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  Subjects -> PHYSICS (Total: 767 journals)
    - ELECTRICITY AND MAGNETISM (8 journals)
    - MECHANICS (20 journals)
    - NUCLEAR PHYSICS (44 journals)
    - OPTICS (91 journals)
    - PHYSICS (557 journals)
    - SOUND (18 journals)
    - THERMODYNAMICS (29 journals)

PHYSICS (557 journals)            First | 1 2 3 4 5 6 | Last

Open Journal of Fluid Dynamics     Open Access   (Followers: 3)
Open Journal of Microphysics     Open Access  
Optical Communications and Networking, IEEE/OSA Journal of     Hybrid Journal   (Followers: 4)
Optofluidics, Microfluidics and Nanofluidics     Open Access  
Organic Electronics     Hybrid Journal   (Followers: 3)
Organic Photonics and Photovoltaics     Open Access   (Followers: 2)
PAJ: A Journal of Performance and Art     Hybrid Journal   (Followers: 11)
Particle Physics Insights     Open Access   (Followers: 2)
Particuology     Hybrid Journal  
Pattern Recognition in Physics     Open Access   (Followers: 1)
Pergamon Materials Series     Full-text available via subscription  
Phase Transitions and Critical Phenomena     Full-text available via subscription   (Followers: 1)
Philosophical Magazine     Hybrid Journal   (Followers: 2)
Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences     Full-text available via subscription   (Followers: 5)
Philosophy and Foundations of Physics     Full-text available via subscription  
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: 18)
Physical Review Special Topics - Physics Education Research     Open Access   (Followers: 6)
Physical Review X     Open Access   (Followers: 6)
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   (Followers: 2)
Physics and Chemistry of the Earth, Parts A/B/C     Hybrid Journal   (Followers: 3)
Physics and Materials Chemistry     Open Access  
Physics Essays     Full-text available via subscription  
Physics in Medicine & Biology     Full-text available via subscription   (Followers: 9)
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: 3)
Physics of Fluids     Hybrid Journal   (Followers: 24)
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: 2)
Physics Research International     Open Access   (Followers: 1)
Physics Today     Hybrid Journal   (Followers: 26)
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 Reports     Hybrid Journal   (Followers: 2)
Pramana     Open Access   (Followers: 9)
Preview     Hybrid Journal  
Proceedings of the National Academy of Sciences     Full-text available via subscription   (Followers: 526)
Proceedings of the National Academy of Sciences, India Section A     Hybrid Journal   (Followers: 3)
Progress in Materials Science     Hybrid Journal   (Followers: 20)
Progress in Planning     Hybrid Journal   (Followers: 1)
Progress of Theoretical and Experimental Physics     Open Access  
Quantum Electronics     Full-text available via subscription   (Followers: 3)
Quantum Measurements and Quantum Metrology     Open Access  
Quantum Studies : Mathematics and Foundations     Hybrid Journal  
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: 3)
Radio Science     Full-text available via subscription   (Followers: 3)
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: 11)
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: 17)
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   (Followers: 1)
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 & Astronomy     Full-text available via subscription   (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: 17)
Sensor Letters     Full-text available via subscription   (Followers: 1)
Sensors and Actuators A: Physical     Hybrid Journal   (Followers: 46)
Services Computing, IEEE Transactions on     Hybrid Journal   (Followers: 3)
Shock and Vibration     Hybrid Journal   (Followers: 7)
Shock Waves     Hybrid Journal   (Followers: 4)

  First | 1 2 3 4 5 6 | Last

Journal Cover   physica status solidi (c)
  [SJR: 0.397]   [H-I: 27]   [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  [1605 journals]
  • Dimensional and defectivity nanometrology of directed self‐assembly
           patterns
    • Authors: C. Simão; D. Tuchapsky, W. Khunsin, A. Amann, M. A. Morris, C. M. Sotomayor Torres
      Pages: n/a - n/a
      Abstract: Defectivity and dimensional metrology are two main challenges in lithography due to the increasing miniaturisation of circuits. Particularly, bottom‐up alternative lithographic masks from directed self‐assembly systems have been extending the limits of critical dimensions in a cost‐effective manner although great challenges in controlling defectivity remain open. To gain insights about the percentage of alignment, defectivity and order quantification, block copolymer fingerprints were investigated via an image analysis methodology. Here we present the analysis of hexagonal phase of polystyrene‐b‐polydimethylsiloxane (PS‐b‐PDMS) forming linear patterns in topological substrates. From our methodology, we have performed dimensional metrology estimating pitch size and error, and the linewidth of the lines was estimated. In parallel, the methodology allowed us identification and quantification of typical defects observable in self‐assembly, such as turning points, disclination or branching points, break or lone points and end points. The methodology presented here represents a step forward in dimensional metrology and defect analysis of self‐ and directed assembly systems. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-25T05:30:08.841375-05:
      DOI: 10.1002/pssc.201400211
       
  • Towards a standardised metrology for multi‐scale characterisation of
           nanostructured durable hydrophobic coatings
    • Authors: Damaso M. De Bono; Alan Taylor, Geraldine Durand
      Pages: n/a - n/a
      Abstract: Nanostructured coatings are gaining an increasing importance in critical applications such as anti‐fouling, low friction and boundary layer control applications, due to their ability to tailor roughness levels and to modify the energy of the underlying surface. The sustainability of a coating is linked to its lifetime and limited durability is one of the main drawbacks for nanostructured coatings. To improve performance and durability of nanostructured coatings a greater understanding of the structure at the nano‐scale and the influence of this on the macro‐scale behaviour is needed. As confirmation of this need, international bodies dealing with metrology standardisation have recognised that one of the main barrier limiting a larger scale exploitation of nanostructured coatings is the lack of understanding and testing methodologies able to link the nanostructure features of the coating with the final macro‐scale performance of the coating itself. This paper will offer an overview on the potential of nanostructured coatings to provide engineering surfaces with durable hydrophobic/super‐hydrophobic properties. The advancements achieved and the work carried out by TWI in this field will be illustrated. The project activities proposing the development and establishment of metrology methodologies for nanostructured coatings will be also mentioned. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-25T05:30:07.905163-05:
      DOI: 10.1002/pssc.201400118
       
  • Multi‐angle spectroscopic extreme ultraviolet reflectometry for
           analysis of thin films and interfaces
    • Authors: Serhiy Danylyuk; Stefan Herbert, Peter Loosen, Rainer Lebert, Anna Schäfer, Jürgen Schubert, Maksym Tryus, Larissa Juschkin
      Pages: n/a - n/a
      Abstract: Modern nanotechnology is constantly raising demands to quality and purity of thin films and interlayer interfaces. As thicknesses of employed layers decrease to single nanometers, traditional characterization tools are no longer able to satisfy throughput, precision or non‐destructibility requirements. Extreme ultraviolet (EUV) and soft X‐ray reflectometry has not only demonstrated the ability to detect sub‐nm thickness variations but also was shown to be very sensitive to chemical composition changes. Since the laboratory radiation sources in this wavelength range often emit in a relatively broad spectral range, a spectroscopic EUV reflectometry has been developed with the added benefit of a rapid measuring time on the order of milliseconds to seconds. In this paper, the extension of the method to multi‐angle measurements will be presented. It allows to reduce a number of fit parameters in the analysis model, making the method suitable for complex samples of unknown composition. First experimental examples for Si‐based layer systems measured under grazing incidence angles between 2° and 15° will be demonstrated and discussed. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-25T05:30:06.84131-05:0
      DOI: 10.1002/pssc.201400117
       
  • Near ambient pressure photoemission spectroscopy of metal and
           semiconductor surfaces
    • Authors: Iain D. Baikie; Angela Grain, James Sutherland, Jamie Law
      Pages: n/a - n/a
      Abstract: We describe a novel photoemission technique utilizing a traditional Kelvin probe as a detector of electrons/atmospheric ions ejected from metal and semiconductor surfaces (Al, Ag, Au, Si) illuminated by a Deep Ultra‐Violet (DUV) source at ambient pressure. In Constant Final State Yield Spectroscopy (CFSYS) the incident photon energy is rastered rather than applying a variable retarding electric field as in conventional UPS. For both ambient‐ and near ambient pressure‐photoemission spectroscopy (NAP‐PES) the CFSYS configuration overcomes the limitation of inelastic electron scattering in air. This arrangement can be applied in several operational modes: using the DUV source to determine the absolute work function (ϕ) of the metal with 50‐100 meV resolution and also the Kelvin probe, under dark conditions, to measure Contact Potential Difference (CPD) with an accuracy of 1‐3 meV. We show that the metal photoresponse agrees with Fowler theory. We have used CPD and linear extrapolated photoemission measurements to produce an energy level diagram for the native‐oxide covered Si. We propose a model of photoemission in air involving atmospheric ions. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-25T05:30:05.838694-05:
      DOI: 10.1002/pssc.201400086
       
  • Designing InGaN/GaN nano‐LED arrays for étendue‐limited
           applications
    • Authors: Sophia Fox; Simon O'Kane, Szymon Lis, Duncan Allsopp
      Pages: n/a - n/a
      Abstract: This paper presents the far field results of a study by simulation using the finite‐difference time‐domain (FDTD) method of vertical light emitting diode structures with an incorporated ordered nanorod array in place of the typical surface roughened region. For a dipole placed directly below the centre nanorod in the FDTD model, highly collimated light is achieved by changing the radii of the nanorods, for a fixed array pitch, which we attribute mainly to Bragg diffraction. By changing the pitch only, higher diffraction orders are observed in the far field emission as the pitch is increased and a relative increase in the directionality of emission is predicted. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-12T07:40:19.018773-05:
      DOI: 10.1002/pssc.201400240
       
  • Investigation of cubic GaN quantum dots grown by the
           Stranski‐Krastanov process
    • Authors: M. Bürger; J. K. N. Lindner, D. Reuter, D. J. As
      Pages: n/a - n/a
      Abstract: We investigate the formation of cubic GaN quantum dots (QDs) on pseudomorphic strained cubic AlN layers on 3C‐SiC (001) substrates grown by means of molecular beam epitaxy. Surface morphologies of various QD sizes and densities were obtained from uncapped samples by atomic force microscopy. These results were correlated with similar but capped samples by photoluminescence experiments. The QD density varies by one order of magnitude from ∼1x1010 cm‐2 to ∼1x1011 cm‐2 as a function of the GaN coverage on the surface. The initial layer thickness for the creation of cubic GaN QDs on cubic AlN was obtained to 1.95 monolayers by a comparison between the experimental results and an analytical model. Our results reveal the strain‐driven Stranski‐Krastanov growth mode as the main formation process of the cubic GaN QDs. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-12T07:40:17.990154-05:
      DOI: 10.1002/pssc.201400132
       
  • Control current stress technique for the investigation of gate dielectrics
           of MIS devices
    • Authors: Vladimir V. Andreev; Gennady G. Bondarenko, Vladimir M. Maslovsky, Alexander A. Stolyarov, Dmitry V. Andreev
      Pages: n/a - n/a
      Abstract: In this study, a modified technique of control current stress to investigation thin gate dielectric of MIS structures is proposed. This technique allows to monitor charge trapping in gate dielectric of MIS structures under high‐field and another stress situations (irradiation, plasma, hot carriers, etc.). The technique also may be used for testing thin gate dielectric defects. Unlike simple techniques, for example constant current stress and J‐ramp current stress, the proposed method uses a sequence of stress current and measuring current pulses. At the same time, the processes of charging and discharging of the MIS structure capacitance as well as the charge trapping in the gate dielectric are taken into account. Charging of MIS structure from inversion to accumulation modes or back way allows one to retrieve a low frequency capacitive‐voltage characteristic. Account charging capacitance of MIS structure and charge trapping in gate dielectric at injective mode lets considerably increase metrological characteristics of this technique and reduce inaccuracies. The models describing the change in the charge state of MIS structures, both in the charge capacity, and in the mode of injection of charge carriers were developed. Using these models let to choose optimal algorithm of current stress and increase measurement accuracy. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-09T06:14:52.100241-05:
      DOI: 10.1002/pssc.201400119
       
  • Micro‐Raman spectroscopy as a complementary technique to high
           resolution X‐ray diffraction for the characterization of
           Si1‐xGex thin layers
    • Authors: Aurèle Durand; Denis Rouchon, Delphine Le‐Cunff, Patrice Gergaud
      Pages: n/a - n/a
      Abstract: In advanced transistor technology, Silicon‐Germanium alloy (SiGe) is being used as a replacement for Si channels to achieve higher mobility. Among the various characterization techniques μ‐Raman spectroscopy is a promising candidate due to a good spatial resolution and low detection threshold. This study presents the evaluation of the technique for the measurement of Ge concentration and comparison to other metrology techniques. As a first step to evaluate the μ‐Raman capability, we considered a simple case of thin SiGe films from 12nm down to 4 nm thickness. Assuming an epitaxial pseudomorphic structure, the Ge content has been extracted for all samples with an average 0.3% stability and at least 1% accuracy as confirmed by high resolution X‐ray diffraction (HRXRD) and secondary ion mass spectrometry analysis (SIMS). We then studied a more complex structure of SiGe on fully depleted‐silicon on insulator (FD‐SOI) as being critical for the development of condensation process of advanced transistor technology. Since μ‐Raman requires prior knowledge of the structural state of the layer, we discuss the interest to combine μ‐Raman measurements with X‐rays diffraction in order to extract the Ge composition on such stacks. μ‐Raman shows a real potential for thin SiGe film characterization and it does not suffers of the lack of precision for very thin films as HRXRD does, however there are still some developments to be made before using it as a metrology technique. Moreover, it could be interesting to couple the technique with HRXRD measurement. The approach to control SiGe condensation process on FD‐SOI might suggest interesting experiment. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-09T06:14:50.483456-05:
      DOI: 10.1002/pssc.201400113
       
  • Boron doped cubic silicon probed by high resolution X‐ray
           diffraction
    • Authors: Tatjana Ulyanenkova; Maksym Myronov, Alex Ulyanenkov
      Pages: n/a - n/a
      Abstract: Highly boron doped epitaxial silicon, with boron concentrations well above 1x1020 cm‐3, is of great interest for applications in large variety of electronic and photonic devices where it is used as a low resistivity contact. The Bragg peak position of a homogeneous solid solution epitaxial film is directly related to the solid solution concentration, film strain and, consequently residual stress. The peak shape contains information about defects present in an epilayer. Here we report structural experiments performed at room temperature and atmospheric pressure on a set of boron doped Si thin epilayers grown on a Si(001) substrate. We analyzed the BSi epilayers using high resolution X‐ray rocking curve, reflectivity measurements and high resolution reciprocal space mapping (HR‐RSM). The measurements were carried out by Rigaku SmartLab diffractometer. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-09T06:14:49.11475-05:0
      DOI: 10.1002/pssc.201400102
       
  • Characterization and simulation of optical absorption in Si nanocrystals
    • Authors: Xuguang Jia; Lingfeng Wu, Ziyun Lin, Tian Zhang, Terry Chien‐Jen Yang, Hongze Xia, Binesh Puthen‐Veettil, Gavin Conibeer, Ivan Perez‐Wurfl
      Pages: n/a - n/a
      Abstract: The application of silicon quantum dot (Si QD) based material is regarded as a promising approach for the realization of high efficiency solar cells. When silicon nanocrystals are made very small (within the vicinity of the exciton Bohr radius of bulk Si), they behave as quantum dots due to the three‐dimensional quantum confinement, which could cause the material's effective optical band gap to increase. The optical band gap can be deduced from the absorption coefficient. In this paper, we analyze optical absorption and emission processes in Si QD and attempt to simulate the band‐edge absorption features based on the photoluminescence spectrum. We also investigate the application of ellipsometry in the study of optical properties of Si QD thin films. Based on WVASE32 modeling tool, a homogeneous mixture model is developed to extract the absorption coefficient of this material. From these results, we extract the effective optical band gap and analyze optical properties of Si QDs materials. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-09T06:14:48.190386-05:
      DOI: 10.1002/pssc.201400089
       
  • Synthesis and utilization of LaVO4:Eu3+ nanoparticles as fluorescent
           near‐field optical sensors
    • Authors: S. G. Nedilko; O. Chukova, Yu. Hizhnyi, S. A. Nedilko, T. Voitenko, L. Billot, L. Aigouy
      Pages: n/a - n/a
      Abstract: We report the use of fluorescent La1‐xEuxVO4 (0.1 ≤ x ≤ 0.3) nanoparticles as near‐field optical sensors. A single particle was glued at the end of a sharp atomic force microscope tip and scanned on the surface of a test sample made of sub‐micron sized holes in a thin silver film. Illumination of the sample was performed at λ = 532 nm in a transmission configuration. The light transmitted through the apertures induced the fluorescence of europium ions. The collection of the fluorescence light as a function of the tip position above the surface allowed to map the near‐field distribution in the vicinity of the holes, at different heights above the surface showing the beam divergence in free space above the sample. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-09T06:14:47.241731-05:
      DOI: 10.1002/pssc.201400090
       
  • XPS study of MoO3 and WO3 oxide surface modification by low‐energy
           Ar+ ion bombardment
    • Authors: Nikolai V. Alov
      Pages: n/a - n/a
      Abstract: The surface modification of oxides MoO3and WO3 under irradiation by Ar+ ions with an energy of 3 keV in high vacuum is investigated by X‐ray photoelectron spectroscopy. It is shown that under irradiation by Ar+ ions lower and intermediate oxides and unoxidized metals are formed in the surface layers of higher oxides. It is found that the process of ion‐beam reduction of the surface of oxides MoO3and WO3 substantially depends on the irradiation dose and difference in energy of the metal–oxygen bond in oxides. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-09T06:14:46.704362-05:
      DOI: 10.1002/pssc.201400108
       
  • Ga+ implantation in a PZT film during focused ion beam
           micro‐machining
    • Authors: Nicole Wollschläger; Werner Österle, Ines Häusler, Mark Stewart
      Pages: n/a - n/a
      Abstract: The objective of the present work was to study the impact of Focused Ion Beam (FIB) machining parameters on the thickness of the damaged layer within a thin film PZT. Therefore, different Ga+‐ ion doses and ion energies were applied to a standard PZT film (80/20 lead zirconium titanate) under two beam incidence angles (90° and 1°). The thicknesses of the corresponding Ga+‐implanted layers were then determined by cross‐sectional TEM in combination with energy dispersive spectroscopic (EDS) line‐scans and correlated with polarisation hysteresis loops. The results show a decrease of Ga+‐implanted layer thickness with decreasing inclination angle, whereas ion energy and ion dose could be correlated with gallium concentration in the implanted layers.. Under the most unfavorable conditions the depth of the affected zone was 26 nm, it was only 2 nm for the most favorable conditions. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-09T06:14:45.90314-05:0
      DOI: 10.1002/pssc.201400096
       
  • In situ UHVEM irradiation study of intrinsic point defect behavior in Si
           nanowire structures
    • Authors: J. Vanhellemont; S. Anada, T. Nagase, H. Yasuda, H. Bender, R. Rooyackers, A. Vandooren
      Pages: n/a - n/a
      Abstract: Si nanowire‐based Tunnel‐Field Effect Transistor (TFET) characteristics are intensively studied as function of nanowire diameter and doping. A significant reduction of B diffusion with decreasing nanowire diameter is e.g. observed and attributed to reduced transient enhanced diffusion close to the nanowire surface caused by the recombination and out‐diffusion of excess self‐interstitials. In an Ultra High Voltage Electron Microscope (UHVEM), the formation of self‐interstitial clusters can be studied in situ while varying e‐beam flux, irradiation temperature, impurity concentration and capping layers surrounding the nanowires. Results are presented on {113}‐defect formation in Si nanowires with diameters between 40 and 500 nm. The Si nanowires are embedded in SiO2 and are etched into an epitaxial Si stack on a heavily As doped Si substrate. The top layer of the epitaxial stack is in situ B doped or B implanted. In situ UHVEM studies are performed on focused ion beam prepared cross‐section samples, irradiating with different fluxes of 2 MeV electrons between room temperature and 375 °C. A strong dependence of {113}‐defect formation on nanowire radius and doping is observed. The observations are compared with simulations based on quasi‐chemical reaction rate theory. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-02-09T06:14:45.389196-05:
      DOI: 10.1002/pssc.201400100
       
  • Issue Information: Phys. Status Solidi C 1–2/2015
    • Pages: n/a - n/a
      PubDate: 2015-01-27T07:33:10.870551-05:
      DOI: 10.1002/pssc.201570069
       
  • Cover Picture: Phys. Status Solidi C 1–2/2015
    • Pages: n/a - n/a
      Abstract: Fast ion conduction is often found in materials that provide highly anisotropic diffusion pathways. Tetragonal BaSnF4, a two‐dimensional F anion conductor, represents a prominent candidate among these materials. Besides the crystal structure, lattice defects are necessary to allow the ions to diffuse locally and over long distances. Moreover, structural disorder or strain generated and frozen in during preparation may assist in ion self‐diffusion. Additional defects can be introduced by mechano‐assisted techniques such as high‐energy ball milling representing a versatile preparation method. It can facilitate or improve conventional synthesis strategies and allows the preparation of metastable compounds that otherwise require very high temperatures or complex synthesis routes. In their paper on pp. 10–14, Preishuber–Pflügl et al. demonstrate the mechano‐assisted preparation of defect‐rich, layer‐structured BaSnF4, which is a very fast fluorine ion conductor. Its metastable cubic modification, initially obtained after mechanical activation of the binary fluorides in a planetary mill, transforms into the tetragonal form upon annealing at moderate temperatures. At 300 K the ionic conductivity reaches almost 1 mS/cm; such a high value agrees well with the low activation energy of only 0.27 eV probed.
      PubDate: 2015-01-27T07:33:07.612081-05:
      DOI: 10.1002/pssc.201570067
       
  • Cover Picture: Phys. Status Solidi C 1–2/2015
    • Pages: n/a - n/a
      Abstract: Physarum polycephalum slime mold is depicted in this optical microscope image, once it has created protoplasmic tubes network on polyaniline substrate from the starting blob (the yellow part above). Physarum is a unicellular organism whose features, in the uncon‐ventional computing field, have been widely demonstrated and exploited. Starting from mold's skill in creating smart networks, capable of competing against engineering and scientists designs, the paper of Dimonte and coworkers on pp. 197–201 establishes the basis for future developments related to the growth targeting and bio‐electronic circuit realization. The DEFLECTOR, they introduced here, is a new, softer tool able of directing and influencing the motions of Physarum. To obtain this result it is necessary that the slime mold becomes more sensitive to external magnetic field, requiring the formation of a Physarum–magnetic nanoparticles hybrid sample. Moreover, deflecting Physarum's movement on polyaniline (PANI) substrates, it is possible to realize networks with varied conductivity. Indeed, Physarum growth results in changing conductivity state of PANI layers in different ways, providing negative and positive patterning of the sample. Therefore, joining the two mentioned approaches (patterning and deflection), it will be possible to push Physarum creating predesigned networks on PANI, realizing circuits and connections “ad hoc” according to circumstances.
      PubDate: 2015-01-27T07:33:06.052272-05:
      DOI: 10.1002/pssc.201570068
       
  • Towards single‐trap spectroscopy: Generation‐recombination
           noise in UTBOX SOI nMOSFETs
    • Authors: Eddy Simoen; Bogdan Cretu, Wen Fang, Marc Aoulaiche, Jean‐Marc Routoure, Regis Carin, Sara dos Santos, Jun Luo, Chao Zhao, Joao Antonio Martino, Cor Claeys
      Pages: n/a - n/a
      Abstract: An overview is given on the possibilities of using generation‐recombination (GR) noise as a tool for defect spectroscopy in semiconductor materials and devices. The method is illustrated by n‐channel MOSFETs fabricated on silicon‐on‐insulator (SOI) substrates with an ultra‐thin buried oxide (UTBOX). As will be shown, the use of fully depleted (FD) UTBOX devices offers some unique opportunities and challenges. In the first instance, one can apply the standard GR noise spectroscopy in function of the temperature to derive the relevant deep‐level parameters like the activation energy, the capture cross section and the concentration. In addition, some new type of spectroscopy can be applied to defects in the silicon film by exploiting the front‐ and/or back‐gate bias dependence of the Lorentzian noise parameters. Finally, it is shown that for small geometry transistors the GR noise is generated by one or only a few centres. This becomes obvious in the time domain, where the channel current exhibits random telegraph signal (RTS) fluctuations. The up and down time constants and the relative RTS amplitude can be used to derive the GR centre parameters and, moreover, its spatial location, when combined with numerical device simulations. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-01-23T08:10:50.318829-05:
      DOI: 10.1002/pssc.201400075
       
  • Plasma‐assisted molecular beam epitaxy of strain‐compensated
           a‐plane InGaN/AlGaN superlattices
    • Authors: Ryan W. Enck; N. Woodward, C. Gallinat, G. Metcalfe, A. V. Sampath, H. Shen, M. Wraback
      Pages: n/a - n/a
      Abstract: Strain‐compensated InGaN/AlGaN structures can enable the growth of thick layers of InGaN epitaxial films far beyond the critical thickness for InGaN grown pseudomorphically to GaN. In this paper, we demonstrate the epitaxial growth of high‐quality strain‐compensated a‐plane In0.12Ga0.88N/Al0.19Ga0.81N superlattices up to 5 times thicker than the critical thickness on free‐standing a‐plane GaN substrates by plasma‐assisted molecular beam epitaxy (PA‐MBE). The superlattices consist of 50 to 200 periods of 10 nm thick In0.12Ga0.88N and 6 nm thick Al0.19Ga0.81N layers. The structures are characterized using a double crystal X‐ray diffractometer, asymmetric reciprocal space mapping, and atomic force microscopy. We use X‐ray diffraction to determine the strain, composition, degree of relaxation, and superlattice period of our samples. The structural characteristics of periodic structures containing from 50 to 200 periods are compared to single layer, uncompensated In0.12Ga0.88N films. A 100 period structure exhibited only 15% relaxation compared to 69% relaxation for the bulk In0.12Ga0.88N film grown with the same total InGaN thickness but without strain‐compensating layers. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-01-23T08:10:49.21007-05:0
      DOI: 10.1002/pssc.201400208
       
  • HVPE homoepitaxy on freestanding AlN substrate with trench pattern
    • Authors: Yoshinobu Watanabe; Hideto Miyake, Kazumasa Hiramatsu, Yosuke Iwasaki, Shunro Nagata
      Pages: n/a - n/a
      Abstract: Conditions on chemical surface treatment and thermal treatment of sublimation‐freestanding AlN substrates were investigated to remove damage layers on surfaces for high‐quality and crack‐free AlN films grown by hydride vapour phase epitaxy (HVPE). By wet etching, the residue on the surface was removed and the polishing scratches were reduced. Atomic steps were formed on the surface by the subsequent thermal treatment at 1450 °C for 10 min, and surface layer of 220 nm in thickness was removed, Homoepitaxial growth on freestanding AlN substrate with trench pattern was also performed. A crack‐free AlN film with atomic steps was obtained on the trench‐patterned bulk AlN substrate, and the emission at the band edge near 206.9 nm was dominant. The wavelength of luminescence from cross‐sectional and surface of the HVPE‐AlN layer was maintained. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-01-23T08:10:48.179394-05:
      DOI: 10.1002/pssc.201400202
       
  • Time‐resolved photoluminescence characterization of 2 eV band in AlN
    • Authors: Ivan A. Aleksandrov; Vladimir G. Mansurov, Victor F. Plyusnin, Konstantin S. Zhuravlev
      Pages: n/a - n/a
      Abstract: We report time‐resolved and temperature‐dependent photoluminescence investigations of 2 eV photoluminescence band in AlN with below bandgap excitation. Series of the samples grown by molecular beam epitaxy on sapphire substrates with varying growth conditions have been studied. Intensity of the 2 eV photoluminescence band has been found to increase with increasing III/V flux ratio. The 2 eV photoluminescence band has been described in one‐dimensional configuration coordinate model. A possible origin of this orange emission has been discussed. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-01-23T08:10:47.139747-05:
      DOI: 10.1002/pssc.201400175
       
  • Degradation of external quantum efficiency of AlGaN UV LEDs grown by
           hydride vapor phase epitaxy
    • Authors: Natalia Shmidt; Alexander Usikov, Eugenia Shabunina, Anton Chernyakov, Alexey Sakharov, Sergey Kurin, Andrei Antipov, Iosif Barash, Alexander Roenkov, Heikki Helava, Yuri Makarov
      Pages: n/a - n/a
      Abstract: A comparative study of the degradation of HVPE‐grown 360 nm AlGaN/GaN UV and commercially available InGaN/GaN blue LED chips was performed. The common feature of the degradation of these two types of LEDs was found to be the increase of the conductivity of shunt paths under current injection. The paths (shunts) are localized in the extended defects system (EDS). It is proposed that the conductivity increase is due to defect formation under multiphonon carriers recombination in a part of the EDS enriched by Ga or In atoms. This process is accompanied by a local overheating and migration of Ga or In atoms. To increase the lifetime of the AlGaN/GaN UV LEDs to more than 2000 h it is necessary to improve their nano‐structural and nanoscale AlGaN composition ordering. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-01-23T08:10:46.189625-05:
      DOI: 10.1002/pssc.201400172
       
  • Unusual phonon mode behaviour in zinc‐blende BN/GaN superlattices
    • Authors: Devki N. Talwar; Andrew F. Zhou, Tzuen‐Rong Yang
      Pages: n/a - n/a
      Abstract: Comprehensive calculations of the long‐wavelength optical phonons are reported for zinc‐blende BN films by exploiting a linear response theory to simulate far‐infrared reflectivity and transmission spectra at oblique incidence. A rigid‐ion‐model is used to study the lattice dynamics of the unconventional BN/GaN short‐period superlattices (SLs). Besides empathizing, the anisotropic mode behaviour of optical phonons, the study has offered evidence of acoustic‐mode anti‐crossing, mini‐gap formation, confinement, as well as BN‐like modes falling between the gap regions separating the optical phonons of the two bulk (BN, GaN) semiconductor materials. A bond‐polarizability approach within the second‐nearest‐neighbour linear‐chain model is also employed to visualize the Raman intensity profiles of the short‐period BN/GaN SLs, revealing major trends of the phonon characteristics noted in many conventional SLs, while eliciting some interesting contrasts. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-01-23T08:10:45.055269-05:
      DOI: 10.1002/pssc.201400157
       
  • Accurate measurement of atomic segregation to grain boundaries or to
           planar faults by analytical transmission electron microscopy
    • Authors: Thomas Walther
      Pages: n/a - n/a
      Abstract: A method of analytical transmission electron microscopy is described that has been successfully applied to study dopant segregation to inversion domain boundaries in zinc oxide, to quantify the thicknesses of sub‐nanometre thin epitaxial layers grown by molecular beam epitaxy of indium arsenide (InAs) on gallium arsenide (GaAs) or silicon/germanium on silicon and proved the absence of any gettering of As or Ga dopants at Sigma=3 {111} grain boundaries in silicon, with a precision of
      PubDate: 2015-01-23T08:10:43.66336-05:0
      DOI: 10.1002/pssc.201400121
       
  • Characterization of TiO2 antireflection coatings elaborated by APCVD for
           monocrystalline silicon solar cells
    • Authors: D. Hocine; M. S. Belkaid, M. Pasquinelli, L. Escoubas, P. Torchio, A. Moreau
      Pages: n/a - n/a
      Abstract: In this work, high quality titanium dioxide thin films were grown by an efficient, less expensive and rapid method of Atmospheric Pressure Chemical Vapor Deposition (APCVD) from TiCl4 precursor for application as antireflection coatings on monocrystalline silicon solar cells with the aim to reduce the front surface reflection losses. The microstructural, electrical and optical properties of the produced coatings were successfully characterized by Atomic Force Microscopy (AFM), Four Point Probe (FPP) and Spectroscopic Ellipsometry (SE). The produced coatings were uniform, homogenous and relatively smooth. The density of the deposited TiO2 films is found to be ρ ′ = 3.11 g/cm3. The porosity of these films is estimated to ϕ = 24 %. A perfect agreement between the AFM results and the ellipsometric results was confirmed. The refractive index of our TiO2 thin films was found to be n = 2.25 at the wavelength λ = 550 nm, with a thickness of 56.2 nm. Our results show the possibility to fabricate TiO2 layers with the optimal optical qualities required for antireflection coating, using the APCVD technique. An excellent agreement is reached between our experimental results and calculated results for TiO2 single‐layer antireflection coating on monocrystalline silicon solar cells. The electrical resistivity of the deposited TiO2 films at 450°C annealed at 450°C for 1 hr, was found to be ρ = 1.7 × 10‐3 Ω.cm. The sheet resistance of our TiO2 films was equal to R□ = 303 Ω/□. The obtained results demonstrate the real opportunity of the APCVD technique to prepare high quality antireflection coatings for high efficiency silicon solar cells. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-01-23T08:10:42.468015-05:
      DOI: 10.1002/pssc.201400085
       
  • Reflectance analysis on the MOCVD growth of AlN on Si(111) by the virtual
           interface model
    • Authors: Tuoh‐Bin Ng; David A. Ewoldt, Debra A. Shepherd, Mark J. Loboda
      Pages: n/a - n/a
      Abstract: The reflectance‐time profile of AlN‐on‐Si(111) growth by MOCVD as acquired through an in‐situ optical reflectance monitor is analyzed. It is found that, similar to the case of GaN‐on‐sapphire nucleation and growth through the low temperature GaN or AlN buffer layer techniques, the reflectance profile for AlN‐on‐Si also contains information that relate to the growth mechanism, which can then be correlated to the as‐grown material quality. Based on the equations for the Virtual Interface model, a set of 6 parameters can be used to curve‐fit the reflectance traces of AlN growth as acquired by the in‐situ optical monitor. By analyzing a range of 405 nm AlN reflectance‐time data from single layer AlN growth to multilayer AlN/AlGaN/GaN stack grown on Si(111), the “goodness of fit” statistics are found to correlate with material quality metrics such as the XRD (002) rocking curve FWHM for AlN, microscopic morphological roughness of the AlN surface, as well as the resultant wafer bow and curvature for GaN/AlGaN grown on the AlN/Si(111) substrate. The correlations provide useful insight into the desirable mechanism and growth mode for the high temperature MOCVD growth of AlN and GaN on Si(111). When fully established, the technique has the potential of being used as an in‐situ pass/fail screen for the MOCVD growth of GaN‐on‐Si. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-01-23T08:10:41.27289-05:0
      DOI: 10.1002/pssc.201400159
       
  • A long road to a bright future
    • Authors: Sabine Bahrs; Stefan Hildebrandt
      Pages: 1 - 2
      Abstract: Dear pss readers, “This year's Nobel Prize in Physics recognizes the pioneering work of Professors Isamu Akasaki, Hiroshi Amano and Shuji Nakamura for the breakthrough developments in GaN materials and devices that enabled the field of solid state lighting. Blue LEDs have revolutionized display technology and enabled high efficiency white light sources.” said our Editorial Advisory Board member Jim Speck in response to our enthusiastic congratulations to his colleague at University of California, Santa Barbara. It was certainly an exceptional moment for a journal that has extensively documented GaN‐related research for decades. Isamu Akasaki and Hiroshi Amano, then both Meijo University and Nagoya University, published in pss on dislocations and stress in AlGaN/GaN thin films, e.g. [1, 2], Hiroshi Amano repeatedly acted as a guest editor [3–5], and all three laureates together have more than a 150 articles in pss and continue to publish on the topic. Obviously, though these contributions have gathered more than 1400 citations to date, not all are “breakthroughs”. Most are documenting continuous achievements in an important and highly specialized area. But together they witness the exceptional persistence required to master the growth of GaN to the degree of perfection that enabled blue LEDs. It is an example for the amount of patient, high‐level work that is necessary to turn a brilliant idea into a widespread invention, and pss is proud to accompany such progress along the way. Regarding today's promising trends in materials physics, we would like to showcase some of the special issues and topical sections that appeared in pss sister journals in 2014: “Oxide materials might form the basis for the next technological revolutions” according to J. M. Knaup, T. Frauenheim, P. Broqvist, and S. Ramanathan, the guest editors of the pss (RRL) Focus issue “Functional Oxides” [6]. These materials' enhanced complexity proposes both a greater challenge and greater benefits for future electronics and energy applications, and the 3 Reviews and 20 Letters offer computational and experimental perspectives on the current understanding. A topical section “Nanoscaled Magnetism and Applications”, guest‐edited by A. Zhukov, features contributions on magnetocaloric materials, spin relaxation, magnetization processes and magnetic nanostructures in pss (a) [7]. Another bustling topic in pss (a) are the recurring annual diamond and The logo of our journal assembled with blue GaN‐on‐Si LEDs (courtesy of Armin Dadgar, Otto‐von Guericke‐Universität, Magdeburg, Germany) nanocarbon special issues, this time focused on “Advances on Diamond Surfaces and Devices” edited by B. Rezek, M. Nesládek, and K. Haenen [8], and kicked‐off by a Feature Article “Photoelectron emission from lithiated diamond” by K. M. O'Donnell, L. Ley, and others [9]. pss (b) ventured on new grounds of theoretical method development: “Computational Thermodynamics” is a joint effort of scientists from the density functional theory and CALPHAD user communities to pave the way to a connection of these two approaches of materials description. The extended Preface by T. Hickel, U. R. Kattner, and S. G. Fries and five Feature Articles ([10] and references therein) have been ranking among the most accessed articles of pss (b) ever since January. P. Entel et al. propose a promising perspective on materials in the Special Issue “Ferroic Glasses: Magnetic, Polar and Strain Glass”, comprising 21 contributions [11]. A core topic for pss is discussed in the Feature Article “Zinc oxide – From dilute magnetic doping to spin transport” by M. Opel et al. [12], which is part of the Special Issue “Semiconductor Spintronics” guest‐edited by M. Oestreich and J. König [13]. The presentation of this and other great content in pss is possible only with the dedicated work of our editors, authors, and reviewers. Let us take the opportunity to say: Thank you. Looking to the near future we are delighted to welcome new members to the Editorial Advisory Board: Zexian Cao (Institute of Physics, Chinese Academy of Sciences, Beijing), Claudia Felser (Max Planck Institute for Chemical Physics of Solids, Dresden, Germany), Marius Grundmann (Universität Leipzig, Germany), Ken Haenen (Universiteit Hasselt, Belgium), and S. N. Piramanayagam (A*STAR, Singapore) have agreed to join. We are much looking forward to their help and support with further strengthening pss bonds to the scientific community worldwide. With best wishes, Sabine Bahrs and Stefan Hildebrandt
      PubDate: 2015-01-27T07:33:05.308153-05:
      DOI: 10.1002/pssc.201570070
       
  • Contents: Phys. Status Solidi C 1–2/2015
    • Pages: 3 - 8
      PubDate: 2015-01-27T07:33:03.035026-05:
      DOI: 10.1002/pssc.201570071
       
  • Defect‐induced effects in nanomaterials
    • Authors: Flyura Djurabekova; Eugene Kotomin, Mark C. Ridgway, Nikolai A. Sobolev
      Pages: 9 - 9
      Abstract: “Crystals are like people, it is the defects in them which tend to make them interesting!” said Cambridge Professor Sir Colin Humphrey once upon a time. Today, this statement still rings true. Defects govern the properties of nanostructures to the same or even to a greater extent as they do in bulk solids. Any surface or interface is already a perturbation of an ideal solid, and the role of interfaces increases with decreasing dimensionality of objects. However, the research field of defects in nanostructures extends much farther, encompassing doping, diffusion, radiation effects, phase transitions – virtually all fields of solid‐state science and technology. A burst of research activity in two‐dimensional materials has been brought about by the isolation of graphene from bulk graphite in 2004 by Geim and Novoselov (Nobel prize in Physics 2010). The invention of efficient blue light‐emitting diodes crowned with the very recent Nobel prize in Physics awarded to Isamu Akasaki, Hiroshi Amano and Shuji Nakamura goes hand‐in‐hand with the defect engineering in semiconductors. The first EMRS symposium on defects in nanomaterials was held during the 2012 Fall meeting in Warsaw, and the success of the event was a motivation to organize a follow‐up symposium during the 2014 Spring Meeting in Lille. The Symposium E entitled “Defect‐induced effects in nanomaterials” attracted even more participants from all over the world, and this volume includes 36 papers based on presentations from the five days of oral and poster sessions, from May 26 to 30. The program of the symposium comprised 15 invited and 47 oral talks, as well as 98 poster presentations. The presenters came from 44 countries located on five continents: Africa, North and South America, Asia, Australia, and Europe. The following topics have been covered: – Swift heavy ion irradiation as the means to tailor nanomaterials; – Effects of grain boundaries and interfaces on diffusion and transport processes in nanomaterials; – Electronic structure of defects in nanostructures; consequences for carrier transport, magnetism, optical and electronic properties, as well as device parameters; – Creation, evolution and properties of radiation defects in nanosize materials and heterostructures; the role of interfaces, nonstoichiometry, strain and adjacent layers; – Defects in two‐dimensional materials; – Use of defects as microprobes; – Multiscale computer modeling of defect creation in nanomaterials; – Novel technological processes of micro‐, nano‐ and optoelectronics using defects and radiation effects in nanostructures. The latest achievements in theory and experiment as well as technological applications have been presented and discussed by academic and industrial researchers. We are deeply grateful to all participants who, through their valuable contributions, friendly and open discussions, turned the symposium into an exciting event. We also greatly acknowledge the financial and administrative support of the E‐MRS Headquarters which allowed the organization of the symposium. Last but not least, our thank goes to Wiley‐VCH that took over the publication of the symposium proceedings. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2015-01-27T07:33:09.111345-05:
      DOI: 10.1002/pssc.201570072
       
  • Established and emerging nanocolloids: from synthesis and characterization
           to applications
    • Authors: Pascal André; Mathieu Maillard, Gordana Dukovic, Laurence Motte, Richard Tilley
      Pages: 136 - 137
      Abstract: Colloidal nanomaterials are part of an emergent class of materials prepared in solution and providing unprecedented levels of functionality. Such nanostructures can not only be used to study new physical and chemical phenomena in low‐dimensional systems but they also enable a route for the development of new technologies in key areas. Examples include communications and information processing, sensing and renewable energy, electronic and photonic devices, as well as biomedicine. This symposium provided a platform to discuss the preparation of nanocolloids, including well‐established nanomaterials such as quantum dots and metal nanoparticles, as well as emerging nanostructures such as doped semiconductors, ferroelectrics and multiferroics. This symposium brought insight into the relevant fundamental materials and interface issues as well as material design, device fabrication, and functionality.
      PubDate: 2015-01-27T07:33:08.6057-05:00
      DOI: 10.1002/pssc.201570073
       
  • Memristor materials, mechanisms and devices for unconventional computing
    • Authors: Victor Erokhin
      Pages: 163 - 163
      Abstract: Memristive devices are amongst key elements in the experimental realization of unconventional and bio‐inspired computational systems. Our symposium was the first ever event dedicated to the technological aspects of the realization of different types of memristive devices. There were about 100 participants; top level presentations; very fruitful final round table, where a possibility of the next E‐MRS related symposia organization was considered. The future will show whether we have done a fruitful start‐up.
      PubDate: 2015-01-27T07:33:12.886468-05:
      DOI: 10.1002/pssc.201570074
       
  • Hybrid ZnO:polystyrene nanocomposite for all‐polymer photonic
           crystals
    • Authors: Paola Lova; Giovanni Manfredi, Luca Boarino, Michele Laus, Giulia Urbinati, Tonia Losco, Franco Marabelli, Valentina Caratto, Maurizio Ferretti, Maila Castellano, Cesare Soci, Davide Comoretto
      Pages: n/a - n/a
      Abstract: We report on ZnO nanoparticles‐polystyrene (PS) nanocomposites (NC) engineered to modify PS matrix permeability and refractive index (n), and to fabricate 1D all‐polymer photonic crystals (PC) for sensing applications. The new NC can be easily processed from solutions to prepare high quality thin films by spin coating. ZnO nanoparticles (n = 1.98) have been synthetized by solvothermal route and grafted with a silane to reduce phase segregation in the PS matrix (n = 1.58). Such procedure led to an increase of the matrix refractive index of about 1%. By casting alternated layers of the NC and cellulose acetate (CA, n = 1.46), we fabricated free‐standing and flexible distributed Bragg reflectors (DBRs) of excellent optical quality. Preliminary results on the use of such DBRs as solvent vapor sensors are reported. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-26T06:30:11.689709-05:
      DOI: 10.1002/pssc.201400209
       
  • Influence of doping on the optical properties of silicon nanocrystals
           embedded in SiO2
    • Authors: Mathieu Frégnaux; Rim Khelifi, Yann Le Gall, Dominique Muller, Daniel Mathiot
      Pages: n/a - n/a
      Abstract: Co‐implantation, with overlapping implantation projected ranges, of Si and doping species (P, As, B) followed by a thermal annealing step is a viable route to form doped Si nanocrystals (NCs) embedded in SiO2. This presentation deals with optical characterizations of both doped and undoped Si‐NC prepared by this method. The NC effective presence in the oxide layer and their crystallinity is verified by Raman spectrometry. Photoluminescence (PL) and PL excitation measurements reveal quantum confinement effects and a gradual PL quenching with increasing dopant concentrations. The measured Stokes shift remains constant and its value ∼ 0.2 eV is almost twice the Si–O vibration energy. This suggests that a possible radiative recombination path is a fundamental transition assisted by a local phonon. Lifetime investigations show that PL time‐decays follow a stretched exponential. Atomic probe tomography analyses demonstrate that n‐type dopants (P, As) are efficiently introduced in the NC core, whereas p‐type dopant (B) are located at the NC/SiO2 interface. All together these experimental observations question on possible different carrier recombination paths in P or As doped NC compared to B one's. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-26T06:30:10.354883-05:
      DOI: 10.1002/pssc.201400079
       
  • Localization of dislocation‐related luminescence centers in
           self‐ion implanted silicon and effect of additional boron ion doping
           
    • Authors: D. I. Tetelbaum; A. N. Mikhaylov, A. I. Belov, D. S. Korolev, A. N. Shushunov, A. I. Bobrov, D. A. Pavlov, E. I. Shek, N. A. Sobolev
      Pages: n/a - n/a
      Abstract: The depth distribution of light‐emitting centers of the D1 dislocation‐related photoluminescence line (∼ 1.5 μm) in silicon implanted with Si+ ions and annealed at 1100 °C in the oxidizing chlorine‐containing atmosphere has been investigated by means of the layer‐by‐layer chemical etching. It is established with the application of cross‐sectional transmission electron microscopy that the main contribution to the D1 line is made by the centers located at the depths of up to ∼ 150 nm, i.e. in the region of Si+ ion ranges, whereas the dislocations produced by Si+ implantation and annealing at 1100 °C penetrate to the depth of ∼ 1000 nm. Additional boron ion doping with subsequent annealing at 800 °C in N2 atmosphere improves the emission in comparison with the undoped but annealed reference sample, however the additional annealing at 800 °C per se results in the photoluminescence weakening. The dependence of the D1 line intensity on boron ion dose is found to be nonmonotonous. The interpretation of the obtained results is given in relation to the key role of selfinterstitials and boron impurity in the formation of radiative and nonradiative centers. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-26T06:30:09.233848-05:
      DOI: 10.1002/pssc.201400099
       
  • Bio‐organic memristive device: polyaniline–Physarum
           polycephalum interface
    • Authors: Angelica Cifarelli; Tatiana Berzina, Victor Erokhin
      Pages: n/a - n/a
      Abstract: Organic memristive device is an electronic system mimicking some properties of biological synapses. Slime mold – Physarum polycephalum – is a single cell living being, widely considered now for the unconventional computing application. This work is dedicated to the realization of hybrid organic memristive device/Physarum polycephalum system and studying of its electrical properties. It was found that the slime mold remains alive only when the appropriate biocompatible layer is inserted into the structure and that the characteristics of the system are very different from those of the standard organic memristive devices. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:40:13.603688-05:
      DOI: 10.1002/pssc.201400191
       
  • Resistive switching on MgO‐based metal‐insulator‐metal
           structures grown by molecular beam epitaxy
    • Authors: M. Menghini; C. Quinteros, C.‐Y Su, P. Homm, P. Levy, J. Kittl, J.‐P. Locquet
      Pages: n/a - n/a
      Abstract: We report on non‐polar switching of the resistance between a low and a high resistive state in MgO‐based metal‐insulator‐metal structures. The MgO films were grown by MBE on top of Pt/Si substrates and Pt electrodes were evaporated on top. The obtained resistance ratio is of the order of 108‐109, much larger than previously reported values in similar devices. We observe a gradual degradation during consecutive switching events and a significant large dispersion of the voltages at which the resistance switch occurs. The overall behavior of the devices is assigned to a low defect density in these samples. The obtained results suggest that the resistive switching is produced by the formation and disruption of Mg metallic filaments. In order to analyze the influence of interfaces, we also study the effect of adding an intermediate layer of either Al2O3 or Mg within the Pt/MgO/Pt structures. The switching performance appears to be enhanced when Al2O3 is used. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:40:12.408238-05:
      DOI: 10.1002/pssc.201400192
       
  • Defect‐enhanced F– ion conductivity in layer‐structured
           nanocrystalline BaSnF4 prepared by high‐energy ball milling combined
           with soft annealing
    • Authors: Florian Preishuber‐Pflügl; Viktor Epp, Suliman Nakhal, Martin Lerch, Martin Wilkening
      Pages: n/a - n/a
      Abstract: Fast ion conductors play one of the most important roles in solid state ionics as there is a great demand for their application in safe and powerful electrochemical energy storage systems. For such materials, it is known that the synthesis conditions may have significant impact on the final properties of the materials prepared. In this contribution, we made use of mechanosynthesis, carried out via high‐energy ball milling, to influence the ionic transport parameters of tetragonal, i.e., layer‐structured, BaSnF4. X‐ray powder diffraction (XRD) revealed that mechanical treatment of the binary fluorides BaF2 and SnF2 leads to a powder pointing to a nanocrystalline fluoride with (distorted) cubic symmetry. Differential scanning calorimetry (DSC) as well as preliminary in situ XRD measurements were used to follow the transformation towards the tetragonal modification with the composition BaSnF4. Broadband impedance spectroscopy was used to measure the overall electrical conductivity of the ternary fluoride. Remarkably, the layered form shows a room temperature conductivity of 7 × 10–4 S cm–1. Further emphasis was put on the characterization of the dielectric properties of the material, which was investigated by using different electrode materials to distinguish artefacts from intrinsic properties. Since we found a strong dependence of the real part of the permittivity on the electrode materials applied (carbon paste or sputtered Pt), we tend to assign the huge increase in permittivity, which was recently interpreted as giant dielectric constant, to interfacial polarization effects rather than to intrinsic properties. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:40:11.012985-05:
      DOI: 10.1002/pssc.201400193
       
  • Detection of nano‐structured particles with organic electrochemical
           transistors
    • Authors: Agostino Romeo; Giuseppe Tarabella, Pasquale D'Angelo, Nicola Coppedè, Francesca Rossi, Roberto Mosca, Salvatore Iannotta
      Pages: n/a - n/a
      Abstract: Recently big efforts have been addressed to the development of techniques for sensing and characterization of nanoparticles (NPs), especially in aqueous environment, due to their possible harmfulness related to their nanometric size. In this work we describe a real time detection of NPs based on organic electrochemical transistors (OECTs). OECTs were employed to detect core‐shell super‐paramagnetic NPs (Fe3O4) functionalized with different polymeric coatings. The OECT response resulted to be a function of the density of NPs suspended in the solution, with sensitivity down to tens of µg/ml. The data, interpreted in terms of the effective gate voltage shift induced by the NPs, indicate that the sensing mechanism is correlated to the electrostatic interaction of NPs with the PEDOT:PSS transistor channel. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:40:09.841928-05:
      DOI: 10.1002/pssc.201400195
       
  • Employing threshold‐based behavior and network dynamics for the
           creation of memristive logic circuits and architectures
    • Authors: Ioannis Vourkas; Georgios Ch. Sirakoulis
      Pages: n/a - n/a
      Abstract: This work focuses on the creation of logic circuits by employing the collective dynamics of assembles of reciprocal memristors. A novel circuit design methodology is described where the computing systems comprise passive memristors interfaced with active CMOS circuitry, working under already known circuit design principles from the CMOS technology. The accuracy and completeness of this straightforward methodology is demonstrated through SPICE simulations which are based on a threshold‐type device model for memristors. Overall, this work contributes to the creation of proper methodologies which will enable the development of efficient design flows for circuits and architectures comprising memristors. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:30:16.949571-05:
      DOI: 10.1002/pssc.201400161
       
  • Numerical investigation of nanoscale SiGe DG MOSFET performance against
           the interfacial defects
    • Authors: Toufik Bentrcia; Fayçal Djeffal, Zouhir Dibi, Djemai Arar
      Pages: n/a - n/a
      Abstract: The SiGe‐based alloy is considered as one of the most promising materials for reliable and high performance microelectronic devices. The use of a lower band‐gap material in the channel region of the MOSFET, such as SiGe, is a potential candidate given their compatibility with the process developed for pure Si‐based devices. Moreover, the important increasing in the drain current due to the increased electrons mobility in SiGe material is expected. However, the growth of this material is not totally controlled, and the presence of defects is more than expected after a growth run of this material. Therefore, in order to obtain a global view of SiGe‐based nanoscale Double Gate (DG) MOSFET performance under critical conditions, numerical modeling of nanoscale SiGe DG MOSFET including Interfacial defect effects (SiGe/Si) is indispensable for the comprehension of the fundamentals of such device characteristics. Based on numerical investigation of a nanoscale SiGe DG MOSFET, including the defects in the interface region, in the present paper a numerical model for I‐V and small signal characteristics by including the interfacial defects, after considering the uniform function approximation for the interface defects distribution at the drain side, is developed to explain the immunity behavior of the nanoscale SiGe‐based transistor against the defect densities. In this context, DC and RF characteristics of the proposed design are analyzed by 2‐D numerical simulation and compared with conventional Si DG MOSFET characteristics. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:30:15.916208-05:
      DOI: 10.1002/pssc.201400088
       
  • Implementation of adaptive coupling through memristor
    • Authors: Mattia Frasca; Lucia Valentina Gambuzza, Arturo Buscarino, Luigi Fortuna
      Pages: n/a - n/a
      Abstract: Since its discovery, memristor attracted a lot of attention for its potential applications as next generation electronic device, as system for modeling and implementing biological synapses and as key component in nonlinear circuits. Here we exploit the peculiarities of the HP memristor in order to realize an adaptive coupling, able to reach consensus and synchronization between two dynamical systems. In particular, the coupling scheme consists of two HP memristors connected in antiparallel which allow to deal with consensus/synchronization error of either positive and negative sign. Simulation results on consensus of two agents with integrator dynamics and synchronization of two Chua's circuits show the suitability of the proposed approach. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:30:15.067691-05:
      DOI: 10.1002/pssc.201400097
       
  • Memristors under the influence of noise and temperature
    • Authors: G. A. Patterson; F. Sangiuliano Jimka, P. I. Fierens, D. F. Grosz
      Pages: n/a - n/a
      Abstract: We study the performance of a manganite sample meant for memresistive applications. In particular, we experimentally address the interplay between temperature and electrical noise the sample is subject to. Results reveal an optimum noise amplitude that maximizes the contrast between low‐ and high‐resistive states, and a decaying contrast with increasing temperature. We introduce a numerical model accounting for the observed experimental behavior. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:30:14.041592-05:
      DOI: 10.1002/pssc.201400125
       
  • Comparative study of defect evolution in carbon implanted strained SiGe
           and SiSn layers
    • Authors: Peter I. Gaiduk; John Lundsgaard Hansen, Arne Nylandsted Larsen, Wolfgang Skorupa
      Pages: n/a - n/a
      Abstract: By combining secondary ion‐mass spectrometry, transmission‐electron microscopy (TEM) and Rutherford‐backscattering spectrometry we show that the redistribution of implanted carbon atoms around epitaxially strained Si/SiGe layers results in their accumulation on the Si side and depletion on the SiGe side. On the contrary, uphill diffusion of carbon into SiSn layers takes place in the case of Si/SiSn structures. The TEM study demonstrates formation of dislocation loops, stacking faults and interstitial clusters in the Si/SiGe layers, but elimination of interstitial dislocation loops and suppression of tin precipitates in the Si/SiSn layers. We deduced different evolution of dislocation loops and a precipitate is due to dopant‐defect complexes. The complex formation is enhanced by separation of implanted point defects in strain‐fields of Si/SiSn and Si/SiGe layers. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:30:12.913759-05:
      DOI: 10.1002/pssc.201400135
       
  • Formation of nanodimensional structures on surfaces of GaAs and Si by
           means of ion implantation
    • Authors: S. B. Donaev; F. Djurabekova, D. A. Tashmukhamedova, B. E. Umirzakov
      Pages: n/a - n/a
      Abstract: We obtained the two‐ and three‐component nanostructures by means of ion implantation of low‐energy Co and Ba ions in the surface layers of Si and GaAs in combination with the post‐implantation annealing. We show that flat shaped nanocrystals (nanoislands) of two‐ and three‐component composition, Co‐Si and Ga‐Ba‐As, start forming at ion fluences of Φ = (6¸8)×1014 cm‐2. After the laser annealing and short time electron heating we observed the formation of CoSi2 and Ga0.4Ba0.6As nanocrystals. Our results show that the size effects are clearly seen in electronic properties (opening of the band gap) when the lateral size of nanocrystals is less than 15‐30 nm, or in case of solid nanofilms, similar effect is observed at the thickness less than 3‐4 nm. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:30:11.72748-05:0
      DOI: 10.1002/pssc.201400156
       
  • Memristive sorting networks
    • Authors: Milan Frátrik; Martin Klimo, Ondrej Šuch, Ondrej Škvarek
      Pages: n/a - n/a
      Abstract: Resistive switching in thin‐film solid state devices is a rapidly progressing research area. Several new devices and applications, based on resistive switching, were proposed. The devices fall into realm of unconventional computing. In this paper we present memristor implementation of fuzzy logic. We describe fuzzy logic operations, simulation method used in our experiments and finally we compare two sorting algorithms implemented in memristive network. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:30:10.00131-05:0
      DOI: 10.1002/pssc.201100000
       
  • Charged defects and defect‐induced processes in nitrogen films
    • Authors: Elena Savchenko; Ivan Khyzhniy, Sergey Uyutnov, Andrey Barabashov, Galina Gumenchuk, Alexey Ponomaryov, Vladimir Bondybey
      Pages: n/a - n/a
      Abstract: Radiation effects in solid nitrogen irradiated with an electron beam were studied with emphasis on the role of charged centers in radiation‐induced phenomena. The experiments were performed employing luminescence method and activation spectroscopy techniques – spectrally resolved thermally stimulated luminescence TSL and thermally stimulated exoelectron emission. Samples were probed in depth by varying electron energy, thus discriminating radiation‐induced processes in the bulk and at the surface. Spectroscopic evidence of the excited N2* (C3Πu) molecule desorption was obtained for the first time and mechanism of the phenomenon based on recombination of electron with intrinsic charged center N4+ was proposed. The key role of N3+ center dissociative recombination in generation of N radicals is suggested. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:30:08.845066-05:
      DOI: 10.1002/pssc.201400166
       
  • Error control on spectral data of four‐wave mixing based on
           a‐SiC technology
    • Authors: M. A. Vieira; M. Vieira, V. Silva, P. Louro, M. Barata
      Pages: n/a - n/a
      Abstract: In this paper we exploit the nonlinear property of the SiC multilayer devices to design an optical processor for error detection that enables reliable delivery of spectral data of four‐wave mixing over unreliable communication channels. The SiC optical processor is realized by using double pin/pin a‐SiC:H photodetector with front and back biased optical gating elements. Visible pulsed signals are transmitted together at different bit sequences. The combined optical signal is analyzed. Data show that the background acts as selector that picks one or more states by splitting portions of the input multi optical signals across the front and back photodiodes. Boolean operations such as EXOR and three bit addition are demonstrated optically, showing that when one or all of the inputs are present, the system will behave as an XOR gate representing the SUM. When two or three inputs are on, the system acts as AND gate indicating the present of the CARRY bit. Additional parity logic operations are performed using four incoming pulsed communication channels that are transmitted and checked for errors together. As a simple example of this approach, we describe an all‐optical processor for error detection and then provide an experimental demonstration of this idea. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:23:40.372568-05:
      DOI: 10.1002/pssc.201400067
       
  • Unconventional digital computing approach: memristive nanodevice platform
    • Authors: Mahyar Shahsavari; M. Faisal Nadeem, S. Arash Ostadzadeh, Philippe Devienne, Pierre Boulet
      Pages: n/a - n/a
      Abstract: Memristor is a two‐terminal nanodevice that has recently attracted the attention of many researchers. Its simple structure, non‐volatility behavior, high‐density integration, and low‐power consumption make the memristor a promising candidate to act as a switch in digital gates for future high‐performance and low‐power nanocomputing applications. In this paper, we model the behavior of memristor by using Verilog‐A. To investigate its characteristics in a circuit, we use the HSPICE simulator. Furthermore, a library of digital gates are provided by using two approaches to make digital gates: the first one is based on material implication (IMP) and the second one is based on crossbar arrays. Finally, we perform a comparison and evaluation between the two methods. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:23:39.214285-05:
      DOI: 10.1002/pssc.201400069
       
  • Band alignment and effective work function of atomic‐layer deposited
           VO2 and V2O5 films on SiO2 and Al2O3
    • Authors: F. Cerbu; H.‐S. Chou, I. P. Radu, K. Martens, A. P. Peter, V. V. Afanas'ev, A. Stesmans
      Pages: n/a - n/a
      Abstract: The effective work function (EWF) and the energy position of the valence band in 20‐40‐nm thick VO2and V2O5layers grown by atomic layer deposition (ALD) on top of insulating SiO2 and γ‐Al2O3 films were evaluated using the comparison between capacitance‐voltage and internal photoemission measurements. From the capacitance measured at different temperatures on the metal‐VO2(V2O5)‐insulator‐silicon and metal‐insulator‐silicon diodes we found that the both studied vanadium oxides have the same EWF as gold electrodes evaporated on the same oxides. This result is further collaborated by the internal photoemission experiments at the VO2/SiO2 and V2O5/SiO2 interfaces which indicate the energy barrier between the top of the vanadium oxide valence band (in the insulating phase) and the insulator conduction band to be 4.1 ± 0.1 eV. Since the transition from the narrow‐gap VO2 to the wide‐gap V2O5 oxide causes no change in the WF or in the photoemission threshold, we conclude that the ALD‐grown VO2 in its insulating phase represents a a heavily‐doped semiconductor which becomes metallic upon metal‐insulator transition without significant EWF change. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-20T06:23:32.486562-05:
      DOI: 10.1002/pssc.201400037
       
  • Conductivity patterning with Physarum polycephalum: natural growth and
           deflecting
    • Authors: Alice Dimonte; Tatiana Berzina, Angelica Cifarelli, Valentina Chiesi, Franca Albertini, Victor Erokhin
      Pages: n/a - n/a
      Abstract: The present work is dedicated to the use of Physarum polycephalum slime mold, an unicellular organism self‐adapting, self‐repairing and self‐repellent, for the realization of elements for unconventional computational systems. Physarum continuously changes its shape under the influence of different stimuli like attractors (food in the most of cases) and repellents (light, temperature, humidity, chemicals), creating optimized networks. Here we introduced a new, softer, element able to influence the motion and the shape of Physarum: the DEFLECTOR. Physarum polycephalum, loaded with magnetic particles and placed under a magnetic field, is conditioned in its active zones routing and shape topology networks. Thus, slime mold can be used as particles carrier and, moreover, it is possible to deflect the mold movement and realize chemical composites in defined places what allows to consider Physarum as a simple version of bio‐robot. On the other hand, we have realized the idea of creating networks with the varied conductivity with the slime mold on polyaniline (PANI) substrates. As the result, it was shown that Physarum growth results in the changing of the conductivity state of PANI layers in different ways, providing negative and positive patterning of the sample. The possibility to control mold's direction with a deflector together with the capability of Physarum to pattern PANI surfaces are the main points of this work. This paper opens new possibilities of the development in many fields and areas from the electrical circuit design and the bio‐actuators (bio‐) robot research, up to the unconventional computing and realization of a novel category of polymer‐mold‐modified. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T08:10:25.729133-05:
      DOI: 10.1002/pssc.201400077
       
  • Nanoengineered polymeric capsules as elements of unconventional computing
           systems
    • Authors: Svetlana Erokhina; Laura Pastorino
      Pages: n/a - n/a
      Abstract: Nanoengineered polymeric capsules are smart objects with a shell of 4‐20 nm thick and a core volume, that can be filled with the different substances. The capsules can be delivered to a desirable place and the encapsulated material release can be triggered by the variation of the environmental medium parameters or by the external action. In this paper, we present important steps of the capsule preparation and discuss how they can be used in the field of chemical and bio‐chemical unconventional computer systems. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T08:10:24.536825-05:
      DOI: 10.1002/pssc.201400074
       
  • Microscopic and spectroscopic analysis of the nature of conductivity
           changes during resistive switching in silicon‐rich silicon oxide
    • Authors: Mark Buckwell; Luca Montesi, Adnan Mehonic, Omer Reza, Leon Garnett, Manveer Munde, Stephen Hudziak, Anthony J. Kenyon
      Pages: n/a - n/a
      Abstract: Redox‐based resistive random access memory (RRAM) has the scope to greatly improve upon current methods of data storage, despite incomplete understandings of material switching mechanisms. We make use of atomic force microscopy (AFM), conductive atomic force microscopy (cAFM) and X‐ray photoelectron spectroscopy (XPS) to characterise the physical processes occurring in the changes in conductance state in silicon‐rich silicon oxide RRAM. Surface analyses of the insulating oxide layer of our devices are employed to establish the chemical and structural properties of pristine and switched states. The removal of oxygen from the active layer is observed to be concomitant with the appearance of varying degrees of surface distortion and regions of high conductivity in an otherwise‐insulating material. These results support the currently‐recognised model of a resistive switching mechanism that is reliant upon the migration of oxygen ions under an electrical bias. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T07:40:25.645425-05:
      DOI: 10.1002/pssc.201400160
       
  • Formation and properties of SiC and C particle nano‐colloids in
           non‐polar liquids
    • Authors: Hamza Hajjaji; Yuriy Zakharko, Sergeï Alekseev, Gérard Guillot, David Philippon, Philippe Vergne, Jean‐Marie Bluet
      Pages: n/a - n/a
      Abstract: Electrochemical etching of polycrystalline SiC is used in order to form SiC nanoparticles. During the process, both SiC and carbon‐related nanoparticles like onion like carbon are formed. The two different species can be selected by centrifugation. Both nanoparticles have been functionalized for dispersion in non‐polar liquids. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T07:40:24.383773-05:
      DOI: 10.1002/pssc.201400210
       
  • Perspectives of enhancement of p‐type conductivity in ZnO nanowires
    • Authors: Tamar Tchelidze; Tamaz Kereselidze, Teimuraz Nadareishvili
      Pages: n/a - n/a
      Abstract: Semiconductor nanowires are believed to act as key elements in future nanoscaled optoelectronic devices, as they offer intriguing electrical and optoelectronic properties. However, the future of any semiconductor nanowire technology will essentially rely on their doping capability. The availability of both n‐ and p‐type semiconductors is important for the realization of nanowire‐based electronics. Wide band gap semiconductors, such as ZnO, suffer from doping polarity. They can be easily doped n‐ (or p‐type) to the expense of difficulties for doping of opposite type. Space confinement changes donor and acceptor ionization energies. The main factor that makes difficult to obtain n‐ or p‐conductivity is the formation of compensating defects. Compensating processes are strongly affected by electronic structure of the system: band gap, ionization energies of donors, acceptors and their compensation centers. In the presented work we calculated energy levels of an electron bound to Coulomb impurity that is incorporated in semiconductor nanowire. Effect of dielectric confinement on ionization energies are considered as well. For analyzing perspectives of suppressing processes of compensation and achieving low ohmic p‐conductivity Kröger method of quasi‐chemical equations is used. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T07:40:23.506535-05:
      DOI: 10.1002/pssc.201400150
       
  • Crystalline structure and optical properties of GaS‐CdS
           nanocomposite
    • Authors: Iuliana Caraman; Elmira Vatavu, Liviu Leontie, Marius Stamate, Dumitru Untila
      Pages: n/a - n/a
      Abstract: The GaS‐CdS composite has been obtained by intercalation of Cd in GaS single crystalline plates. The XRD analysis show that peaks determined by CdS and CdGa2S4 are found along with GaS characteristic reflection in intercalated samples. The spectral dependence of absorption coefficient for the GaS‐CdS composite is determined by both absorption mechanisms in GaS and in CdS components for α > 103 cm–1. The photoluminescence spectrum (78 K) of the composite consists of radiative recombination bands characteristic for both CdS and GaS. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T07:40:22.527132-05:
      DOI: 10.1002/pssc.201400146
       
  • Ion current rectification effect of porous graphene membrane
    • Authors: Jian Zeng; Huijun Yao, Dan Mo, Jinglai Duan, Jiande Liu, Dianliang Cao, Pengfei Zhai, Jie Liu, Youmei Sun
      Pages: n/a - n/a
      Abstract: Graphene, as an important ideal two‐dimensional material, is driving more and more attention because of its unique mechanical strength and chemical stability. In this work, the rectification effect of nanopores in graphene/PET structure at different KCl concentration is investigated. Porous graphene membrane is obtained by using heavy ion irradiation technology. During investigating the ion current rectification effect, PET membrane with conical pores acts as porous graphene's substrate. The rectification coefficient of nanopores in graphene/PET is deduced from the current‐voltage curves at KCl solution with different concentrations. The porous graphene/PET shows a relative higher rectification ratio and is more resistive to pH value while comparing the nanopores in PET. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T07:40:21.71662-05:0
      DOI: 10.1002/pssc.201400144
       
  • X‐ray photoelectron spectroscopy of gold nanowire arrays embodied in
           ion‐track template
    • Authors: Huijun Yao; Lu Xie, Jinglai Duan, Dan Mo, Yonghui Chen, Shuangbao Lv, Jie Liu, Youmei Sun
      Pages: n/a - n/a
      Abstract: The gold nanowire arrays with different diameter and length were successfully prepared in etched ion‐track template assisted with electrochemical deposition method and the nanowire's crystal structure and morphology were characterized by transmission electron spectroscopy (TEM) and scanning electron spectroscopy (SEM). The X‐ray photoelectron spectroscopy (XPS) was used to analyse the electronic states of gold nanowire arrays embodied in the template. It was found that the 4f core level binding energy of gold nanowire shifted toward higher binding energy when comparing with bulk gold. The positive binding energy shift increased significantly with decreasing nanowire's length or diameter. The enhanced final‐state effect was considered to explain the 4f binding energy shift of gold nanowire arrays embodied in template finally. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T07:40:20.556391-05:
      DOI: 10.1002/pssc.201400134
       
  • Effect of TiOx/TiO2 layer thickness on the properties of the pulsed laser
           deposited memristive device
    • Authors: G. I. Tselikov; A. V. Emelyanov, I. M. Antropov, V. A. Demin, P. K. Kashkarov
      Pages: n/a - n/a
      Abstract: Memristive properties of the pulsed laser deposited Pt/TiOx/TiO2/Pt heterostructures with different layer thicknesses are studied. It was found that the memristor device provides nonmonotonic dependence of the ratio of its resistance in low and high conductive states Roff/Ron on layers thickness. The maximum value of the ratio Roff/Ron = 200 is obtained when the thickness of both TiOx and TiO2 layers is 30 nm. The dependence of the stoichiometry index of deposited layers from their thicknesses is studied by means of Auger spectroscopy measurements. The nonmonotonic behaviour of the ratio Roff/Ron on layer thickness is discussed in terms of wide stoichiometry distribution through the amorphous TiOx/TiO2 structure. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T07:40:19.341634-05:
      DOI: 10.1002/pssc.201400123
       
  • Features of titanium oxide memristor fabrication by pulsed laser
           deposition
    • Authors: Natalia Maslova; Yulia Khrapovitskaya, Ivan Sokolov, Yulia Grishchenko, Dmitry Mamichev, Maxim Zanaveskin
      Pages: n/a - n/a
      Abstract: The structural and electrophysical properties of titanium oxide based memristor obtained by pulsed laser deposition were analysed. The experimental results found the possibility of fine tuning of memristor active layers stoichiometry during deposition. In addition, the atomic force microscopy analysis of the surface of titanium oxide films revealed its high morphological homogeneity and continuity. The obtained memristors with gold contacts have been possessed bipolar switching mechanism and high endurance. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T07:40:18.480223-05:
      DOI: 10.1002/pssc.201400110
       
  • The titanium oxide memristor contact material's influence on element's
           cyclic stability to degradation
    • Authors: Yulia Khrapovitskaya; Natalia Maslova, Ivan Sokolov, Yulia Grishchenko, Dmitry Mamichev, Maxim Zanaveskin
      Pages: n/a - n/a
      Abstract: The effect of contact material on cyclic degradation stability of titanium oxide based memristor has been investigated. The memristors were made by pulsed laser deposition which has several advantages in comparison with other methods of memristor fabrication. The use of gold instead of platinum as a contact allows significantly the increase in memristor endurance. The results obtained are interpreted with a lower oxygen diffusion by gold contact compared to platinum which retains the properties of memristor functional layers. The titanium oxide memristor with high stability to cyclic resistive switching (up to 3000 cycles) has been obtained. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T07:40:17.503183-05:
      DOI: 10.1002/pssc.201400109
       
  • Morphologic, structural, and optical characterization of sol‐gel
           derived TiO2 thin films for memristive devices
    • Authors: Valentina Prusakova; Cristina Armellini, Alessandro Carpentiero, Andrea Chiappini, Cristian Collini, Sandra Dirè, Maurizio Ferrari, Leandro Lorenzelli, Marco Nardello, Simone Normani, Alessandro Vaccari, Alessandro Chiasera
      Pages: n/a - n/a
      Abstract: Sol‐gel derived TiO2 thin films were prepared by spin‐ coating from an alcoholic solution of titanium isopropoxide. With the aim to develop titania layers suitable for memristive devices, the films were deposited onto test structures based on fused silica quartz substrates patterned with a Ti (5nm)/Pt (50nm) layer. The reported fabrication protocol is suitable for the development of a memristive device. Optical, structural, and morphological features of the samples were investigated with complementary techniques, such as scanning electron microscopy (SEM), prism coupling m‐line and micro‐Raman spectroscopy as well as transmittance and profilometry measurements. The quality of the surface of the obtained films was evaluated by SEM technique, and the morphology of samples deposited with different fabrication protocols was investigated. Additionally, a computer code for the refractive index and thickness estimation from the transmittance spectra was developed by unconstrained optimization procedure. The results of simulation were in good agreement with the experimental data obtained by m‐line measurements. Moreover, the porosity of a specific set of test unannealed films has been estimated. TiO2 films exhibit thickness of tens of nm, and micro‐Raman spectroscopy in conjunction with SEM indicate the presence of anatase phase after thermal annealing at 400 °C. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-11-19T07:40:16.314219-05:
      DOI: 10.1002/pssc.201400101
       
  • Preparation and characterization of doped and undoped nanoporous carbon
           for heavy metal removal from aqueous solution
    • Authors: Imed Ghiloufi; Lassaad El Mir
      Pages: n/a - n/a
      Abstract: Nanoporous composites based on pyrogallol and formaldehyde (PF) reached by metallic nickel nanoparticles have been prepared using sol‐gel method to obtain PF/Ni adsorbent materials. The obtained samples were subjected of heat treatment under inert atmosphere at different pyrolysis temperatures during two hours. The X‐ray diffraction analysis (XRD) shows that PF sample were composed by amorphous material while PF/Ni XRD spectra exhibited the presence of metal nickel characteristic lines. The transmission electron microscopy (TEM) images indicate that PF sample was formed by homogenous material, and metallic nickel nanoparticles sized around 30 nm were dispersed in the PF/Ni nanocomposite. These materials were used to study the effect of pyrolysis temperatures on the uptake of Cr, Ni, Cd and Co from aqueous solution. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:22.550571-05:
      DOI: 10.1002/pssc.201400017
       
  • Investigation of AlGaInP heterostructures under gamma‐irradiation in
           the field of restructuring defect structure
    • Authors: Alexander Gradoboev; Ksenia Orlova
      Pages: n/a - n/a
      Abstract: The given paper presents the results of studying the resistance of AlGaInP heterostructures with multiple quantum wells to 60Co gamma‐quantum irradiation. The research was completed for light emitting diodes (λ = 630 nm). The irradiation was completed under the passive powering mode without the imposition of the electric field while the level of exposure was characterized by the absorbed dose. It has been established that the emission power reduction has three stages. At the first stage the radiation power reduces due to radiation‐induced transformation of the initial structure defects, at the second stage – due to the introduction of radiation defects, in the extreme case the second stage transforms into the third stage (low electron injection mode). On the boundary between the first and the second stages transient processes are observed – restoration of emission power against its general reduction. The authors identify the heterostructures for which a pronounced effect of small doses is observed – restoration of emission power due to radiation‐induced relaxation of mechanical stresses without formation additional structural defects. The given process precedes the first stage of emission power reduction under gamma quantum irradiation. Besides, the authors identify the heterostructures which demonstrate two additional transient processes at the first stage. The researchers also establish the relations allowing describing the emission power change at the given stages. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:21.200279-05:
      DOI: 10.1002/pssc.201400072
       
  • Magnetic resonance in ion‐beam synthesized Fe3Si films (computer
           simulation)
    • Authors: N. A. Balakirev; V. A. Zhikharev
      Pages: n/a - n/a
      Abstract: High dose Fe+ ion implantation into Si assisted by an external magnetic field parallel to silicon surface results in the formation of thin granular film with pronounced uniaxial magnetic anisotropy in the film plane. It was suggested that the anisotropy is caused by the growth of elongated clusters of magnetic silicide Fe3Si. In the present work, the features of magnetic resonance spectra for two‐dimensional array of elongated clusters are numerically studied. Absorption spectra reveal anisotropy when observed in the magnetic field lying in the film plane. In magnetic field perpendicular to the film the dipole‐dipole interaction between the clusters results in a bimodal resonance signal at low level of the film filling. The dipolar field distribution over the (400x400) lattice for several values of the lattice filling is computer simulated. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:20.182638-05:
      DOI: 10.1002/pssc.201400083
       
  • Effect of 2.5 MeV proton irradiation on the critical parameters of
           composite HTS tapes
    • Authors: Landysh Antonova; Timofey Demikhov, Alexey Troitskii, Alexander Didyk, Alexander Kobzev, Alexander Yurasov, Sergey Samoilenkov, Galina Mikhailova
      Pages: n/a - n/a
      Abstract: In this paper we study the radiation resistance of high temperature superconductor (HTS) tapes based on GdBCO produced by SuperOx‐Japan Company to proton irradiation with an energy of 2.5 MeV in the fluence range from 6.1×1014 p/cm2 to 1×1017 p/cm2. The dependences of critical parameters on radiation fluencies were investigated. Strong influence of radiation on critical current is revealed at T=77 K in the self‐field of the sample. The change of the critical temperature dependence is not so significant. The critical current increase after proton irradiation was not revealed at the experiment conditions (at T = 77 K). The Van de Graaff accelerator in Dubna was used for the iradiation. Measurements of Tc and Ic of the samples were carried out by the DC resistive method. A radiation resistance threshold Φ = 6×1015 p/cm2 was determined. This means that the critical current does not drop by more than 20% of the initial value. The current decreases by more than an order of magnitude at Φ = 6×1016 p/cm2 and 77 K without external magnetic field. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:19.659513-05:
      DOI: 10.1002/pssc.201400104
       
  • Ion beam synthesis of embedded III‐As nanocrystals in silicon
           substrate
    • Authors: Rim Khelifi; Mathieu Frégnaux, Yann Le Gall, Dominique Muller, Guy Schmerber, Daniel Mathiot
      Pages: n/a - n/a
      Abstract: Our goal is to use the versatility of ion beam synthesis to grow nanocrystals of InxGa1‐xAs alloys embedded in a silicon substrate. We study, first, the annealing conditions necessary to grow well defined InAs and GaAs binary nanocrystals. High dose of As, Ga and In is implanted, respectively, at 130, 130 and 180 keV to have overlapping as‐implanted profiles. The nanocrystals growth is then achieved by rapid thermal annealing at various temperatures between 650 and 800 °C for 1 min under an argon gas flow. Rutherford backscattering spectroscopy profiles show that no significant impurity out‐diffusion occurs below 800 °C for both systems. In and As thermal redistributions lead to superposed profiles. Raman spectroscopy measurements prove that InAs nanocrystals are formed above 650 °C, while 800 °C annealing is necessary to obtain GaAs nanocrystals and show that these thermal budgets are enough to fully recrystallize the implanted layer. Grazing incidence X‐ray diffraction patterns exhibit clearly InAs and GaAs related peaks. These results prove that GaAs and InAs nanocrystals can be grown in a common temperature range (700‐800 °C), opening the route to the growth of ternary InxGa1‐xAs alloys in the same conditions. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:18.297695-05:
      DOI: 10.1002/pssc.201400107
       
  • Contribution of iron silicide nanoparticles to the magnetic behavior of
           annealed Fe‐implanted 6H‐SiC
    • Authors: M. L. Diallo; A. Fnidiki, M. Viret, M. Drouet, D. Eyidi, A. Declémy
      Pages: n/a - n/a
      Abstract: The Fe‐implanted SiC is an interesting system in the DMS field although ion implantation induces strong microstructural defects needing post‐implantation treatments for recovery. These post‐implantation treatments often induce the formation of parasitic magnetic secondary phases. In this work, using XRD, SEM, TEM, CEMS and SQUID it is shown that post‐annealing of Fe‐implanted 6H‐SiC at 380°C with a few 1016Fe+ ions/cm2 at 900°C/60min, 1000°C/85min and 1300°C/4min enhanced the ferromagnetic ordering which can be partially explained by the formation of iron rich superparamagnetic nanoparticles. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:17.51796-05:0
      DOI: 10.1002/pssc.201400114
       
  • Photoluminescence properties of lamellar nano‐composites obtained by
           Cd intercalation of GaSe and GaSe:Eu single crystals
    • Authors: Dumitru Untila; Valeriu Cantser, Mihail Caraman, Igor Evtodiev, Liviu Leontie, Liliana Dmitroglo
      Pages: n/a - n/a
      Abstract: In this work surface morphology, composition and photoluminescence at 293 K and 78 K, of composite obtained by intercalation of GaSe and GaSe:Eu (0.49 at.% and 1.00 at.%) single crystal lamellas with Cd from vapor phase at 753 K and 830 K are investigated. As‐obtained composite consists of CdSe and microstructured GaSe single crystallites. Photoluminescence spectrum of GaSe:Eu single crystal lamellas is composed of Eu3+ emission band 5D0 → 7F1, 5D0 → 7F2 and 5D1 → 7F3 transitions) and indirect exciton line in GaSe crystallites. Emission spectrum of single crystalline GaSe–CdSe composite, at 78 K and 293 K, consists of donor‐acceptor band in GaSe microcrystallites and emission band of CdSe crystallites. Composite derived from the intercalation of GaSe:Eu (0.49 at.%) single crystals with Cd exhibits strong visible luminescence. Its quasi‐continuous photoluminescence spectrum is produced by superposition of luminescent emissions of CdSe nano‐ and microparticles, and microstructured GaSe. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:16.088233-05:
      DOI: 10.1002/pssc.201400127
       
  • Raman microscopy as a defect microprobe for hydrogen bonding
           characterization in materials used in fusion applications
    • Authors: Cédric Pardanaud; Younès Addab, Céline Martin, Pascale Roubin, Bernard Pegourié, Martin Oberkofler, Martin Köppen, Timo Dittmar, Christian Linsmeier
      Pages: n/a - n/a
      Abstract: We present the Raman microscopy ability to detect and characterize the way hydrogen is bonded with elements that will be used for ITER's plasma facing components. For this purpose we first use hydrogenated amorphous carbon samples, formed subsequently to plasma‐wall interactions (hydrogen implantation, erosion, deposition...) occurring inside tokamaks, to demonstrate how this technique can be used to retrieve useful information. We pay attention in identifying which spectroscopic parameters are sensitive to the local structure (sp3/sp2) and which gives information on the hydrogen content using isothermal and linear temperature ramp studies on reference samples produced by plasma enhanced chemical vapor deposition. We then focus on the possibility to use this fast, non‐destructive and non‐contact technique to characterize the influence of hydrogen isotope implantation in few nanometers of graphite and beryllium as C is still used in the JT‐60 tokamak and Be is used in JET and will be used as plasma‐facing component in the future reactor ITER. We also pay attention on implantation in tungsten oxide which may be formed accidently in the machine. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:15.463186-05:
      DOI: 10.1002/pssc.201400141
       
  • Ion‐induced degradation of phase stability and hardness of TiZrSiN
           nanocomposite thin films
    • Authors: V. V. Uglov; G. Abadias, S. N. Dub, G. N. Tolmachova, S. V. Zlotski, A. Michel, I. A. Saladukhin, S. S. Leshkevich, P. I. Gaiduk, V. Jasulaitene
      Pages: n/a - n/a
      Abstract: The effects of ion irradiation (180 keV Xe2+, doses 1×1016 cm–2 and 5×1016 cm–2) on the structure, phase composition and hardness of thin (300 nm) nanocomposite (Ti,Zr)1‐xSixNy films deposited by magnetron sputtering (silicon concentration x≤0.22) were studied. It was found that the increase in Si content results in the transformation of structure from nanocrystalline (x ≤ 0.07, grain size about 18 nm) to nanocomposite (0.07 ≤ x ≤ 0.11, grain size about 8 nm) and then to amorphous (x ≥ 0.18) state. Nanocomposite films consist of two‐phase: crystalline cubic (Ti,Zr)N grains (∼ 8 nm size) surrounded by a thin amorphous a ‐TiSiN layer. Ion irradiation with Xe ions triggers the crystallization of (Ti,Zr)N‐rich grains for amorphous films (x≥0.18). It was found that irradiation leads to a decrease in nanoindentation hardness, due to the accumulation of Xe ion in the film, as well as the elemental redistribution of solid solution constituents in the area of collisions cascades. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:13.959331-05:
      DOI: 10.1002/pssc.201400142
       
  • Kinetic Monte Carlo simulation of nanostructural evolution under
           post‐irradiation annealing in dilute FeMnNi
    • Authors: M. Chiapetto; C. S. Becquart, C. Domain, L. Malerba
      Pages: n/a - n/a
      Abstract: Post‐irradiation annealing experiments are often used to obtain clearer information on the nature of defects produced by irradiation. However, their interpretation is not always straightforward without the support of physical models. We apply here a physically‐based set of parameters for object kinetic Monte Carlo (OKMC) simulations of the nanostructural evolution of FeMnNi alloys under irradiation to the simulation of their post‐irradiation isochronal annealing, from 290 to 600 °C. The model adopts a “grey alloy” scheme, i.e. the solute atoms are not introduced explicitly, only their effect on the properties of point‐defect clusters is. Namely, it is assumed that both vacancy and SIA clusters are significantly slowed down by the solutes. The slowing down increases with size until the clusters become immobile. Specifically, the slowing down of SIA clusters by Mn and Ni can be justified in terms of the interaction between these atoms and crowdions in Fe. The results of the model compare quantitatively well with post‐irradiation isochronal annealing experimental data, providing clear insight into the mechanisms that determine the disappearance or re‐arrangement of defects as functions of annealing time and temperature. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:13.214493-05:
      DOI: 10.1002/pssc.201400143
       
  • Study on optical properties and γ‐ray irradiation resistance of
           heavy metal oxide tellurite glasses
    • Authors: Yongtao Zhou; Stefania Baccaro, Alessia Cemmi, Yunxia Yang, Guorong Chen
      Pages: n/a - n/a
      Abstract: Optical properties and irradiation resistance of heavy metal oxide tellurite glasses in the TeO2‐PbO‐Bi2O3‐B2O3 system doped with different ions are investigated. The results indicate that the matrix glass has a moderate UV cut‐off edges at about 386 nm wavelength. The UV cut‐off positions are obviously shifted to red by the addition of Ce4+. The introduction of Cr3+, Ce4+ and Ni2+ into the matrix glass exerts positive influences on irradiation resistance of glasses and cerium plays the most pronounced role. Such phenomena are mainly attributed to the variable valences of these cations. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:11.935369-05:
      DOI: 10.1002/pssc.201400148
       
  • The inelastic thermal spike model applied to metal/insulator interfaces
    • Authors: A. Chettah; H. Amekura, R. Baeker, H. Kucal, Y. Takeda, M. Matsuda, A. Iwase
      Pages: n/a - n/a
      Abstract: Recently, inter‐diffusion induced by 200 MeV Xe ion irradiation in metal‐insulator interfaces (Bi/Al2O3and Au/Al2O3) was investigated experimentally via in‐situ RBS measurements using 16 MeV C ions. In this work, the experimental results were tried to be explained by the inelastic thermal spike model (ITSM). Although these results explained qualitatively the inter‐diffusion, the experimentally observed diffusion length (∼800 nm) at a fluence value of 7 x 1013cm‐2was much larger than the estimated maximum value within the ITSM (∼80 nm). It was found that the Bi concentration profiles measured via in‐situ RBS could not be fitted by simple diffusional ones. We suggested that the main responsible of the huge atomic diffusion exhibited by Bi in Al2O3could be the directional motion of Bi atoms in molten Al2O3triggered off by the pressure due to liquid‐vapor phase transition of Bi near the interface. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:11.231224-05:
      DOI: 10.1002/pssc.201400149
       
  • Modification and reduction of defects in thin gate dielectric of MIS
           devices by injection‐thermal and irradiation treatments
    • Authors: Vladimir V. Andreev; Gennady G. Bondarenko, Vladimir M. Maslovsky, Alexander A. Stolyarov, Dmitry V. Andreev
      Pages: n/a - n/a
      Abstract: The effect of high‐field injection‐thermal and irradiation treatments on the MIS structures reliability and defect reduction in the nanoscale gate dielectric has been investigated. Injection‐thermal treatment (ITT) of MIS structures consisted of high‐field electron injection into gate dielectric with the charge of defined value and subsequent parameter stabilization of MIS structures by means of thermal annealing. The MIS structures have been studied using novel techniques of multilevel current stress. Our study shows that the ITT can improve reliability of MIS structures (increase of charge‐to‐breakdown value) and identify defective structures. The ITT provides structural modification of SiO2 and Si–SiO2 interfaces. It has been shown that the ITT at elevated temperatures can reduce the reliability of MIS devices. Performing ITT at high temperatures leads to decrease of charge‐to‐breakdown average value in MIS structures. It has been demonstrated that irradiation treatment allows to reduce density of defects in thermal SiO2 films, SiO2 films doped with phosphorus, oxynitride films and as a result to increase reliability of MIS devices. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:09.449695-05:
      DOI: 10.1002/pssc.201400151
       
  • Thermodynamic analysis of defect formation in BiFeO3
    • Authors: T. Tchelidze; T. Gagnidze, A. Shengelaya
      Pages: n/a - n/a
      Abstract: In this paper the thermodynamic analysis of equilibrium concentration of defects for the system BiFeO3(solid)‐O2 (gas) is carried out. The analysis is performed by the Kroger method of quasi‐chemical equations. The concentration of defects and free carriers vs. oxygen partial pressure in surrounding atmosphere at definite temperature are obtained. The calculations were carried out for 3 nm BiFeO3 nanowires too. When the defects ionization energies and material band gap are increased in nanowires, the picture of defects thermodynamics is changed. In 3 nm nanowire the area of self‐compensation is significantly broadened. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-29T05:10:08.322224-05:
      DOI: 10.1002/pssc.201400153
       
  • Thermodynamic study of the ternary system
           gallium‐arsenic‐bismuth
    • Authors: N. Elayech; H. Fitouri, Y. Essouda, A. Rebey, B. El Jani
      Pages: n/a - n/a
      Abstract: Binary thermodynamic data, successfully used for phase diagram calculations of binary system Ga‐As, Ga‐Bi and As‐Bi were used for prediction of phase equilibria in ternary Ga‐As‐Bi system. The parameters for the thermodynamic models of the constituent binary systems and those for the Ga‐As‐Bi system are optimized in this study using data on phase equilibria and data on the different alloys available in the literature and calculated in the present work. The implications of the phase data for solution epitaxy are discussed. The liquidus surface and isothermal section were calculated. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-10T08:20:54.653667-05:
      DOI: 10.1002/pssc.201400147
       
  • Optical properties of plasmonic nanoparticles distributed in size
           determined from a modified Maxwell‐Garnett‐Mie theory
    • Authors: Y. Battie; A. Resano‐Garcia, N. Chaoui, A. En Naciri
      Pages: n/a - n/a
      Abstract: The optical properties of spherical gold and silver nanoparticles distributed in size are investigated through a new effective medium theory. It is about the modified Maxwell‐Garnett‐Mie theory (MMGM) that takes into account the intrinsic confinement, dynamic effects and the nanoparticle radius distribution. In the case of monodispersed nanoparticles with a radius in the 1 nm‐25 nm range, MMGM is equivalent to the Mie theory. Compared to the conventional effective medium theory, we demonstrate that MGMM gives better description of the measured extinction spectra of colloidal gold and silver solutions. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-10T08:20:53.365108-05:
      DOI: 10.1002/pssc.201400190
       
  • Green light‐emitting CdTe nanocrystals: synthesis and optical
           characterizations
    • Authors: Luciana Algieri; Roberta Rosato, Maria Elena Mosca, Maria Lucia Protopapa, Anna Grazia Scalone, Francesca Di Benedetto, Luigi Bucci, Leander Tapfer
      Pages: n/a - n/a
      Abstract: In this work, we report on the synthesis of CdTe nanocrystals (NCs) by using of two different saturated long‐chain capping ligands, oleic (OA) and myristic acids (MA), and investigate their influence on the nanocrystals optical properties. The main goal of our study is to identify the ligand that allows slowing down the growth rate of the NCs after nucleation, in order to obtain small enough nanocrystals emitting in the blue‐green part of the optical spectrum. Our results show clearly that oleic acid allows a good control on the CdTe NCs growth, finally leading to a fine‐tuning of the NCs size‐dependent emission from the green to the yellow part of the spectrum. Instead, a faster reaction kinetics, which arises in a lower possibility to produce small NCs emitting in the green part of the spectrum, was noticed using myristic acid. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
      PubDate: 2014-10-10T08:20:50.640015-05:
      DOI: 10.1002/pssc.201400203
       
  • 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
       
  • 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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