A method of manufacturing a substrate includes forming a support structure by providing a polycrystalline ceramic core, encapsulating the polycrystalline ceramic core in a first adhesion shell, encapsulating the first adhesion shell in a conductive shell, encapsulating the conductive shell in a second adhesion shell, and encapsulating the second adhesion shell in a barrier shell. The method also includes joining a bonding layer to the support structure, joining a substantially single crystalline silicon layer to the bonding layer, forming an epitaxial silicon layer by epitaxial growth on the substantially single crystalline silicon layer, and forming one or more epitaxial layers by epitaxial growth on the epitaxial silicon layer.

A method for producing an AlN single crystal substrate, the method including: i) preparing a first base substrate consisting of a first AlN single crystal; ii) growing a first AlN single crystal layer over a main face of the first base substrate, to obtain a layered body; iii) cutting the first MN single crystal layer of the layered body, to separate the layered body into a second base substrate and a first part of the first AlN single crystal layer, the second base substrate including the first base substrate and a thin film layered thereon, the thin film being a second part of the first AlN single crystal layer; iv) polishing a surface of the thin film, to obtain a third base substrate consisting of a second AlN single crystal; and v) growing a second AlN single crystal layer over the polished surface of the third base substrate.

A method for producing an AlN single crystal substrate, the method including: i) preparing a first base substrate consisting of a first AlN single crystal; ii) growing a first AlN single crystal layer over a main face of the first base substrate, to obtain a layered body; iii) cutting the first MN single crystal layer of the layered body, to separate the layered body into a second base substrate and a first part of the first AlN single crystal layer, the second base substrate including the first base substrate and a thin film layered thereon, the thin film being a second part of the first AlN single crystal layer; iv) polishing a surface of the thin film, to obtain a third base substrate consisting of a second AlN single crystal; and v) growing a second AlN single crystal layer over the polished surface of the third base substrate.

A method of manufacturing a substrate includes forming a support structure by providing a polycrystalline ceramic core, encapsulating the polycrystalline ceramic core in a first adhesion shell, encapsulating the first adhesion shell in a conductive shell, encapsulating the conductive shell in a second adhesion shell, and encapsulating the second adhesion shell in a barrier shell. The method also includes joining a bonding layer to the support structure, joining a substantially single crystalline silicon layer to the bonding layer, forming an epitaxial silicon layer by epitaxial growth on the substantially single crystalline silicon layer, and forming one or more epitaxial III-V layers by epitaxial growth on the epitaxial silicon layer.

A method of manufacturing a substrate includes forming a support structure by providing a polycrystalline ceramic core, encapsulating the polycrystalline ceramic core in a first adhesion shell, encapsulating the first adhesion shell in a conductive shell, encapsulating the conductive shell in a second adhesion shell, and encapsulating the second adhesion shell in a barrier shell. The method also includes joining a bonding layer to the support structure, joining a substantially single crystalline silicon layer to the bonding layer, forming an epitaxial silicon layer by epitaxial growth on the substantially single crystalline silicon layer, and forming one or more epitaxial III-V layers by epitaxial growth on the epitaxial silicon layer.

A transparent timepiece component, in particular a watch glass, has a substantially planar or curved interior surface, and has mainly a transparent material colored by a zone of modified chemical composition within the component through an introduction of at least one coloring chemical element of the transparent material, this zone of modified chemical composition extending in one part only of the total thickness of the timepiece component.

A transparent timepiece component, in particular a watch glass, has a substantially planar or curved interior surface, and has mainly a transparent material colored by a zone of modified chemical composition within the component through an introduction of at least one coloring chemical element of the transparent material, this zone of modified chemical composition extending in one part only of the total thickness of the timepiece component.

Reduced and low work function materials capable of optimizing electron emission performance in a range of vacuum and nanoscale electronic devices and processes and a method for reducing work function and producing reduced and low work function materials are described. The reduced and low work function materials advantageously may be made from single crystal materials, preferably metals, and from amorphous materials with optimal thicknesses for the materials. A surface geometry is created that may significantly reduce work function and produce a reduced or low work function for the material. It is anticipated that low and ultra-low work function materials may be produced by the present invention and that these materials will have particular utility in the optimization of electron emissions in a wide range of vacuum microelectronics and other nanoscale electronics and processes.

Reduced and low work function materials capable of optimizing electron emission performance in a range of vacuum and nanoscale electronic devices and processes and a method for reducing work function and producing reduced and low work function materials are described. The reduced and low work function materials advantageously may be made from single crystal materials, preferably metals, and from amorphous materials with optimal thicknesses for the materials. A surface geometry is created that may significantly reduce work function and produce a reduced or low work function for the material. It is anticipated that low and ultra-low work function materials may be produced by the present invention and that these materials will have particular utility in the optimization of electron emissions in a wide range of vacuum microelectronics and other nanoscale electronics and processes.

A large-scale multi-step synthesis method for ultralong silver nanowire with controllable diameter, comprises: an ethylene glycol solution containing polyvinylpyrrolidone and sodium chloride is fully heated to obtain a solution with strong reducibility, and then silver nitrate in glycol solution is added for a generation of a large number of crystal seeds; hydrogen peroxide is used to achieve the selection of the crystal seeds for a small amount of crystal seeds with particular sizes; the temperature is immediately raised to increase the reaction rate until the threshold of the etching crystal seeds of nitric acid is broke through; the temperature is lowered for long-timed reaction to slow down the reaction rate, reduce the probability of the isotropic seeds by self-nucleation and promote the absorption of small nucleus in the radial direction of large nucleus or nanowire, thus obtaining the ultralong silver nanowire.