Abstract: A light emitting device includes several LEDs, mounted on a shared submount, and coupled to circuitry formed on the submount. The LEDs can be of the III-Nitride type. The architecture of the LEDs can be either inverted, or non-inverted. Inverted LEDs offer improved light generation. The LEDs may emit light of the same wavelength or different wavelengths. The circuitry can couple the LEDs in a combination of series and parallel, and can be switchable between various configurations. Other circuitry can include photosensitive devices for feedback and control of the intensity of the emitted light, or an oscillator, strobing the LEDs.

Abstract: A light emitting device and a method of making the same are provided. The light emitting device includes a light emitting diode and a submount. A phosphormaterial is disposed around at least a portion of the light emitting diode. An underfill is disposed between a first surface of the light emitting diode and a first surface of the submount. The underfill reduces contamination of the light emitting diode by the phosphor material.

Abstract: A device includes a submount, and a semiconductor light emitting device mounted on first and second conductive regions on a first side of the submount in a flip chip architecture configuration. The submount has third and fourth conductive regions on a second side of the submount. The third and fourth conductive regions may be used to solder the submount to structure such as a board, without the use of wire bonds. The first and third conductive regions are electrically connected by a first conductive layer and the second and fourth conductive regions are electrically connected by a second conductive layer. The first and second conductive layers may be disposed on the outside of the submount or within the submount.

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: A low defect gallium nitride based semiconductor, and method for its production, is disclosed. A first gallium nitride based semiconductor layer overlying a substrate of a dissimilar material is grown. A trench is formed in the first gallium nitride based semiconductor layer. A material is deposited on a surface of the first gallium nitride based semiconductor layer to prevent a second gallium nitride based semiconductor layer, of a material different from the first gallium nitride based semiconductor layer, from nucleating thereon. The bottom surface of the trench is of a material such that the second gallium nitride based semiconductor layer will not nucleate thereon. The second gallium nitride based semiconductor material is grown, extending from at least one of the side walls of the trench, the second gallium nitride based semiconductor material having fewer defects than the first gallium nitride based semiconductor layer.

Abstract: A method for fabricating a light-emitting semiconductor device including a III-Nitride quantum well layer includes selecting a facet orientation of the quantum well layer to control a field strength of a piezoelectric field and/or a field strength of a spontaneous electric field in the quantum well layer, and growing the quantum well layer with the selected facet orientation. The facet orientation may be selected to reduce the magnitude of a piezoelectric field and/or the magnitude of a spontaneous electric field, for example. The facet orientation may also be selected to control or reduce the magnitude of the combined piezoelectric and spontaneous electric field strength.

Abstract: A III-nitride device includes a first n-type layer, a first p-type layer, and an active region separating the first p-type layer and the first n-type layer. The device may include a second n-type layer and a tunnel junction separating the first and second n-type layers. First and second contacts are electrically connected to the first and second n-type layers. The first and second contacts are formed from the same material, a material with a reflectivity to light emitted by the active region greater than 75%. The device may include a textured layer disposed between the second n-type layer and the second contact or formed on a surface of a growth substrate opposite the device layers.

Abstract: The present invention is an inverted III-nitride light-emitting device (LED) with enhanced total light generating capability. A large area device has an n-electrode that interposes the p-electrode metallization to provide low series resistance. The p-electrode metallization is opaque, highly reflective, and provides excellent current spreading. The p-electrode at the peak emission wavelength of the LED active region absorbs less than 25% of incident light per pass. A submount may be used to provide electrical and thermal connection between the LED die and the package. The submount material may be Si to provide electronic functionality such as voltage-compliance limiting operation. The entire device, including the LED-submount interface, is designed for low thermal resistance to allow for high current density operation. Finally, the device may include a high-refractive-index (n>1.8) superstrate.

Abstract: A color, transmissive LCD uses a backlight that supplies a uniform blue light to the back of the liquid crystal layer in an LCD. The blue light, after being modulated by the liquid crystal layer, is then incident on the back surface of phosphor material located above the liquid crystal layer. A first phosphor material, when irradiated with the blue light, generates red light for the red pixel areas of the display, and a second phosphor material, when irradiated with the blue light, generates green light for the green pixel areas of the display. No phosphor is deposited over the blue pixel areas.

Abstract: A III-nitride light emitting device includes an n-type layer, a p-type layer, and an active region capable of emitting light between the p-type layer and the n-type layer. The active region includes at least one additional p-type layer. The p-type layer in the active region may be a quantum well layer or a barrier layer. In some embodiments, both the quantum well layers and the barrier layers in the active region are p-type. In some embodiments, the p-type layer in the active region has an average dislocation density less than about 5×108 cm−2.

Abstract: An LED driver circuit and method are disclosed where a plurality of arrays of light emitting diodes each have a transistor connected to each respective array of light emitting diodes. A PWM controller has an input for receiving a voltage reference and an output connected to selected transistors for driving the selected transistors and setting a PWM duty cycle for the selected arrays of light emitting diodes to determine the brightness of selected light emitting diodes. An oscillator is connected to the PWM controller for driving the PWM controller.

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.

Abstract: A III-nitride light emitting device including a substrate, a first conductivity type layer overlying the substrate, a spacer layer overlying the first conductivity type layer, an active region overlying the spacer layer, a cap layer overlying the active region, and a second conductivity type layer overlying the cap layer is disclosed. The active region includes a quantum well layer and a barrier layer containing indium. The barrier layer may be doped with a dopant of first conductivity type and may have an indium composition between 1% and 15%. In some embodiments, the light emitting device includes an InGaN lower confinement layer formed between the first conductivity type layer and the active region. In some embodiments, the light emitting device includes an InGaN upper confinement layer formed between the second conductivity type layer and the active region. In some embodiments, the light emitting device includes an InGaN cap layer formed between the upper confinement layer and the active region.

Abstract: A structure that may be used as a backlight for a liquid crystal display includes a light source and an optical waveguide. The optical waveguide is illuminated by the light source from an edge of the optical waveguide. The optical waveguide has a plurality of adjacent areas for illuminating corresponding parts of a liquid crystal panel. Each of the areas is provided with an independently controllable light source for illuminating the area.

Abstract: In accordance with the invention, a light emitting device includes a substrate, a layer of first conductivity type overlying the substrate, a light emitting layer overlying the layer of first conductivity type, and a layer of second conductivity type overlying the light emitting layer. A plurality of vias are formed in the layer of second conductivity type, down to the layer of first conductivity type. The vias may be formed by, for example, etching, ion implantation, or selective growth of the layer of second conductivity type. A set of first contacts electrically contacts the layer of first conductivity type through the vias. A second contact electrically contacts the layer of second conductivity type. In some embodiments, the area of the second contact is at least 75% of the area of the device. In some embodiments, the vias are between 2 and 100 microns wide and spaced between 5 and 1000 microns apart.

Abstract: A light emitting device includes a first active region, a second active region, and a tunnel junction. The tunnel junction includes a layer of first conductivity type and a layer of second conductivity type, both thinner than a layer of first conductivity type and a layer of second conductivity type surrounding the first active region. The tunnel junction permits vertical stacking of the active regions, which may increase the light generated by a device without increasing the size of the source.

Abstract: A backlight illumination system for illuminating a large area with light of a uniform color has a set of a pre-determined number of light emitters arranged along a straight line. The set is divided in a plurality of subsets, each subset including at least two light emitters. Each subset comprises light emitters with substantially the same light-emission color point, the respective subsets having color points different from each other. As a first step, the light emitters of the subset with a smallest number of light emitters are assigned to respective substantially equidistant positions. The light emitters of the set are assigned to the respective positions by iteratively starting with the subset with the smallest number of light emitters, assigning the light emitters of the subset to substantially equidistant positions which are not yet occupied. The backlight illumination system according to the invention has a uniform light and color distribution.

Abstract: A III-nitride light-emitting structure including a p-type layer, an n-type layer, and a light emitting layer is grown on a growth substrate. The III-nitride light-emitting structure is wafer bonded to a host substrate, then the growth substrate is removed. In some embodiments, a first electrical contact and first bonding layer are formed on the III-nitride light-emitting structure. A second bonding layer is formed on the host substrate. In such embodiments, wafer bonding the III-nitride light emitting structure to the host substrate comprises bonding the first bonding layer to the second bonding layer. After the growth substrate is removed, a second electrical contact may be formed on a side of the III-nitride light-emitting device exposed by removal of the growth substrate.

Abstract: A strip lighting device includes an elongate housing, a plurality of light sources arranged at intervals within the housing, and a fastener for fastening the elongate housing to a surface. The elongate housing overlies the plurality of light sources and diffuses, disperses or scatters light from the light sources such that individuals of the plurality of light sources are substantially not distinguishable when the housing is viewed from the outside.

Abstract: A method for improving the operating stability of compound semiconductor minority carrier devices and the devices created using this method are described. The method describes intentional introduction of impurities into the layers adjacent to the active region, which impurities act as a barrier to the degradation process, particularly undesired defect formation and propagation. A preferred embodiment of the present invention uses O doping of III-V optoelectronic devices during an epitaxial growth process to improve the operating reliability of the devices.