Cree Gmbh

Creeled, Inc.

Brian Thomas Collins

David T Emerson

Christopher P Hussell

Michael John Bergmann

Ronan P Le Toquin

Harry A Seibel

Florin A Tudorica

Daniel Carleton Driscoll

Robert David Schmidt

Thomas A Kuhr

Iliya Todorov

Jasper S Cabalu

David Clatterbuck

Jesse Colin Reiherzer

Robert Wilcox

John Adam Edmond

Bernd P Keller

Peter Scott Andrews

Eric J Tarsa

Matthew Donofrio

Kevin Haberern

Colin Kelly Blakely

Derek Miller

Bradley E Williams

Amber Christine Salter

Bennett Dean Langsdorf

Nathaniel O Cannon

Harry A Seibel, Ii

Walter Weare

Anoop Mathew

Group III nitride based light emitting diode (LED) structures include multiple quantum wells with barrier-well units that include III nitride interface layers. Each interface layer may have a thickness of no greater than about 30% of an adjacent well layer, and a comparatively low concentration of indium or aluminum. One or more interface layers may be present in a barrier-well unit. Multiple barrier-well units having different properties may be provided in a single active region.

Group III nitride based LED structures including multiple quantum wells with barrier-well unit interface layers

Solid-state lighting devices including light-emitting diodes (LEDs), and more particularly binder materials for light-emitting devices are disclosed. A lumiphoric material for a light-emitting device may include lumiphoric particles embedded within a binder material. The lumiphoric material may be formed according to sol-gel chemistry techniques where a solution of binder precursors and lumiphoric particles is applied to a surface, dried to reduce liquid phase, and fired to form a hardened and dense lumiphoric material. The binder precursors may include metal oxide precursors that result in a metal oxide binder. In this manner, the lumiphoric material may have high thermal conductivity while also being adaptable for liquid-phase processing. In further embodiments, binder materials with or without lumiphoric particles may be utilized in place of conventional encapsulation materials for light-emitting devices.

Binder materials for light-emitting devices

A method is disclosed for forming a blended phosphor composition. The method includes the steps of firing precursor compositions that include europium and nitrides of at least calcium, strontium and aluminum, in a refractory metal crucible and in the presence of a gas that precludes the formation of nitride compositions between the nitride starting materials and the refractory metal that forms the crucible. The resulting compositions can include phosphors that convert frequencies in the blue portion of the visible spectrum into frequencies in the red portion of the visible spectrum.

Phosphor composition

Group III nitride based light emitting diode (LED) structures include multiple quantum wells with barrier-well units that include Ill nitride interface layers. Each interface layer may have a thickness of no greater than about 30% of an adjacent well layer, and a comparatively low concentration of indium or aluminum. One or more interface layers may be present in a barrier-well unit. Multiple barrier-well units having different properties may be provided in a single active region.

A phosphor-converted light emitting device includes a light emitting diode (LED) on a substrate, where the LED comprises a stack of epitaxial layers comprising a p-n junction. A wavelength conversion material is in optical communication with the LED. According to one embodiment of the phosphor-converted light emitting device, a selective filter is adjacent to the wavelength conversion material, and the selective filter comprises a plurality of nanoparticles for absorbing light from the LED not down-converted by the wavelength conversion material. According to another embodiment of the phosphor-converted light emitting device, a perpendicular distance between a perimeter of the LED on the substrate and an edge of the substrate is at least about 24 microns. According to another embodiment of the phosphor-converted light emitting device, the LED comprises a mirror layer on one or more sidewalls thereof for reducing light leakage through the sidewalls.

Phosphor-converted light emitting device

Phosphor Composition

A semiconductor light emitting device includes an LED and an associated recipient luminophoric medium that includes respective first through fourth luminescent materials that down-convert respective first through fourth portions of the radiation emitted by the LED to radiation having respective first through fourth peak wavelengths. The first peak wavelength is in the green color range and the second through fourth peak wavelengths are in the red color range. The second and third luminescent materials each emit light having a full-width half maximum bandwidth of at least 70 nanometers, while the fourth luminescent material emits light having a full-width half maximum bandwidth of less than 60 nanometers. Embodiments that only include three luminescent materials are also disclosed.

Light-emitting devices having closely-spaced broad-spectrum and narrow-spectrum luminescent materials and related methods

A light emitting device includes a light emitting diode chip ('LED') that emits light having a dominant wavelength in the blue color range and a recipient luminophoric medium that is configured to down-convert at least some of the light emitted by the LED. The recipient luminophoric medium includes a green phosphor, a yellow phosphor, a first red phosphor having a first dominant wavelength and a second red phosphor having a second dominant wavelength that is different from the first dominant wavelength.

Semiconductor light emitting devices including multiple red phosphors that exhibit good color rendering properties with increased brightness

Group III nitride based light emitting diode (LED) structures include multiple quantum wells with barrier-well units that include III nitride interface layers. Each interface layer may have a thickness of no greater than about 30% of an adjacent well layers, and a comparatively low concentration of indium or aluminum. One or more interface layers may be present in a barrier-well unit. Multiple barrier-well units having different properties may be provided in a single active region.

A semiconductor light emitting device includes an LED and a recipient luminophoric medium that includes a first narrow-spectrum luminescent material that down-converts a first portion of the radiation emitted by the LED to radiation having a first peak wavelength in the green-yellow color range and a second narrow-spectrum luminescent material that down-converts a second portion of the radiation emitted by the LED to radiation having a second peak wavelength in an orange-red color range. The first and second luminescent materials and any additional narrow-spectrum luminescent materials that are included in the recipient luminophoric medium generate at least 80% of the light emitted by the recipient luminophoric medium. A CRI value of the combined light emitted by the semiconductor light emitting device is at least 60 and less than 80.

High brightness, low-cri semiconductor light emitting devices including narrow-spectrum luminescent materials

Light emitting devices having closely-spaced broad-spectrum and narrow-spectrum luminescent materials and related methods

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Holly Springs, NC, United States of America

Brian Thomas Collins