A single-crystal diamond material has a transmittance of light with a wavelength of greater than or equal to 410 nm and less than or equal to 750 nm of less than or equal to 15% for any wavelength, and is at least either of an electrical insulator according to optical evaluation and an electrical insulator according to electrical evaluation. A criterion of the optical evaluation can be a transmittance of light with a wavelength of 10.6 μm of greater than or equal to 1%. A criterion of the electrical evaluation can be an average resistivity of greater than or equal to 1×10.sup.6 Ωcm. Accordingly, a single-crystal diamond material having a low transmittance of light in the entire region of the visible light region and exhibiting a black color is provided.

Described herein is a method for growing indium nitride (InN) materials by growing hexagonal and/or cubic InN using a pulsed growth method at a temperature lower than 300° C. Also described is a material comprising InN in a face-centered cubic lattice crystalline structure having an NaCl type phase.

A method of manufacturing synthetic diamond material using a chemical vapour deposition process, and a diamond obtained by such a method are described. The method comprises providing a freestanding synthetic single crystal diamond substrate wafer having a dislocation density of at least 10.sup.7cm.sup.−2. The synthetic single crystal diamond substrate wafer is located over a substrate holder within a chemical vapour deposition reactor. Process gases are fed into the reactor, the process gases including a gas comprising carbon. Crack-free synthetic diamond material is grown on a surface of the single crystal diamond substrate wafer at a temperature of at least 900° C. to a thickness of at least 0.5 mm and with lateral dimensions of at least 4 mm by 4 mm.

A method of forming a diamond composite body and the diamond composite body. A first single crystal diamond body is provided, which contains nitrogen and has a uniform strain such that over an area of at least 1×1 mm, at least 90 percent of points display a modulus of strain-induced shift of NV resonance of less than 200 kHz, wherein each point in the area is a resolved region of 50 μm.sup.2. The first single crystal diamond body is treated to convert at least some of the nitrogen to form at least 0.3 ppm nitrogen-vacancy, NV.sup.−, centres. A CVD process is used to grow a second single crystal diamond body on a surface of the first single crystal diamond body. The second single crystal diamond body has an NV concentration less than or equal to 10 times lower than the NV.sup.− concentration in the first single crystal diamond body.

A method of growing single crystal diamond assisted by polycrystalline diamond growth to enhance dimensions and quality of the single crystal diamond includes thermally mating a diamond seed on a top surface of a substrate holder providing a growth surface for a combination of single crystal diamond and polycrystalline diamond. A predetermined temperature difference between the diamond seed and the substrate holder during processing along with the plasma process conditions causes a single crystal diamond growth rate to be different from a polycrystalline growth rate by a predetermined amount. Process gasses are introduced, and a plasma is formed to grow both single crystal diamond and polycrystalline diamond on the growth surface so that the polycrystalline diamond grown adjacent to the single crystal diamond shields side surfaces of the growing single crystal diamond, thereby improving growth quality across the growing single crystal diamond.

A process for manufacturing a porous diamond having a tridimensional (3D) structure. The process comprises the steps of using a substrate with a pre-defined shape and a plurality of pores of a defined porosity shape and size, heating a reactant hydrocarbon gas and reactant hydrogen in a filament to form a product gas, depositing an activated carbon atom from the product gas onto the substrate, wherein the activated carbon atom reacts with the substrate to form a diamond structure on the substrate, and completely removing the substrate to obtain the 3D pure porous diamond structure, wherein the 3D pure porous diamond structure is formed entirely of diamond and is identical in shape and porosity shape and size of the plurality of pores as that of the substrate. The 3D pure porous diamond structure formed is of a controlled thickness and porosity, and devoid of the substrate.

Described herein is a method for growing indium nitride (InN) materials by growing hexagonal InN using a pulsed growth method at a temperature lower than 300° C.

A SiC epitaxial wafer includes a SiC substrate and an epitaxial layer laminated on the SiC substrate, wherein the epitaxial layer contains an impurity element which determines the conductivity type of the epitaxial layer and boron which has a conductivity type different from the conductivity type of the impurity element, and the concentration of boron is less than 1.0×10.sup.14 cm.sup.−3 at any position in the plane of the epitaxial layer.

Single crystal CVD diamond material comprising a total nitrogen concentration of at least 5 ppm and a neutral single substitutional nitrogen. N.sub.s.sup.0, to total single substitutional nitrogen, N.sub.s, ratio of at least 0.7. Such a diamond is observed to have a relatively low amount of brown colouration despite the relatively high concentration of nitrogen A method of making the single crystal diamond is also disclosed, the method including growing the CVD diamond in process gases comprising 60 to 200 ppm nitrogen, in addition to a carbon-containing gas, and hydrogen, wherein the ratio of carbon atoms in the carbon-containing gas to hydrogen atoms in the hydrogen gas is 0.5 to 1.5%.

A method for producing a substrate for the epitaxial growth of a gallium-based III-N alloy layer comprises the following successive steps: —providing a donor substrate of single-crystal silicon carbide; —implanting ions in the donor substrate to form an embrittlement zone defining a thin film layer of single-crystal SiC; —bonding the donor substrate onto a first receiving substrate via a bonding layer; —detaching the donor substrate along the embrittlement zone to transfer the thin film of SiC onto the first receiving substrate; —epitaxially growing a layer of semi-insulating SiC having a thickness greater than 1 μm on the thin film of SiC; —bonding the layer of semi-insulating SiC onto a second receiving substrate having a high electrical resistivity; —removing at least a portion of the bonding layer to detach the first receiving substrate; and —removing the transferred thin film of single-crystal SiC, to expose the semi-insulating SiC layer.