Embodiments described herein relate generally to the large scale production of functionalized graphene. In some embodiments, a method for producing functionalized graphene includes combining a crystalline graphite with a first electrolyte solution that includes at least one of a metal hydroxide salt, an oxidizer, and a surfactant. The crystalline graphite is then milled in the presence of the first electrolyte solution for a first time period to produce a thinned intermediate material. The thinned intermediate material is combined with a second electrolyte solution that includes a strong oxidizer and at least one of a metal hydroxide salt, a weak oxidizer, and a surfactant. The thinned intermediate material is then milled in the presence of the second electrolyte solution for a second time period to produce functionalized graphene.

Embodiments described herein relate generally to the large scale production of functionalized graphene. In some embodiments, a method for producing functionalized graphene includes combining a crystalline graphite with a first electrolyte solution that includes at least one of a metal hydroxide salt, an oxidizer, and a surfactant. The crystalline graphite is then milled in the presence of the first electrolyte solution for a first time period to produce a thinned intermediate material. The thinned intermediate material is combined with a second electrolyte solution that includes a strong oxidizer and at least one of a metal hydroxide salt, a weak oxidizer, and a surfactant. The thinned intermediate material is then milled in the presence of the second electrolyte solution for a second time period to produce functionalized graphene.

A method for growing a GaN crystal suitable as a material of GaN substrates including C-plane GaN substrates includes: a first step of preparing a GaN seed having a nitrogen polar surface; a second step of arranging a pattern mask on the nitrogen polar surface of the GaN seed, the pattern mask being provided with a periodical opening pattern comprising linear openings and including intersections, the pattern mask being arranged such that longitudinal directions of at least part of the linear openings are within ±3° from a direction of an intersection line between the nitrogen polar surface and an M-plane; and a third step of ammonothermally growing a GaN crystal through the pattern mask such that a gap is formed between the GaN crystal and the pattern mask.

A method for growing a GaN crystal suitable as a material of GaN substrates including C-plane GaN substrates includes: a first step of preparing a GaN seed having a nitrogen polar surface; a second step of arranging a pattern mask on the nitrogen polar surface of the GaN seed, the pattern mask being provided with a periodical opening pattern comprising linear openings and including intersections, the pattern mask being arranged such that longitudinal directions of at least part of the linear openings are within ±3° from a direction of an intersection line between the nitrogen polar surface and an M-plane; and a third step of ammonothermally growing a GaN crystal through the pattern mask such that a gap is formed between the GaN crystal and the pattern mask.

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 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 manufacturing a peeled substrate has a laser condensing step for focusing laser light at a prescribed depth from the surface of a substrate and a positioning step for moving and positioning a laser condenser relative to the substrate, the method involving forming a processed layer in the substrate. The laser condensing step includes a laser light adjustment step in which a diffraction optical element is used to branch the laser light into a plurality of branched laser beams, and at least one of the branched laser beams is branched such that the intensity thereof differs from the other branched laser beams. The processed layer is elongated using the branched laser beam having a relatively high intensity among the plurality of branched laser beams to process the substrate, and the elongation of the processed layer is restrained using the branched laser beams having a relatively low intensity.

In various embodiments, growth of large, high-quality single crystals of aluminum nitride is enabled via a two-stage process utilizing two different crystalline seeds.

In various embodiments, growth of large, high-quality single crystals of aluminum nitride is enabled via a two-stage process utilizing two different crystalline seeds.

An aluminum nitride plate satisfies a “c1>97.5%”, a “c2>97.0%”, a “w1<2.5 degrees”, and a “w1/w2<0.995” where c1 is a c-plane degree of orientation that is defined as a ratio of a diffraction intensity of (002) plane when a surface layer of the aluminum nitride plate is subjected to an X-ray diffraction measurement, and c2 is a c-plane degree of orientation that is defined as a ratio of the diffraction intensity of (002) plane when a portion other than the surface layer of the aluminum nitride plate is subjected to the X-ray diffraction measurement, wherein w1 is a half-value width in an X-ray rocking curve profile of (102) plane of the surface layer and w2 is a half-value width in the X-ray rocking curve profile of (102) plane of the portion other than the surface layer.