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.

There is provided a method for manufacturing a group-III nitride substrate, including: (a) preparing a substrate which is made of a group III-nitride crystal and which has a high oxygen concentration domain where an oxygen concentration is higher than that of a matrix of the crystal; (b) irradiating the substrate with laser beam aiming at the high oxygen concentration domain, forming a through-hole penetrating the substrate in a thickness direction, and removing at least a part of the high oxygen concentration domain from the substrate; and (c) embedding at least a part of an inside of the through-hole by growing the group-III nitride crystal in the through-hole.

There is provided a method for manufacturing a group-III nitride substrate, including: (a) preparing a substrate which is made of a group III-nitride crystal and which has a high oxygen concentration domain where an oxygen concentration is higher than that of a matrix of the crystal; (b) irradiating the substrate with laser beam aiming at the high oxygen concentration domain, forming a through-hole penetrating the substrate in a thickness direction, and removing at least a part of the high oxygen concentration domain from the substrate; and (c) embedding at least a part of an inside of the through-hole by growing the group-III nitride crystal in the through-hole.

A high-pressure high-temperature, HPHT, diamond tool piece and a method of producing an HPHT diamond tool piece. At least a portion of the HPHT diamond tool piece comprises an aggregated nitrogen centre to C-nitrogen centre ratio of greater than 30%. The method includes irradiating an HPHTdiamond material to introduce vacancies in the diamond crystal lattice, annealing the HPHT diamond material such that at least a portion of the HPHT diamond material comprises an aggregated nitrogen centre to C-nitrogen centre ratio of greater than 30%,andprocessing the HPHT diamond material to form an HPHT diamond tool piece.

A high-pressure high-temperature, HPHT, diamond tool piece and a method of producing an HPHT diamond tool piece. At least a portion of the HPHT diamond tool piece comprises an aggregated nitrogen centre to C-nitrogen centre ratio of greater than 30%. The method includes irradiating an HPHTdiamond material to introduce vacancies in the diamond crystal lattice, annealing the HPHT diamond material such that at least a portion of the HPHT diamond material comprises an aggregated nitrogen centre to C-nitrogen centre ratio of greater than 30%,andprocessing the HPHT diamond material to form an HPHT diamond tool piece.

The present invention discloses a high-resistivity single crystal zinc oxide (ZnO) wafer and a high-resistivity single crystal ZnO-based radiation detector, and preparation method and use thereof. The preparation method of the high-resistivity single crystal zinc oxide wafer is to place a single crystal ZnO wafer in a metal lithium electrochemical device for a constant-current discharge treatment, and then to place the single crystal ZnO wafer in a high-pressure oxygen atmosphere at 800 to 1000 C. and 10 to 30 atm for an annealing treatment for 20 to 28 hours. The preparation method of the radiation detector is to evaporate a metal electrode layer at both sides of the high-resistivity single crystal ZnO wafer, then to bond the wafer onto a circuit board, and to connect the wafer with the circuit board by a gold thread.

The present invention discloses a high-resistivity single crystal zinc oxide (ZnO) wafer and a high-resistivity single crystal ZnO-based radiation detector, and preparation method and use thereof. The preparation method of the high-resistivity single crystal zinc oxide wafer is to place a single crystal ZnO wafer in a metal lithium electrochemical device for a constant-current discharge treatment, and then to place the single crystal ZnO wafer in a high-pressure oxygen atmosphere at 800 to 1000 C. and 10 to 30 atm for an annealing treatment for 20 to 28 hours. The preparation method of the radiation detector is to evaporate a metal electrode layer at both sides of the high-resistivity single crystal ZnO wafer, then to bond the wafer onto a circuit board, and to connect the wafer with the circuit board by a gold thread.

Embodiments transfer thin layers of material utilized in electronic devices (e.g., GaN for optoelectronic devices), from a donor to a handle substrate. Certain embodiments employ bond-and-release system(s) where release occurs along a cleave plane formed by implantation of particles into the donor. Some embodiments may rely upon release by converting components from solid to liquid under carefully controlled thermal conditions (e.g., solder-based materials and/or thermal decomposition of Indium-containing materials). Some embodiments utilize laser-induced film release processes using epitaxially grown or implanted regions as an optically absorptive region. A single bond-and-release sequence may involve processing an exposed N-face of GaN material. Multiple bond-and-release sequences (involving processing an exposed Ga-face of GaN material) may be employed in series, for example utilizing a temporary handle substrate as an intermediary. Particular embodiments form template blanks of high quality GaN suitable for manufacturing High Brightness-Light Emitting Diode (HB-LED) devices.

A method of fabricating plates of super-hard material and cutting techniques suitable for such a method. A method of fabricating a plate (14) of super-hard material, the method comprising: providing a substrate (4) have a lateral dimension of at least 40 mm; growing a layer of super-hard material on the substrate (4) using a chemical vapor deposition process; and slicing one or more plates (14) of super-hard material from the substrate using a collimated cutting beam (8), the or each plate of super-hard material (14) having a lateral dimension of at least 40 mm, wherein the collimated cutting beam (8) is collimated with a half angle divergence of no more than 5 degrees.

A method of fabricating plates of super-hard material and cutting techniques suitable for such a method. A method of fabricating a plate (14) of super-hard material, the method comprising: providing a substrate (4) have a lateral dimension of at least 40 mm; growing a layer of super-hard material on the substrate (4) using a chemical vapor deposition process; and slicing one or more plates (14) of super-hard material from the substrate using a collimated cutting beam (8), the or each plate of super-hard material (14) having a lateral dimension of at least 40 mm, wherein the collimated cutting beam (8) is collimated with a half angle divergence of no more than 5 degrees.