A SiC ingot includes a core portion; and a surface layer that is formed on a plane of the core portion in a growing direction, and a coefficient of linear thermal expansion of the surface layer is smaller than a coefficient of linear thermal expansion of the core portion.

Compositions comprising Group V/III nanowires, and methods of making such nanowires are described. Some compositions comprise one or more core-shell nanowires comprising a core and a first shell surrounding or substantially surrounding the core. The core is formed from GaAs.sub.(1-y)Sb.sub.y, where y=about 0.03-0.07 and the first shell is formed from GaAs.sub.(1-x)Sb.sub.xN, where x=0.27-0.34. The nanowires have an average emission maximum of 1.4-1.7 μm. Some nanowires further comprise a second shell surrounding or substantially surrounding the first shell. The second shell is formed from a Group V/III material such as Ga.sub.1-mAl.sub.mAs, where m=0-0.2. Some nanowires have the structure GaAs.sub.(0.93-0.97)Sb.sub.(0.03-0.07)/GaAs.sub.(0.66-0.73)Sb.sub.(0.27-0.34)N/Ga.sub.(0.8-1)Al.sub.(0-0.2)As.

A nano-twinned copper layer is disclosed, wherein over 50% of a volume of the nano-twinned copper layer comprises a plurality of columnar crystal grains, the plurality of columnar crystal grains connect to each other, at least 70% of the plurality of columnar crystal grains are formed by a plurality of nano-twins stacking in an orientation of a [111] crystal axis, and an angle included between two adjacent columnar crystal grains is greater 20° and less than or equal to 60°. In addition, a method for manufacturing the nano-twinned copper layer and a substrate comprising the same are also disclosed.

A method is provided. The method includes providing an alignment structure at least partially defining a predetermined alignment pattern. The method also includes forming a solid crystal on the alignment structure. Crystal molecules of the solid crystal are aligned in the predetermined alignment pattern.

An optical element is provided. The optical element includes a solid crystal including crystal molecules aligned in a predetermined alignment pattern at least partially defined by an alignment structure.

[Object] It is an object of the present invention to provide a lithium tantalate single crystal substrate which undergoes only small warpage, is free from cracks and scratches, has better temperature non-dependence characteristics and a larger electromechanical coupling coefficient than a conventional Y-cut LiTaO.sub.3 substrate. [Means to solve the Problems] The lithium tantalate single crystal substrate of the present invention is a rotated Y-cut LiTaO.sub.3 single crystal substrate having a crystal orientation of 36° Y-49° Y cut characterized in that: the substrate is diffused with Li from its surface into its depth such that it has a Li concentration profile showing a difference in the Li concentration between the substrate surface and the depth of the substrate; and the substrate is treated with single polarization treatment so that the Li concentration is substantially uniform from the substrate surface to a depth which is equivalent to 5-15 times the wavelength of either a surface acoustic wave or a leaky surface acoustic wave propagating in the LiTaO.sub.3 substrate surface.

The present invention provides polycrystalline silicon suitably used as a raw material for producing single crystal silicon. The polycrystalline silicon rod of the present invention is a polycrystalline silicon rod grown by chemical vapor deposition performed under a pressure of 0.3 MPaG or more, wherein when a plate-shaped sample piece collected from an arbitrary portion of the polycrystalline silicon rod is observed with a microscope with a temperature increased from a temperature lower than a melting point of silicon up to a temperature exceeding the melting point of silicon, a heterogeneous crystal region, which is a crystal region including a plurality of crystal grains heterogeneously assembled and including no needle-like crystal, having a diameter exceeding 10 m is not observed.

An electrical device includes an aluminum nitride passivation layer for a mercury cadmium telluride (Hg.sub.1-xCd.sub.xTe) (MCT) semiconductor layer of the device. The AlN passivation layer may be an un-textured amorphous-to-polycrystalline film that is deposited onto the surface of the MCT in its as-grown state, or overlying the MCT after the MCT surface has been pre-treated or partially passivated, in this way fully passivating the MCT. The AlN passivation layer may have a coefficient of thermal expansion (CTE) that closely matches the CTE of the MCT layer, thereby reducing strain at an interface to the MCT. The AlN passivation layer may be formed with a neutral inherent (residual) stress, provide mechanical rigidity, and chemical resistance to protect the MCT.

The present application discloses a method of preparing quantum dots. The method includes combining a first quantum dots precursor and a second quantum dots precursor to form a first reaction mixture including a supercritical liquid medium; nucleating and growing the quantum dots from the first quantum dots precursor and the second quantum dots precursor in the first reaction mixture including the supercritical liquid medium; and forming a solid quantum dots material in the presence of the supercritical liquid medium.

A method of the fabricating a metal-nitride vertically aligned nanocomposites is disclosed which includes applying a pulsed laser onto a composite target, the composite target including a two-phase metal-nitride plasmonic nanostructure, depositing adatoms of the composite target onto a substrate, and nucleating metal over the substrate and growing metal and nitride thereover until a predetermined size of vertically aligned metal nitride nanocomposite is achieved including metal nanorods embedded in nitride.