Abstract: The invention relates to a tri-color lamp for generating white light comprising a phosphor composition comprising a phosphor of general formula (Ba1-x-y-z-SrxCay)2SiO4:Euz, wherein 0?x?1, 0?y?1 and 0<z<1. The phosphor composition may also comprise a red phosphor. The two phosphors can absorb radiation emitted by a light emitting diode, particularly a blue LED. This arrangement provides a mixing of three light sources—light emitted from the two phosphors and unabsorbed light from the LED. The invention also relates to an alternative to a green LED comprising a single green phosphor of general formula (Ba1-x-y-z-SrxCay)2SiO4:Euz, wherein 0?x?0 1, 0?y?1 and 0<z<1, that absorbs radiation from a blue LED. A resulting device provides green light of high absorption efficiency and high luminous equivalent values.

Abstract: A semiconductor light emitting device is combined with a wavelength converting material. The semiconductor light emitting device is configured to emit first light of a first peak wavelength. The wavelength converting material is configured to absorb at least a portion of the first light and emit second light of a second peak wavelength. In some embodiments, the first wavelength converting material is (Ba1-xSrx)2-y-0.5zSi5N8-zOz:Euy2+ where 0.2<x<0.3, (Ba1-xCax)2-y-0.5zSi5N8-zOz:Euy2+ where 0.01<x<0.2, or M2Si5-aAaN8-aOa:Eu2+ where M=Sr, Ba, Ca; A=Al, B, Ga, Sc; and 0.01<a<0.2.

Abstract: The invention relates to a tri-color lamp for generating white light comprising a phosphor composition comprising a phosphor of general formula (Ba1?x?y?z?SrxCay)2SiO4:Euz, wherein 0?x?1, 0?y?1 and 0<z<1. The phosphor composition may also comprise a red phosphor. The two phosphors can absorb radiation emitted by a light emitting diode, particularly a blue LED. This arrangement provides a mixing of three light sources—light emitted from the two phosphors and unabsorbed light from the LED. The invention also relates to an alternative to a green LED comprising a single green phosphor of general formula (Ba1?x?y?z ?SrxCay)2SiO4:Euz, wherein 0?x?1, 0?y?1 and 0<z<1, that absorbs radiation from a blue LED. A resulting device provides green light of high absorption efficiency and high luminous equivalent values.

Abstract: A semiconductor light emitting device is provided with a separately fabricated wavelength converting element. The wavelength converting element, of e.g., phosphor and glass, is produced in a sheet that is separated into individual wavelength converting elements, which are bonded to light emitting devices. The wavelength converting elements may be grouped and stored according to their wavelength converting properties. The wavelength converting elements may be selectively matched with a semiconductor light emitting device, to produce a desired mixture of primary and secondary light.

Abstract: A semiconductor light emitting device is provided with a separately fabricated wavelength converting element. The wavelength converting element, of e.g., phosphor and glass, is produced in a sheet that is separated into individual wavelength converting elements, which are bonded to light emitting devices. The wavelength converting elements may be grouped and stored according to their wavelength converting properties. The wavelength converting elements may be selectively matched with a semiconductor light emitting device, to produce a desired mixture of primary and secondary light.

Abstract: A ceramic body comprising a wavelength converting material is disposed in the path of light emitted by the light emitting region of a semiconductor structure comprising a light emitting region disposed between an n-type region and a p-type region. A layer of transparent material is also disposed in the path of light emitted by the light emitting region. The transparent material may connect the ceramic body to the semiconductor structure. Particles configured to scatter light emitted by the light emitting region are disposed in the layer of adhesive material. In some embodiments the particles are phosphor; in some embodiments the particles are not a wavelength-converting material.

Abstract: A semiconductor light emitting device comprising a light emitting layer configured to emit light of a first wavelength disposed between an n-type region and a p-type region is combined with a cerium-doped garnet phosphor having a wider excitation spectrum than conventional cerium-doped garnet phosphors. In some embodiments, the phosphor has a cerium concentration between about 4 mol % and about 8 mol %.

Abstract: A phosphor converted light emitting device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region, the light emitting layer being configured to emit light having a first peak wavelength; a first phosphor configured to emit light having a second peak wavelength; and a second phosphor configured to emit light having a third peak wavelength. The second phosphor is an Eu3+-activated phosphor, configured such that in the excitation spectrum at 298K and 1.013 bar, a maximum intensity in a wavelength range between 460 nm and 470 nm is at least 5% of a maximum intensity in a wavelength range between 220 nm to 320 nm.

Abstract: A structure includes a semiconductor light emitting device including a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer emits first light of a first peak wavelength. A wavelength-converting material that absorbs the first light and emits second light of a second peak wavelength is disposed in the path of the first light. A filter material that transmits a portion of the first light and absorbs or reflects a portion of the first light is disposed over the wavelength-converting material.

Abstract: A ceramic body is disposed in a path of light emitted by a light source. The light source may include a semiconductor structure comprising a light emitting region disposed between an n-type region and a p-type region. The ceramic body includes a plurality of first grains configured to absorb light emitted by the light source and emit light of a different wavelength, and a plurality of second grains. For example, the first grains may be grains of luminescent material and the second grains may be grains of a luminescent material host matrix without activating dopant.

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 ceramic body comprising a wavelength converting material is disposed in the path of light emitted by the light emitting region of a semiconductor structure comprising a light emitting region disposed between an n-type region and a p-type region. A layer of transparent material is also disposed in the path of light emitted by the light emitting region. The transparent material may connect the ceramic body to the semiconductor structure. Particles configured to scatter light emitted by the light emitting region are disposed in the layer of adhesive material. In some embodiments the particles are phosphor; in some embodiments the particles are not a wavelength-converting material.

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 method of bonding a transparent optical element to a light emitting device having a stack of layers including semiconductor layers comprising an active region is provided. The method includes elevating a temperature of the optical element and the stack and applying a pressure to press the optical element and the stack together. In one embodiment, the method also includes disposing a layer of a transparent bonding material between the stack and the optical element. The bonding method can be applied to a premade optical element or to a block of optical element material which is later formed or shaped into an optical element such as a lens or an optical concentrator.

Abstract: In a wavelength converted semiconductor light emitting device with at least two wavelength converting materials, the wavelength converting materials in the device are arranged relative to the light emitting device and relative to each other to tailor interaction between the different wavelength converting materials in order to maximize one or more of the luminous equivalent, color rendering index, and color gamut of the combined visible light emitted by the device.

Abstract: A light emitting diode capable of emitting first light having a first peak wavelength is combined with a first phosphor layer overlying the light emitting diode, the first phosphor layer capable of absorbing the first light and emitting second light having a second peak wavelength and a second phosphor layer overlying the light emitting diode, the second phosphor layer capable of emitting third light having a third peak wavelength.

Abstract: Light-emitting devices are disclosed that comprise a light source emitting first light, a first material substantially transparent to and located to receive at least a portion of the first light, and particles of a second material dispersed in the first material. The second material has an index of refraction greater than an index of refraction of the first material at a wavelength of the first light. The particles of the second material have diameters less than about this wavelength. Particles of a third material may also be dispersed in the first material.

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 having a refractive index for light emitted by the active region preferably greater than about 1.5, more preferably greater than about 1.8. A method of bonding a transparent optical element (e.g., a lens or an optical concentrator) to a light emitting device comprising an active region includes elevating a temperature of the optical element and the stack and applying a pressure to press the optical element and the light emitting device together. A block of optical element material may be bonded to the light emitting device and then shaped into an optical element. Bonding a high refractive index optical element to a light emitting device improves the light extraction efficiency of the light emitting device by reducing loss due to total internal reflection.

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 lens having a refractive index for light emitted by the active region preferably greater than about 1.5, more preferably greater than about 1.8. A method of bonding a transparent lens to a light emitting device having a stack of layers including semiconductor layers comprising an active region includes elevating a temperature of the lens and the stack and applying a pressure to press the lens and the stack together. Bonding a high refractive index lens to a light emitting device improves the light extraction efficiency of the light emitting device by reducing loss due to total internal reflection. Advantageously, this improvement can be achieved without the use of an encapsulant.

Abstract: A system includes a radiation source capable of emitting first light and a fluorescent material capable of absorbing the first light and emitting second light having a different wavelength than the first light. The fluorescent material is a phosphor having the formula (Lu1-x-y-a-bYxGdy)3(Al1-zGaz)5O12:CeaPrb wherein 0<x<1, 0<y<1, 0<z?0.1, 0<a?0.2 and 0<b?0.1. In some embodiments, the (Lu1-x-y-a-bYxGdy)3(Al1-zGaz)5O12:CeaPrb is combined with a second fluorescent material capable of emitting third light. The second fluorescent material may be a red-emitting phosphor, such that the combination of first, second, and third light emitted from the system appears white.