The present invention provides a metal nitride platform for semiconductor devices, including, a pre-defined array of catalyst sites, disposed on a substrate. Metal nitride islands with lateral to vertical size ratios of at least greater than one (1) are disposed on the array of catalyst sites, where the surfaces of the metal nitride islands are with reduced dislocation densities and side walls with bending of dislocations. The platform of metal nitride islands is further used to build electrically and optically-active devices. The present invention also provides a process for the preparation of a metal nitride platform, selectively, on the array of catalyst sites, in the presence of a reactive gas and precursors and under preferred reaction conditions, to grow metal nitride islands with lateral to vertical size ratios of at least greater than one (1).

A method of processing a SiC single crystal includes a measuring step of measuring a shape of an atomic arrangement plane of the SiC single crystal along at least a first direction passing through a center in plan view and a second direction orthogonal to the first direction; and a surface processing step of processing a first plane serving as an attachment plane of the SiC single crystal, in which the surface processing step includes a grinding step of grinding the first plane, and in the grinding step, a difference is given to a surface state between the first plane and a second plane facing the first plane, and the atomic arrangement plane is flattened by Twyman's effect.

A polycrystalline silicon wafer is provided. The polycrystalline silicon wafer, includes a plurality of silicon grains, wherein the carbon content of the polycrystalline silicon wafer is greater than 4 ppma, and the resistivity of the polycrystalline silicon wafer is greater than or equal to 1.55 -cm.

A method of making an ordered graphene structure includes exposing a substrate to a laser beam to locally melt a portion of the substrate, exposing the substrate to a laser beam in the presence of a carbon source, to form a nucleation site for a graphene crystal, and either a) moving either the substrate or the laser beam relative to the other, or b) decreasing the laser beam power, in order to increase the size of the graphene crystal, thereby forming an ordered graphene structure. The ordered structure can be a plurality of columns, hexagons, or quadrilaterals. Each ordered structure can have a single crystal of graphene. A polymer coating can be formed on the ordered graphene structure to form a coated graphene structure.

Embodiments of the present invention are directed to novel methods for the solution-based production of silver nanowires by adaptation of the polyol process. Some embodiments of the present invention can be practiced at lower temperature and/or at higher concentration than previously described methods. In some embodiments reactants are added in solid form rather than in solution. In some embodiments, an acid compound is added to the reaction.

An assembly for the deposition of silicon nanostructures comprising a deposition chamber, which is defined by a side wall and by two end walls; a microwave generator, which is adapted to generate microwaves inside the deposition chamber; an electromagnetic termination wall, made of a conductor material and reflecting the microwave radiation, which is such as to create a termination for a TE-mode waveguide and is housed inside the deposition chamber; and a substrate-carrier support, which is made of a dielectric material and on which the substrate is housed on which to perform the growth of silicon nanostructures. The substrate-carrier support is arranged inside the deposition chamber above the termination wall.

There is provided a self-supporting polycrystalline gallium nitride substrate having excellent characteristics such as high luminous efficiency and high conversion efficiency when used for devices, such as light emitting devices and solar cells. The self-supporting polycrystalline gallium nitride substrate is composed of gallium nitride-based single crystal grains having a specific crystal orientation in a direction approximately normal to the substrate, and has a top surface and a bottom surface. The crystal orientations of individual gallium nitride-based single crystal grains as determined from inverse pole figure mapping by electron backscatter diffraction (EBSD) analysis on the top surface are distributed at various tilt angles from the specific crystal orientation, in which the average tilt angle thereof is 0.1 or more and less than 1 and the cross-sectional average diameter D.sub.T of the gallium nitride-based single crystal grains at the outermost surface exposed on the top surface is 10 m or more.

The process for growing at least one semiconductor nanowire (3), said growth process comprising a step of forming, on a substrate (1), a nucleation layer (2) for the growth of the nanowire (3) and a step of growth of the nanowire (3). The step of formation of the nucleation layer (2) comprises the following steps: deposition onto the substrate (1) of a layer of a transition metal (4) chosen from Ti, V, Cr, Zr, Nb, Mo, Hf, Ta; nitridation of at least a part (2) of the transition metal layer so as to form a transition metal nitride layer having a surface intended for growing the nanowire (3).

The crystal plane in the interior of the diamond substrate has a curvature higher than 0 km.sup.1 and equal to or lower than 1500 km.sup.1 by preparing a base substrate, forming a plurality of pillar-shaped diamonds formed of diamond single crystals on one side of the base substrate, causing diamond single crystals to grow from tips of each pillar-shaped diamond, coalescing each of the diamond single crystals grown from the tips of each pillar-shaped diamond to form a diamond substrate layer, separating the diamond substrate layer from the base substrate, and manufacturing the diamond substrate from the diamond substrate layer.

Disclosed herein is a multilayer nanocrystal structure comprising a nanocrystal alloy core comprising two or more nanocrystals and including an alloy interlayer formed at an interface between the two or more nanocrystals, and one or more layers of nanocrystal shells formed sequentially on the surface of the nanocrystal alloy core, wherein the nanocrystal shells each have different band gaps. The multilayer nanocrystal structure can be applied to various electronic devices owing to its advantages of high luminescence efficiency, superior optical stability, and superior chemical stability.