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The relationship between In incorporation in InGaN/GaN quantum wells (QWs) and the plane orientation was investigated by using eight different GaN substrates, including non-polar, semi-polar and polar planes. Applying simultaneous metalorganic vapor-phase epitaxial (MOVPE) growth, a series of InGaN-based LEDs was fabricated on various planar GaN substrates and variations in In content in QWs, surface morphology and electroluminescence peak wavelength were examined. Samples made with the semi-polar ( 11 2 ¯ 2 ) plane and the polar ( 0001 ) plane had the high In contents, while specimens incorporating the non-polar ( 10 1 ¯ 0 ) plane had the low In content. The In content was most readily increased in the QWs produced using ( 11 2 ¯ 2 ) , ( 0001 ) , ( 10 1 ¯ 1 ) and ( 10 1 ¯ 0 ) planes, and the surface morphologies of samples made on the ( 0001 ) , ( 11 2 ¯ 2 ) , ( 20 2 ¯ 1 ) and ( 20 2 ¯ 1 ¯ ) planes were smoother than those of samples fabricated on the other planes. [ABSTRACT FROM AUTHOR]

Abstract: Al–40% Cu hypereutectic alloy samples were successfully directionally solidified at a growth rate of 10μm/s in different sizes (4mm, 1.8mm, and 0.45mm thickness in transverse section). Using the serial sectioning technique, the three-dimensional (3D) microstructures of the primary intermetallic Al2Cu phase of the alloy can be observed with various growth patterns, L-shape, E-shape, and regular rectangular shape with respect to growth orientations of the (110) and (310) plane. The L-shape and regular rectangular shape of Al2Cu phase are bounded by {110} facets. When the sample size was reduced from 4mm to 0.45mm, the solidified microstructures changed from multi-layer dendrites to single-layer dendrite along the growth direction, and then the orientation texture was at the plane (310). The growth mechanism for the regular faceted intermetallic Al2Cu at different sample sizes was interpreted by the oriented attachment mechanism (OA). The experimental results showed that the directionally solidified Al–40% Cu alloy sample in a much smaller size can achieve a well-aligned morphology with a specific growth texture. [Copyright &y& Elsevier]