Cree Gmbh

Cree Research Inc.

Northrop Grumman Systems Corporation

Creeled, Inc.

Robert C Glass

Bernd P Keller

Eric J Tarsa

James Ibbetson

David Beardsley Slater, Jr

Charles M Swoboda

Brian Thibeault

Valeri Fedorovich Tsvetkov

Calvin H Carter, Jr

Antony Paul Van De Ven

Tao Tong

Ronan P LeToquin

Ryan Gresback

Fan Zhang

Walter E Gaida

Hudson McDonald Hobgood

Ronald R Ronallo

Calvin H Carter

Ronan P Letoquin

David B Slater

Solid state lighting devices with melatonin suppression characteristics that ameliorate or reduce symptoms of circadian rhythm disorders or other health conditions. Aspects disclosed herein additionally relate to providing one or more of the foregoing effects while maintaining color rendering index (CRI) values acceptably high for the intended use, as well as providing lighting devices with high luminous efficacy and enhanced energy efficiency. A solid state lighting device includes one or more solid state emitters and one or more lumiphoric materials that provide aggregated emissions of the solid state lighting device. The aggregated emissions have a warm correlated color temperature (CCT) with a color point that is off of the blackbody locus (BBL) by a certain distance.

Solid state lighting devices with reduced melatonin suppression characteristics

Light emitting devices include a light emitting diode ('LED') and a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED. In some embodiments, the recipient luminophoric medium includes a first broad-spectrum luminescent material and a narrow-spectrum luminescent material. The broad-spectrum luminescent material may down-convert radiation emitted by the LED to radiation having a peak wavelength in the red color range. The narrow-spectrum luminescent material may also down-convert radiation emitted by the LED into the cyan, green or red color range.

Recipient luminophoric mediums having narrow spectrum luminescent materials and related semiconductor light emitting devices and methods

Light emitting diodes include a diode region comprising a gallium nitride-based n-type layer, an active region and a gallium nitride-based p-type layer. A substrate is provided on the gallium nitride-based n-type layer and optically matched to the diode region. The substrate has a first face remote from the gallium nitride-based n-type layer, a second face adjacent the gallium nitride-based n-type layer and a sidewall therebetween. At least a portion of the sidewall is beveled, so as to extend oblique to the first and second faces. A reflector may be provided on the gallium nitride-based p-type layer opposite the substrate. Moreover, the diode region may be wider than the second face of the substrate and may include a mesa remote from the first face that is narrower than the first face and the second face.

Light emitting diodes including optically matched substrates

A light emitting diode includes a diode region having a gallium nitride based n-type layer, an active region and a gallium nitride based p-type layer. A first reflector layer is provided on the gallium nitride based p-type layer, and a second reflector layer is provided on the gallium nitride based n-type layer. Bonding layers, a mounting support, a wire bond and/or transparent oxide layers also may be provided.

Light emitting diodes including two reflector layers

Light emitting diodes include a substrate having first and second opposing faces and that is transparent to optical radiation in a predetermined wavelength range and that is patterned to define, in cross-section, a plurality of pedestals that extend into the substrate from the first face towards the second face. A diode region on the second face is configured to emit light in the predetermined wavelength range, into the substrate upon application of voltage across the diode region. A mounting support on the diode region, opposite the substrate is configured to support the diode region, such that the light that is emitted from the diode region into the substrate, is emitted from the first face upon application of voltage across the diode region. A reflector is provided between the mounting support and the diode region, that is configured to reflect light that is emitted from the diode region back into the diode region, through the substrate that is transparent to optical radiation in the predetermined wavelength range and from the plurality of pedestals, upon application of voltage across the diode region. A layer of Indium Tin Oxide (ITO) is provided between the reflector and the diode region.

Light emitting diodes including transparent oxide layers

Light emitting diodes include a substrate having first and second opposing faces and that is transparent to optical radiation in a predetermined wavelength range and that is patterned to define, in cross-section, a plurality of pedestals that extend into the substrate from the first face towards the second face. A diode region on the second face is configured to emit light in the predetermined wavelength range, into the substrate upon application of voltage across the diode region. A mounting support on the diode region, opposite the substrate is configured to support the diode region, such that the light that is emitted from the diode region into the substrate, is emitted from the first face upon application of voltage across the diode region. The first face of the substrate may include therein a plurality of grooves that define the plurality of triangular pedestals in the substrate. The grooves may include tapered sidewalls and/or a beveled floor. The first face of the substrate also may include therein an array of via holes. The via holes may include tapered sidewalls and/or a floor.

Light emitting diodes including pedestals

Light emitting diodes including modifications for light extraction

Large single crystals of silicon carbide are grown in a furnace sublimation system. The crystals are grown with compensating levels of p-type and n-type dopants (i.e., roughly equal levels of the two dopants) in order to produce a crystal that is essentially colorless. The crystal may be cut and fashioned into synthetic gemstones having extraordinary toughness and hardness, and a brilliance meeting or exceeding that of diamond.

Colorless silicon carbide gemstones

Colorless silicon carbide crystals

Large single crystals of silicon carbide are grown in a furnace sublimation system. The crystals are grown with compensating levels of p-type and n-type dopants (i.e., roughly equal to levels of the two dopants) in order to produce a crystal that is essentially colorless. The crystal may be cut and fashioned into synthetic gemstones having extraordinary toughness and hardness, and a brilliance meeting or exceeding that of diamond.

Growth of colorless silicon carbide crystals

A silicon carbide growth container for placement into a crystal growing furnace. The growth container has a liner of pyrolytic graphite which seals the inside of the container and allows for easy removal of the grown silicon carbide crystal.

Growing community of inventors

Chapel Hill, NC, United States of America

Robert C Glass