Abstract: A substrate comprises a Group III-V material having an upper surface and a buffer layer having a thickness of not greater than about 1.3 ?m and overlying the upper surface of the substrate. A plurality of optoelectronic devices formed on the substrate having a normalized light emission wavelength standard deviation of not greater than about 0.0641 nm/cm2 at a wavelength within a range of between about 400 nm to about 550 nm.

Abstract: A detector of ionizing radiation comprises a photodetector and a scintillator in the shape of truncated cone comprising a large base, a small base and a lateral surface, the large base of the scintillator being coupled to the photodetector, any half-angle at the apex of the cone being in the range between 5° and 35°, the lateral face being coated with a black coating. The detector in accordance with an embodiment can produce a very short pulse.

Abstract: A method of forming a semiconductive substrate material for an electronic device including forming a plurality of semiconductive layers on a substrate during a continuous growth process in a reaction chamber, wherein during the continuous growth process, a release layer is formed between a base layer and an epitaxial layer by altering at least one growth process parameter during the continuous growth process. The method also including separating the plurality of semiconductive layers from the substrate.

Abstract: The invention relates to a method for manufacturing a single crystal of nitride by epitaxial growth on a support (100) comprising a growth face (105), the method comprising the steps of formation of a sacrificial bed (101) on the support (100), formation of pillars (102) on said sacrificial bed, said pillars being made of a material compatible with GaN epitaxial growth, growth of a nitride crystal layer (103) on the pillars, under growing conditions such that the nitride crystal layer does not extend down to the support in holes (107) formed between the pillars, and removing the nitride crystal layer from the support.

Abstract: A method of forming a semiconductive substrate material for an electronic device including forming a plurality of semiconductive layers on a substrate during a continuous growth process in a reaction chamber, wherein during the continuous growth process, a release layer is formed between a base layer and an epitaxial layer by altering at least one growth process parameter during the continuous growth process. The method also including separating the plurality of semiconductive layers from the substrate.

Abstract: A substrate including a body comprising a Group III-V material and having an upper surface, the body comprising an offcut angle defined between the upper surface and a crystallographic reference plane, and the body further having an offcut angle variation of not greater than about 0.6 degrees.

Abstract: A substrate comprises a Group III-V material having an upper surface and a buffer layer having a thickness of not greater than about 1.3 ?m and overlying the upper surface of the substrate. A plurality of optoelectronic devices formed on the substrate having a normalized light emission wavelength standard deviation of not greater than about 0.0641 nm/cm2 at a wavelength within a range of between about 400 nm to about 550 nm.

Abstract: The invention relates to an inorganic scintillator material of formula Lu(2-y)Y(y-z-x)CexMzSi(1-v)M?vO5, in which: M represents a divalent alkaline earth metal and M? represents a trivalent metal, (z+v) being greater than or equal to 0.0001 and less than or equal to 0.2; z being greater than or equal to 0 and less than or equal to 0.2; v being greater than or equal to 0 and less than or equal to 0.2; x being greater than or equal to 0.0001 and less than 0.1; and y ranging from (x+z) to 1. In particular, this material may equip scintillation detectors for applications in industry, for the medical field (scanners) and/or for detection in oil drilling. The presence of Ca in the crystal reduces the afterglow, while stopping power for high-energy radiation remains high.

Abstract: The invention relates to an inorganic scintillator material of formula Lu(2-y)Y(y-z-x)CexMzSi(1-v)M?vO5, in which: M represents a divalent alkaline earth metal and M? represents a trivalent metal, (z+v) being greater than or equal to 0.0001 and less than or equal to 0.2; z being greater than or equal to 0 and less than or equal to 0.2; v being greater than or equal to 0 and less than or equal to 0.2; x being greater than or equal to 0.0001 and less than 0.1; and y ranging from (x+z) to 1. In particular, this material may equip scintillation detectors for applications in industry, for the medical field (scanners) and/or for detection in oil drilling. The presence of Ca in the crystal reduces the afterglow, while stopping power for high-energy radiation remains high.

Abstract: A method for manufacturing a single crystal of nitride by epitaxial growth on a substrate appropriate for the growth of the crystal. The substrate includes, deposited on the edges of its growth surface, a mask appropriate to prevent growing of the single crystal on the edges of the substrate.

Abstract: A scintillator material comprises a rare-earth halide coated with a layer comprising a resin and a pigment. In an embodiment, the scintillator material is used in an ionizing-radiation detector, and in particular embodiment, a gamma camera. The layer can adhere well and act as an absorbent or reflector depending on the color of the pigment.

Abstract: The invention relates to a process for manufacturing a single crystal comprising a rare-earth halide, having improved machining or cleavage behavior, comprising heat treatment in a furnace, the atmosphere of which is brought, for at least 1 hour, to between 0.70 times Tm and 0.995 times Tm of a single crystal comprising a rare-earth halide, Tm representing the melting point of said single crystal, the temperature gradient at any point in the atmosphere of the furnace being less than 15 K/cm for said heat treatment. After carrying out the treatment according to the invention, the single crystals may be machined or cleaved without uncontrolled fracture. The single crystals may be used in a medical imaging device, especially a positron emission tomography system or a gamma camera or a CT scanner, for crude oil exploration, for detection and identification of fissile or radioactive materials, for nuclear and high-energy physics, for astrophysics or for industrial control.

Abstract: A scintillator material comprises a rare-earth halide coated with a layer comprising a resin and a pigment. In an embodiment, the scintillator material is used in an ionizing-radiation detector, and in particular embodiment, a gamma camera. The layer can adhere well and act as an absorbent or reflector depending on the color of the pigment.

Abstract: A detector of ionizing radiation comprises a photodetector and a scintillator in the shape of truncated cone comprising a large base, a small base and a lateral surface, the large base of the scintillator being coupled to the photodetector, any half-angle at the apex of the cone being in the range between 5° and 35°, the lateral face being coated with a black coating. The detector in accordance with an embodiment can produce a very short pulse.

Abstract: The invention relates to a single-crystal scintillator material comprising at least 50 wt % of rare-earth halide and comprising a polished first face. This material is integrated into an ionizing-radiation detector comprising a photoreceiver, the photoreceiver being optically coupled to the material via a face other than the polished first face. The material provides a good energy resolution and a high light intensity. The polishing may be carried out whatever the crystal orientation of the crystal. Loss of material due to this orientation is therefore prevented.

Abstract: The invention relates to a method of preparing a polycrystalline block of a halide of formula AeLnfX(3f+e) in which Ln represents one or more rare earths, X represents one or more halogen atoms selected from the group consisting of Cl, Br and I, and A represents one or more alkali metals selected from the group consisting of K, Li, Na, Rb and Cs, e, which may be zero, being less than or equal to 3f, and f being greater than or equal to 1, having a low water and oxyhalide content, in which the method comprises heating a mixture of, on the one hand, at least one compound having at least one Ln—X bond and, on the other hand, a sufficient amount of NH4X in order to obtain the oxyhalide content, resulting in a molten mass comprising the rare-earth halide, the heating being followed by cooling, and the heating, after having reached 300° C., never going below 200° C. before the molten mass has been obtained.

Abstract: A method for fabricating a textured single crystal including depositing pads made of metal on a surface of a single crystal. A protective layer is deposited on the pads and on the single crystal between the pads; and etching the surface with a first compound that etches the metal more rapidly than the protective layer is carried out. Processing continues with etching the surface with a second compound that etches the single crystal more rapidly than the protective layer; and etching the surface with a third compound that etches the protective layer more rapidly than the single crystal. The textured substrate may be used for the epitaxial growth of GaN, AlN or III-N compounds (i.e. a nitride of a metal the positive ion of which carries a +3 positive charge) in the context of the fabrication of LEDs, electronic components or solar cells.

Abstract: The invention relates to a scintillator material comprising a cerium-doped rare-earth silicate, characterized in that its absorbance at a wavelength of 357 nm is less than its absorbance at 280 nm. This material has an afterglow of generally less than 200 ppm after 100 ms relative to the intensity measured during an X-ray irradiation. It is preferably codoped. It may be obtained using an oxidizing anneal. It is particularly suited to integration in an ionizing particle detector that may be used in a medical imaging apparatus.

Abstract: The invention relates to an inorganic scintillator material of formula Lu(2-y)Y(y-z-x)CexMzSi(1-v)M?vO5, in which: M represents a divalent alkaline earth metal and M? represents a trivalent metal, (z+v) being greater than or equal to 0.0001 and less than or equal to 0.2; z being greater than or equal to 0 and less than or equal to 0.2; v being greater than or equal to 0 and less than or equal to 0.2; x being greater than or equal to 0.0001 and less than 0.1; and y ranging from (x+z) to 1. In particular, this material may equip scintillation detectors for applications in industry, for the medical field (scanners) and/or for detection in oil drilling. The presence of Ca in the crystal reduces the afterglow, while stopping power for high-energy radiation remains high.

Abstract: The invention relates to a method of preparing a polycrystalline block of a halide of formula AeLnfX(3f+e) in which Ln represents one or more rare earths, X represents one or more halogen atoms selected from the group consisting of Cl, Br and I, and A represents one or more alkali metals selected from the group consisting of K, Li, Na, Rb and Cs, e, which may be zero, being less than or equal to 3f, and f being greater than or equal to 1, having a low water and oxyhalide content, in which the method comprises heating a mixture of, on the one hand, at least one compound having at least one Ln-X bond and, on the other hand, a sufficient amount of NH4X in order to obtain the oxyhalide content, resulting in a molten mass comprising the rare-earth halide, the heating being followed by cooling, and the heating, after having reached 300° C., never going below 200° C. before the molten mass has been obtained.