Nano-structures of Aluminum Nitride and a method of producing nano-structures of Aluminum Nitride from nut shells comprising milling agricultural nuts into a fine nut powder, milling nanocrystalline Al.sub.2O.sub.3 into a powder, mixing, pressing the fine nut powder and the powder of nanocrystalline Al.sub.2O.sub.3, heating the pellet, maintaining the temperature of the pellet at about 1400 C., cooling the pellet, eliminating the residual carbon, and forming nano-structures of AlN. An Aluminum Nitride (AlN) product made from the steps of preparing powders of agricultural nuts using ball milling, preparing powders of nanocrystalline Al.sub.2O.sub.3, mixing the powders of agricultural nuts and the powders of nanocrystalline Al.sub.2O.sub.3 forming a homogenous sample powder of agricultural nuts and Al.sub.2O.sub.3, pressurizing, pyrolyzing the disk, and reacting the disk and the nitrogen atmosphere and forming AlN.

In various embodiments, single-crystal aluminum nitride boules and substrates having high transparency to ultraviolet light and low defect density are formed. The single-crystal aluminum nitride may function as a platform for the fabrication of light-emitting devices such as light-emitting diodes and lasers.

Provided are silicon-containing aluminum nitride particles having a high reflectance, a method for producing the same, and a light emitting device. In certain embodiment, silicon-containing aluminum nitride particles having a total amount of aluminum and nitrogen of 90% by mass or more, a content of silicon in a range of 1.5% by mass or more and 4.0% by mass or less, and a content of oxygen in a range of 0.5% by mass or more and 2.0% by mass or less, and having an average reflectance in a wavelength range of 380 nm or more and 730 nm or less of 85% or more.

Provided are silicon-containing aluminum nitride particles having a high reflectance, a method for producing the same, and a light emitting device. In certain embodiment, silicon-containing aluminum nitride particles having a total amount of aluminum and nitrogen of 90% by mass or more, a content of silicon in a range of 1.5% by mass or more and 4.0% by mass or less, and a content of oxygen in a range of 0.5% by mass or more and 2.0% by mass or less, and having an average reflectance in a wavelength range of 380 nm or more and 730 nm or less of 85% or more.

A semiconductor nanocrystal can be made by an in situ redox reaction between an M donor and an E donor.

A method for producing AlN crystals includes using at least one element, excluding Si, that satisfies a condition under which the element forms a compound with neither Al nor N or a condition under which the element forms a compound with any of Al and N provided that the standard free energy of formation of the compound is larger than that of AlN; melting a composition containing at least Al and the element; and reacting the Al vapor with nitrogen gas at a predetermined reaction temperature to produce AlN crystals.

A method for producing AlN crystals includes using at least one element, excluding Si, that satisfies a condition under which the element forms a compound with neither Al nor N or a condition under which the element forms a compound with any of Al and N provided that the standard free energy of formation of the compound is larger than that of AlN; melting a composition containing at least Al and the element; and reacting the Al vapor with nitrogen gas at a predetermined reaction temperature to produce AlN crystals.

An aluminum nitride plate satisfies both of a relation 1: c1>97.5% and a relation 2: c2/c1<0.995 where c1 is a c-plane degree of orientation that is defined as a ratio of a diffraction intensity of (002) plane to a sum of the diffraction intensity of (002) plane and a diffraction intensity of (100) plane when the surface layer of the aluminum nitride plate is subjected to an X-ray diffraction measurement, and c2 is a c-plane degree of (002) plane to the sum of the diffraction intensity of (002) plane and the diffraction intensity of (100) plane when a portion other than the surface layer of the aluminum nitride plate is subjected to the X-ray diffraction. Moreover, in the aluminum nitride plate, a difference in nitrogen content between the surface layer and the portion other than the surface layer is less than 0.15% in weight ratio.

An aluminum nitride plate satisfies both of a relation 1: c1>97.5% and a relation 2: c2/c1<0.995 where c1 is a c-plane degree of orientation that is defined as a ratio of a diffraction intensity of (002) plane to a sum of the diffraction intensity of (002) plane and a diffraction intensity of (100) plane when the surface layer of the aluminum nitride plate is subjected to an X-ray diffraction measurement, and c2 is a c-plane degree of (002) plane to the sum of the diffraction intensity of (002) plane and the diffraction intensity of (100) plane when a portion other than the surface layer of the aluminum nitride plate is subjected to the X-ray diffraction. Moreover, in the aluminum nitride plate, a difference in nitrogen content between the surface layer and the portion other than the surface layer is less than 0.15% in weight ratio.

A method for forming an aluminum nitride layer (310, 320) comprises the provision of a substrate (100) and the forming of a patterned metal nitride layer (110). A bottom electrode metal layer (210) is formed on the exposed portions (101) of the substrate. An aluminum nitride layer portion (320) grown above the exposed portion (101) of the substrate (100) exhibits piezoelectric properties. An aluminum nitride layer portion (310) grown above the patterned metal nitride layer (110) exhibits no piezoelectric properties (310). Both aluminum nitride layer portions (320, 310) are grown simultaneously.