bluuebunny/crossref_metadata_2025_split huggingface dataset:
5% Efficient evaporated solid‐phase crystallised polycrystalline silicon thin‐film solar cells
Authors: Kunz O. , Ouyang Z. , Varlamov S. , Aberle A. G. 
Published: June 2009

AbstractThe first energy conversion efficiencies of over 5% are reported for evaporated solid‐phase crystallised (SPC) polycrystalline silicon thin‐film solar cells. All cells have a size of 2 cm2 and are formed on planar glass superstrates. Back surface reflectance is provided by a simple coating with commercial white paint. The best cells have short‐circuit current densities of about 19 mA/cm2 and external quantum efficiencies peaking at above 80%. The diffusion length in the base of the solar cells is larger than the base thickness, providing significant room for further efficiency improvements via an increased thickness of the base layer. Additional improvements are expected via the use of textured glass sheets, boosting the light trapping capabilities of the cells. Copyright © 2009 John Wiley & Sons, Ltd.
Positive Ion Mass Spectrometry during an Atmospheric Pressure Plasma Treatment of Polymers
Authors: Beck Alison J. , Aranda Gonzalvo Yolanda , Pilkington Antony , Yerokhin Aleksey , Matthews Allan 
Published: June 2009

AbstractA low power atmospheric pressure helium plasma torch was used to modify the surface chemistry of poly(α‐methylstyrene), polystyrene, poly(propylene) and polyethylene. Mass spectra of the positive ions present in the plasma during the treatment revealed dominant ions with structures that reflected the structure of the polymer, e.g. C6H5CnH2n containing a phenyl group in the aromatic polymers and hydrocarbon structures CnH2n ± 1 up to n = 14 for poly(propylene). Ions up to m/z 300 were detected. X‐ray photoelectron spectroscopy showed that this treatment introduced oxygen‐containing functional groups into the surface of the polymers.magnified image
Fundamental and Innovations in Plasma Assisted Diffusion of Nitrogen and Carbon in Austenitic Stainless Steels and Related Alloys
Authors: Czerwiec Thierry , He Huan , Marcos Grégory , Thiriet Tony , Weber Sylvain , Michel Henri 
Published: June 2009

AbstractAn improvement of the surface properties of austenitic stainless steels and nickel‐based alloys is obtained by low temperature plasma assisted nitriding (PAN), plasma assisted carburizing (PAC) and plasma assisted nitrocarburizing (PANC). At low temperature, PAN treatment produces a peculiar phase usually called expanded austenite, S phase, m phase or γN phase. Replacing nitrogen by hydrocarbon for conducting a low temperature PAC gives a carburized layer containing the carbon expanded austenite phase (γC). These two phases can simultaneously be obtained by combining hydrocarbon and nitrogen in the gas phase through a low temperature PANC. Several fundamental aspects concerning the expanded austenite phases are presented in this paper.magnified image
Effect of High Ion Irradiation on the Structure, Properties and High Temperature Tribology of Nanoscale CrAlYN/CrN Multilayer Coating Deposited by HIPIMS‐HIPIMS Technique
Authors: Hovsepian Papken Eh. , Ehiasarian Arutiun P. , Purandare Yashodhan P. , Braun Reinhold , Ross Ian M. 
Published: June 2009

AbstractThe high degree of ionisation of the sputtered particles in High power impulse magnetron sputtering (HIPIMS) discharge was utilised to deposit very dense nanoscale multilayer CrAlYN/CrN coatings. These newly developed coatings are designed to meet the demands for high oxidation and wear resistant coatings of light weight materials such as γ‐TiAl alloys for future applications in aerospace and automotive engines. The coatings were produced by a HIPIMS‐HIPIMS methodology in which HIPIMS was employed for adhesion enhancement surface pre‐treatment as well as for coating deposition in combination with standard unbalanced magnetron sputtering (UBM). TEM studies revealed extremely sharp interfaces between the individual layers in the nanolaminated material and almost no layer waviness. The coatings exhibited low friction and wear coefficients (Kc) at ambient and elevated temperatures of 300 and 650 °C. Quasi‐isothermal oxidation tests carried out at 850 °C for exposure time of 2 000 h exhibited a lower mass gain of HIPIMS‐HIPIMS coatings by a factor of 2 and 6 as compared to the HIPIMS/UBM deposited coatings and uncoated γ‐TiAl substrate respectively.
The Influence of the Coating Thickness on the Phase and Element Composition of a ‘Ti Coating/Steel’ System Surface Layer Treated by a Compression Plasma Flow
Authors: Cherenda Nikolai N. , Uglov Vladimir V. , Poluyanova Marina G. , Astashynski Valentin M. , Kuzmitski Anton M. , Pogrebnjak Alexander D. , Stritzker Bernd 
Published: June 2009

AbstractThe phase and element composition, microhardness of a ‘Ti/steel’ system mixed under the action of compression plasma flows have been investigated in this work. Non‐Rutherford backscattering, X‐ray diffraction, scanning electron microscopy and Vickers microhardness measurements were used for samples characterization. The findings showed that the change of the coating thickness in the range of 0.5–5 µm resulted in the Ti concentration change in the mixed layer from 4 to 30 at.‐%. The increase of the titanium content was accompanied by the formation of a supersaturated α‐Fe(Ti) solid solution, Fe2Ti and TiN. The phase composition changes and quenching effect led to the surface layer microhardness increase.
Deposition of Barrier Layers for Thin Film Solar Cells Assisted by Bipolar Substrate Biasing
Authors: Häberle Evelyn , Kopecki Jochen , Schulz Andreas , Walker Matthias , Stroth Ulrich 
Published: June 2009

AbstractFor the development of diffusion and insulation barriers for thin film solar cells on unpolished steel with a rough surface as substrate, investigations of the shape of deposited SiOx layers in dependence on an applied substrate biasing are carried out. Si‐wafers with a well‐defined surface structure in the range of micrometre are used as ‘model’ substrate. As a result, the deposition in the indentations of this surface is much higher in the case of a biased substrate. To determine the influence of the bias on the molecular structure, first investigations of the deposited layer without an applied bias are performed with in situ Fourier Transform InfraRed (FTIR) spectroscopy. Hence the molecular composition of the films is monitored during the deposition. In these spectra the Berreman effect occurs and is analysed.
Comparison Between Non‐equilibrium Atmospheric‐Pressure and Low‐Pressure Plasma Treatments of Poly(styrene–butadiene–styrene) Elastomers
Authors: Tyczkowski Jacek , Zieliński Jakub , Kopa Agnieszka , Krawczyk Iwona , Woźniak Bogusław 
Published: June 2009

AbstractLow‐pressure plasma generated in a typical parallel plate reactor and atmospheric pressure plasma produced by a plasma needle were utilized to modify the surface of poly(styrene–butadiene–styrene) (SBS) elastomers. An RF discharge (13.56 MHz) in helium was used in the both cases. The SBS surfaces were investigated by T‐peel tests, contact‐angle measurements, and IRS–FTIR spectroscopy. It has been found that such plasma treatments drastically improve the strength of adhesive‐bonded joints between the SBS surfaces and polyurethane adhesives, however, the plasma needle operation has turned out to be more effective. The molecular processes proceeding on the SBS surfaces have been briefly discussed.
Atmospheric Pressure Plasma Deposition of Adhesion Promotion Layers on Aluminium
Authors: Bringmann Philipp , Rohr Oliver , Gammel Franz J. , Jansen Irene 
Published: June 2009

AbstractThe paper presents investigations on the deposition of plasma polymerised films at atmospheric pressure as a pretreatment for painting and adhesive bonding of aircraft aluminium structures. Two different plasma jet sources are employed, one based on a controlled arc discharge and air as process gas, and another based on a dielectric barrier discharge (DBD) and He as plasma gas. The organosilicon precursors HMDSO, TEOS and OMCTS are used with both plasma sources. Deposition in the arc discharge plasma jet leads to almost carbon‐free silica coatings, whereas coatings deposited with the DBD jet source contain a high amount of carbon, varying with precursor type. The obtained results of corrosion investigations and adhesion tests are promising, as some representative aircraft industry requirements could be achieved. However, the investigations show a strong dependency on the used precursor and type of polymer (paint or adhesive) applied on the plasma polymerised film.
The Influence of Process Parameters on Chemistry, Roughness and Morphology of Siloxane Films Deposited by an Atmospheric Plasma Jet System
Authors: Ramamoorthy Amsarani , Rahman Mahfujur , Mooney Damian A. , Don MacElroy James M. , Dowling Denis P. 
Published: June 2009

AbstractSiloxane coatings were deposited onto Vycor™ glass and silicon substrates from a tetraethyl orthosilicate (TEOS) precursor using the PlasmaStream™ atmospheric plasma jet system. The TEOS precursor was nebulized into He/O2 plasma and the coating growth rate was controlled by the number of passes of the jet over the ceramic substrates. The system process parameters were systematically varied to study their influence on the coating properties. The chemical properties, surface roughness, and morphology of the 1–200 nm thick coatings were studied as a function of both applied plasma power and TEOS flow rate. The deposited coatings were examined using ellipsometry, contact angle measurement, optical profilometry, Fourier transform infrared spectroscopy (FT‐IR), X‐ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM).
Depositon of Dielectric Films with Inductively Coupled Plasma‐CVD in Dependence on Pressure and Two RF‐Power‐Sources
Authors: Jatta Sandro , Haberle Klaus , Klein Andreas , Schafranek Robert , Koegel Benjamin , Meissner Peter 
Published: June 2009

AbstractThis paper presents the investigations of thin dielectric silicon oxide (SiOx) and silicon nitride (SiNx) films deposited below 100 °C by a plasma enhanced chemical vapour deposition (PECVD) using an inductively coupled plasma (ICP)‐source. The influence of the deposition pressure and the applied RF‐power to the plasma from the ICP‐source and a second RF‐power at substrate electrode on the characteristics of the deposited films are studied. The investigated characteristics are refractive index R.I. at 632 nm, deposition rate Rdep, stress σ and etching rate Retch in buffered hydrofluoric acid (BHF). Measurements from electron spectroscopy for chemical analysis (ESCA) support the investigations. The results are discussed and compared with other PECVD deposition methods. A significant influence of the RF‐generator connected to substrate electrode on etching rate and hence on film quality is identified for SiOx but the converse effect is identified for SiNx‐films.
Angularly and Spatially Resolved Measurements of the Energy Flux in an RF Plasma Using a Thermal Probe
Authors: Wolter Matthias , Stahl Marc , Kersten Holger 
Published: June 2009

AbstractThe total energy flux for an RF plasma (13.56 MHz) has been measured by means of a simple thermal probe. The procedure is based on the measurement of time dependent changes of the probe temperature during the plasma process. A substrate dummy which is thermally isolated and inserted into the plasma at substrate position served as thermal probe which can be moved in vertical and horizontal directions in order to measure the different energy fluxes and their distribution in the reactor vessel. The knowledge of the spatial distribution is important, for example, for coating or sputtering processes. Different contributions to the total energy flux are identified by different orientations of the thermal probe, e.g., if the probe is facing the RF electrode the energy flux is much higher than in the opposite direction. This difference can be addressed to an additional energetic contribution due to secondary electron emission from the powered RF electrode.
Multilayer Diffusion Barrier Coatings on Poly(propylene) with Improved Temperature Durability
Authors: Körner Lutz , Sonnenfeld Axel , Rudolf von Rohr Philipp 
Published: June 2009

AbstractThe improvement of temperature durability for autoclaving of silicon oxide (SiOx) diffusion barrier coatings on poly(propylene) (PP) by deposition of thin amorphous hydrogenated carbon‐nitrogen (a‐C:N:H) intermediate layers was investigated. Attenuated total reflection Fourier transform infrared (ATR‐FTIR) spectroscopy revealed terminating amino and nitrile groups responsible for low compressive stress in a‐C:N:H. Uniaxial tensile tests showed a higher crack onset strain (COS) for a‐C:N:H of 2.7% compared to 0.7% for SiOx. Best temperature durability was achieved by a three‐layer coating from a‐C:N:H, an intermediate layer deposited by a mixture of N2, C2H2, hexamethyldisiloxane (HMDSO), and a SiOx layer. The oxygen transmission rate (OTR) was only increased from 6 to 22 cm3·m−2·d−1·bar−1 after exposure to 140 °C for 30 min, whereas for single SiOx barrier coatings, severe loss of barrier properties of 1 040 cm3·m−2·d−1·bar−1 was evidenced due to the formation of cracks.
1‐D Self‐consistent Fluid Modelling of the Pulsed Magnetron Discharge
Authors: Thomason Philip , Browning Philippa , Bradley James 
Published: June 2009

AbstractA 1‐D fluid code simulation of the region above the racetrack in a magnetron discharge has been developed to yield predictions for the temporal evolution of the axial plasma parameters during pulsed DC operation. To take into account anomalous cross‐field diffusion transport rates, an effective magnetic field profile has been calculated based on the real experimental values, to yield ratios in the effective electron gyro and collision frequencies comparable with Bohm diffusion. Pulse frequencies from 100 to 500 kHz are considered, with gas pressures ranging from 0.25 to 0.65 Pa. The model results for the plasma potential, electron and ion densities, during the pulse cycle agree well with experimental measurements made in the Liverpool magnetron using time‐resolved Langmuir and emissive probes. In the bulk plasma, the predictions for electron temperature are close to the measured values; however, in the sheath region they are artificially high due to the model assumption that only Maxwellian distributed electrons exist in all regions of the discharge. This inadequacy in the model and the methods to improve has been discussed. Results for DC magnetrons are also shown.
Chemically Directed Assembling of Functionalized Luminescent Nanocrystals onto Plasma Modified Substrates Towards Sensing and Optoelectronic Applications
Authors: Sardella Eloisa , Liuzzi Francesco D. , Comparelli Roberto , Depalo Nicoletta , Striccoli Marinella , Curri M. Lucia , Agostiano Angela , Favia P. , d'Agostino Riccardo 
Published: June 2009

AbstractIn this work semiconductor nanocrystals (NCs) were assembled by means of a layer‐by‐layer procedure, by properly combining RF (13.56 MHz) glow discharge‐assisted processes with wet chemistry approaches. Colloidal core shell type NCs formed by CdSe coated with an epitaxial layer of ZnS (CdSe@ZnS) were then assembled, from aqueous solution, onto the plasma modified materials. The obtained results show that spatially resolved NC assembling can be successfully achieved on micro‐structured domains obtained by means of plasma assisted processes. Layers of functionalized NCs are thus demonstrated to be materials that can be effectively integrated into devices for application in photovoltaics, electronic nano‐devices and biological sensors.
Effects of spinosad on Helicoverpa armigera (Lepidoptera: Noctuidae) from China: tolerance status, synergism and enzymatic responses
Authors: Wang Dong , Qiu Xinghui , Ren Xuexiang , Zhang Wencheng , Wang Kaiyun 
Published: June 2009

AbstractBACKGROUND: Spinosad is increasingly used in pest management programmes, and resistance to it has been detected in recent years. However, there is no report on the susceptibilities of field populations of Helicoverpa armigera (Hübner) from China. Furthermore, the impact of spinosad on metabolic enzymes in this pest remains unknown.RESULTS: Four populations of H. armigera from different locations in China displayed less than 6.5‐fold difference in LC50 to spinosad, the highest being in the Xinjiang population, followed by Xiajin, Taian and Hubei populations, while there was no significant difference at LC99 level among the four populations. The toxicity of spinosad could be synergised by piperonyl butoxide (PBO) and triphenylphosphate (TPP), but not by diethyl maleate (DEM). Spinosad exposure for 48 h significantly increased the activities of p‐nitroanisole O‐demethylase (ODM), while no significant changes in glutathione‐S‐transferase (GST) and carboxyl esterase (CarE) were observed.CONCLUSION: Field populations of H. armigera from China displayed marginally different susceptibilities to spinosad and had a relatively low LC50. Cytochrome P450 monooxygenase might be involved in the metabolism of, and hence resistance to, spinosad in this pest in China. Copyright © 2009 Society of Chemical Industry
Formation of extended defects in 4H‐SiC epitaxial growth and development of a fast growth technique
Authors: Tsuchida Hidekazu , Ito Masahiko , Kamata Isaho , Nagano Masahiro 
Published: June 2009

AbstractThis paper surveys extended defects in 4H‐SiC epilayers and reports recent results concerning fast epitaxial growth. Synchrotron X‐ray topography, transmission electron microscopy, Nomarski optical microscopy and defect selective etching analysis are applied to investigate the nucleation and propagation of carrot defects, basal plane Frank‐type defects, polytype inclusions and basal plane dislocations (BPDs) in 4H‐SiC epitaxial growth. In the development of the 4H‐SiC fast epitaxial growth technique, a very high growth rate of up to 250 μm/h is obtained in a newly developed vertical hot‐wall‐type reactor under low system pressure using a H2 + SiH4 + C3H8 system. Good thickness and impurity doping uniformity are also obtained simultaneously over a large area, with the retention of a high growth rate. A 4H‐SiC epilayer virtually free from BPDs is obtained on a 4° off Si‐face substrate. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A study of defect evolution in multi‐energy helium implanted monocrystalline and polycrystalline silicon
Authors: Abrams K. J. , Donnelly S. E. , Beaufort M.‐F. , Terry J. , Haworth L. I. , Alquier D. 
Published: June 2009

AbstractUpon implantation, He ions interact with radiation damage in metals and semiconductors to form bubbles (V. Raineri, Phys. Rev. B 2, 937 (2000) [1]). As far as Si is concerned, recent literature contains much information on the effects of ion implantation, defect formation and the transport of point defects in He‐irradiated crystalline silicon (c‐Si) whereas little information exists on the effects of He implantation on polycrystalline Si (poly‐Si). This paper reports on a systematic comparison of the effects of He implantation on c‐Si and poly‐Si. Interesting and significant differences were observed in the defect morphology in the two cases. Results on the differences between the two materials are presented and discussed in terms of the role that grain boundaries in poly‐Si play in trapping interstitials and the effects that this may have on the overall defect morphology. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Extended defects generated in the slip plane by moving dislocation in diamond lattice crystals: morphology and properties
Authors: Eremenko V. , Demenet J.‐L. , Rabier J. 
Published: June 2009

AbstractAn analysis of the morphology of the extended defects revealed behind dislocation in the slip plane of silicon is presented. These extended defects show an electrical activity contradictorily to dislocations themselves; this is confirmed by Electron Induced Surface Potential (EISP) measurements. It is shown, that the generation of these extended defects is a common phenomenon for diamond lattice materials. The defects generation which has to be elucidated is considered to be relevant to a dynamical dislocation core structure during the plastic deformation of semiconductor materials with covalent lattice. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Localisation and identification of recombination‐active extended defects in crystalline silicon by means of focused ion‐beam preparation and transmission electron microscopy
Authors: Stolze L. , Saring P. , Rudolf C. , Seibt M. 
Published: June 2009

AbstractThis paper reports on the localisation of extended defects related to the co‐precipitation of transition metal impurities in silicon and their preparation for subsequent analysis using techniques of transmission electron microscopy (TEM). Two approaches are described, i.e. (i) localisation of recombination‐active defects by light‐beam induced current followed by preferential chemical etching and TEM sample preparation using focused‐ion beam (FIB), and (ii) the replacement of the chemical etching by in situ Ga+ irradiation in the FIB system. The former technique is successfully applied to copper‐rich precipitate colonies in silicon whereas the latter proofs to be the superior approach for nickel‐rich particles. Structural and chemical analyses using TEM techniques are described for both cases (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic effects and ring strain influences on the electron uptake by selenium‐containing bonds
Authors: Dumont Élise , Loos Pierre‐François , Laurent Adèle D. , Assfeld Xavier 
Published: June 2009

AbstractThe gas‐phase electron attachment of thiaselena and diselena derivatives is investigated on model organic systems by ab initio calculations (level of theory MP2/DZP++). Electronic contributions favor the one‐electron addition on selenium‐containing compounds, with adiabatic electron affinities of 0.03, 0.24, and 0.43 eV, respectively, for dimethyldisulfide, dimethylselenenylsulfide, and dimethyldiselenide. This ensures the possibility of an excess electron binding on SeS and SeSe linkages. The so‐formed radical anionic intermediates present a three‐electrons two‐centers 2c3e bond, whose nature is confirmed by Mulliken spin densities and NBO analysis. They are stable towards dissociation, with a low barrier evaluated between about 25–60 kJ/mol. Cyclization strongly enhances dichalcogen propensity to fix an excess electron. Adiabatic electron affinities of a series of 1,2‐thiaselena‐cycloalkanes and 1,2‐diselena‐cycloalkanes are positive and range from 0.24 to 1.30 eV. This can be traced back to the release of ring strain energy upon one‐electron addition: this geometrical effect is nevertheless less marked than for disulfide analogs. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Nuclear quantum effects on the He2H+ complex with the nuclear molecular orbital approach
Authors: González Sergio A. , Reyes Andrés 
Published: June 2009

AbstractThe nuclear quantum effects (NQE) on the geometries and energies of the HeH+ and He2H+ complexes and their hydrogen isotopologues are investigated with the recently developed APMO/MP2 code. This code implements the Nuclear Molecular Orbital Approach (NMO) at a MP2 level of theory for electrons and quantum nuclei. In a first investigation of NQE on HeH+, we have observed a reduction in the bond distance as the mass of the hydrogen isotope is increased. Our calculated bond distances are in good agreement with experiment. We have also studied the H/D/T isotope effects on the geometry, total energy and stabilization energy of HeHHe+. We have also determined the relation between nuclear mass and delocalization and found that the lighter the nucleus the more delocalized it is. Our results demonstrate the importance of including nuclear quantum effects in these systems. To our knowledge, these are the first reported results on isotope effects on the HeH+ and He2H+ complexes using a NMO method. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010