| Patent application number | Description | Published |
|---|
| 20080283864 | Single Crystal Phosphor Light Conversion Structures for Light Emitting Devices - Solid state light emitting devices include a solid state light emitting die and a light conversion structure. The light conversion structure may include a single crystal phosphor and may be on a light emitting surface of the solid state light emitting die. The light conversion structure may be attached to the light emitting surface of the solid state light emitting die via an adhesive layer. The light conversion structure may also be directly on a light emitting surface of the solid state light emitting die. Related methods are also disclosed. | 11-20-2008 |
| 20080308825 | Encapsulant with scatterer to tailor spatial emission pattern and color uniformity in light emitting diodes - A light emitting device having an encapsulant with scattering features to tailor the spatial emission pattern and color temperature uniformity of the output profile. The encapsulant is formed with materials having light scattering properties. The concentration of these light scatterers is varied spatially within the encapsulant and/or on the surface of the encapsulant. The regions having a high density of scatterers are arranged in the encapsulant to interact with light entering the encapsulant over a desired range of source emission angles. By increasing the probability that light from a particular range of emission angles will experience at least one scattering event, both the intensity and color temperature profiles of the output light beam can be tuned. | 12-18-2008 |
| 20090050911 | Light emitting device packages using light scattering particles of different size - A radiation emitting device comprising light scattering particles of different sizes that at least partially surround an emitter, improving the spatial color mixing and color uniformity of the device. Multiple sizes of light scattering particles are dispersed in a medium to at least partially surround a single- or multiple-chip polychromatic emitter package. The different sizes of light scattering particles interact with corresponding wavelength ranges of emitted radiation. Thus, radiation emitted over multiple wavelength ranges or sub-ranges can be efficiently scattered to eliminate (or intentionally create) spatially non-uniform color patterns in the output beam. | 02-26-2009 |
| 20090057690 | Wafer level phosphor coating technique for warm light emitting diodes - Methods for wafer level fabricating of light emitting diode (LED) chips are disclosed with one embodiment of a method according to the present invention comprising providing a plurality of LEDs and then coating of the LEDs with a layer of first conversion material so that at least some light from the LEDs passes through the first conversion material. The light is converted to different wavelengths of light having a first conversion material emission spectrum. The LEDs are then coated with a layer of second conversion material arranged on the first layer of conversion. The second conversion material has a wavelength excitation spectrum, and at least some light from the LEDs passes through the second conversion material and is converted. The first conversion material emission spectrum does not substantially overlap with the second conversion material excitation spectrum. Methods according to the present invention can also be used in wafer level fabrication of LED chips and LED packages with pedestals for electrically contacting the LEDs through the conversion coatings. | 03-05-2009 |
| 20090072254 | Polarization doping in nitride based diodes - A light emitting device comprising a three-dimensional polarization-graded (3DPG) structure that improves lateral current spreading within the device without introducing additional dopant impurities in the epitaxial structures. The 3DPG structure can include a repeatable stack unit that may be repeated several times within the 3DPG. The stack unit includes a compositionally graded layer and a silicon (Si) delta-doped layer. The graded layer is compositionally graded over a distance from a first material to a second material, introducing a polarization-induced bulk charge into the structure. The Si delta-doped layer compensates for back-depletion of the electron gas at the interface of the graded layers and adjacent layers. The 3DPG facilitates lateral current spreading so that current is injected into the entire active region, increasing the number of radiative recombination events in the active region and improving the external quantum efficiency and the wall-plug efficiency of the device. | 03-19-2009 |
| 20090146162 | FABRICATION OF NONPOLAR INDIUM GALLIUM NITRIDE THIN FILMS, HETEROSTRUCTURES AND DEVICES BY METALORGANIC CHEMICAL VAPOR DEPOSITION - A method for the fabrication of nonpolar indium gallium nitride (InGaN) films as well as nonpolar InGaN-containing device structures using metalorganic chemical vapor deposition (MOVCD). The method is used to fabricate nonpolar InGaN/GaN violet and near-ultraviolet light emitting diodes and laser diodes. | 06-11-2009 |
| 20090152565 | PENDEO EPITAXIAL STRUCTURES AND DEVICES - A substrate comprising a trench lateral epitaxial overgrowth structure including a trench cavity, wherein the trench cavity includes a growth-blocking layer or patterned material supportive of a coalescent Pendeo layer thereon, on at least a portion of an inside surface of the trench. Such substrate is suitable for carrying out lateral epitaxial overgrowth to form a bridged lateral overgrowth formation overlying the trench cavity. The bridged lateral overgrowth formation provides a substrate surface on which epitaxial layers can be grown in the fabrication of microelectronic devices such as laser diodes, high electron mobility transistors, ultraviolet light emitting diodes, and other devices in which low dislocation density is critical. The epitaxial substrate structures of the invention can be formed without the necessity for deep trenches, such as are required in conventional Pendeo epitaxial overgrowth structures. | 06-18-2009 |
| 20090173958 | LIGHT EMITTING DEVICES WITH HIGH EFFICIENCY PHOSPOR STRUCTURES - A light emitting device includes a light emitting die configured to emit light having a first dominant wavelength, and an index matched wavelength conversion structure configured to receive light emitted by the light emitting die. The index matched wavelength conversion structure includes wavelength converting particles having a first index of refraction embedded in a matrix material. The matrix material has a second index of refraction that may be substantially matched to the first index of refraction. The light emitting device may include a graded index layer having an index of refraction that is continuously graded from a first index of refraction in a first region of the graded index layer near the light emitting die to a second index of refraction in the graded index layer away from the light emitting die. | 07-09-2009 |
| 20090194775 | SEMICONDUCTOR LIGHT EMITTING DEVICES WITH HIGH COLOR RENDERING - A packaged light emitting device (LED) includes a light emitting diode configured to emit primary light having a peak wavelength that is less than about 465 nm and having a shoulder emission component at a wavelength that is greater than the peak wavelength, and a wavelength conversion material configured to receive the primary light emitted by the light emitting diode and to responsively emit light having a color point with a ccx greater than about 0.4 and a ccy less than about 0.6. | 08-06-2009 |
| 20090230411 | INTERDIGITATED MULTIPLE PIXEL ARRAYS OF LIGHT-EMITTING DEVICES - The present invention discloses a plurality of interdigitated pixels arranged in an array, having a very low series-resistances with improved current spreading and improved heat-sinking. Each pixel is a square with sides of dimension l. The series resistance is minimized by increasing the perimeter of an active region for the pixels. The series resistance is also minimized by shrinking the space between a mesa and n-contact for each pixel. | 09-17-2009 |
| 20090236621 | Low index spacer layer in LED devices - A light emitting diode (LED) device having a low index of refraction spacer layer separating the LED chip and a functional layer. The LED chip has a textured light emission surface to increase light extraction from the chip. The spacer layer has an index of refraction that is lower than both the LED chip and the functional layer. Most of the light generated in the LED chip passes easily into the spacer layer due to the textured surface of the chip. At the interface of the spacer layer and the functional layer the light sees a step-up in index of refraction which facilitates transmission. A portion of the light that has passed into the functional layer will be reflected or scattered back toward the spacer layer where some of it will experience total internal reflection. Total internal reflection at this interface may increase extraction efficiency by reducing the amount of light that re-enters the spacer layer and, ultimately, the LED chip where it may be absorbed. The spacer layer also provides a thermal buffer between the LED chip and the functional layer. Thus, the functional layer, which may be a wavelength conversion layer comprising phosphors, for example, is insulated from direct thermal transfer from the LED chip. The spacer layer can also function as a passivation layer. | 09-24-2009 |
| 20090256163 | LEDs using single crystalline phosphor and methods of fabricating same - Methods for fabricating LED chips from a wafer and devices fabricated using the methods with one method comprising depositing LED epitaxial layers on an LED growth wafer to form a plurality of LEDs on the growth wafer. A single crystalline phosphor is bonded over at least some the plurality of LEDs so that at least some light from the covered LEDs passes through the single crystalline phosphor and is converted. The LED chips can then be singulated from the wafer to provide LED chips each having a portion of said single crystalline phosphor to convert LED light. | 10-15-2009 |
| 20090272996 | Encapsulation for phosphor-converted white light emitting diode - An improved light emitting device, especially a phosphor-converted white light device, wherein the light extraction efficiency and the color temperature distribution uniformity are improved by the introduction of both nanoparticles and light scattering particles proximate to the light source. Nanoparticles having a high index of refraction are dispersed throughout a wavelength conversion layer to adjust the index of refraction of the layer for improved light extraction. Light scattering particles may be dispersed in the wavelength conversion layer and/or in a surrounding medium to improve the spatial correlated color temperature uniformity. | 11-05-2009 |
| 20100079059 | Solid State Lighting Devices Including Light Mixtures - A solid state lighting apparatus includes a plurality of light emitting diodes (LEDs) including at least a first LED and a second LED. Chromaticities of the first and second LEDs are selected so that a combined light generated by a mixture of light from the pair of LEDs has about a target chromaticity. The first LED may include a first LED chip that emits light in the blue portion of the visible spectrum and a phosphor that emits red light in response to blue light emitted by the first LED chip. The second LED emits light having a color point that is above the planckian locus of a 1931 CIE Chromaticity diagram, and in particular may have a yellow green, greenish yellow or green hue. | 04-01-2010 |
| 20100193911 | IN-SITU DEFECT REDUCTION TECHNIQUES FOR NONPOLAR AND SEMIPOLAR (Al, Ga, In)N - A method for growing reduced defect density planar gallium nitride (GaN) films is disclosed. The method includes the steps of (a) growing at least one silicon nitride (SiN | 08-05-2010 |
| 20100195684 | PHOTOELECTROCHEMICAL ETCHING FOR LASER FACETS - A method for fabricating a semiconductor laser device, by etching facets using a photoelectrochemical (PEC) etch, so that the facets are sufficiently smooth to support optical modes within a cavity bounded by the facets. | 08-05-2010 |
| 20100273281 | LASER DIODE AND METHOD FOR FABRICATING SAME - A laser diode and method for fabricating same, wherein the laser diode generally comprises an InGaN compliance layer on a GaN n-type contact layer and an AlGaN/GaN n-type strained super lattice (SLS) on the compliance layer. An n-type GaN separate confinement heterostructure (SCH) is on said n-type SLS and an InGaN multiple quantum well (MQW) active region is on the n-type SCH. A GaN p-type SCH on the MQW active region, an AlGaN/GaN p-type SLS is on the p-type SCH, and a p-type GaN contact layer is on the p-type SLS. The compliance layer has an In percentage that reduces strain between the n-type contact layer and the n-type SLS compared to a laser diode without the compliance layer. Accordingly, the n-type SLS can be grown with an increased Al percentage to increase the index of refraction. This along with other features allows for reduced threshold current and voltage operation. | 10-28-2010 |
| 20100309943 | LONG WAVELENGTH NONPOLAR AND SEMIPOLAR (Al,Ga,In)N BASED LASER DIODES - A laser diode, grown on a miscut nonpolar or semipolar substrate, with lower threshold current density and longer stimulated emission wavelength, compared to conventional laser diode structures, wherein the laser diode's (1) n-type layers are grown in a nitrogen carrier gas, (2) quantum well layers and barrier layers are grown at a slower growth rate as compared to other device layers (enabling growth of the p-type layers at higher temperature), (3) high Al content electron blocking layer enables growth of layers above the active region at a higher temperature, and (4) asymmetric AlGaN SPSLS allowed growth of high Al containing p-AlGaN layers. Various other techniques were used to improve the conductivity of the p-type layers and minimize the contact resistance of the contact layer. | 12-09-2010 |
| 20110056429 | Rapid Growth Method and Structures for Gallium and Nitrogen Containing Ultra-Thin Epitaxial Structures for Devices - A method for rapid growth of gallium and nitrogen containing material is described. The method includes providing a bulk gallium and nitrogen containing substrate. A first epitaxial material of first thickness is formed over the substrate, preferably with a pseudomorphical process. The method also forms a second epitaxial layer over the first to create a stacked structure. The stacked structure consists of a total thickness of less than about 2 microns. | 03-10-2011 |
| 20110062415 | ANISOTROPIC STRAIN CONTROL IN SEMIPOLAR NITRIDE QUANTUM WELLS BY PARTIALLY OR FULLY RELAXED ALUMINUM INDIUM GALLIUM NITRIDE LAYERS WITH MISFIT DISLOCATIONS - An epitaxial structure for a III-Nitride based optical device, comprising an active layer with anisotropic strain on an underlying layer, where a lattice constant and strain in the underlying layer are partially or fully relaxed in at least one direction due to a presence of misfit dislocations, so that the anisotropic strain in the active layer is modulated by the underlying layer. | 03-17-2011 |
| 20110062449 | TECHNIQUE FOR THE GROWTH AND FABRICATION OF SEMIPOLAR (GA,AL,IN,B)N THIN FILMS, HETEROSTRUCTURES, AND DEVICES - A method for growth and fabrication of semipolar (Ga, Al, In, B)N thin films, heterostructures, and devices, comprising identifying desired material properties for a particular device application, selecting a semipolar growth orientation based on the desired material properties, selecting a suitable substrate for growth of the selected semipolar growth orientation, growing a planar semipolar (Ga, Al, In, B)N template or nucleation layer on the substrate, and growing the semipolar (Ga, Al, In, B)N thin films, heterostructures or devices on the planar semipolar (Ga, Al, In, B)N template or nucleation layer. The method results in a large area of the semipolar (Ga, Al, In, B)N thin films, heterostructures, and devices being parallel to the substrate surface. | 03-17-2011 |
| 20110064103 | SEMIPOLAR NITRIDE-BASED DEVICES ON PARTIALLY OR FULLY RELAXED ALLOYS WITH MISFIT DISLOCATIONS AT THE HETEROINTERFACE - A dislocation-free high quality template with relaxed lattice constant, fabricated by spatially restricting misfit dislocation(s) around heterointerfaces. This can be used as a template layer for high In composition devices. Specifically, the present invention prepares high quality InGaN templates (In composition is around 5-10%), and can grow much higher In-composition InGaN quantum wells (QWs) (or multi quantum wells (MQWs)) on these templates than would otherwise be possible. | 03-17-2011 |
| 20110073881 | LEDs USING SINGLE CRYSTALLLINE PHOSPHOR AND METHODS OF FABRICATING SAME - Methods for fabricating LED chips from a wafer and devices fabricated using the methods with one method comprising depositing LED epitaxial layers on an LED growth wafer to form a plurality of LEDs on the growth wafer. A single crystalline phosphor is bonded over at least some the plurality of LEDs so that at least some light from the covered LEDs passes through the single crystalline phosphor and is converted. The LED chips can then be singulated from the wafer to provide LED chips each having a portion of said single crystalline phosphor to convert LED light. | 03-31-2011 |
| 20110089399 | LIGHT EMITTING DEVICE WITH A STAIR QUANTUM WELL STRUCTURE - A light emitting device with a stair quantum well structure in an active region. The stair quantum well structure may include a primary well and a single step or multiple steps. The light emitting device may be a nonpolar, semipolar or polar (Al,Ga,In)N based light emitting device. The stair quantum structure improves the radiative efficiency of the light emitting device. | 04-21-2011 |
| 20110101301 | LIGHT EMITTING DEVICE WITH A COUPLED QUANTUM WELL STRUCTURE - A light emitting device with a coupled quantum well structure in an active region. The coupled quantum well structure may include two or more wells are separated by one or more mini-barriers, and the wells and mini-barriers together are sandwiched by barriers. The coupled quantum well structure provides almost the same effect as a wide quantum well, due to the coupling of the wavefunctions through the mini-barrier. The light emitting device may be a nonpolar, semipolar or polar (Al,Ga,In)N based light emitting device. | 05-05-2011 |
| 20110156572 | INTERDIGITATED MULTIPLE PIXEL ARRAYS OF LIGHT-EMITTING DEVICES - The present invention discloses a plurality of interdigitated pixels arranged in an array, having a very low series-resistances with improved current spreading and improved heat-sinking. Each pixel is a square with sides of dimension l. The series resistance is minimized by increasing the perimeter of an active region for the pixels. The series resistance is also minimized by shrinking the space between a mesa and n-contact for each pixel. | 06-30-2011 |
