bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion Track Enabled High Aspect Ratio Flexible PCB Via Technology
Authors: Lindeberg Mikael , Yousef Hanna , Öjefors Erik , Rydberg Anders , Hjort Klas 
Published: April 2011

ABSTRACTBy combining ion track technology with ordinary low-resolution printed circuitboard lithography it is possible at low cost to create high aspect ratios via connectors, as solid plugs or consisting of bundles of sub-micron connector wires at a small total cross-section.Ion track enabled microwave circuits in flexible printed circuit boards are suggested to be used in applications like inductors, ferromagnetic resonance microwave filters, circulators and magnetoresistive sensors. In this paper we demonstrate this technology with integrated printed circuitboard devices in two different flexible polyimide-based foils (Espandex and Kapton HN), using the ultra-high-density vias and the sub-micron wires.
Observation of Enhanced Faraday Effect in Garnet-Based Magnetophotonic Crystals
Authors: Fedyanin A. A. , Kobayashi D. , Nishimura K. , Uchida H. , Inoue M. , Aktsipetrov O. A. 
Published: April 2011

ABSTRACTThe fabrication of one-dimensional magnetophotonic crystals (MPC) composed from Bi-substituted yttrium-iron-garnet films separated by the silicon oxide layers is presented. The enhancement of the Faraday rotation angle is observed at the spectral regions of the photonic band gap edges. The effective Faraday rotation achieves the values up to 1.5 degrees per micron at 1100-nm-wavelength.
Photonic Crystal Ridge Waveguides on Magnetic Garnet Films
Authors: Li R. , Huang X. , Levy M. , Yang H. C. 
Published: April 2011

ABSTRACTThis paper discusses the fabrication and testing of on-chip photonic crystals in ferrite waveguides. Photonic bandgap engineering can produce Faraday rotators with highly enhanced polarization rotation for ultra-small integrated optical isolators. The main challenges to such devices are the elimination of linear birefringence and the fabrication of planar photonic bandgap nanostructures. These challenges are addressed in the present article. In particular, we demonstrate the presence of stopbands and resonant polarization response in single-defect magneto-optic photonic crystal ridge waveguides.
YIG Thin Film-Based Two-Dimensional Magnonic and Magneto-Photonic Crystals
Authors: Nikitov S.A. , Tsai C.S. , Gulyaev Yu.V. , Filimonov Yu.A. , Volkov A.I. , Vysotskii S.L. , Tailhades Ph. 
Published: April 2011

ABSTRACTA new type of photonic crystals entitled “magnonic crystals (MC)” that exhibit forbidden gaps in the microwave spectrum of magnetostatic spin waves (MSW) are reported. The topography of the MCs that consist of two-dimensional (2-D) etched holes periodic structure in yttrium iron garnet films was studied by atomic force and magnetic force magnetometry. The propagation characteristics of spin waves in such 2-D MCs was measured and analyzed.
Effective energy landscapes for mobile ions in solid electrolytes
Authors: Adams Stefan 
Published: April 2011

ABSTRACTBond valence mismatch landscapes may serve as simple models of the effective energy landscapes for mobile ions in solid electrolytes. Thereby they provide a tool to identify the ion transport mechanism and allow to predict the activation energy of the ionic conduction. Accounting for the mass dependence of the conversion from the BV mismatch into an activation energy scale yields a correlation that holds for different types of mobile cations. While in most cases the analysis of bond valence mismatch landscapes is consistent with the ion transport mechanism derived from experimental or other computational evidence, the presumed prototype of trivalent cation conductors Sc2(WO4)3 is discussed as an example, where the BV analysis of transport pathways suggests that the interpretation of previous experimental investigations has to be reconsidered. Both bond valence calculations and molecular dynamics simulations suggests that the most probable mobile species in stoichiometric Sc2(WO4)3 is neither Sc3+ nor individual O2- but the complex divalent anion WO42-.
Structure and Electrochemical Performances of the Li1+x(Ni0.425Mn0.425Co0.15)1−xO2 Materials
Authors: Tran N. , Croguennec L. , Weill F. , Jordy C. , Biensan P. , Delmas C. 
Published: April 2011

ABSTRACTLayered Li1+x(Ni0.425Mn0.425Co0.15)1−xO2 materials (x = 0 and 0.12) have been prepared by a coprecipitation method. The substitution of × Li+ ions for × metal ions in the transition metal layers leads to an increase in the average transition metal oxidation state for charge compensation, which was found to be due to the oxidation of Ni2+ ions into Ni3+ ions. The refinement in the R-3m space group of the X-ray diffraction data has shown an increasing lamellar character for the structure of these materials, with increasing overlithiation. Electron diffraction has revealed the presence of a √3.ahex. × √3.ahex. superstructure due to a cationic ordering in the transition metal layers, those being packed with faults along the chex.-axis. From an electrochemical point of view, the reversible capacity in the 2–4.3V decreased with overlithiation, in agreement with a decreasing amount of exchangeable electrons.
Solution Synthesis and Electrochemical Properties of V2O5 Nanostructures
Authors: Takahashi Katsunori , Wang Ying , Lee Kyoungho , Cao Guozhong 
Published: April 2011

ABSTRACTWe have prepared Ni-V2O5·nH2O core-shell nanocable arrays for Li+ intercalation applications. Ni-V2O5·nH2O nanocables were prepared via formation of Ni nanorod arrays through the template based electrochemical deposition, followed by coating of V2O5·nH2O on Ni nanorods through electrophoretic deposition. Transmission electron microscopy (TEM) micrograph clearly shows the Ni core was covered completely by a V2O5·nH2O shell. Electrochemical analysis demonstrates that in a current density of 1.6 A/g, the Li+ intercalation capacity of Ni-V2O5·nH2O nanocable array is approximately 10 times higher than that of single-crystal V2O5 nanorod array and 20 times higher than that of sol-gel-derived V2O5 film. Both energy density and power density of such nanocable-array electrodes are higher than the V2O5 film electrode by at least one order of magnitude. Such significant improvement in electrochemical performance is due to the large surface area and short diffusion path offered by the nanostructured V2O5·nH2O.
Oxide Ion Conduction in Oxygen Rich Doped Ba2In2O5+δBrownmillerite
Authors: Rolle Aurélie , Giridharan Nambi V. , Roussel Pascal , Abraham Francis , Vannier Rose-Noëlle 
Published: April 2011

ABSTRACTIn order to stabilize the fast oxide ion conducting properties of the high temperature form of Ba2In2O5at lower temperature, oxygen rich doped Ba2In2O5+δbrownmillerite were prepared by partial substitution of Ba and In with higher valence cation. Vanadium, niobium, tantalum, molybdenum and tungsten were introduced on indium site and bismuth on barium site. Solid solutions were evidenced in all the cases. They were characterized by high temperature X-ray diffraction and impedance spectroscopy. A neutron diffraction study was carried out and allowed to extract preferential oxygen pathways in these materials.
Electrochemical and electrical properties of. Nb- and/or C-containing LiFePO4 composites
Authors: Delacourt C. , Wurm C. , Laffont L. , Sauvage F. , Leriche J.-B. , Bouchet R. , Morcrette M. , Tarascon J-M. , Masquelier C. 
Published: April 2011

AbstractLiFePO4-based powders prepared through various synthesis conditions are presented. Depending on whether the precursors contain carbon or not, LiFePO4-based composites obtained contain significant amounts of carbon as well. We did not succeed in doping LiFePO4 with Nb and produced, instead, crystalline β-NbOPO4 and/or an amorphous (Nb, Fe, C, O, P) matrix around LiFePO4 particles. The total electrical conductivity is of ∼10−9 S.cm−1 at 25°C with an activation energy of ca. 0.65 eV for pure LiFePO4 and LiFePO4/β-NbOPO4 composite. C-containing LiFePO4 samples, including those that had been tentatively doped with Nb, are much more conductive (up to 1.6.10−1 S.cm−1) with an activation energy ΔE ∼ 0.08 eV.
The kinetic and thermodynamic analysis of Li+ in multi-walled carbon nanotubes
Authors: Lin Kezhi , Xu Yanhui , Wang Xiaolin 
Published: April 2011

AbstractThe multi-walled carbon nanotubes (MWNTs) prepared by CVD were used in electrochemical intercalation reaction with Li+. The results of the first several charge-discharge cycles showed that the reversible capacity of the MWNTs was larger than the theoretical capacity of graphitized carbon. The equivalent circuit of the Li+ intercalated into the MWNTs was simulated The diffusion coefficient calculated based on the results of the impedance was in the range between 1 ∼ 4×10−10 cm2s−1. The diffusion coefficient calculated based on the technique of the chronoamperometery was 3.5×10−10 cm2s−1. The diffusion coefficients of the Li+ reacted with MWNTs was in the range of that of the most carbon materials. Using EMF method the partial molar entropy (ΔSx) and partial molar enthalpy (ΔHx) of the Li+ intercalated into the MWNTs were calculated as a function of × in Lix C6 at different temperatures. The values of ΔSx were in the range of 150 ∼ 550 J mol-1K-1. The values of ΔHx at 35 °C were in the range of 40∼110 kJ mol−1. Both of the ΔSx and ΔHx were lower and the changes were smaller than the values of some other carbonaceous materials. By analyzing the results conclusion is obtained that Li+ exist in MWNTs with different types which include adsorption and intercalation types.
Preparation of La1.61GeO5-δ Based Oxide Ion Conducting Film by Pulsed Laser Deposition Method and its Application for SOFC
Authors: Ishihara Tatsumi , Yan Jingwang 
Published: April 2011

ABSTRACTLa1.61GeO5 thin film was fabricated on porous NiO-Ce0.80Sm0.20O2-δ (SDC) substrates by pulsed laser deposition (PLD) under various deposition conditions and the deposition parameters were optimized for obtaining the dense La1.61GeO5-δ film for the electrolyte of SOFC. It has been found that the high substrate temperature and the low oxygen pressure in chamber are suitable for obtaining the dense La1.61GeO5-δ thin film on porous NiO-SDC anode substrate. Since the as-deposited film is amorphous state, post-anneal treatment is essential for obtaining the crystalline La1.61GeO5-δ film. Under the optimized deposition condition, a dense and La1.61GeO5-δ thin film with a thickness of 3 μm can be successfully obtained. The obtained La1.61GeO5-δ film exhibits the electromotive force, which is slightly smaller that that of the theoretical open circuit potential. The power generation property of the cell using the obtained La1.61GeO5-δ film was studied and it was found that the maximum output density of a SOFC single cell using a La1.61GeO5-δ thin film deposited on a porous NiO-SDC substrate reached to 1948.2 mW/cm2 at 1173 K and 424.4 mW/cm2 at 873 K.
Application of CuBr Ion Conductor Thin-Films for Ammonia Gas Detection
Authors: Lauque Pascal , Bendahan Marc , Seguin Jean Luc , Knauth Philippe 
Published: April 2011

ABSTRACTCuBr films are used to design an ammonia gas microsensor operating at ambient temperature, with high sensitivity and much improved selectivity in comparison with usual conductometric microsensors. The specific detection mechanism relies on adsorption of ammonia molecules and interactions with mobile Cu+ ions in the ionic conductor film. The CuBr films can be prepared by r.f. sputtering, but more simply and cost efficiently by chemical reaction of copper metal with bromine ions. Photolithographic techniques are applied to miniaturize the sensor.
Effect of Anodization Bath Chemistry on Photochemical Water Splitting Using Titania Nanotubes
Authors: Mor Gopal K. , Varghese Oomman K. , Paulose Maggie , Shankar Karthik , Grimes Craig A. 
Published: April 2011

ABSTRACTIn this study highly-ordered titania nanotube arrays of variable wall-thickness and length are used to photocleave water under ultraviolet irradiation. We demonstrate that the wall thickness, and length, of the nanotubes can be controlled via anodization bath composition and temperature. The nanotube length and wall thickness are key parameters influencing the magnitude of the photoanodic response and the overall efficiency of the water-splitting reaction. For 22 nm inner-pore diameter nanotube-arrays 6 μm in length, with 9 nm wall thickness, upon 320–400 nm illumination at an intensity of 100 mW/cm2, hydrogen gas was generated at the power-time normalized rate of 51 mL/hr•W at an overall conversion efficiency of 12.5%. To the best of our knowledge, this hydrogen generation rate is the highest reported for a titania-based photoelectrochemical cell.
Nanoporous Si – Organic Composite Photovoltaics
Authors: Levitsky I. A. , Euler W. B. , Tokranova N. , Xu B. , Castracane J. 
Published: April 2011

ABSTRACTWe report novel composite photovoltaics fabricated from nanoporous Si filled with Copper Phthalocyanine (CuPC) and its derivatives, including discotic liquid crystal CuPC. Porous n-type Si (PSi) was prepared electrochemically (pore size 10–20 nm) and filled with CuPC solution by impregnation under pressure or spin casting (liquid crystal CuPC) onto a porous surface followed by heating to the temperature of the mesophase transition. For porous layer with the thickness more than 1500–2000 nm, the conversion efficiency was up to 3% under a tungsten lamp with solar filters (30 mW/cm2). The porous structure and pore filling were examined by SEM and XPS techniques. Photocurrent spectra of the CuPC-PSi cell demonstrate two bands that correspond to the absorbance of the protonated form of CuPC. A comparative analysis between CuPC and liquid crystal CuPC has been made and conclusions about possible mechanisms of charge transfer and transport are drawn. The solar cell optimization is discussed as well.
Polymer solar cells: screen-printing as a novel deposition technique
Authors: Aernouts Tom , Vanlaeke Peter , Poortmans Jef , Heremans Paul 
Published: April 2011

ABSTRACTScreen-printing is studied as deposition technique for conjugated material based layers. Photovoltaics based on the principle of bulk donor-acceptor heterojunction are tested using a blend of poly(2-methoxy-5-(2'-ethyl-hexyloxy)-1, 4-phenylene vinylene) (MEH-PPV) mixed with the C60-derivative (6, 6)-phenyl C61-butyric acid methyl ester (PCBM). First, different solution concentrations of the donor MEH-PPV material and of the blend are subjected to rheology measurements. Addition of the acceptor (PCBM) to a donor material based solution induces a decrease of the solution viscosity. However, the overall flow behaviour of the blend remains similar to that of the MEH-PPV based solution. Secondly, it is shown that specific printer settings have to be used to obtain active layers that are suitable for opto-electronic applications. Finally, devices with an overall energy conversion efficiency of 1.25% under standardized simulated solar illumination (AM1.5G; 100mW/cm2) have been obtained showing that screen-printing can be a suitable technique for the deposition of the active layer of polymer solar cells.
Controlling Organization in Photovoltaic Diodes from Discotic Liquid Crystals via Anode Surface Energy Alteration
Authors: Schmidtke Johanna P. , Müllen Klaus , Friend Richard H. 
Published: April 2011

ABSTRACTWe report the control of molecular ordering of discotic liquid crystals in thin, blended films used in photovoltaic diodes. The external quantum efficiency (EQE%) of photovoltaic diodes incorporating a crystalline hexabenzocoronene (HBC) derivative is improved by lowering the surface energy of the transparent anode surface with a short alkyl chain. Upon increasing the length of the functionalizing group on the anode, we find that the relative efficiency of the HBC component in the blend improves. Evidence of changed film morphology is also presented.
Preparation of CuInGaSe2 Absorber Layer by Nanoparticles-Based Spray Deposition
Authors: Kim Ki-Hyun , Chun Young-Gab , Park Byung-Ok , Yoon Kyung-Hoon 
Published: April 2011

ABSTRACTCIGS nanoparticles for the CIGS absorber layer have been synthesized by low temperature colloidal routes. The CIGS absorber layers for solar cells have been prepared by spray deposition of CIGS nanoparticle precursors (∼20 nm) in glove box under inert atmosphere. An automatic air atomizing nozzle spray system with computer controlled X-Y step motor system was used to spray. The nanoparticle precursor CIGS film was deposited onto molybdenum-coated soda-lime glass substrates (2.5 cm × 5.0 cm) heated to 160°C. The film thickness in the range of 2 μm ± 0.3 μm was attained by spraying of 3 mM colloidal over an area of 12.5 cm2. The coalescence between particles was observed in the CIGS absorber layer under post-treatment of over 550 °C. This is related to the reactive sintering among the nanoparticles to reduce surface energy of the particles. The CuxSe thin film, formed on Mo film by evaporation, improved adhesion between CIGS and Mo layers and enhanced the coalescence of the particles in the CIGS layer. These are closely related to the fluxing of Cu2Se phase which has relatively low melting temperature. The CdS buffer layer was deposited on the CIGS/Mo/soda-lime glass substrate by chemical bath deposition. The CIGS nanoparticles-based absorber layers were characterized by using energy dispersive spectroscopy (EDS), x-ray diffraction (XRD) and high-resolution scanning electron microscopy (HRSEM).
Efficient Bulk Heterojunction Photovoltaic Cells using Sublimable Transition Metal Complex as Photosensitizers
Authors: Wong Hei Ling , Man Kitty Ka Yan , Chan Wai Kin , Kwong Chung Yin , Djurišić Aleksandra B. 
Published: April 2011

ABSTRACTMultilayer bulk heterojunction photovoltaic cells using chlorotricarbonyl rhenium (I) bis(phenylimino)acenaphthene (Re-DIAN) complex as photosensitizer were studied. The complex is sublimable, has lower band gap, good thermal stability and good processibility. It has broad absorption in UV-visible region. Therefore, Re-DIAN exhibits good photosensitising property for photovoltaic cells. Multilayer bulk heterojunction photovoltaic cells with simple structures were fabricated base on Re-DIAN complex. The active layer consists of a blend of Re-DIAN and fullerene that were co-deposited in the same layer by vacuum deposition. The photovoltaic properties of the devices were studied by irradiaton under AM1.5 simulated solar light. The effects of changing the co-deposition film thickness, amount of Re-DIAN photosensitizer, and hole transporting materials were studied.
Bath pH Dependence on the Structural and Optical Properties of Chemical Bath Deposited CdS Thin Films
Authors: Ketipearachchi Udaya S. , Lane David W. , Rogers Keith D. , Painter Jonathan D. , Cousins Michael A. 
Published: April 2011

ABSTRACTHigh quality CdS thin films made with ultrasonic agitation during chemical bath deposition were investigated. The change in band gap and variation of atomic stacking during the film growth was observed as a function of bath pH. The band gap of as-deposited thin films of CdS was found to be between 2.26 eV and 2.50 eV, the highest being observed when the pH was 9.0. The transition from cubic (β-CdS) to hexagonal (a-CdS) was observed with decreasing pH. The lattice parameters of CdCl2 treated CdS were found to be a = 0.414 nm and c = 0.672 nm. Calculations based on the Sherrer formula showed significant grain growth after annealing with CdCl2. No apparent effect of ultrasonication on crystalline structure of CdS was seen in this method, although ultrasonication was noted to produce films with a higher quality optical surface. A maximum bath temperature was fixed at 70°C in order to suppress the rate of homogeneous reaction and minimise the evaporation of ammonia from the chemical bath.
The Band Offsets of Isomeric Boron Carbide Overlayers
Authors: Caruso A. N. , Lunca-Popa P. , Losovyj Y. B. , Gunn A. S. , Brand J. I. 
Published: April 2011

ABSTRACTSemiconducting boron carbide overlayers, formed from the decomposition of orthocarborane and metacarborane have been studied by angle resolved photoemission. The incurrence of surface photovoltage and the photovoltaic process, from the photoemission experiment, reveal band offsets in the orthocarborane multilayer configurations that are invereted relative to single layer configurations. Defect induced gap states which trap charge at the heterostructure interface is used as one explanation of these results. The role of defects is also used to help illuminate why opposite semiconducting type materials are formed from the decomposition of isomer carborane molecules.
Synthesis and Characterization of Cux(In, Ga)ySez Nanoparticles by Colloidal Route
Authors: Kim Ki-Hyun , Chun Young-Gab , Park Byung-Ok , Yoon Kyung-Hoon 
Published: April 2011

ABSTRACTThe quarternary CIGS nanoparticles for absorber layer of solar cells have been synthesized with various mole ratios by colloidal route. The CIGS nanoparticles were prepared by reacting CuI, InI3, GaI3 in pyridine with Na2Se in methanol at 0°C under inert atmosphere. For Cu0.9In0.8Ga0.3Se2 and Cu0.9In0.7Ga0.4Se2 stoichiometric ratios, tube-type nanofibers were obtained with the widths in the range of 20–50 nm and lengths of 0.1–3 μm from reaction at 0°C for 20 min. For Cu1.1In0.68Ga0.23Se1.91, and Cu0.9In0.68Ga0.23Se1.91 ratios, spherical nanoparticles were obtained from the same reaction condition. As compared to particles from Cu0.9In0.68Ga0.23Se1.91 ratio, more uniform and smaller nanoparticles with diameter in the range of 5–20 nm were obtained from the Cu1.1In0.68Ga0.23Se1.91 stoichiometric ratio. The morphology change of the CIGS particles seems to be closely related to the ratio of Cu/(In, Ga).
1MeV electron irradiation effects of GaAs/Si solar cells
Authors: Chandrasekaran N. , Soga T. , Inuzuka Y. , Imaizumi M. , Taguchi H. , Jimbo T. 
Published: April 2011

ABSTRACTThe characteristics of 1 MeV electron irradiated GaAs solar cells grown on GaAs and Si substrates are studied under dark and AM 0 conditions. The short circuit currents (Isc) for GaAs/GaAs cell and GaAs/Si cell have been decreased at higher fluences. The degradation rate of Voc and Pmax for GaAs/Si is slower than that of GaAs/GaAs at the fluence 1×1016 cm−2. This is due to the high radiation resistance of saturation current. It has been due to slow generation of arsnic vacancies related defect (VAs) in the GaAs/Si solar cell, which is determined by photoluminescence analyses and deep level transient spectroscopy.
Scanning Tunneling Luminescence of Semiconductors
Authors: Romero M. J. 
Published: April 2011

ABSTRACTWe review scanning tunneling luminescence (STL) – a photon emission spectroscopy based on scanning tunneling microscopy (STM) – and report on its application to photovoltaics. As part of this exploratory research, we have investigated CuInSe2 thin films, solar cells based on quantum dots, and dilute nitride compounds. STL is very attractive because it is capable of nanometer resolution, which is being demanded by the spectacular advancement of nanoscience and nanotechnology. In addition, STM offers both unipolar and bipolar excitation of the luminescence and, consequently, the transport and recombination of electrons and holes can be investigated independently.