Abstract: A light emitting diode is provided which is capable of emitting a first light having a first peak wavelength. The light emitting diode is provided with a phosphor layer overlying the light emitting diode and capable of absorbing the first light and emitting a second light having a second peak wavelength. The phosphor layer includes a pattern of holes positioned to allow the first peak wavelength to exit through the holes without being absorbed by the phosphor layer, and wherein the holes are placed to facilitate more of the first peak wavelength to exit the phosphor in the area of the holes than the second peak wavelength.

Abstract: A semiconductor structure includes a light emitting region, a p-type region disposed on a first side of the light emitting region, and an n-type region disposed on a second side of the light emitting region. At least 10% of a thickness of the semiconductor structure on the first side of the light emitting region comprises indium. Some examples of such a semiconductor light emitting device may be formed by growing an n-type region, growing a p-type region, and growing a light emitting layer disposed between the n-type region and the p-type region. The difference in temperature between the growth temperature of a part of the n-type region and the growth temperature of a part of the p-type region is at least 140° C.

Abstract: A multi-primary light emitting diode system includes the use of a polarization based dichroic element to combine light from different color channels. At least one of the color channels includes two light emitting diodes that produce light with a different range of wavelengths. The use of the polarization based dichroic element permits overlapping spectra from different color channels to be combined without loss. Accordingly, the brightness of the system is improved relative to conventional systems in which losses occur when combining overlapping spectra from different channels.

Abstract: A transient voltage suppressor circuit is disclosed for a plurality (N) of LEDs connected in series. Only one zener diode is created for connection to each node between LEDs, and a pair of zener diodes (the “end” zener diodes) are connected to the two pins (anode and cathode pads) of the series string. Therefore, only N+1 zener diodes are used. The end zener diodes (Q1 and Qn+1) effectively create back-to-back zener diodes across the two pins since the zener diodes share a common p+ substrate. The n+ regions of the end zener diodes Q1 and Qn+1 have the highest breakdown voltage requirement and must be placed relatively far apart. Adjacent n+ regions of the intermediate zener diodes have a much lower breakdown voltage requirement so may be located close together. Since there are fewer zener diodes and their spacings may be small, the zener diodes may be placed within a very small footprint or can be larger for better suppressor performance.

Abstract: A semiconductor structure comprises a III-nitride light emitting layer disposed between an n-type region and a p-type region. The semiconductor structure further comprises a curvature control layer grown on a first layer. The curvature control layer is disposed between the n-type region and the first layer. The curvature control layer has a theoretical a-lattice constant less than the theoretical a-lattice constant of GaN. The first layer is a substantially single crystal layer.

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 light emitting device is produced by depositing a layer of wavelength converting material over the light emitting device, testing the device to determine the wavelength spectrum produced and correcting the wavelength converting member to produce the desired wavelength spectrum. The wavelength converting member may be corrected by reducing or increasing the amount of wavelength converting material. In one embodiment, the amount of wavelength converting material in the wavelength converting member is reduced, e.g., through laser ablation or etching, to produce the desired wavelength spectrum.

Abstract: A uniform high brightness light source is provided using a plurality of light emitting diode (LED) chips with slightly different pump wavelengths with a wavelength converting element that includes at least two different wavelength converting materials that convert the light to different colors of light. The intensity of the light produced by the LED chips may be varied to provide a tunable CCT white point. The wavelength converting element may be, e.g., a stack or mixture of phosphor or luminescent ceramics. Moreover, the manufacturing process of the light source is simplified because the LED chips are all manufactured using the same technology eliminating the need to manufacture different types of chips.

Abstract: After flip chip LEDs are mounted on a submount wafer and their growth substrates removed, a phosphor plate is affixed to the exposed top surface of each LED. A reflective material, such as silicone containing at least 5% TiO2 powder, by weight, is then spun over or molded over the wafer to cover the phosphor plates and the sides of the LEDs. The top surface of the reflective material is then etched using microbead blasting to expose the top of the phosphor plates and create a substantially planar reflective layer over the wafer surface. Lenses may then be formed over the LEDs. The wafer is then singulated. The reflective material reflects all side light back into the LED and phosphor plate so that virtually all light exits the top of the phosphor plate to improve the light emission characteristics.

Abstract: The invention provides an illumination system and a method for illumination. The illumination system includes one or more light sources that produce a primary light, a light-mixing zone that homogenizes the primary light, a wavelength-converting layer that converts the primary light to a secondary light, and a light-transmitting zone that receives the secondary light and transmits the secondary light to, for example, a Liquid Crystal Display (LCD).

Abstract: A semiconductor light emitting device comprises a light emitting layer disposed between an n-type region and a p-type region. The light emitting layer is adapted to emit first light having a first peak wavelength. A first wavelength converting material is adapted to absorb the first light and emit second light having a second peak wavelength. A second wavelength converting material is adapted to absorb either the first light or the second light and emit third light having a third peak wavelength. A filter is adapted to reflect fourth light having a fourth peak wavelength. The fourth light is either a portion of the second light or a portion of the third light. The filter is configured to transmit light having a peak wavelength longer or shorter than the fourth peak wavelength. The filter is disposed over the light emitting device in the path of at least a portion of the first, second, and third light.

Abstract: A method for fabricating a light emitting device is described where an array of flip-chip light emitting diode (LED) dies are mounted on a submount wafer. Over each of the LED dies is simultaneously molded a hemispherical first silicone layer. A preformed flexible phosphor layer, comprising phosphor powder infused in silicone, is laminated over the first silicone layer to conform to the outer surface of the hemispherical first silicone layer. A silicone lens is then molded over the phosphor layer. By preforming the phosphor layer, the phosphor layer may be made to very tight tolerances and tested. By separating the phosphor layer from the LED die by a molded hemispherical silicone layer, color vs. viewing angle is constant, and the phosphor is not degraded by heat. The flexible phosphor layer may comprise a plurality of different phosphor layers and may comprise a reflector or other layers.

Abstract: A semiconductor structure includes a light emitting layer disposed between an n-type region and a p-type region. A p-electrode is disposed on a portion of the p-type region. The p-electrode includes a reflective first material in direct contact with a first portion of the p-type region and a second material in direct contact with a second portion of the p-type region adjacent to the first portion. The first material and second material are formed in planar layers of substantially the same thickness.

Abstract: A light emitting diode (LED) package includes an LED die includes a stack of semiconductor layers including an active region, and a wavelength converting element over the LED die. The wavelength converting element includes two or more non-flat surfaces that produce a desired angular color distribution pattern.

Abstract: A submount wafer, having mounted on it an array of LEDs with a phosphor layer, is positioned with respect to a mold having an array of indentions. A mixture of silicone and 10%-50%, by weight, TiO2, is dispensed between the wafer and the indentions, creating a molded substantially reflective material. The molded mixture forms a reflective wall covering the sidewalls of the LED. The reflective material is then cured, and the submount wafer is separated from the mold such that the reflective material covering the sidewalls contains light emitted from the LED. The submount wafer is then diced. A piece (e.g., a reflector, support bracket, etc.) may then be affixed to the submount so the LED protrudes through a center hole in the piece. The inner edge of the piece is easily formed so that it is located at any height above or below the top surface of the LED.

Abstract: A light-emitting diode (LED) is fabricated by forming the LED segments with bond pads covering greater than 85% of a mounting surface of the LED segments and isolation trenches that electrically isolate the LED segments, mounting the LED segments on a submount with a bond pad that couples two or more bond pads from the LED segments, and applying a laser lift-off to remove the growth substrate from the LED layer.

Abstract: A compliant bonding structure is disposed between a semiconductor light emitting device and a mount. When the semiconductor light emitting device is attached to the mount, for example by providing pressure, heat, and/or ultrasonic energy to the semiconductor light emitting device, the compliant bonding structure collapses to partially fill a space between the semiconductor light emitting device and the mount. In some embodiments, the compliant bonding structure is plurality of metal bumps that undergo plastic deformation during bonding. In some embodiments, the compliant bonding structure is a porous metal layer.

Abstract: An underfill formation technique for LEDs molds a reflective underfill material to encapsulate LED dies mounted on a submount wafer while forming a reflective layer of the underfill material over the submount wafer. The underfill material is then hardened, such as by curing. The cured underfill material over the top of the LED dies is removed using microbead blasting while leaving the reflective layer over the submount surface. The exposed growth substrate is then removed from all the LED dies, and a phosphor layer is molded over the exposed LED surface. A lens is then molded over the LEDs and over a portion of the reflective layer. The submount wafer is then singulated. The reflective layer increases the efficiency of the LED device by reducing light absorption by the submount without any additional processing steps.

Abstract: A semiconductor structure comprises a light emitting layer disposed between an n-type region and a p-type region. A wavelength converting material is disposed over the semiconductor structure. The wavelength converting material is configured to absorb light emitted by the semiconductor structure and emit light of a different wavelength. A filter configured to reflect blue ambient light is disposed over the wavelength converting material. A scattering structure is disposed over the wavelength converting layer. The scattering structure is configured to scatter light. In some embodiments, the scattering structure is a transparent material having a rough surface, containing non-wavelength-converting particles that appear substantially white in ambient light, or including both a rough surface and white particles.

Abstract: A device according to embodiments of the invention includes a waveguide, typically formed from a first section of transparent material. A light source is disposed proximate a bottom surface of the waveguide. The light source comprises a semiconductor light emitting diode and a second section of transparent material disposed between the semiconductor light emitting diode and the waveguide. Sidewalls of the second section of transparent material are reflective. A surface to be illuminated is disposed proximate a top surface of the waveguide. In some embodiments, an edge of the waveguide is curved.