Abstract: Large area seed crystals for ammonothermal GaN growth are fabricated by deposition or layer transfer of a GaN layer on a CTE-matched handle substrate. The sides and back of the handle substrate are protected from the ammonothermal growth environment by a coating comprising an adhesion layer, a diffusion barrier layer, and an inert layer. A patterned mask, also comprising an adhesion layer, a diffusion barrier layer, and an inert layer, may be provided over the GaN layer to allow for reduction of the dislocation density by lateral epitaxial growth.

Abstract: A III-nitride light emitting layer is disposed between an n-type region and a p-type region in a double heterostructure. At least a portion of the III-nitride light emitting layer has a graded composition.

Abstract: A light-emitting system for emitting light, comprising: (a) at least one light-emitting diode (LED) configured to emit LED light; (b) at least one optical element optically coupled to said at least one LED and configured to direct a first fraction of said LED light along a first optical path and a second fraction of said LED light along a second optical path; and (c) a color modification element disposed along said second optical path and configured to modify the spectrum of said second fraction of said LED light to emit modified light.

Abstract: Light emitting devices with improved light extraction efficiency are provided. The light emitting devices have a stack of layers including semiconductor layers comprising an active region. The stack is bonded to a transparent optical element.

Abstract: A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension.

Abstract: Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

Abstract: Multi-part heat exchangers for hot/cold temperature domain isolation in LED lamps are disclosed.

Abstract: A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers.

Abstract: Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

Abstract: LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm.

Abstract: A semiconductor light emitting device comprising a light emitting layer disposed between an n-type region and a p-type region is combined with a ceramic layer which is disposed in a path of light emitted by the light emitting layer. The ceramic layer is composed of or includes a wavelength converting material such as a phosphor. Luminescent ceramic layers according to embodiments of the invention may be more robust and less sensitive to temperature than prior art phosphor layers. In addition, luminescent ceramics may exhibit less scattering and may therefore increase the conversion efficiency over prior art phosphor layers.

Abstract: A light emitting diode device has a bulk gallium and nitrogen containing substrate with an active region. The device has a lateral dimension and a thick vertical dimension such that the geometric aspect ratio forms a volumetric diode that delivers a nearly uniform current density across the range of the lateral dimension.

Abstract: LED illumination systems and techniques for apportioning optical projection paths in an LED lamp are disclosed.

Abstract: A plurality of III-nitride semiconductor structures, each including a light emitting layer disposed between an n-type region and a p-type region, are grown on a composite substrate. The composite substrate includes a plurality of islands of III-nitride material connected to a host by a bonding layer. The plurality of III-nitride semiconductor structures are grown on the III-nitride islands. The composite substrate may be formed such that each island of III-nitride material is at least partially relaxed. As a result, the light emitting layer of each semiconductor structure has an a-lattice constant greater than 3.19 angstroms.

Abstract: LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm.

Abstract: LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm.

Abstract: A photonic crystal is grown within a semiconductor structure, such as a III-nitride structure, which includes a light emitting region disposed between an n-type region and a p-type region. The photonic crystal may be multiple regions of semiconductor material separated by a material having a different refractive index than the semiconductor material. For example, the photonic crystal may be posts of semiconductor material grown in the structure and separated by air gaps or regions of masking material. Growing the photonic crystal, rather than etching a photonic crystal into an already-grown semiconductor layer, avoids damage caused by etching which may reduce efficiency, and provides uninterrupted, planar surfaces on which to form electric contacts.

Abstract: Methods and apparatus for providing circadian-friendly LED light sources are disclosed. A light source is formed to include a first LED emission (e.g., one or more LEDs emitting a first spectrum) and a second LED emission (e.g., one or more LEDs emitting a second spectrum) wherein the first and second LED emissions are combined in a first ratio and in a second ratio such that while changing from the first ratio to the second ratio the relative circadian stimulation is varied while maintaining a color rendering index above 80.

Abstract: LED lamp systems having improved light quality are disclosed. The lamps emit more than 500 lm and more than 2% of the power in the spectral power distribution is emitted within a wavelength range from about 390 nm to about 430 nm.

Abstract: The present disclosure relates generally to semiconductor techniques. More specifically, embodiments of the present disclosure provide methods for efficiently dicing substrates containing gallium and nitrogen material. Additionally, the present disclosure provides techniques resulting in an optical device comprising a substrate having a dislocation bundle center being used as a conductive region for a contact.