Cree Gmbh

Iliya Todorov

Brian Thomas Collins

Michael John Bergmann

Jasper S Cabalu

Florin A Tudorica

Harry A Seibel

David Clatterbuck

Matthew Donofrio

Kevin Haberern

Bradley E Williams

Bennett Dean Langsdorf

Anoop Mathew

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

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

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

A yellow phosphor having an increased activator concentration includes a host lattice comprising yttrium aluminum garnet (YAG) and an activator comprising cerium in the host lattice, where the cerium is present at a concentration of at least about 5 wt. % Ce. A method of making a yellow phosphor includes forming a reaction mixture comprising: a first precursor comprising cerium and oxygen; a second precursor comprising cerium and fluorine; a third precursor comprising yttrium; and a fourth precursor comprising aluminum. The reaction mixture is heated in a reducing environment at a temperature sufficient to form a yellow phosphor including a host lattice comprising yttrium aluminum garnet and an activator comprising cerium (Ce) incorporated in the host lattice.

Yellow phosphor having an increased activator concentration and a method of making a yellow phosphor

Light emitting devices include a blue LED that emits blue light having a peak wavelength between 430 nanometers and 480 nanometers and a recipient luminophoric medium that includes luminescent materials that down-convert a portion of the blue light emitted by the blue LED to light having a peak wavelength that is between about 500 nanometers and about 545 nanometers. The combination of the blue light emitted by the blue LED and the light emitted by the luminescent materials in the recipient luminophoric medium comprises light that is perceived as blue light having a color point that falls within the region on the 1931 CIE Chromaticity Diagram defined by ccx, ccy chromaticity coordinates of (0.1355, 0.0399), (0.175, 0.0985), (0.1743 0.1581), (0.1096, 0.0868), (0.1355, 0.0399).

Blue light emitting devices that include phosphor-converted blue light emitting diodes

Growing community of inventors

Durham, NC, United States of America

Iliya Todorov