Abstract:
A high-power, high-brightness lighting system for large venue lighting, which includes a laser diode as the excitation source and one or more phosphor materials placed at a remote distance from the laser source. The invention offers a lighting system with the advantages of high brightness, high efficiency, high luminous efficacy, long lifetimes, quick turn-on times, suitable color properties, environmental sustainability, and easy maintenance, which may allow for smart and flexible control over large area lighting systems with resulting savings in operating and maintenance costs.
Abstract:
A method for increasing the luminous efficacy of a white light emitting diode (WLED), comprising introducing optically functional interfaces between an LED die and a phosphor, and between the phosphor and an outer medium, wherein at least one of the interfaces between the phosphor and the LED die provides a reflectance for light emitted by the phosphor away from the outer medium and a transmittance for light emitted by the LED die. Thus, a WLED may comprise a first material which surrounds an LED die, a phosphor layer, and at least one additional layer or material which is transparent for direct LED emission and reflective for the phosphor emission, placed between the phosphor layer and the first material which surrounds the LED die.
Abstract:
A method for the reuse of gallium nitride (GaN) epitaxial substrates uses band-gap-selective photoelectrochemical (PEC) etching to remove one or more epitaxial layers from bulk or free-standing GaN substrates without damaging the substrate, allowing the substrate to be reused for further growth of additional epitaxial layers. The method facilitates a significant cost reduction in device production by permitting the reuse of expensive bulk or free-standing GaN substrates.
Abstract:
A nonpolar III-nitride film grown on a miscut angle of a substrate, in order to suppress the surface undulations, is provided. The surface morphology of the film is improved with a miscut angle towards an a-axis direction comprising a 0.15° or greater miscut angle towards the a-axis direction and a less than 30° miscut angle towards the a-axis direction.
Abstract:
A method for the reuse of gallium nitride (GaN) epitaxial substrates uses band-gap-selective photoelectrochemical (PEC) etching to remove one or more epitaxial layers from bulk or free-standing GaN substrates without damaging the substrate, allowing the substrate to be reused for further growth of additional epitaxial layers. The method facilitates a significant cost reduction in device production by permitting the reuse of expensive bulk or free-standing GaN substrates.
Abstract:
A transparent light emitting diode (LED) includes a plurality of III-nitride layers, including an active region that emits light, wherein all of the layers except for the active region are transparent for an emission wavelength of the light, such that the light is extracted effectively through all of the layers and in multiple directions through the layers. Moreover, the surface of one or more of the III-nitride layers may be roughened, textured, patterned or shaped to enhance light extraction.
Abstract:
An epitaxial structure for a III-Nitride based optical device, comprising an active layer with anisotropic strain on an underlying layer, where a lattice constant and strain in the underlying layer are partially or fully relaxed in at least one direction due to a presence of misfit dislocations, so that the anisotropic strain in the active layer is modulated by the underlying layer.
Abstract:
An (Al,In,B,Ga)N or III-nitride based laser diode epitaxially grown on orientations other than a c-plane orientation, namely various semipolar and nonpolar orientations, and having polished facets. The semipolar orientation may be a semipolar (11-22), (11-2-2), (101-1), (10-1-1), (20-21), (20-2-1), (30-31) or (30-3-1) orientation, and the nonpolar orientation may be a nonpolar (10-10) or (11-20) orientation. The facets are chemically mechanically or mechanically polished.
Abstract:
A high brightness III-Nitride based Light Emitting Diode (LED), comprising multiple surfaces covered by Zinc Oxide (ZnO) layers, wherein the ZnO layers are grown in a low temperature aqueous solution and each have a (0001) c-orientation and a top surface that is a (0001) plane.
Abstract:
A method for increasing the luminous efficacy of a white light emitting diode (WLED), comprising introducing optically functional interfaces between an LED die and a phosphor, and between the phosphor and an outer medium, wherein at least one of the interfaces between the phosphor and the LED die provides a reflectance for light emitted by the phosphor away from the outer medium and a transmittance for light emitted by the LED die. Thus, a WLED may comprise a first material which surrounds an LED die, a phosphor layer, and at least one additional layer or material which is transparent for direct LED emission and reflective for the phosphor emission, placed between the phosphor layer and the first material which surrounds the LED die.