Patent application number | Description | Published |
20090230381 | AlInGaP LED HAVING REDUCED TEMPERATURE DEPENDENCE - To increase the lattice constant of AlInGaP LED layers to greater than the lattice constant of GaAs for reduced temperature sensitivity, an engineered growth layer is formed over a substrate, where the growth layer has a lattice constant equal to or approximately equal to that of the desired AlInGaP layers. In one embodiment, a graded InGaAs or InGaP layer is grown over a GaAs substrate. The amount of indium is increased during growth of the layer such that the final lattice constant is equal to that of the desired AlInGaP active layer. In another embodiment, a very thin InGaP, InGaAs, or AlInGaP layer is grown on a GaAs substrate, where the InGaP, InGaAs, or AlInGaP layer is strained (compressed). The InGaP, InGaAs, or AlInGaP thin layer is then delaminated from the GaAs and relaxed, causing the lattice constant of the thin layer to increase to the lattice constant of the desired overlying AlInGaP LED layers. The LED layers are then grown over the thin InGaP, InGaAs, or AlInGaP layer. | 09-17-2009 |
20090261361 | III-NITRIDE LIGHT EMITTING DEVICE WITH DOUBLE HETEROSTRUCTURE LIGHT EMMITTING REGION - 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. | 10-22-2009 |
20100109568 | COMMON OPTICAL ELEMENT FOR AN ARRAY OF PHOSPHOR CONVERTED LLIGHT EMITTING DEVICES - A device is provided with an array of a plurality of phosphor converted light emitting devices (LEDs) that produce broad spectrum light. The phosphor converted LEDs may produce light with different correlated color temperature (CCT) and are covered with an optical element that assists in mixing the light from the LEDs to produce a desired correlated color temperature. The optical element may be bonded to the phosphor converted light emitting devices. The optical element may be a dome mounted over the phosphor converted light emitting devices and filled with an encapsulant. | 05-06-2010 |
20100148151 | LIGHT EMITTING DEVICES WITH IMPROVED LIGHT EXTRACTION EFFICIENCY - A device includes a light emitting structure and a wavelength conversion member comprising a semiconductor. The light emitting structure is bonded to the wavelength conversion member. In some embodiments, the light emitting structure is bonded to the wavelength conversion member with an inorganic bonding material. In some embodiments, the light emitting structure is bonded to the wavelength conversion member with a bonding material having an index of refraction greater than 1.5. | 06-17-2010 |
20100200886 | WAVELENGTH-CONVERTED SEMICONDUCTOR LIGHT EMITTING DEVICE - Embodiments of the invention include a light emitting structure comprising a light emitting layer. A first luminescent material comprising a phosphor is disposed in a path of light emitted by the light emitting layer. A second luminescent material comprising a semiconductor is also disposed in a path of light emitted by the light emitting layer. The second luminescent material is configured to absorb light emitted by the light emitting layer and emit light of a different wavelength. In some embodiments, one of the first and second luminescent materials may be bonded to the semiconductor structure. | 08-12-2010 |
20110027975 | SUBSTRATE FOR GROWING A III-V LIGHT EMITTING DEVICE - A substrate including a host and a seed layer bonded to the host is provided, then a semiconductor structure including a light emitting layer disposed between an n-type region and a p-type region is grown on the seed layer. In some embodiments, a bonding layer bonds the host to the seed layer. The seed layer may be thinner than a critical thickness for relaxation of strain in the semiconductor structure, such that strain in the semiconductor structure is relieved by dislocations formed in the seed layer, or by gliding between the seed layer and the bonding layer an interface between the two layers. In some embodiments, the host may be separated from the semiconductor structure and seed layer by etching away the bonding layer. | 02-03-2011 |
20110084301 | PACKAGE-INTEGRATED THIN FILM LED - LED epitaxial layers (n-type, p-type, and active layers) are grown on a substrate. For each die, the n and p layers are electrically bonded to a package substrate that extends beyond the boundaries of the LED die such that the LED layers are between the package substrate and the growth substrate. The package substrate provides electrical contacts and conductors leading to solderable package connections. The growth substrate is then removed. Because the delicate LED layers were bonded to the package substrate while attached to the growth substrate, no intermediate support substrate for the LED layers is needed. The relatively thick LED epitaxial layer that was adjacent the removed growth substrate is then thinned and its top surface processed to incorporate light extraction features. There is very little absorption of light by the thinned epitaxial layer, there is high thermal conductivity to the package because the LED layers are directly bonded to the package substrate without any support substrate therebetween, and there is little electrical resistance between the package and the LED layers so efficiency (light output vs. power input) is high. The light extraction features of the LED layer further improves efficiency. | 04-14-2011 |
20120021543 | LIGHT EMITTING DEVICES WITH IMPROVED LIGHT EXTRACTION EFFICIENCY - 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. | 01-26-2012 |
20120043564 | COMMON OPTICAL ELEMENT FOR AN ARRAY OF PHOSPHOR CONVERTED LIGHT EMITTING DEVICES - A device is provided with at least one light emitting device (LED) die mounted on a submount with an optical element subsequently thermally bonded to the LED die. The LED die is electrically coupled to the submount through contact bumps that have a higher temperature melting point than is used to thermally bond the optical element to the LED die. In one implementation, a single optical element is bonded to a plurality of LED dice that are mounted to the submount and the submount and the optical element have approximately the same coefficients of thermal expansion. Alternatively, a number of optical elements may be used. The optical element or LED die may be covered with a coating of wavelength converting material. In one implementation, the device is tested to determine the wavelengths produced and additional layers of the wavelength converting material are added until the desired wavelengths are produced. | 02-23-2012 |
20120161187 | Grown Photonic Crystals in Semiconductor Light Emitting Devices - 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. | 06-28-2012 |
20130293145 | BONDING AN OPTICAL ELEMENT TO A LIGHT EMITTING DEVICE - A device is provided with at least one light emitting device (LED) die mounted on a submount with an optical element subsequently thermally bonded to the LED die. The LED die is electrically coupled to the submount through contact bumps that have a higher temperature melting point than is used to thermally bond the optical element to the LED die. In one implementation, a single optical element is bonded to a plurality of LED dice that are mounted to the submount and the submount and the optical element have approximately the same coefficients of thermal expansion. Alternatively, a number of optical elements may be used. The optical element or LED die may be covered with a coating of wavelength converting material. In one implementation, the device is tested to determine the wavelengths produced and additional layers of the wavelength converting material are added until the desired wavelengths are produced. | 11-07-2013 |
20130313562 | PACKAGE-INTEGRATED THIN FILM LED - LED epitaxial layers (n-type, p-type, and active layers) are grown on a substrate. For each die, the n and p layers are electrically bonded to a package substrate that extends beyond the boundaries of the LED die such that the LED layers are between the package substrate and the growth substrate. The package substrate provides electrical contacts and conductors leading to solderable package connections. The growth substrate is then removed. Because the delicate LED layers were bonded to the package substrate while attached to the growth substrate, no intermediate support substrate for the LED layers is needed. The relatively thick LED epitaxial layer that was adjacent the removed growth substrate is then thinned and its top surface processed to incorporate light extraction features. There is very little absorption of light by the thinned epitaxial layer, there is high thermal conductivity to the package because the LED layers are directly bonded to the package substrate without any support substrate therebetween, and there is little electrical resistance between the package and the LED layers so efficiency (light output vs. power input) is high. The light extraction features of the LED layer further improves efficiency. | 11-28-2013 |
20140021883 | POWER LIGHT EMITTING DIODE AND METHOD WITH CURRENT DENSITY OPERATION - A light emitting diode device emitting at a wavelength of 390-415 nm has a bulk gallium and nitrogen containing substrate with an active region. The device has a current density of greater than about 175 Amps/cm | 01-23-2014 |
20140103356 | INDIUM GALLIUM NITRIDE LIGHT EMITTING DEVICES - InGaN-based light-emitting devices fabricated on an InGaN template layer are disclosed. | 04-17-2014 |
20140191265 | LIGHT EMITTING DEVICES WITH IMPROVED LIGHT EXTRACTION EFFICIENCY - 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. | 07-10-2014 |
20140301062 | LED LAMPS WITH IMPROVED QUALITY OF LIGHT - 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. | 10-09-2014 |
20150049460 | LED LAMPS WITH IMPROVED QUALITY OF LIGHT - 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. | 02-19-2015 |
20150062892 | CIRCADIAN FRIENDLY LED LIGHT SOURCE - 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. | 03-05-2015 |