Abstract: A method for growing a nitride crystal and a crystalline composition selected from one of AlN, InGaN, AlGaInN, InGaN, and AlGaNInN is provided. The composition comprises a true single crystal, grown from a single nucleus, at least 1 mm in diameter, free of lateral strain and tilt boundaries, with a dislocation density less than about 104 cm?2.

Abstract: A crystalline composition is provided. The crystalline composition may include gallium and nitrogen; and the crystalline composition may have an infrared absorption peak at about 3175 cm?1, with an absorbance per unit thickness of greater than about 0.01 cm?1.

Abstract: A crystalline composition is provided that includes gallium and nitrogen. The crystalline composition may have an amount of oxygen present in a concentration of less than about 3×1018 per cubic centimeter, and may be free of two-dimensional planar boundary defects in a determined volume of the crystalline composition. The volume may have at least one dimension that is about 2.75 millimeters or greater, and the volume may have a one-dimensional linear defect dislocation density of less than about 10,000 per square centimeter.

Abstract: A crystal comprising gallium nitride is disclosed. The crystal has at least one grain having at least one dimension greater than 2.75 mm, a dislocation density less than about 104 cm?2, and is substantially free of tilt boundaries.

Abstract: A crystalline composition is provided that includes gallium and nitrogen. The crystalline composition may have an amount of oxygen present in a concentration of less than about 3×1018 per cubic centimeter, and may be free of two-dimensional planar boundary defects in a determined volume of the crystalline composition. The volume may have at least one dimension that is about 2.75 millimeters or greater, and the volume may have a one-dimensional linear defect dislocation density of less than about 10,000 per square centimeter.

Abstract: There is provided a GaN single crystal at least about 2 millimeters in diameter, with a dislocation density less than about 104 cm?1, and having no tilt boundaries. A method of forming a GaN single crystal is also disclosed. The method includes providing a nucleation center, a GaN source material, and a GaN solvent in a chamber. The chamber is pressurized. First and second temperature distributions are generated in the chamber such that the solvent is supersaturated in the nucleation region of the chamber. The first and second temperature distributions have different temperature gradients within the chamber.

Abstract: A crystalline composition is provided. The crystalline composition may include gallium and nitrogen; and the crystalline composition may have an infrared absorption peak at about 3175 cm?1, with an absorbance per unit thickness of greater than about 0.01 cm?1.

Abstract: A method may produce a resonant cavity light emitting device. A seed gallium nitride crystal and a source material in a nitrogen-containing superheated fluid may provide a medium for mass transport of gallium nitride precursors therebetween. A seed crystal surface may be prepared by applying a first thermal profile between the seed gallium nitride crystal and the source material. Gallium nitride material may be grown on the prepared surface of the seed gallium nitride crystal by applying a second thermal profile between the seed gallium nitride crystal and the source material while the seed gallium nitride crystal and the source material are in the nitrogen-containing superheated fluid. A stack of group III-nitride layers may be deposited on the single-crystal gallium nitride substrate. The stack may include a first mirror sub-stack and an active region adaptable for fabrication into one or more resonant cavity light emitting devices.

Abstract: A capsule for containing at least one reactant and a supercritical fluid in a substantially air-free environment under high pressure, high temperature processing conditions. The capsule includes a closed end, at least one wall adjoining the closed end and extending from the closed end; and a sealed end adjoining the at least one wall opposite the closed end. The at least one wall, closed end, and sealed end define a chamber therein for containing the reactant and a solvent that becomes a supercritical fluid at high temperatures and high pressures. The capsule is formed from a deformable material and is fluid impermeable and chemically inert with respect to the reactant and the supercritical fluid under processing conditions, which are generally above 5 kbar and 550° C. and, preferably, at pressures between 5 kbar and 80 kbar and temperatures between 550° C. and about 1500° C.

Abstract: A GaN crystal having up to about 5 mole percent of at least one of aluminum, indium, and combinations thereof. The GaN crystal has at least one grain having a diameter greater than 2 mm, a dislocation density less than about 104 cm?2, and is substantially free of tilt boundaries.

Abstract: In a method for producing a resonant cavity light emitting device, a seed gallium nitride crystal (14) and a source material (30) are arranged in a nitrogen-containing superheated fluid (44) disposed in a sealed container (10) disposed in a multiple-zone furnace (50). Gallium nitride material is grown on the seed gallium nitride crystal (14) to produce a single-crystal gallium nitride substrate (106, 106?). Said growing includes applying a temporally varying thermal gradient (100, 100?, 102, 102?) between the seed gallium nitride crystal (14) and the source material (30) to produce an increasing growth rate during at least a portion of the growing. A stack of group III-nitride layers (112) is deposited on the single-crystal gallium nitride substrate (106, 106?), including a first mirror sub-stack (116) and an active region (120) adapted for fabrication into one or more resonant cavity light emitting devices (108, 150, 160, 170, 180).