Abstract: A light emitting diode (LED) is fabricated using an underfill layer that is deposited on either the LED or the submount prior to mounting the LED to a submount. The deposition of the underfill layer prior to mounting the LED to the submount provides for a more uniform and void free support, and increases underfill material options to permit improved thermal characteristics. The underfill layer may be used as support for the thin and brittle LED layers during the removal of the growth substrate prior to mounting the LED to the submount. Additionally, the underfill layer may be patterned to and/or polished back so that only the contact areas of the LED and/or submount are exposed. The patterns in the underfill may also be used as a guide to assist in the singulating of the devices.

Abstract: 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.

Abstract: A device includes a semiconductor structure with at least one III-P light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure further includes a GaAsxP1-x p-contact layer, wherein x<0.45. A first metal contact is in direct contact with the GaAsxP1-x p-contact layer. A second metal contact is electrically connected to the n-type region. The first and second metal contacts are formed on a same side of the semiconductor structure.

Abstract: Embodiments of the invention include a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region. A contact disposed on the p-type region includes a transparent conductive material in direct contact with the p-type region, a reflective metal layer, and a transparent insulating material disposed between the transparent conductive layer and the reflective metal layer. In a plurality of openings in the transparent insulating material, the transparent conductive material is in direct contact with the reflective metal layer.

Abstract: A device includes a semiconductor structure comprising a III-nitride light emitting layer disposed between an n-type region and a p-type region and a plurality of layer pairs disposed within one of the n-type region and the p-type region. Each layer pair includes an InGaN layer and pit-filling layer in direct contact with the InGaN layer. The pit-filling layer may fill in pits formed in the InGaN layer.

Abstract: A backlight for a color LCD includes white light LEDs formed using a blue LED die with a layer of red and green phosphors over it. The attenuation by the LCD layers of the blue light component of the white light is typically greater as the blue wavelength becomes shorter. In order to achieve a uniform blue color component across the surface of an LCD screen and achieve uniform light output from one LCD to another, the blue light leakage of the phosphor layer is tailored to the dominant or peak wavelength of the blue LED die. Therefore, the white points of the various white light LEDs in a backlight should not match when blue LED dies having different dominant or peak wavelengths are used in the backlight. The different leakage amounts through the tailored phosphor layers offset the attenuation vs. wavelength of the LCD layers.

Abstract: A device includes a semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure includes an n-contact region and a p-contact region. A cross section of the n-contact region comprises a plurality of first regions wherein portions of the light emitting layer and p-type region are removed to expose the n-type region. The plurality of first regions are separated by a plurality of second regions wherein the light emitting layer and p-type region remain in the device. The device further includes a first metal contact formed over the semiconductor structure in the p-contact region and a second metal contact formed over the semiconductor structure in the n-contact region. The second metal contact is in electrical contact with at least one of the second regions in the n-contact region.

Abstract: A semiconductor structure comprising a light emitting layer disposed between an n-type region and a p-type region is formed. A first metal contact is formed on a portion of the n-type region and a second metal contact is formed on a portion of the p-type region. The first and second metal contacts are formed on a same side of the semiconductor structure. A dielectric material is disposed between the first and second metal contacts. The dielectric material is in direct contact with a portion of the semiconductor structure, a portion of the first metal contact, and a portion of the second metal contact.

Abstract: A light emitting device comprises a flip-chip light emitting diode (LED) die mounted on a submount. The top surface of the submount has a reflective layer. Over the LED die is molded a hemispherical first transparent layer. A low index of refraction layer is then provided over the first transparent layer to provide TIR of phosphor light. A hemispherical phosphor layer is then provided over the low index layer. A lens is then molded over the phosphor layer. The reflection achieved by the reflective submount layer, combined with the TIR at the interface of the high index phosphor layer and the underlying low index layer, greatly improves the efficiency of the lamp. Other material may be used. The low index layer may be an air gap or a molded layer. Instead of a low index layer, a distributed Bragg reflector may be sputtered over the first transparent layer.

Abstract: An illumination source includes at least one light emitting diode, e.g., in array of LEDs that produce short wavelength light. One or more wavelength converting elements, such as phosphor elements, convert at least a portion of the short wavelength light from the LED(s) to longer wavelengths, such as Red and Green. A dichroic element positioned between the LED(s) and the wavelength converting element(s) transmits the light from the LED(s) and reflects the longer wavelengths from the wavelength converting element(s). A color selection panel selects the colors of light to be produced by the illumination device and to be recycled for another opportunity to be converted by the wavelength converting element(s) or to be reflected by the dichroic element. The color selection panel may operate in one or both of the spatial domain and the temporal domain.

Abstract: A process for forming electrical contacts for a semiconductor light emitting apparatus is disclosed. The light emitting apparatus has a first layer of first conductivity type, an active layer for generating light overlying the first layer, and a second layer of second conductivity type overlying the active layer.

Abstract: A mount for a semiconductor device includes a carrier, at least two metal leads disposed on a bottom surface of the carrier, and a cavity extending through a thickness of the carrier to expose a portion of the top surfaces of the metal leads. A semiconductor light emitting device is positioned in the cavity and is electrically and physically connected to the metal leads. The carrier may be, for example, silicon, and the leads may be multilayer structures, for example a thin gold layer connected to a thick copper layer.

Abstract: A low profile side-emitting lens for an LED die has two tiers of different waveguides radially extending out from a center side-emitting lens. An LED emits light into the center side-emitting lens, which has a curved surface that internally reflects the LED light outward approximately parallel to the top surface of the LED die. The center lens has a height of 2 mm, required for reflecting the LED light outward. Radially extending from the periphery of the bottom half of the center lens is a bottom tier of waveguides, each having a height of 1 mm, and radially extending from the periphery of the top half of the center lens is a top tier of waveguides, each having a height of 1 mm. The light output areas of the top and bottom tiers of waveguides are parallel with each other so that the 2 mm high side emission is reduced to a 1 mm side emission without reducing the emission area.

Abstract: A white light LED is described that uses an LED die that emits visible blue light in a wavelength range of about 450-470 nm. A red phosphor or quantum dot material converts some of the blue light to a visible red light having a peak wavelength between about 605-625 nm with a full-width-half-maximum (FWHM) less than 80 nm. A green phosphor or quantum dot material converts some of the blue light to a green light having a FWHM greater than 40 nm, wherein the combination of the blue light, red light, and green light produces a white light providing a color rendering of Ra,8>90 and a color temperature of between 2500K-5000K. Preferably, the red and green converting material do not saturate with an LED die output of 100 W/cm2 and can reliably operate with an LED die junction temperature over 100 degrees C.

Abstract: A substantially hemispherical lens surrounding an LED die is described that creates a sparkle as an observer views the lens from different angles. The lens is formed of an interconnected array of 100-10,000 or more lenslets. Each lenslet focuses an image of the LED die at an output of the lenslet such that the LED die image area at the output is less than 1/9 the area of the LED die to create a substantially point source image of the LED die at an outer surface of the lens. When the LED die is energized, the shape of each lenslet causes point source images of the LED die to be perceived by an observer at various viewing angles, such that the emitted LED light appears to sparkle and speckle as the observer moves relative to the lens.

Abstract: Light emitting diode (LED) dies are fabricated by forming LED layers including a first conductivity type layer, a light-emitting layer, and a second conductivity type layer. Trenches are formed in the LED layers that reach at least partially into the first conductivity type layer. Electrically insulation regions are formed in or next to at least portions of the first conductivity type layer along the die edges. A first conductivity bond pad layer is formed to electrically contact the first conductivity type layer and extend over the singulation streets between the LED dies. A second conductivity bond pad layer is formed to electrically contact the second conductivity type layer, and extend over the singulation streets between the LED dies and the electrically insulated portions of the first conductivity type layer. The LED dies are mounted to submounts and the LED dies are singulated along the singulation streets between the LED dies.

Abstract: Light emitting diode (LED) structures are fabricated in wafer scale by mounting singulated LED dies on a carrier wafer or a stretch film, separating the LED dies to create spaces between the LED dies, applying a reflective coating over the LED dies and in the spaces between the LED dies, and separating or breaking the reflective coating in the spaces between the LED dies such that some reflective coating remains on the lateral sides of the LED die. Portions of the reflective coating on the lateral sides of the LED dies may help to control edge emission.

Abstract: A device includes a reflector and a wavelength converting material disposed on the reflector. A backlight is disposed between the reflector and a surface to be illuminated, such as a liquid crystal display panel. The backlight includes a light source and a waveguide. The waveguide is configured to direct a majority of light from the light source toward the reflector. At least a portion of the light is converted by the wavelength converted material, reflected by the reflector, and incident on the surface to be illuminated.

Abstract: In accordance with embodiments of the invention, at least partial strain relief in a light emitting layer of a III-nitride light emitting device is provided by configuring the surface on which at least one layer of the device grows such that the layer expands laterally and thus at least partially relaxes. This layer is referred to as the strain-relieved layer. In some embodiments, the light emitting layer itself is the strain-relieved layer, meaning that the light emitting layer is grown on a surface that allows the light emitting layer to expand laterally to relieve strain. In some embodiments, a layer grown before the light emitting layer is the strain-relieved layer. In a first group of embodiments, the strain-relieved layer is grown on a textured surface.

Abstract: A light source such as a semiconductor light emitting diode is positioned in a first opening in a transparent member, which may function as a waveguide in a display. The transparent member surrounds the light source. No light source is positioned in a second opening in the transparent member. In some embodiments, the first opening is shaped to direct light into the transparent member. In some embodiments, a reflector is positioned over the light source. The reflector includes a flat portion and a shaped portion. The shaped portion extends from the flat portion toward the light source.