‐film solar cells
    • Authors: Ammar Messous; Abdesselam Bouloufa, Kamal Djessas, Idris Bouchama
      Pages: n/a - n/a
      Abstract: Near‐stoichiometry composition CuGaTe2 (CGT) thin films prepared by close‐spaced vapour transport (CSVT) with copper excess in the source has been investigated and was confirmed by energy dispersive spectroscopy. The influence of temperature substrate on structural properties of CGT was studied, with the optimal substrate temperature at 480 °C. Morphological and structural analyses allowed identifying the type of crystallites. Crystalline phases of the films were examined using X‐ray diffraction. A strong (112) orientation perpendicular to substrate plane was observed and additional reflections planes were also detected. The electrical resistivity was determined using the four probe method and lies in the 0.127‐0.271 Ω cm range. The direct bandgap is about 1.7 eV and resistivity showed a low value. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-05-02T06:10:08.368508-05:
      DOI: 10.1002/pssc.201300657
  • Electrical resistivity and its thermal coefficient of TiW alloy thin films
           prepared by two different sputtering systems
    • Authors: Yutaka Sakurai; Yuya Takeda, Shinji Ikeda, Yoshinori Sakamoto
      Pages: n/a - n/a
      Abstract: Electrical resistivity and its thermal coefficient (TCR) of TiW alloy thin films which were prepared by using two different sputtering systems have been investigated. System A is a DC‐magnetron sputtering system equipped with a single composite‐target that allows the contents controllable by an external field of solenoid as reported in previous papers (Sakurai and Takeda, Abstract of E‐MRS 2005 Fall Meeting [1] and Sakurai et al., Solid State Phenom. 154, 175 (2009) [2]). The system A prepared specimens with the range of 21.6 to 36.6 at% of W‐contents. The TCR varies from minus to plus at 32 at % of W‐content. On the other hand, System B is a RF‐magnetron sputtering system equipped with multi‐targets and multi‐sputtering‐sources. The system B covered the whole binary composition ranges by controlling power ratio for two independent sputtering sources. The resistivity characteristics show a parabolic curve with the maximum value on Ti‐rich contents. The TCR decreases at the contents that shows the maximum resistivity, but the TCR is always plus and does not cross zero. Difference of the properties by using the two systems will be discussed. In the system A, the background is exhausted by an oil diffusion pump and the pressure is higher (lower vacuum degree) than the background in the system B with a turbo molecular pump. This suggests that zero TCR would be achieved by introducing the controlled impurities (O2 or N2) into the binary alloy films. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-04-29T02:23:08.833515-05:
      DOI: 10.1002/pssc.201300621
  • Nanostructured Y‐doped ZrO2 powder: peculiarities of light emission
           under electron beam excitation
    • Authors: N. Korsunska; V. Papusha, O. Kolomys, V. Strelchuk, A. Kuchuk, V. Kladko, Yu. Bacherikov, T. Konstantinova, L. Khomenkova
      Pages: n/a - n/a
      Abstract: Present work deals with the study of luminescence and structural properties of Y‐doped ZrO2 nanopowders sintered by co‐precipitation of Zr and Y nitrates. The structural and light emitting properties were controlled by X‐ray diffraction, transmission electron microscopy, Raman scattering, photo‐ (PL) and cathodoluminescence (CL) methods. Generally, room temperature PL spectra showed several bands in UV‐orange range, whose shapes depend on the excitation light wavelength. Along with this, CL spectra demonstrate additional “red” emission, which intensity exceeds that of other CL bands. At lower temperatures, preferable enhancement of “red” CL band, its narrowing and peak position shift to the longer wavelengths were found. This behavior testifies to the non‐elementary nature of “red” CL band. Its nature and mechanism of its excitation are discussed. It is supposed that some impurities (such as Fe and/or Zn) or complex defects, containing oxygen vacancies and these impurities, are responsible for “red” emission appeared under electron beam excitation only. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-04-29T02:23:07.869618-05:
      DOI: 10.1002/pssc.201300597
  • Enhanced dielectric properties of nitrogen doped epitaxial Gd2O3 thin
           films on Si
    • Authors: Ayan Roy Chaudhuri; A. Fissel, H. Jörg Osten
      Pages: n/a - n/a
      Abstract: The impact of nitrogen doping on the growth electronic band structure and electrical properties of epitaxial Gd2O3 thin films on Si (111) has been investigated. Epitaxial layers of Gd2O3:N were grown on p‐type Si (111) substrates by solid source molecular beam epitaxy technique using molecular N2O as the nitridation agent. Substitutional nitrogen incorporation into the dielectric layer was confirmed by secondary ion mass spectroscopy and X‐ray photoelectron spectroscopy measurements. Significant reduction of the leakage current density and disappearance of capacitance‐voltage hysteresis in the Gd2O3:N layers indicate that nitrogen doping in Gd2O3 successfully eliminates the adverse effects of the oxygen vacancy induced defects in the oxide layer. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-04-29T02:23:07.01246-05:0
      DOI: 10.1002/pssc.201300596
  • Influence of solar radiation on the performance of organic solar cell
    • Authors: Abla Guechi; Mohamed Chegaar, Abdelali Merabet
      Pages: n/a - n/a
      Abstract: The electrical current generated by the solar cells is very sensitive to the incident spectral distribution and intensity. This distribution varies greatly during the day due to changes in the sun's position or weather conditions. This work investigates the feasibility of using a solar spectral radiation model SMARTS2 to estimate the global solar irradiance and assess the influence of solar spectrum on the conversion efficiency of the organic thin film solar cells (PBDTTT) (poly[4,8‐bis‐substituted‐benzo[1,2‐b:4,5‐b0]dithiophene‐2,6‐diyl‐alt‐4‐substituted‐ thieno[3, 4‐b]thiophene‐ 2,6‐diyl])). The variation of the common performance indicators such as short circuit current, fill factor, open circuit voltage, and efficiency are shown and discussed for each month. The results show that the variations in the solar spectrum affect the different materials to different extent. The maximum efficiency is obtained in the summer months; however the lower efficiency is obtained during winter. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-04-29T02:23:06.103212-05:
      DOI: 10.1002/pssc.201300594
  • Growth of Fe nanocrystals on LaAlO3 (001) and epitaxial relationship
           determination by RHEED and XPS
    • Authors: Mohamed Zanouni; Emmanuel Denys, Mickael Derivaz, Didier Dentel, Mustapha Diani, Chiraz Ben Azzouz, Jean‐Luc Bischoff
      Pages: n/a - n/a
      Abstract: Non‐volatiles flash memories embedding nanocrystals are promising devices. These memories are made of semiconducting or metallic nanostructures inserted in an insulating matrix. SiO2, traditionally used as an insulator, is gradually replaced by high‐dielectric materials called “high‐k” oxides, to reduce leakage currents. In this context, we used a crystalline lanthanum aluminate (LaAlO3) oxide. The magnetic properties of nanoparticles of Fe can increase the storage capacity in the memories compared to the semiconductor nanostructures as Si or Ge. Memories combining these two materials require complex monolithic structures such as “LaAlO3/Fe/LaAlO3/Si(001)”. In this context we have studied the initial growth of Fe on a solid substrate of LaAlO3 (001). Fe deposits were performed by molecular beam epitaxy (MBE) at different substrate temperatures. Chemical and structural properties were investigated by X‐ray photoelectron spectroscopy (XPS) and reflection high‐energy electron diffraction (RHEED). The temperature dependence study indicates that the growth of Fe on LaAlO3 is epitaxial with a single epitaxial relationship in a tight temperature window around 500 °C. The plane (001) of Fe is parallel with the LaAlO3(001) surface, but the iron unit cell is rotated of 45° around the growth direction compared with the substrate one (Fe // LaAlO3). This configuration minimizes the elastic strain of the Fe which grow with the Volmer‐Weber mode. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-04-29T02:20:13.451936-05:
      DOI: 10.1002/pssc.201300566
  • New approach to the growth of SiO2 nanowires using Sn catalyst on Si
    • Authors: Alexandr Zamchiy; Evgeniy Baranov, Sergey Khmel
      Pages: n/a - n/a
      Abstract: Silica nanowires were synthesized from mixture monosilane with hydrogen by gas‐jet electron beam plasma chemical vapor deposition method for the first time. The synthesis was carried out on silicon substrate with up to micrometer‐sized particles of Sn catalyst. SEM observations show that this method provides different morphology of the nanowires and catalyst. Oriented arrays of silica nanowires bunches (microropes) were synthesized in the area corresponding to the mixture jet axis. Cocoons‐like, bamboo‐like, and jellyfish‐like morphology was observed in the area corresponding to periphery of the jet. Probably there was realised vapor‐liquid‐solid (VLS) growth mechanism, where multiple nanowires grow simultaneously from the surface of one catalyst drop. The growth rate of the microropes is about 25 nm/s at synthesis temperature 330 °C. Possible growth model has been suggested in order to explain the results. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-04-29T02:20:12.355306-05:
      DOI: 10.1002/pssc.201300574
  • A comparative analysis of infrared luminescence spectra of ZnSe:Yb,
           ZnSe:Gd, and ZnSe:Cr crystals
    • Authors: Gleb Colibaba; Evghenii Goncearenco, Dmitrii Nedeoglo, Natalia Nedeoglo
      Pages: n/a - n/a
      Abstract: Photoluminescent and optical properties of ZnSe crystals doped with Yb and Gd rare‐earth elements (REEs) and Cr impurity are investigated in infrared (IR) spectral range. The influence of stoichiometric deviation on photoluminescence (PL) spectra of the crystals is investigated and the structure of complex IR PL bands is analysed. The good coincidence between the IR PL spectra of the samples doped with Yb, Gd, and Cr is shown. Correlation between the component parts of the bands at 1 and 2 µm is found and possibility to control the composition of IR PL spectra by enrichment of the samples with Zn or Se is discussed. The model that explains the formation of associative centres based on the REEs and background Cu impurity fixed in the nodes of crystal lattice with tetrahedral symmetry, which are responsible for IR PL bands, is proposed. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-04-29T02:20:11.549179-05:
      DOI: 10.1002/pssc.201300587
  • Obtaining of II‐VI compound substrates with controlled electrical
           parameters and prospects of their application for nanoporous structures
    • Authors: Gleb Colibaba; Evghenii Goncearenco, Dmitrii Nedeoglo, Natalia Nedeoglo, Eduard Monaico, Ion Tiginyanu
      Pages: n/a - n/a
      Abstract: Substrates of II‐VI semiconductor compounds may be widely used in fabrication of nanoporous matrices (NM), which give the possibility to obtain nanowires and nanotubes of various materials with good application prospects in various fields. The easiest and cost‐effective method to obtain nanoporous matrices is electrochemical etching (ECE), which, however, depends on conductive properties of the substrates. The conditions of growing homogeneous ZnSe, ZnS, ZnSSe, ZnO, and ZnCdS single crystals by physical and chemical vapour transport methods are discussed. Based on the results of investigation of electrical, optical, and photoluminescence properties of the samples with various doping levels, the prospect of examined technology for manufacturing the substrates of these compounds with large area and controlled n‐type electrical conductivity varied up to 20, 0.3, 0.3, 9, and 30 Ω–1cm–1, respectively, is estimated. Possible utilization of these substrates for preparation of NM by ECE is analyzed. The results of nanostructuring using various electrolytes are shown. The prospect of using ZnSe and ZnCdS compounds for manufacturing nanopore arrays with diameter down to 30 nm and nanopo‐rous structures with a specific morphology on ZnO substrates is demonstrated. Technological limitations for fabrication of the similar structures on the basis of ZnS and ZnSSe substrates are also analyzed. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-04-29T02:20:10.619365-05:
      DOI: 10.1002/pssc.201300590
  • Contents: Phys. Status Solidi C 9–10/2014
    • Pages: 1383 - 1387
      PubDate: 2014-09-10T09:52:14.664381-05:
      DOI: 10.1002/pssc.201470059
  • Novel materials for electronic, optoelectronic, photovoltaic, and energy
           saving applications
    • Authors: M. Godlewski; A. J. Zakrzewski
      Pages: 1388 - 1388
      Abstract: The Symposium F: “Novel materials for electronic, optoelectronic, photovoltaic and energy saving applications” of the 2013 E‐MRS Fall Meeting (held in Warsaw, Poland, on 16–20 September 2013) was organized to cover many important aspects of basic and applied research of novel materials for present and future industrial applications. Particular emphasis was given to new technological and application concepts concerning both bulk crystals and various quantum structures of reduced dimensionality, like quantum wells and quantum dots (nanoparticles). The presented results on application‐oriented materials were mostly focused on light emitting structures, light detectors, solar cells and materials for spintronics. Special attention was given to the technological aspects and challenges: growth techniques, defect control and structure optimization, doping procedures, optical properties and degradation processes. Relevant experimental techniques and crystal growth procedures were also discussed. Experimental results were compared with theoretical calculations giving deeper insight into many problems of modern materials science. Over 100 researchers from all over the world participated in this symposium, giving in all 15 invited lectures, 38 contributed talks and 70 poster presentations.
      PubDate: 2014-09-10T09:52:12.330793-05:
      DOI: 10.1002/pssc.201470060
  • ZnO – Materials Science from Research to Electronic Applications
    • Authors: George Lashkarev; Vitalii Karpyna
      Pages: 1459 - 1459
      Abstract: The following section contains invited and contri‐ buted papers presented at Symposium K “ZnO – Material science from research to electronic applications” of EMRS Fall Meeting held in Warsaw, Poland, September 16–20, 2013. The symposium was organized by the principal organizer George Lashkarev (Institute for Problems of Material Science, Ukraine) and four co‐organizers: Robert Triboulet (CNRS/GEMAC, Univ. of Versailles, France), Robert Kudra‐wiec (Institute of Physics, Wrocław University of Technology, Poland), Serhii Trushkin (Institute of Physics PAS, Poland) and Rositza Yakimova (Department of Physics, Chemistry and Biology (IFM), Sweden). Symposium K gathered 82 participants from 28 countries with 10 invited talks, 25 oral presentations and 42 posters. The symposium was focused on the fundamental understanding of growth processes of ZnO films and structures, the role of point defects and impurities, electrical and optical properties and priority applications of ZnO in electronics and optoelectronics. The main idea of Symposium K was to narrow the evident gap between the research groundwork on ZnO and its possible industrial introduction. We consider this symposium as the next turn in the direction of wide applications of ZnO in the future. We take this opportunity to thank the colleagues who acted as scientific committee members and program committee members as well as the presenters who submitted a manuscript for publication and referees who ensured the scientific quality of the proceedings.
      PubDate: 2014-09-10T09:52:16.334482-05:
      DOI: 10.1002/pssc.201470061
  • CdTe and Cd‐rich Ternary Tellurides
    • Authors: Robert Triboulet
      Pages: 1509 - 1509
      Abstract: The E‐MRS Symposium entitled “CdTe and Cd‐rich ternary tellurides: Growth and characterization, physics of defects and impurities, surfaces and applications” was organized in Warsaw (16–20 September 2013), three years after the meeting dedicated to the “Smart growth” of CdTe and Cd‐rich ternary tellurides which was held in the framework of the 2010 E‐MRS Fall Meeting. It covered the most prominent, modern and fundamental aspects of research on these materials as well as their applications in fields such as nuclear detectors and photovoltaic cells. While CdTe‐based nanostructures are displaying a spectacular boom and are at the forefront of CdTe research, as illustrated by several hundreds of papers devoted to them in the recent literature, a significant activity is nevertheless still dedicated to bulk CdTe and associated Cd‐rich ternary tellurides, mainly CdZnTe and CdMnTe. The principal focus areas are in the fields of physics of macro‐defects, point‐defects and impurities in as‐grown and annealed crystals; surfaces and interfaces; refinement of the growth and characterization of crystals and devices; appli‐ cations dealing mainly with photovoltaic cells for which mass production has begun, and X‐ray and γ‐ray detectors, which are under development with material quality widely recognized as the key remaining issue. These topics were emphasized during the symposium and the different issues associated with them are identified and discussed. A few manuscripts only were submitted for publication in the proceedings, according to a recent deplorable and unfortunate fashion. The present proceedings are then constituted of a very limited number of contributions in which we hope the readers will nevertheless find a great interest.
      PubDate: 2014-09-10T09:52:17.35873-05:0
      DOI: 10.1002/pssc.201470062
  • Numerical analysis of light elements transport in a unidirectional
           solidification furnace
    • Authors: Koichi Kakimoto; Bing Gao, Satoshi Nakano
      Pages: n/a - n/a
      Abstract: Quantitative study of light elements such as carbon and oxygen in multi‐crystalline silicon for solar cells is required to grow crystals with high quality. The transport of both carbon and oxygen is one of the critical issues to increase efficiency of solar cells made of silicon materials. Concentrations of carbon and oxygen in a furnace affect each others, therefore it is important to control mass transfer of carbon and oxygen in a furnace. Numerical calculation with a chemical reaction between carbon and oxygen was carried out to study how both light impurities are incorporated into crystals through the melt and gas during solidification process. The effects of flow rate and pressure on the impurities were examined. An increase in the flow rate can reduce both carbon and oxygen impurities in the crystal, though the reduction of carbon is more obvious. An increase in gas pressure can also obviously reduce the oxygen impurity but has only a small effect on the carbon impurity (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2010-11-15T04:22:05.648279-05:
      DOI: 10.1002/pssc.200900117
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