Tensile-strained GaAs(x)P(1-x) buffers grown on GaAs


Tensile-strained GaAs(x)P(1-x) buffers grown on GaAs

using unoptimized conditions exhibited asymmetric strain relaxation GSK1904529A in vitro along with formation of faceted trenches, 100-300 nm deep, running parallel to the [0 (1) over bar1] direction. We engineered a 6 mu m thick grading structure to minimize the faceted trench density and achieve symmetric strain relaxation while maintaining a threading dislocation density of <= 10(6) cm(-2). In comparison, compressively-strained graded GaAs(x)P(1-x) buffers on GaP showed nearly-complete strain relaxation of the top layers and no evidence of trenches but possessed threading dislocation densities that were one order of magnitude higher. We subsequently grew and fabricated wide-bandgap In(y)Ga(1-y)P solar cells on our GaAs(x)P(1-x) buffers. Transmission electron microscopy measurements gave no indication of CuPt ordering. We obtained open circuit voltage as high as 1.42 V for In(0.39)Ga(0.61)P with a bandgap of 2.0 eV. Our results indicate MBE-grown In(y)Ga(1-y)P is a promising material for the top junction of a AZD7762 mw future multijunction solar cell. (C) 2011 American

Institute of Physics. [doi: 10.1063/1.3525599]“
“New wood-based epoxy resins were synthesized from alcohol-liquefied wood. Wood was first liquefied by the reaction with polyethylene glycol and glycerin. The alcohol-liquefied wood with plenty of hydroxyl groups were precursors for synthesizing the wood-based epoxy resins. Namely, the alcoholic OH groups of the liquefied wood reacted with epichlorohydrin under alkali condition with a phase transfer catalyst, Staurosporine so that the epoxy groups were put in the liquefied wood. The wood-based epoxy resins and the alcohol-based epoxy resins as reference materials were cured with polyamide amine. The glass transition temperature (Tg), the tensile strength, and the modulus of elasticity of the wood-based epoxy resin were higher than those of the alcohol-based epoxy resin.

Also, the shear adhesive strength of the wood-based epoxy resin to steel plates was higher than those of the alcohol-based epoxy resins, which was equivalent to the level of petroleum-based bisphenol-A type epoxy resins. The higher Tg of the wood-based epoxy resin than that of the alcohol-based epoxy resin is one of the evidences that the wood-derived molecules were chemically incorporated into the network structures. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 120: 745-751, 2011″
“Yttria stabilized zirconia single crystal fibers doped with europium ions were developed envisaging optical applications. The laser floating zone technique was used in order to grow millimetric high quality single crystal fibers. The as-grown fibers are completely transparent and inclusion free, exhibiting a cubic structure. Under ultraviolet (UV) excitation, a broad emission band appears at 551 nm.

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