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Film Quality (film + quality)
Selected AbstractsUV-photodimerization in uracil-substituted dendrimers for high density data storageJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 19 2007Brian Lohse Abstract Two series of uracil-functionalized dendritic macromolecules based on poly (amidoamine) PAMAM and 2,2-bis(hydroxymethylpropionic acid) bis-MPA backbones were prepared and their photoinduced (2,+2,) cycloaddition reactions upon exposure to UV light at 257 nm examined. Dendrimers up to 4th generation were synthesized and investigated as potential materials for high capacity optical data storage with their dimerization efficiency compared to uracil as a reference compound. This allows the impact of increasing the generation number of the dendrimers, both the number of chromophores, as well as the different steric environments, on the performance of each series of dendrimers to be investigated. The (uracil)12 -[G-2]-bis-MPA and (uracil)8 -[G-1]-PAMAM were observed to have high dimerization efficiency in solution with different behavior being observed for the PAMAM and bis-MPA dendrimers. The dendrimers with the best dimerization efficiency in solution were then examined in the solid state as thin films cast on quartz plates, and their film qualities along with their photodimerization performance studied. High quality films with a transmission response of up to 70% in 55 s. when irradiated at 257 nm with an intensity of 70 mW/cm2 could be obtained suggesting future use as recording media for optical data storage. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4401,4412, 2007 [source] Increasing process understanding by analyzing complex interactions in experimental dataJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 5 2009Kaisa Naelapää Abstract There is a recognized need for new approaches to understand unit operations with pharmaceutical relevance. A method for analyzing complex interactions in experimental data is introduced. Higher-order interactions do exist between process parameters, which complicate the interpretation of experimental results. In this study, experiments based on mixed factorial design of coating process were performed. Drug release was analyzed by traditional analysis of variance (ANOVA) and generalized multiplicative ANOVA (GEMANOVA). GEMANOVA modeling is introduced in this study as a new tool for increased understanding of a coating process. It was possible to model the response, that is, the amount of drug released, using both mentioned techniques. However, the ANOVA model was difficult to interpret as several interactions between process parameters existed. In contrast to ANOVA, GEMANOVA is especially suited for modeling complex interactions and making easily understandable models of these. GEMANOVA modeling allowed a simple visualization of the entire experimental space. Furthermore, information was obtained on how relative changes in the settings of process parameters influence the film quality and thereby drug release. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:1852,1861, 2009 [source] Investigation of structural properties of high-rate deposited SiNx films prepared at low temperatures (100,300 °C) by atmospheric-pressure plasma CVDPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3-4 2010Y. Yamaguchi Abstract We have investigated the structural properties of silicon nitride (SiNx) films deposited at low temperatures (100,300 °C with very high rates (>50 nm/s) in atmospheric-pressure He/H2/SiH4/NH3 plasma excited by a 150 MHz very high-frequency (VHF) power using a cylindrical rotary electrode. For this purpose, SiNx films are prepared on Si(001) wafers varying NH3/SiH4 ratio, H2 concentration in the plasma and substrate temperature (Tsub). Infrared absorption spectroscopy is used to analyze the bonding configurations of Si, N and H atoms in the films. It is shown that by decreasing NH3/SiH4 ratio or increasing H2 concentration, Si,N and Si,H bond densities increase, while N,H bond density decreases. A reasonably good-quality film showing a BHF etching rate of 28 nm/min and a refractive index of 1.81 is obtained at Tsub = 300 °C despite the very high deposition rate of 166 nm/s. However, it is found that the decrease in Tsub causes the deterioration of film quality. Further surface excitation by increasing VHF power and/or H2 concentration together with the optimization of other deposition parameters will be needed to form high-quality SiNx films with high rates at lower temperatures (Tsub , 100 °C). (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Ultra-flat and high-quality AlN thin films on sapphire (0001) substrates grown by rf-MBEPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2003X. Q. Shen Abstract AlN films on sapphire (0001) substrates grown by plasma-assisted molecular beam epitaxy are investigated. In-situ reflection high-energy electron diffraction shows a streak pattern from the beginning of the AlN growth indicating the 2-dimensional (2D) growth mode of AlN. High-resolution X-ray diffraction measurements illustrate that the full-width at half maximum of AlN (0002) peak is less than 80 arcsec when the thickness of AlN is more than 200 nm showing high structural film quality. Clear near-band edge emission at 77 K is observed from an 800 nm-thick AlN film by cathodoluminescence measurements. Atomic force microscopy observations show ultra-flat surface morphologies of AlN with rms as small as 0.12 nm. All characterization results suggest the high-quality of AlN films. (© 2003 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Electromechanical Behavior of Nanoscale Silver Coatings on PET FibersPLASMA PROCESSES AND POLYMERS, Issue 9 2008Martin Amberg Abstract Plasma-assisted deposition of silver films on PET mono- and multifilament fibers provides conductive fibers for wearable electronics. The nanoscale films were prepared in a continuously running low pressure plasma process using an ICM design for sputtering from a silver target combined with a prior RF cleaning step. The electrical resistance of the as-deposited layers was measured in situ enabling an immediate feedback of the electrical properties, the film quality, applied Ag mass, and film thickness. The deposited quantity of Ag mass on the PET fibers was investigated by ICP-OES and was correlated with the electrical resistance of the film. The metallized fibers showed excellent mechanical properties for wearable electronics as demonstrated by tensile properties measurement. [source] High-quality surface passivation of silicon solar cells in an industrial-type inline plasma silicon nitride deposition systemPROGRESS IN PHOTOVOLTAICS: RESEARCH & APPLICATIONS, Issue 1 2004Jens D. Moschner Abstract We have studied the surface passivation of silicon by deposition of silicon nitride (SiN) in an industrial-type inline plasma-enhanced chemical vapor deposition (PECVD) reactor designed for the continuous coating of silicon solar cells with high throughput. An optimization study for the passivation of low-resistivity p -type silicon has been performed exploring the dependence of the film quality on key deposition parameters of the system. With the optimized films, excellent passivation properties have been obtained, both on undiffused p -type silicon and on phosphorus-diffused n+ emitters. Using a simple design, solar cells with conversion efficiencies above 20% have been fabricated to prove the efficacy of the inline PECVD SiN. The passivation properties of the films are on a par with those of high-quality films prepared in small-area laboratory PECVD reactors. Copyright © 2004 John Wiley & Sons, Ltd. [source] | ||||||||||